| 74. | M Golkowski; S R Sarker; C Renick; R C Moore; M B Cohen; A Kulak; J Mlynarczyk; J Kubisz Ionospheric D Region Remote Sensing Using ELF Sferic Group Velocity Journal Article Geophysical Research Letters, 45 (23), pp. 12,739-12,748, 2018. @article{10.1029/2018GL080108, title = {Ionospheric D Region Remote Sensing Using ELF Sferic Group Velocity}, author = {M Golkowski and S R Sarker and C Renick and R C Moore and M B Cohen and A Kulak and J Mlynarczyk and J Kubisz}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080108}, doi = {10.1029/2018GL080108}, year = {2018}, date = {2018-01-01}, journal = {Geophysical Research Letters}, volume = {45}, number = {23}, pages = {12,739-12,748}, abstract = {The lowest region of the ionosphere, the D region, plays an important role in magnetosphere-ionosphere coupling but is challenging to directly observe. The group velocity of the extremely low frequency (ELF; 3–300 Hz) portion of lightning induced electromagnetic radiation can be used to diagnose the D region electron density profile. Day-night conditions can be assessed using ELF receivers and lightning detection networks. Analytical formulations and the Long Wave Propagation Capability software package show that ELF group velocity has particular sensitivity to the sharpness of the exponential electron density profile. Applying the technique to sudden ionospheric disturbances shows that the group velocity increases in response to incidence of solar X-ray flux . A small number of ELF receivers can provide a large-scale diagnostic of the D region. ELF remote sensing using lightning is complementary to very low frequency remote sensing and can be used to assess the Earth-ionosphere propagation channel for very low frequency transmitters.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The lowest region of the ionosphere, the D region, plays an important role in magnetosphere-ionosphere coupling but is challenging to directly observe. The group velocity of the extremely low frequency (ELF; 3–300 Hz) portion of lightning induced electromagnetic radiation can be used to diagnose the D region electron density profile. Day-night conditions can be assessed using ELF receivers and lightning detection networks. Analytical formulations and the Long Wave Propagation Capability software package show that ELF group velocity has particular sensitivity to the sharpness of the exponential electron density profile. Applying the technique to sudden ionospheric disturbances shows that the group velocity increases in response to incidence of solar X-ray flux . A small number of ELF receivers can provide a large-scale diagnostic of the D region. ELF remote sensing using lightning is complementary to very low frequency remote sensing and can be used to assess the Earth-ionosphere propagation channel for very low frequency transmitters. |
| 73. | Ilona Piekarz; Jakub Sorocki; Krzysztof Wincza; Slawomir Gruszczynski Liquids Permittivity Measurement Using Two-Wire Transmission Line Sensor Journal Article IEEE Sensors Journal, 18 (18), pp. 7458-7466, 2018. @article{10.1109/JSEN.2018.2856889, title = {Liquids Permittivity Measurement Using Two-Wire Transmission Line Sensor}, author = {Ilona Piekarz and Jakub Sorocki and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/8412541}, doi = {10.1109/JSEN.2018.2856889}, year = {2018}, date = {2018-01-01}, journal = {IEEE Sensors Journal}, volume = {18}, number = {18}, pages = {7458-7466}, abstract = {A novel method for the measurement of complex permittivity of liquid dielectric materials in a wide frequency range is proposed. The technique utilizes an open-ended two-wire transmission line sensor that is submerged in a liquid-under-test to determine its complex permittivity from the measured differential reflection coefficient. The proposed approach has been theoretically analyzed to derive the appropriate sensor's model and the required calibration procedure as well as experimentally validated by measurements of three liquids having frequency-dependent complex permittivity. Moreover, measurement accuracy analysis has been provided, including the method`s uncertainty estimation and error sources' discussion. Finally, the measured permittivity of each liquid has been compared against tabularized data. Good agreement has been obtained proving the validity and applicability of the proposed method.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel method for the measurement of complex permittivity of liquid dielectric materials in a wide frequency range is proposed. The technique utilizes an open-ended two-wire transmission line sensor that is submerged in a liquid-under-test to determine its complex permittivity from the measured differential reflection coefficient. The proposed approach has been theoretically analyzed to derive the appropriate sensor's model and the required calibration procedure as well as experimentally validated by measurements of three liquids having frequency-dependent complex permittivity. Moreover, measurement accuracy analysis has been provided, including the method`s uncertainty estimation and error sources' discussion. Finally, the measured permittivity of each liquid has been compared against tabularized data. Good agreement has been obtained proving the validity and applicability of the proposed method. |
| 72. | Kamil Staszek; Ilona Piekarz; Jakub Sorocki; Sebastian Koryciak; Krzysztof Wincza; Slawomir Gruszczynski Low-Cost Microwave Vector System for Liquid Properties Monitoring Journal Article IEEE Transactions on Industrial Electronics, 65 (2), pp. 1665-1674, 2018. @article{10.1109/TIE.2017.2733423, title = {Low-Cost Microwave Vector System for Liquid Properties Monitoring}, author = {Kamil Staszek and Ilona Piekarz and Jakub Sorocki and Sebastian Koryciak and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7995091}, doi = {10.1109/TIE.2017.2733423}, year = {2018}, date = {2018-01-01}, journal = {IEEE Transactions on Industrial Electronics}, volume = {65}, number = {2}, pages = {1665-1674}, abstract = {In this paper, we propose a novel low-cost microwave vector system dedicated for monitoring the properties of liquid samples. The system is composed of the differentially fed coupled-line sensor and five-port correlator allowing for measurement of both magnitude and phase of a signal dependent on material under test. An exemplary microwave vector system has been designed to operate at the frequency f0=2.4GHz, manufactured and experimentally verified. The measurement results have proven the increased sensitivity of the proposed sensor on the dielectric materials in comparison to the methods described in the literature. Moreover, the proposed sensor has been utilized for measurements of several milk samples with various fat content, and the obtained results prove the industrial application of the presented approach.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we propose a novel low-cost microwave vector system dedicated for monitoring the properties of liquid samples. The system is composed of the differentially fed coupled-line sensor and five-port correlator allowing for measurement of both magnitude and phase of a signal dependent on material under test. An exemplary microwave vector system has been designed to operate at the frequency f0=2.4GHz, manufactured and experimentally verified. The measurement results have proven the increased sensitivity of the proposed sensor on the dielectric materials in comparison to the methods described in the literature. Moreover, the proposed sensor has been utilized for measurements of several milk samples with various fat content, and the obtained results prove the industrial application of the presented approach. |
| 71. | Jakub Sorocki; Ilona Piekarz; Slawomir Gruszczynski; Krzysztof Wincza Low-Loss Directional Filters Based on Differential Band-Reject Filters With Improved Isolation Using Phase Inverter Journal Article IEEE Microwave and Wireless Components Letters, 28 (4), pp. 314-316, 2018. @article{10.1109/LMWC.2018.2805864, title = {Low-Loss Directional Filters Based on Differential Band-Reject Filters With Improved Isolation Using Phase Inverter}, author = {Jakub Sorocki and Ilona Piekarz and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://ieeexplore.ieee.org/document/8303727}, doi = {10.1109/LMWC.2018.2805864}, year = {2018}, date = {2018-01-01}, journal = {IEEE Microwave and Wireless Components Letters}, volume = {28}, number = {4}, pages = {314-316}, abstract = {In this letter, a novel approach to the design of directional filters (DFs) based on the differential bandstop filter and delay lines is proposed. It is shown that utilization of a phase inverter (PI) and reference line as a mode-converting phase shifter allows for obtaining theoretically ideal bandpass-to-bandstop channels isolation over an infinite bandwidth. The presented theoretical analysis is confirmed by realization of an exemplary low-loss DF with defected ground type PI covering industrial, scientific, and medical, 2.4-GHz band. The obtained measurement results show insertion loss as low as 1.1 dB and almost flat isolation response, better than 27 dB up to 6 GHz proving the validity of the presented approach.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this letter, a novel approach to the design of directional filters (DFs) based on the differential bandstop filter and delay lines is proposed. It is shown that utilization of a phase inverter (PI) and reference line as a mode-converting phase shifter allows for obtaining theoretically ideal bandpass-to-bandstop channels isolation over an infinite bandwidth. The presented theoretical analysis is confirmed by realization of an exemplary low-loss DF with defected ground type PI covering industrial, scientific, and medical, 2.4-GHz band. The obtained measurement results show insertion loss as low as 1.1 dB and almost flat isolation response, better than 27 dB up to 6 GHz proving the validity of the presented approach. |
| 70. | J Bór; Z Zelkó; T Hegedüs; Z Jäger; J Mlynarczyk; M Popek; H D Betz On the Series of +CG Lightning Strokes in Dancing Sprite Events Journal Article Journal of Geophysical Research: Atmospheres, 123 (19), pp. 11,030-11,047, 2018. @article{10.1029/2017JD028251, title = {On the Series of +CG Lightning Strokes in Dancing Sprite Events}, author = {J Bór and Z Zelkó and T Hegedüs and Z Jäger and J Mlynarczyk and M Popek and H D Betz}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2017JD028251}, doi = {10.1029/2017JD028251}, year = {2018}, date = {2018-01-01}, journal = {Journal of Geophysical Research: Atmospheres}, volume = {123}, number = {19}, pages = {11,030-11,047}, abstract = {Abstract In dancing sprite events, sprite entities and groups appear in rapid succession together with a corresponding series of parent lightning strokes. Dancing sprite events, including a case with possible sprite rebrightening, were recorded on video simultaneously from two observation sites above a mesoscale convective system in Central Europe on the night of 6 August 2013. Joint analysis of triangulated locations of sprite elements, position, type, and peak current of lightning strokes from the LINET lightning detection network database and current moment waveforms deduced at the Hylaty station, Poland, showed that subsequent sprite-parent lightning strokes occurred no further than 21 km from the closest preceding sprite entity in the cases analyzed in this study. Additionally, it was found that longer sprite delay times tend to correspond to larger sprite location offsets from the parent +CG stroke. These observations, the occurrence of +CG lightning stroke and sprite sequences, as well as sprite-sprite delay times and displacements can be explained if +CG strokes are part of one extended lightning flash. A corresponding production mechanism based on previous findings on the formation of sprite-producing and general +CG lightning discharges is suggested.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract In dancing sprite events, sprite entities and groups appear in rapid succession together with a corresponding series of parent lightning strokes. Dancing sprite events, including a case with possible sprite rebrightening, were recorded on video simultaneously from two observation sites above a mesoscale convective system in Central Europe on the night of 6 August 2013. Joint analysis of triangulated locations of sprite elements, position, type, and peak current of lightning strokes from the LINET lightning detection network database and current moment waveforms deduced at the Hylaty station, Poland, showed that subsequent sprite-parent lightning strokes occurred no further than 21 km from the closest preceding sprite entity in the cases analyzed in this study. Additionally, it was found that longer sprite delay times tend to correspond to larger sprite location offsets from the parent +CG stroke. These observations, the occurrence of +CG lightning stroke and sprite sequences, as well as sprite-sprite delay times and displacements can be explained if +CG strokes are part of one extended lightning flash. A corresponding production mechanism based on previous findings on the formation of sprite-producing and general +CG lightning discharges is suggested. |
| 69. | Kamil Staszek Six-Port Calibration Utilizing Matched Load and Unknown Calibration Loads Journal Article IEEE Transactions on Microwave Theory and Techniques, 66 (10), pp. 4617-4626, 2018. @article{10.1109/TMTT.2018.2854725, title = {Six-Port Calibration Utilizing Matched Load and Unknown Calibration Loads}, author = {Kamil Staszek}, url = {https://ieeexplore.ieee.org/document/8418317}, doi = {10.1109/TMTT.2018.2854725}, year = {2018}, date = {2018-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {66}, number = {10}, pages = {4617-4626}, abstract = {A six-port calibration technique utilizing matched load and unknown calibration loads having arbitrary magnitude and phase is proposed. A detailed description of the proposed calibration procedure is given and illustrated with the aid of exemplary simulated values. Its performance has been validated with the use of a six-port measurement system operating over 2.5-3.5-GHz bandwidth. This system has been calibrated using the proposed calibration and a reference procedure which utilizes the same calibration loads as known values. Furthermore, five reflection coefficients of broadband one-port devices have been measured. The results obtained for both cases are in good agreement in terms of magnitude and phase. Moreover, they are very close to the values measured using a commercial vector network analyzer.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A six-port calibration technique utilizing matched load and unknown calibration loads having arbitrary magnitude and phase is proposed. A detailed description of the proposed calibration procedure is given and illustrated with the aid of exemplary simulated values. Its performance has been validated with the use of a six-port measurement system operating over 2.5-3.5-GHz bandwidth. This system has been calibrated using the proposed calibration and a reference procedure which utilizes the same calibration loads as known values. Furthermore, five reflection coefficients of broadband one-port devices have been measured. The results obtained for both cases are in good agreement in terms of magnitude and phase. Moreover, they are very close to the values measured using a commercial vector network analyzer. |
| 68. | Szczepan Odrobina; Kamil Staszek; Krzysztof Wincza; Sławomir Gruszczyński Wideband Nine-Port Reflectometer Journal Article International Journal of Electronics and Telecommunications, 64 (1), 2018. @article{10.24425/118141, title = {Wideband Nine-Port Reflectometer}, author = {Szczepan Odrobina and Kamil Staszek and Krzysztof Wincza and Sławomir Gruszczyński}, doi = {10.24425/118141}, year = {2018}, date = {2018-01-01}, journal = {International Journal of Electronics and Telecommunications}, volume = {64}, number = {1}, publisher = {Polish Academy of Sciences Committee of Electronics and Telecommunications}, abstract = {The paper presents a wideband nine-port reflectometer realized as a cascade connection of six- and five-port reflectometers. It is shown that such a solution allows for a convenient adjustment of circuits’ parameters in order to provide significantly reduced measurement uncertainty with respect to other reported reflectometers. Simultaneously, the proposed network features a simple and flexible design. For the experimental verification, the proposed nine-port reflectometer has been manufactured and incorporated into the system intended for reflection coefficient measurements within the frequency range 2.5 – 3.5 GHz. The obtained results are in an excellent agreement with the values measured using a commercial VNA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The paper presents a wideband nine-port reflectometer realized as a cascade connection of six- and five-port reflectometers. It is shown that such a solution allows for a convenient adjustment of circuits’ parameters in order to provide significantly reduced measurement uncertainty with respect to other reported reflectometers. Simultaneously, the proposed network features a simple and flexible design. For the experimental verification, the proposed nine-port reflectometer has been manufactured and incorporated into the system intended for reflection coefficient measurements within the frequency range 2.5 – 3.5 GHz. The obtained results are in an excellent agreement with the values measured using a commercial VNA. |
| 67. | Ilona Piekarz; Jakub Sorocki; Konrad Janisz; Krzysztof Wincza; Slawomir Gruszczynski Wideband three-section symmetrical coupled-line directional coupler operating in differential mode Journal Article IEEE Microwave and Wireless Components Letters, 28 (6), pp. 488-490, 2018. @article{10.1109/LMWC.2018.2824565, title = {Wideband three-section symmetrical coupled-line directional coupler operating in differential mode}, author = {Ilona Piekarz and Jakub Sorocki and Konrad Janisz and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/8347074}, doi = {10.1109/LMWC.2018.2824565}, year = {2018}, date = {2018-01-01}, journal = {IEEE Microwave and Wireless Components Letters}, volume = {28}, number = {6}, pages = {488-490}, abstract = {In this letter, a concept of wideband multisection symmetrical coupled-line directional couplers operating in a differential mode has been presented for the first time. The required different coupling coefficients for each of the coupled-line sections have been achieved by introducing a multilayer dielectric structure and by placing sections on different metallization layers. The theoretical investigation has been supported by measurements of an exemplary three-section symmetrical 3-dB coupled-line directional coupler operating in a differential mode at the center frequency of f 0 = 3 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this letter, a concept of wideband multisection symmetrical coupled-line directional couplers operating in a differential mode has been presented for the first time. The required different coupling coefficients for each of the coupled-line sections have been achieved by introducing a multilayer dielectric structure and by placing sections on different metallization layers. The theoretical investigation has been supported by measurements of an exemplary three-section symmetrical 3-dB coupled-line directional coupler operating in a differential mode at the center frequency of f 0 = 3 GHz. |
| 66. | Izabela Kowalska-Leszczynska; Marie-Anne Bizouard; Tomasz Bulik; Nelson Christensen; Michael Coughlin; Mark Go ł; Jerzy Kubisz; Andrzej Kulak; Janusz Mlynarczyk; Florent Robinet; Maximilian Rohde Globally coherent short duration magnetic field transients and their effect on ground based gravitational-wave detectors Journal Article Classical and Quantum Gravity, 34 (7), pp. 074002, 2017. @article{10.1088/1361-6382/aa60eb, title = {Globally coherent short duration magnetic field transients and their effect on ground based gravitational-wave detectors}, author = {Izabela Kowalska-Leszczynska and Marie-Anne Bizouard and Tomasz Bulik and Nelson Christensen and Michael Coughlin and Mark Go ł and Jerzy Kubisz and Andrzej Kulak and Janusz Mlynarczyk and Florent Robinet and Maximilian Rohde}, url = {https://doi.org/10.1088%2F1361-6382%2Faa60eb}, doi = {10.1088/1361-6382/aa60eb}, year = {2017}, date = {2017-03-01}, journal = {Classical and Quantum Gravity}, volume = {34}, number = {7}, pages = {074002}, publisher = {IOP Publishing}, abstract = {It has been recognized that the magnetic fields from the Schumann resonances could affect the search for a stochastic gravitational-wave background by LIGO and Virgo. Presented here are the observations of short duration magnetic field transients that are coincident in the magnetometers at the LIGO and Virgo sites. Data from low-noise magnetometers in Poland and Colorado, USA, are also used and show short duration magnetic transients of global extent. We measure at least 2.3 coincident (between Poland and Colorado) magnetic transient events per day where one of the pulses exceeds 200 pT. Given the recently measured values of the magnetic coupling to differential arm motion for Advanced LIGO, there would be a few events per day that would appear simultaneously at the gravitational-wave detector sites and could move the test masses of order 10−18 m. We confirm that in the advanced detector era short duration transient gravitational-wave searches must account for correlated magnetic field noise in the global detector network.}, keywords = {}, pubstate = {published}, tppubtype = {article} } It has been recognized that the magnetic fields from the Schumann resonances could affect the search for a stochastic gravitational-wave background by LIGO and Virgo. Presented here are the observations of short duration magnetic field transients that are coincident in the magnetometers at the LIGO and Virgo sites. Data from low-noise magnetometers in Poland and Colorado, USA, are also used and show short duration magnetic transients of global extent. We measure at least 2.3 coincident (between Poland and Colorado) magnetic transient events per day where one of the pulses exceeds 200 pT. Given the recently measured values of the magnetic coupling to differential arm motion for Advanced LIGO, there would be a few events per day that would appear simultaneously at the gravitational-wave detector sites and could move the test masses of order 10−18 m. We confirm that in the advanced detector era short duration transient gravitational-wave searches must account for correlated magnetic field noise in the global detector network. |
| 65. | Rajesh Singh; Ajeet K Maurya; Olivier Chanrion; Torsten Neubert; Steven A Cummer; Janusz Mlynarczyk; Morris B Cohen; Devendraa Siingh; Sushil Kumar Assessment of Unusual Gigantic Jets observed during the Monsoon season: First observations from Indian Subcontinent Journal Article Scientific Reports, 7 , pp. 16436, 2017. @article{10.1038/s41598-017-16696-5, title = {Assessment of Unusual Gigantic Jets observed during the Monsoon season: First observations from Indian Subcontinent}, author = {Rajesh Singh and Ajeet K Maurya and Olivier Chanrion and Torsten Neubert and Steven A Cummer and Janusz Mlynarczyk and Morris B Cohen and Devendraa Siingh and Sushil Kumar}, url = {https://www.nature.com/articles/s41598-017-16696-5}, doi = {10.1038/s41598-017-16696-5}, year = {2017}, date = {2017-01-01}, journal = {Scientific Reports}, volume = {7}, pages = {16436}, abstract = {Gigantic Jets are electric discharges from thunderstorm cloud tops to the bottom of ionosphere at ~90 km altitude and electrically connect the troposphere and lower ionosphere. Since their first report in 2002, sporadic observations have been reported from ground and space based observations. Here we report first observations of Gigantic Jets in Indian subcontinent over the Indo-Gangetic plains during the monsoon season. Two storms each produced two jets with characteristics not documented so far. Jets propagated ~37 km up remarkably in ~5 ms with velocity of ~7.4 × 106ms−1 and disappeared within ~40–80 ms, which is faster compared to jets reported earlier. The electromagnetic signatures show that they are of negative polarity, transporting net negative charge of ~17–23 C to the lower ionosphere. One jet had an unusual form observed for the first time, which emerged from the leading edge of a slowly drifting complex convective cloud close to the highest regions at ~17 km altitude. A horizontal displacement of ~10 km developed at ~50 km altitude before connecting to the lower ionosphere. Modeling of these Gigantic jets suggests that Gigantic Jets may bend when initiated at the edge of clouds with misaligned vertical charge distribution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Gigantic Jets are electric discharges from thunderstorm cloud tops to the bottom of ionosphere at ~90 km altitude and electrically connect the troposphere and lower ionosphere. Since their first report in 2002, sporadic observations have been reported from ground and space based observations. Here we report first observations of Gigantic Jets in Indian subcontinent over the Indo-Gangetic plains during the monsoon season. Two storms each produced two jets with characteristics not documented so far. Jets propagated ~37 km up remarkably in ~5 ms with velocity of ~7.4 × 106ms−1 and disappeared within ~40–80 ms, which is faster compared to jets reported earlier. The electromagnetic signatures show that they are of negative polarity, transporting net negative charge of ~17–23 C to the lower ionosphere. One jet had an unusual form observed for the first time, which emerged from the leading edge of a slowly drifting complex convective cloud close to the highest regions at ~17 km altitude. A horizontal displacement of ~10 km developed at ~50 km altitude before connecting to the lower ionosphere. Modeling of these Gigantic jets suggests that Gigantic Jets may bend when initiated at the edge of clouds with misaligned vertical charge distribution. |
| 64. | Krzysztof Wincza; Kamil Staszek; Slawomir Gruszczynski Broadband Multibeam Antenna Arrays Fed by Frequency-Dependent Butler Matrices Journal Article IEEE Transactions on Antennas and Propagation, 65 (9), pp. 4539-4547, 2017. @article{10.1109/TAP.2017.2722823, title = {Broadband Multibeam Antenna Arrays Fed by Frequency-Dependent Butler Matrices}, author = {Krzysztof Wincza and Kamil Staszek and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7967746}, doi = {10.1109/TAP.2017.2722823}, year = {2017}, date = {2017-01-01}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {65}, number = {9}, pages = {4539-4547}, abstract = {A novel concept of multibeam antenna arrays operating in an octave frequency band has been presented. To achieve multiple beams in such a wide bandwidth N-element antenna arrays are fed by frequency-dependent Butler matrices which smoothly change their properties across the bandwidth. The proposed Butler matrices are designed in such a way that for the selected inputs their amplitude and differential phase characteristics feature the ones obtained for N × N Butler matrices at f 0 , whereas at 2 f 0 they feature the properties of N/2 × N/2 Butler matrices. The proposed concept has been verified by measurements of a multibeam antenna array operating in 1.75-3.5 GHz frequency range and extended showing the possibility of designing antenna arrays with higher number of beams.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel concept of multibeam antenna arrays operating in an octave frequency band has been presented. To achieve multiple beams in such a wide bandwidth N-element antenna arrays are fed by frequency-dependent Butler matrices which smoothly change their properties across the bandwidth. The proposed Butler matrices are designed in such a way that for the selected inputs their amplitude and differential phase characteristics feature the ones obtained for N × N Butler matrices at f 0 , whereas at 2 f 0 they feature the properties of N/2 × N/2 Butler matrices. The proposed concept has been verified by measurements of a multibeam antenna array operating in 1.75-3.5 GHz frequency range and extended showing the possibility of designing antenna arrays with higher number of beams. |
| 63. | Serge Soula; Janusz Mlynarczyk; Martin Füllekrug; Nicolau Pineda; Jean-François Georgis; Oscar van der Velde; Joan Montanyà; Ferran Fabró Dancing sprites: Detailed analysis of two case studies Journal Article Journal of Geophysical Research: Atmospheres, 122 (6), pp. 3173-3192, 2017. @article{10.1002/2016JD025548, title = {Dancing sprites: Detailed analysis of two case studies}, author = {Serge Soula and Janusz Mlynarczyk and Martin Füllekrug and Nicolau Pineda and Jean-François Georgis and Oscar van der Velde and Joan Montanyà and Ferran Fabró}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016JD025548}, doi = {10.1002/2016JD025548}, year = {2017}, date = {2017-01-01}, journal = {Journal of Geophysical Research: Atmospheres}, volume = {122}, number = {6}, pages = {3173-3192}, abstract = {Abstract On 29–30 October 2013, a low-light video camera installed at Pic du Midi (2877 m), recorded transient luminous events above a very active storm over the Mediterranean Sea. The minimum cloud top temperature reached −73°C, while its cloud to ground (CG) flash rate exceeded 30 fl min−1. Some sprite events have long duration and resemble to dancing sprites. We analyze in detail the temporal evolution and estimated location of two series of sprite sequences, as well as the cloud structure, the lightning activity, the electric field radiated in a broad range of low frequencies, and the current moment waveform of the lightning strokes. (i) In each series, successive sprite sequences reflect time and location of corresponding positive lightning strokes across the stratiform region. (ii) The longer time-delayed (>20 ms) sprite elements correspond to the lower impulsive charge moment changes (iCMC) of the parent strokes (<200 C km), and they are shifted few tens of kilometers from their SP + CG stroke. However, both short and long time-delayed sprite elements also occur after strokes that produce a large iCMC and that are followed by a continuing current. (iii) The long time-delayed sprite elements during the continuing current correspond to surges in the current moment waveform. They occur sometimes at an altitude apparently lower than the previous short time-delayed sprite elements, possibly because of changes in the local conductivity. (iv) The largest and brightest sprite elements produce significant current signatures, visible when their delay is not too short (~3–5 ms).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract On 29–30 October 2013, a low-light video camera installed at Pic du Midi (2877 m), recorded transient luminous events above a very active storm over the Mediterranean Sea. The minimum cloud top temperature reached −73°C, while its cloud to ground (CG) flash rate exceeded 30 fl min−1. Some sprite events have long duration and resemble to dancing sprites. We analyze in detail the temporal evolution and estimated location of two series of sprite sequences, as well as the cloud structure, the lightning activity, the electric field radiated in a broad range of low frequencies, and the current moment waveform of the lightning strokes. (i) In each series, successive sprite sequences reflect time and location of corresponding positive lightning strokes across the stratiform region. (ii) The longer time-delayed (>20 ms) sprite elements correspond to the lower impulsive charge moment changes (iCMC) of the parent strokes (<200 C km), and they are shifted few tens of kilometers from their SP + CG stroke. However, both short and long time-delayed sprite elements also occur after strokes that produce a large iCMC and that are followed by a continuing current. (iii) The long time-delayed sprite elements during the continuing current correspond to surges in the current moment waveform. They occur sometimes at an altitude apparently lower than the previous short time-delayed sprite elements, possibly because of changes in the local conductivity. (iv) The largest and brightest sprite elements produce significant current signatures, visible when their delay is not too short (~3–5 ms). |
| 62. | Robert Smolarz; Krzysztof Wincza; Slawomir Gruszczynski Design of low-loss directional couplers with compensated coupled-line sections in suspended microstrip technique Journal Article International Journal of RF and Microwave Computer-Aided Engineering, 27 (8), pp. e21125, 2017. @article{10.1002/mmce.21125, title = {Design of low-loss directional couplers with compensated coupled-line sections in suspended microstrip technique}, author = {Robert Smolarz and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/mmce.21125}, doi = {10.1002/mmce.21125}, year = {2017}, date = {2017-01-01}, journal = {International Journal of RF and Microwave Computer-Aided Engineering}, volume = {27}, number = {8}, pages = {e21125}, abstract = {Abstract Design of coupled line 3dB directional couplers realized in suspended microstrip technique has been presented. The main goal was to minimize the insertion losses of the coupler, what has been achieved by a proper choice of the realization technique. As the chosen coupled line geometry is asymmetric to achieve good electrical performance of the resulting coupler, capacitive compensation technique has been utilized to equalize capacitive and inductive coupling coefficients. Furthermore, a distributed-element approach has been investigated for realization of compensation capacitances, due to their physical size resulting from the dielectric structure. The proposed coupler has been designed in two versions, having center frequencies equal to 0.89 and 1.1 GHz, manufactured and measured. The measurement results show good agreement with electromagnetic analyses and prove the correctness and usefulness of the presented design method. The manufactured couplers exhibit insertion losses as low as 0.08 dB at the center frequency.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Design of coupled line 3dB directional couplers realized in suspended microstrip technique has been presented. The main goal was to minimize the insertion losses of the coupler, what has been achieved by a proper choice of the realization technique. As the chosen coupled line geometry is asymmetric to achieve good electrical performance of the resulting coupler, capacitive compensation technique has been utilized to equalize capacitive and inductive coupling coefficients. Furthermore, a distributed-element approach has been investigated for realization of compensation capacitances, due to their physical size resulting from the dielectric structure. The proposed coupler has been designed in two versions, having center frequencies equal to 0.89 and 1.1 GHz, manufactured and measured. The measurement results show good agreement with electromagnetic analyses and prove the correctness and usefulness of the presented design method. The manufactured couplers exhibit insertion losses as low as 0.08 dB at the center frequency. |
| 61. | Izabela Slomian; Krzysztof Wincza; Slawomir Gruszczynski Folded Single-Layer 8 × 8 Butler Matrix Journal Article Journal of Electromagnetic Waves and Applications, 31 (14), pp. 1386-1398, 2017. @article{10.1080/09205071.2017.1348997, title = {Folded Single-Layer 8 × 8 Butler Matrix}, author = {Izabela Slomian and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://www.tandfonline.com/doi/abs/10.1080/09205071.2017.1348997?journalCode=tewa20}, doi = {10.1080/09205071.2017.1348997}, year = {2017}, date = {2017-01-01}, journal = {Journal of Electromagnetic Waves and Applications}, volume = {31}, number = {14}, pages = {1386-1398}, abstract = {A concept of an 8 × 8 Butler matrix realized in a single-layer structure folded to create a cylindrical surface has been proposed. With the use of such a structure it is possible to eliminate crossovers and to reduce losses within a circuit by maintaining connecting lines as short as possible. The proposed concept has been experimentally verified by simulations and measurements of an 8 × 8 Butler matrix operating at 2.5 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A concept of an 8 × 8 Butler matrix realized in a single-layer structure folded to create a cylindrical surface has been proposed. With the use of such a structure it is possible to eliminate crossovers and to reduce losses within a circuit by maintaining connecting lines as short as possible. The proposed concept has been experimentally verified by simulations and measurements of an 8 × 8 Butler matrix operating at 2.5 GHz. |
| 60. | Krzysztof Wincza; Slawomir Gruszczynski Frequency-Selective Feeding Network Based on Directional Filter for Constant-Beamwidth Scalable Antenna Arrays Journal Article IEEE Transactions on Antennas and Propagation, 65 (8), pp. 4346-4350, 2017. @article{10.1109/TAP.2017.2717962, title = {Frequency-Selective Feeding Network Based on Directional Filter for Constant-Beamwidth Scalable Antenna Arrays}, author = {Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7954726}, doi = {10.1109/TAP.2017.2717962}, year = {2017}, date = {2017-01-01}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {65}, number = {8}, pages = {4346-4350}, abstract = {A concept of scalable antenna arrays with an even number of radiating elements and nonuniform element spacing has been proposed. It has been shown that the proposed arrays can be fed with a frequency-selective network based on a well-known directional filter and with such a network the beamwidth can be kept constant across one frequency octave. The appropriate adjustment of coupled-line sections in such a directional filter allows for flexible selection of transmission coefficients between two outputs, and therefore, can be used for gradual switching of the signals between radiating elements. The proposed frequency-selective feeding network has been applied in a six-element antenna array operating in 1.75-3.5 GHz frequency range in which constant beamwidth around 16° has been achieved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A concept of scalable antenna arrays with an even number of radiating elements and nonuniform element spacing has been proposed. It has been shown that the proposed arrays can be fed with a frequency-selective network based on a well-known directional filter and with such a network the beamwidth can be kept constant across one frequency octave. The appropriate adjustment of coupled-line sections in such a directional filter allows for flexible selection of transmission coefficients between two outputs, and therefore, can be used for gradual switching of the signals between radiating elements. The proposed frequency-selective feeding network has been applied in a six-element antenna array operating in 1.75-3.5 GHz frequency range in which constant beamwidth around 16° has been achieved. |
| 59. | Jakub Sorocki; Ilona Piekarz; Krzysztof Wincza; Slawomir Gruszczynski Impedance transforming directional couplers with increased achievable transformation ratio Journal Article International Journal of Microwave and Wireless Technologies, 9 (3), pp. 509–513, 2017. @article{10.1017/S1759078716000520, title = {Impedance transforming directional couplers with increased achievable transformation ratio}, author = {Jakub Sorocki and Ilona Piekarz and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://www.cambridge.org/core/journals/international-journal-of-microwave-and-wireless-technologies/article/impedance-transforming-directional-couplers-with-increased-achievable-transformation-ratio/A5F16EA6F96435213B8E962B237CD76C}, doi = {10.1017/S1759078716000520}, year = {2017}, date = {2017-01-01}, journal = {International Journal of Microwave and Wireless Technologies}, volume = {9}, number = {3}, pages = {509–513}, publisher = {Cambridge University Press}, abstract = {Novel impedance transforming directional couplers are proposed in which the achievable impedance transformation ratio is increased above the previously reported limit related to coupling of the coupled-line sections. The proposed couplers consist of two coupled-line sections between which uncoupled sections of left-handed lines are connected. The presented concept has been verified by circuit simulations as well as by measurements of the manufactured 3-dB coupled-line impedance transforming directional coupler operating at f 0 = 1.2 GHz and featuring twofold increased impedance transformation ratio R = 4.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Novel impedance transforming directional couplers are proposed in which the achievable impedance transformation ratio is increased above the previously reported limit related to coupling of the coupled-line sections. The proposed couplers consist of two coupled-line sections between which uncoupled sections of left-handed lines are connected. The presented concept has been verified by circuit simulations as well as by measurements of the manufactured 3-dB coupled-line impedance transforming directional coupler operating at f 0 = 1.2 GHz and featuring twofold increased impedance transformation ratio R = 4. |
| 58. | Szczepan Odrobina; Kamil Staszek; Krzysztof Wincza; Slawomir Gruszczynski Measurement uncertainty analysis and design of a broadband four-port reflectometer Journal Article IET Microwaves, Antennas & Propagation, 11 (15), pp. 2162-2167, 2017. @article{10.1049/iet-map.2017.0435, title = {Measurement uncertainty analysis and design of a broadband four-port reflectometer}, author = {Szczepan Odrobina and Kamil Staszek and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/8221901}, doi = {10.1049/iet-map.2017.0435}, year = {2017}, date = {2017-01-01}, journal = {IET Microwaves, Antennas & Propagation}, volume = {11}, number = {15}, pages = {2162-2167}, abstract = {An impact of power distribution provided by the four-port reflectometer network on the uncertainty of complex reflection coefficient measurements is investigated. As a result, parameters of a four-port reflectometer with theoretically optimal power distribution that ensures the lowest obtainable measurement uncertainty are determined. In addition, a new four-port reflectometer that allows for achieving the derived optimal parameters over a wide frequency range is proposed. It also features a simple structure; therefore, low-cost single-layer microstrip realisation can be easily obtained. To verify the circuit's performance, a broadband four-port reflectometer operating in 1-3 GHz frequency range has been designed, manufactured, and used for reflection coefficients' measurements. The obtained results are in a very good accordance with the reference values provided by measurements performed with a commercial vector network analyser.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An impact of power distribution provided by the four-port reflectometer network on the uncertainty of complex reflection coefficient measurements is investigated. As a result, parameters of a four-port reflectometer with theoretically optimal power distribution that ensures the lowest obtainable measurement uncertainty are determined. In addition, a new four-port reflectometer that allows for achieving the derived optimal parameters over a wide frequency range is proposed. It also features a simple structure; therefore, low-cost single-layer microstrip realisation can be easily obtained. To verify the circuit's performance, a broadband four-port reflectometer operating in 1-3 GHz frequency range has been designed, manufactured, and used for reflection coefficients' measurements. The obtained results are in a very good accordance with the reference values provided by measurements performed with a commercial vector network analyser. |
| 57. | Ilona Piekarz; Jakub Sorocki; Krzysztof Wincza; Slawomir Gruszczynski Microwave Sensors for Dielectric Sample Measurement Based on Coupled-Line Section Journal Article IEEE Transactions on Microwave Theory and Techniques, 65 (5), pp. 1615-1631, 2017. @article{10.1109/TMTT.2016.2641438, title = {Microwave Sensors for Dielectric Sample Measurement Based on Coupled-Line Section}, author = {Ilona Piekarz and Jakub Sorocki and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7815418}, doi = {10.1109/TMTT.2016.2641438}, year = {2017}, date = {2017-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {65}, number = {5}, pages = {1615-1631}, abstract = {In this paper, a novel class of sensors composed of coupled-line sections dedicated for complex permittivity measurements of dielectric samples have been proposed. The end-shorted and open-ended coupled-line sections have been used as sensing elements for nonresonant and nondestructive measurements allowing for characterization of dielectric samples. It has been shown that by utilization of an iterative procedure, the complex permittivity of a dielectric material under test can be determined based on the measured complex odd-mode effective permittivity of the system. Since the complex odd-mode effective permittivity is mainly related to the mutual capacitance between coupled strips, high sensitivity on the covering sample has been obtained and the measured sample can be as narrow as the spacing between the coupled strips. The proposed sensors have been theoretically investigated and experimentally validated. The obtained results have been compared and the sensors' advantages and limitations have been discussed. The obtained measurement results have proved the correctness and usefulness of the proposed approach.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a novel class of sensors composed of coupled-line sections dedicated for complex permittivity measurements of dielectric samples have been proposed. The end-shorted and open-ended coupled-line sections have been used as sensing elements for nonresonant and nondestructive measurements allowing for characterization of dielectric samples. It has been shown that by utilization of an iterative procedure, the complex permittivity of a dielectric material under test can be determined based on the measured complex odd-mode effective permittivity of the system. Since the complex odd-mode effective permittivity is mainly related to the mutual capacitance between coupled strips, high sensitivity on the covering sample has been obtained and the measured sample can be as narrow as the spacing between the coupled strips. The proposed sensors have been theoretically investigated and experimentally validated. The obtained results have been compared and the sensors' advantages and limitations have been discussed. The obtained measurement results have proved the correctness and usefulness of the proposed approach. |
| 56. | Kamil Staszek; Artur Rydosz; Erwin Maciak; Krzysztof Wincza; Slawomir Gruszczynski Six-port microwave system for volatile organic compounds detection Journal Article Sensors and Actuators B: Chemical, 245 , pp. 882 - 894, 2017, ISSN: 0925-4005. @article{10.1016/j.snb.2017.01.194, title = {Six-port microwave system for volatile organic compounds detection}, author = {Kamil Staszek and Artur Rydosz and Erwin Maciak and Krzysztof Wincza and Slawomir Gruszczynski}, url = {http://www.sciencedirect.com/science/article/pii/S0925400517302010}, doi = {10.1016/j.snb.2017.01.194}, issn = {0925-4005}, year = {2017}, date = {2017-01-01}, journal = {Sensors and Actuators B: Chemical}, volume = {245}, pages = {882 - 894}, abstract = {An interdigital capacitor with resonant frequency fres ≈ 8.6GHz coated by comb polymer Pc-based thin film as a sensitive layer was investigated under exposure to different concentrations of various VOCs, such as: acetone, ethanol, methanol, isopropanol, butanol and ethylbenzene in a 0–25ppm concentration range. The measurement system has been significantly simplified due to measurement of the reflection coefficient at a single frequency f0=8GHz, at which the sensor exhibits the largest change in reflection coefficient's magnitude. For the reflection coefficient's measurement a new six-port reflectometer has been developed, which provides an enhanced measurement accuracy for the measurements of reflection coefficients having small magnitudes. The developed detector based on microwave measurements can be utilized in a portable exhaled breath analyzers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An interdigital capacitor with resonant frequency fres ≈ 8.6GHz coated by comb polymer Pc-based thin film as a sensitive layer was investigated under exposure to different concentrations of various VOCs, such as: acetone, ethanol, methanol, isopropanol, butanol and ethylbenzene in a 0–25ppm concentration range. The measurement system has been significantly simplified due to measurement of the reflection coefficient at a single frequency f0=8GHz, at which the sensor exhibits the largest change in reflection coefficient's magnitude. For the reflection coefficient's measurement a new six-port reflectometer has been developed, which provides an enhanced measurement accuracy for the measurements of reflection coefficients having small magnitudes. The developed detector based on microwave measurements can be utilized in a portable exhaled breath analyzers. |
| 55. | Janusz Mlynarczyk; Andrzej Kulak; Jacobo Salvador The Accuracy of Radio Direction Finding in the Extremely Low Frequency Range Journal Article Radio Science, 52 (10), pp. 1245-1252, 2017. @article{10.1002/2017RS006370, title = {The Accuracy of Radio Direction Finding in the Extremely Low Frequency Range}, author = {Janusz Mlynarczyk and Andrzej Kulak and Jacobo Salvador}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017RS006370}, doi = {10.1002/2017RS006370}, year = {2017}, date = {2017-01-01}, journal = {Radio Science}, volume = {52}, number = {10}, pages = {1245-1252}, abstract = {Abstract In this work, we study the accuracy of direction finding in the extremely low frequency (ELF) range using a newly installed broadband receiver equipped with two active magnetic antennas. The main natural source of ELF radio waves is lightning. In this work, we analyzed 1000 atmospheric discharges at distances of up to 5000 km from the receiver. We identified the most important factors influencing the accuracy of the angle of arrival: the deviation of the radio waves propagating through the day-night terminator zone and the signal-to-noise ratio resulting from local electromagnetic noise and Schumann resonance background. The obtained results clearly show that the accuracy of estimating the direction of arrival is very high (an average error of 0.1° with the standard deviation of 2.3°) when the signal-to-noise ratio is large (the amplitude of the magnetic field component above 100 pT), except for short periods in the local morning and evening, when the day-night terminator is present on the propagation path of the direct wave. For the day-night propagation paths, the refraction angle was larger than the incidence angle, and for the night-day propagation paths, the refraction angle was smaller than the incidence angle, which is consistent with theory. Using our analytical ELF radio propagation model allowed us to explain the obtained results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract In this work, we study the accuracy of direction finding in the extremely low frequency (ELF) range using a newly installed broadband receiver equipped with two active magnetic antennas. The main natural source of ELF radio waves is lightning. In this work, we analyzed 1000 atmospheric discharges at distances of up to 5000 km from the receiver. We identified the most important factors influencing the accuracy of the angle of arrival: the deviation of the radio waves propagating through the day-night terminator zone and the signal-to-noise ratio resulting from local electromagnetic noise and Schumann resonance background. The obtained results clearly show that the accuracy of estimating the direction of arrival is very high (an average error of 0.1° with the standard deviation of 2.3°) when the signal-to-noise ratio is large (the amplitude of the magnetic field component above 100 pT), except for short periods in the local morning and evening, when the day-night terminator is present on the propagation path of the direct wave. For the day-night propagation paths, the refraction angle was larger than the incidence angle, and for the night-day propagation paths, the refraction angle was smaller than the incidence angle, which is consistent with theory. Using our analytical ELF radio propagation model allowed us to explain the obtained results. |
| 54. | Kamil Staszek; Slawomir Gruszczynski; Krzysztof Wincza Tunable multiport system for measurement of two-port scattering parameters Journal Article International Journal of Microwave and Wireless Technologies, 9 (1), pp. 99–112, 2017. @article{10.1017/S1759078715001312, title = {Tunable multiport system for measurement of two-port scattering parameters}, author = {Kamil Staszek and Slawomir Gruszczynski and Krzysztof Wincza}, doi = {10.1017/S1759078715001312}, year = {2017}, date = {2017-01-01}, journal = {International Journal of Microwave and Wireless Technologies}, volume = {9}, number = {1}, pages = {99–112}, publisher = {Cambridge University Press}, abstract = {A novel multiport system, allowing for measurements of scattering parameters in over-two-octave frequency range is proposed. It is composed of two directional couplers and a standard 4 × 4 Butler matrix, and does not require any isolators. The presented system features a uniform power distribution providing the high precision of measurements, which can be further enhanced by a simple adjustment of the system's parameters. A comprehensive analysis of the proposed system configurations, a fully analytical calibration for transmission coefficient measurement, and the estimation of maximum measurement error are given. The proposed measuring system has been experimentally verified in a wide frequency range 1–5 GHz, by measurements of S-parameters of exemplary components. The measurement results are very close to the values obtained with the use of a commercial vector network analyser within the 50 dB range of measured values’ magnitude.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel multiport system, allowing for measurements of scattering parameters in over-two-octave frequency range is proposed. It is composed of two directional couplers and a standard 4 × 4 Butler matrix, and does not require any isolators. The presented system features a uniform power distribution providing the high precision of measurements, which can be further enhanced by a simple adjustment of the system's parameters. A comprehensive analysis of the proposed system configurations, a fully analytical calibration for transmission coefficient measurement, and the estimation of maximum measurement error are given. The proposed measuring system has been experimentally verified in a wide frequency range 1–5 GHz, by measurements of S-parameters of exemplary components. The measurement results are very close to the values obtained with the use of a commercial vector network analyser within the 50 dB range of measured values’ magnitude. |
| 53. | Krzysztof Wincza; Slawomir Gruszczynski Broadband coupled-line directional couplers with high impedance transformation ratio Journal Article International Journal of Microwave and Wireless Technologies, 9 (7), pp. 1473–1480, 2017. @article{10.1017/S1759078717000113, title = {Broadband coupled-line directional couplers with high impedance transformation ratio}, author = {Krzysztof Wincza and Slawomir Gruszczynski}, doi = {10.1017/S1759078717000113}, year = {2017}, date = {2017-01-01}, journal = {International Journal of Microwave and Wireless Technologies}, volume = {9}, number = {7}, pages = {1473–1480}, publisher = {Cambridge University Press}, abstract = {A new class of 3-dB impedance transforming directional couplers has been proposed in which the recently published coupled-line couplers, consisting of coupled-line sections having different electrical lengths, have been utilized. The main advantage of the proposed directional couplers is the possibility of obtaining high impedance transformation ratio, thus the known limiting condition of realizable impedance transformation in 3-dB couplers is overcome. Moreover, the proposed directional couplers feature significantly wider operational bandwidths. The theoretical analysis of the proposed impedance-transforming directional couplers has been shown and is fully supported by the measurements of the manufactured model operating in 0.5–1.5 GHz frequency range.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new class of 3-dB impedance transforming directional couplers has been proposed in which the recently published coupled-line couplers, consisting of coupled-line sections having different electrical lengths, have been utilized. The main advantage of the proposed directional couplers is the possibility of obtaining high impedance transformation ratio, thus the known limiting condition of realizable impedance transformation in 3-dB couplers is overcome. Moreover, the proposed directional couplers feature significantly wider operational bandwidths. The theoretical analysis of the proposed impedance-transforming directional couplers has been shown and is fully supported by the measurements of the manufactured model operating in 0.5–1.5 GHz frequency range. |
| 52. | Kamil Staszek; Slawomir Gruszczynski; Krzysztof Wincza Ultra-Wideband Dual-Line Multiprobe Reflectometer Journal Article IEEE Transactions on Microwave Theory and Techniques, 65 (4), pp. 1324-1333, 2017. @article{10.1109/TMTT.2016.2638422, title = {Ultra-Wideband Dual-Line Multiprobe Reflectometer}, author = {Kamil Staszek and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://ieeexplore.ieee.org/document/7807333}, doi = {10.1109/TMTT.2016.2638422}, year = {2017}, date = {2017-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {65}, number = {4}, pages = {1324-1333}, abstract = {A new type of dual-line multiprobe reflectometer, featuring an ultra-wideband operational bandwidth, is proposed. The presented reflectometer is composed of two parallel transmission lines along which weakly coupled probes are arranged. By utilization of two separate transmission lines, the minimum distance between two consecutive probes can be smaller than the length of a single probe, which allows for a highly nonuniform probes' arrangement required to ensure ultra-wideband operation. Moreover, an efficient algorithm for the probes' arrangement ensuring maximization of reflectometer's bandwidth is proposed. The proposed concept has been validated by the design of an ultra-wideband dual-line multiprobe reflectometer having six probes and operating frequency range over 0.1-12 GHz. The obtained results are in a very good agreement with the reference values measured using a commercial VNA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new type of dual-line multiprobe reflectometer, featuring an ultra-wideband operational bandwidth, is proposed. The presented reflectometer is composed of two parallel transmission lines along which weakly coupled probes are arranged. By utilization of two separate transmission lines, the minimum distance between two consecutive probes can be smaller than the length of a single probe, which allows for a highly nonuniform probes' arrangement required to ensure ultra-wideband operation. Moreover, an efficient algorithm for the probes' arrangement ensuring maximization of reflectometer's bandwidth is proposed. The proposed concept has been validated by the design of an ultra-wideband dual-line multiprobe reflectometer having six probes and operating frequency range over 0.1-12 GHz. The obtained results are in a very good agreement with the reference values measured using a commercial VNA. |
| 51. | Michael W Coughlin; Nelson L Christensen; Rosario De Rosa; Irene Fiori; Mark Golkowski; Melissa Guidry; Jan Harms; Jerzy Kubisz; Andrzej Kulak; Janusz Mlynarczyk; Federico Paoletti; Eric Thrane Subtraction of correlated noise in global networks of gravitational-wave interferometers Journal Article Classical and Quantum Gravity, 33 (22), pp. 224003, 2016. @article{Coughlin_2016, title = {Subtraction of correlated noise in global networks of gravitational-wave interferometers}, author = {Michael W Coughlin and Nelson L Christensen and Rosario De Rosa and Irene Fiori and Mark Golkowski and Melissa Guidry and Jan Harms and Jerzy Kubisz and Andrzej Kulak and Janusz Mlynarczyk and Federico Paoletti and Eric Thrane}, url = {https://doi.org/10.1088%2F0264-9381%2F33%2F22%2F224003}, doi = {10.1088/0264-9381/33/22/224003}, year = {2016}, date = {2016-10-01}, journal = {Classical and Quantum Gravity}, volume = {33}, number = {22}, pages = {224003}, publisher = {IOP Publishing}, abstract = {The recent discovery of merging black holes suggests that a stochastic gravitational-wave background is within reach of the advanced detector network operating at design sensitivity. However, correlated magnetic noise from Schumann resonances threatens to contaminate observation of a stochastic background. In this paper, we report on the first effort to eliminate intercontinental correlated noise from Schumann resonances using Wiener filtering. Using magnetometers as proxies for gravitational-wave detectors, we demonstrate as much as a factor of two reduction in the coherence between magnetometers on different continents. While much work remains to be done, our results constitute a proof-of-principle and motivate follow-up studies with a dedicated array of magnetometers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The recent discovery of merging black holes suggests that a stochastic gravitational-wave background is within reach of the advanced detector network operating at design sensitivity. However, correlated magnetic noise from Schumann resonances threatens to contaminate observation of a stochastic background. In this paper, we report on the first effort to eliminate intercontinental correlated noise from Schumann resonances using Wiener filtering. Using magnetometers as proxies for gravitational-wave detectors, we demonstrate as much as a factor of two reduction in the coherence between magnetometers on different continents. While much work remains to be done, our results constitute a proof-of-principle and motivate follow-up studies with a dedicated array of magnetometers. |
| 50. | Artur Rydosz; Ewa Brzozowska; Sabina Górska; Krzysztof Wincza; Andrzej Gamian; Slawomir Gruszczynski A broadband capacitive sensing method for label-free bacterial LPS detection Journal Article Biosensors and Bioelectronics, 75 , pp. 328 - 336, 2016, ISSN: 0956-5663. @article{10.1016/j.bios.2015.08.019, title = {A broadband capacitive sensing method for label-free bacterial LPS detection}, author = {Artur Rydosz and Ewa Brzozowska and Sabina Górska and Krzysztof Wincza and Andrzej Gamian and Slawomir Gruszczynski}, url = {http://www.sciencedirect.com/science/article/pii/S0956566315303456}, doi = {10.1016/j.bios.2015.08.019}, issn = {0956-5663}, year = {2016}, date = {2016-01-01}, journal = {Biosensors and Bioelectronics}, volume = {75}, pages = {328 - 336}, abstract = {In this paper, the authors present a new type of highly sensitive label-free microwave sensor in a form of interdigital capacitor coated with T4 bacteriophage gp37 adhesin. The adhesin binds Escherichia coli B (E. coli B) by precise recognizing its bacterial host lipopolysaccharide (LPS). The C-terminal part of the adhesin consists of the receptor-binding amino acid residues which are involved in a specific interaction with two terminal glucose residues of the bacterial LPS. The change of the sensors' capacitance and conductance as a subject to LPS presence is an indicator of the detection. The measurements in the frequency range of 0–3GHz utilizing vector network analyzer have been carried out at different concentrations to verify experimentally the proposed method. The measured capacitance change between the reference and the biofunctionalized sensor equals 15% in the entire frequency range and the measured conductance change exceeds 19%. The changes of both parameters can be used as good indicators of the LPS detection. The selectivity has been confirmed by the ELISA experiments and tested by sensor measurements with lipopolysaccharide (LPS) from E. coli B, E. coli 056, E. coli 0111, Pseudomonas aeruginosa NBRC 13743 and Hafnia alvei 1185.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, the authors present a new type of highly sensitive label-free microwave sensor in a form of interdigital capacitor coated with T4 bacteriophage gp37 adhesin. The adhesin binds Escherichia coli B (E. coli B) by precise recognizing its bacterial host lipopolysaccharide (LPS). The C-terminal part of the adhesin consists of the receptor-binding amino acid residues which are involved in a specific interaction with two terminal glucose residues of the bacterial LPS. The change of the sensors' capacitance and conductance as a subject to LPS presence is an indicator of the detection. The measurements in the frequency range of 0–3GHz utilizing vector network analyzer have been carried out at different concentrations to verify experimentally the proposed method. The measured capacitance change between the reference and the biofunctionalized sensor equals 15% in the entire frequency range and the measured conductance change exceeds 19%. The changes of both parameters can be used as good indicators of the LPS detection. The selectivity has been confirmed by the ELISA experiments and tested by sensor measurements with lipopolysaccharide (LPS) from E. coli B, E. coli 056, E. coli 0111, Pseudomonas aeruginosa NBRC 13743 and Hafnia alvei 1185. |
| 49. | Jakub Sorocki; Ilona Piekarz; Kamil Staszek; Piotr Kaminski; Krzysztof Wincza; Slawomir Gruszczynski Broadband Balun Circuits Composed of Impedance Transforming Directional Couplers and LH Transmission-Line Sections Journal Article International Journal of Information and Electronics Engineering, 6 , pp. 147-150, 2016, ISSN: 2010-3719. @article{10.18178/IJIEE.2016.6.3.613, title = {Broadband Balun Circuits Composed of Impedance Transforming Directional Couplers and LH Transmission-Line Sections}, author = {Jakub Sorocki and Ilona Piekarz and Kamil Staszek and Piotr Kaminski and Krzysztof Wincza and Slawomir Gruszczynski}, url = {http://www.ijiee.org/index.php?m=content&c=index&a=show&catid=65&id=691}, doi = {10.18178/IJIEE.2016.6.3.613}, issn = {2010-3719}, year = {2016}, date = {2016-01-01}, journal = {International Journal of Information and Electronics Engineering}, volume = {6}, pages = {147-150}, abstract = {In this paper, a new approach to the design of a balun circuit is presented. The proposed balun is composed of an impedance-transforming directional coupler and an LH/RH transmission line differential phase shifter. The proposed solution features broadband amplitude and phase response, moreover, a flexibility of the impedance transformation from balanced to imbalanced port is obtained. The proposed concept has been verified by the design of a balun circuit featuring over-an-octave bandwidth and impedance transformation 70 bal. / 50 imbal.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, a new approach to the design of a balun circuit is presented. The proposed balun is composed of an impedance-transforming directional coupler and an LH/RH transmission line differential phase shifter. The proposed solution features broadband amplitude and phase response, moreover, a flexibility of the impedance transformation from balanced to imbalanced port is obtained. The proposed concept has been verified by the design of a balun circuit featuring over-an-octave bandwidth and impedance transformation 70 bal. / 50 imbal. |
| 48. | Krzysztof Wincza; Slawomir Gruszczynski Broadband Integrated 8×8 Butler Matrix Utilizing Quadrature Couplers and Schiffman Phase Shifters for Multibeam Antennas With Broadside Beam Journal Article IEEE Transactions on Microwave Theory and Techniques, 64 , pp. 2596-2604, 2016. @article{10.1109/TMTT.2016.2582877, title = {Broadband Integrated 8×8 Butler Matrix Utilizing Quadrature Couplers and Schiffman Phase Shifters for Multibeam Antennas With Broadside Beam}, author = {Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7502189}, doi = {10.1109/TMTT.2016.2582877}, year = {2016}, date = {2016-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {64}, pages = {2596-2604}, abstract = {A novel realization of a broadband 8 × 8 Butler matrix having phase progressions 0°, ±45°, ±90°, ±135°, and 180° has been proposed. The presented network is composed of coupled-line 3-dB/90° directional couplers and Schiffman phase shifters that ensure its broadband amplitude and phase characteristics. The proposed solution allows for a fully planar realization without any interlayer connections, which has been achieved by both rearrangement of the matrix layout and realization of the selected crossovers as tandem connections of quadrature directional couplers. The proposed concept has been verified experimentally by the design of a Butler matrix operating within 2.5-3.5 GHz and applied in a multibeam antenna array with broadside beam.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel realization of a broadband 8 × 8 Butler matrix having phase progressions 0°, ±45°, ±90°, ±135°, and 180° has been proposed. The presented network is composed of coupled-line 3-dB/90° directional couplers and Schiffman phase shifters that ensure its broadband amplitude and phase characteristics. The proposed solution allows for a fully planar realization without any interlayer connections, which has been achieved by both rearrangement of the matrix layout and realization of the selected crossovers as tandem connections of quadrature directional couplers. The proposed concept has been verified experimentally by the design of a Butler matrix operating within 2.5-3.5 GHz and applied in a multibeam antenna array with broadside beam. |
| 47. | Krzysztof Wincza; Slawomir Gruszczynski Broadband scalable antenna arrays with constant beamwidths fed by frequency-selective networks Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 2936–2943, 2016. @article{10.1109/TAP.2016.2560959, title = {Broadband scalable antenna arrays with constant beamwidths fed by frequency-selective networks}, author = {Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7463052}, doi = {10.1109/TAP.2016.2560959}, year = {2016}, date = {2016-01-01}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {64}, pages = {2936–2943}, abstract = {A novel concept of broadband scalable antenna arrays that allows achieving constant beamwidths across one frequency octave has been proposed. The presented antenna arrays consist of an odd number of broadband antenna elements equally spaced and fed by a frequency-selective feeding network. The feeding network gradually switches the signal between the radiating elements across the bandwidth. The required frequency characteristics for such a selective power divider have been shown and its circuit realization has been proposed. The presented concept has been verified by the design and measurements of an antenna array consisting of five radiating elements in which the beamwidth of around 24° is achieved. The developed antenna operates in the 2-4-GHz frequency range. Moreover, the presented concept has been extended showing the possibility of designing antenna arrays having an arbitrary odd number of effectively radiating elements and constant beamwidths over one frequency octave.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel concept of broadband scalable antenna arrays that allows achieving constant beamwidths across one frequency octave has been proposed. The presented antenna arrays consist of an odd number of broadband antenna elements equally spaced and fed by a frequency-selective feeding network. The feeding network gradually switches the signal between the radiating elements across the bandwidth. The required frequency characteristics for such a selective power divider have been shown and its circuit realization has been proposed. The presented concept has been verified by the design and measurements of an antenna array consisting of five radiating elements in which the beamwidth of around 24° is achieved. The developed antenna operates in the 2-4-GHz frequency range. Moreover, the presented concept has been extended showing the possibility of designing antenna arrays having an arbitrary odd number of effectively radiating elements and constant beamwidths over one frequency octave. |
| 46. | Izabela Slomian; Krzysztof Wincza; Slawomir Gruszczynski Circularly Polarized Switched-Beam Antenna Arrays With Reduced Sidelobe Level Journal Article IEEE Antennas and Wireless Propagation Letters, 15 , pp. 1213-1216, 2016. @article{10.1109/LAWP.2015.2502269, title = {Circularly Polarized Switched-Beam Antenna Arrays With Reduced Sidelobe Level}, author = {Izabela Slomian and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7332742}, doi = {10.1109/LAWP.2015.2502269}, year = {2016}, date = {2016-01-01}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {15}, pages = {1213-1216}, abstract = {A novel method of sidelobe level reduction in switched-beam antenna arrays fed by Butler matrices has been proposed. The presented method takes advantage of circularly polarized two-port antenna elements, hence the sidelobe level reduction is achieved with conceptually lossless feeding networks without increasing the number of radiating elements. The presented approach allows for realization of amplitude taper by combining an N ×N Butler matrix with N two-way power dividers. Theoretical analysis as well as simulation and measurement results of the manufactured prototype operating in 2.4-GHz frequency range have been presented.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel method of sidelobe level reduction in switched-beam antenna arrays fed by Butler matrices has been proposed. The presented method takes advantage of circularly polarized two-port antenna elements, hence the sidelobe level reduction is achieved with conceptually lossless feeding networks without increasing the number of radiating elements. The presented approach allows for realization of amplitude taper by combining an N ×N Butler matrix with N two-way power dividers. Theoretical analysis as well as simulation and measurement results of the manufactured prototype operating in 2.4-GHz frequency range have been presented. |
| 45. | Izabela Slomian; Jakub Sorocki; Slawomir Gruszczynski; Krzysztof Wincza Composite right/left-handed leaky-wave antenna with adjustable radiation bandwidth Journal Article Journal of Electromagnetic Waves and Applications, 30 , pp. 1054-1063, 2016. @article{10.1080/09205071.2016.1169950, title = {Composite right/left-handed leaky-wave antenna with adjustable radiation bandwidth}, author = {Izabela Slomian and Jakub Sorocki and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://www.tandfonline.com/doi/abs/10.1080/09205071.2016.1169950}, doi = {10.1080/09205071.2016.1169950}, year = {2016}, date = {2016-01-01}, journal = {Journal of Electromagnetic Waves and Applications}, volume = {30}, pages = {1054-1063}, abstract = {A novel approach to the design of a 1-D CRLH leaky-wave antenna has been proposed in which the frequency range of beam scanning can be adjusted without the change of unit cell’s physical length. The presented antenna is based on a unit cell composed of series capacitor connected in cascade with four sections of transmission lines and two symmetrically located transmission-line stubs. The unique feature of such a unit cell is that the phase constant’s slope vs. frequency and the resulting scanning bandwidth can be adjusted by controlling the characteristic impedance and the electrical length of the open-ended transmission-line stubs while all other parameters are fixed. The theoretical investigation as well as experimental results of the developed antenna operating at 2.5 GHz are shown, proving the correctness of the described design technique.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel approach to the design of a 1-D CRLH leaky-wave antenna has been proposed in which the frequency range of beam scanning can be adjusted without the change of unit cell’s physical length. The presented antenna is based on a unit cell composed of series capacitor connected in cascade with four sections of transmission lines and two symmetrically located transmission-line stubs. The unique feature of such a unit cell is that the phase constant’s slope vs. frequency and the resulting scanning bandwidth can be adjusted by controlling the characteristic impedance and the electrical length of the open-ended transmission-line stubs while all other parameters are fixed. The theoretical investigation as well as experimental results of the developed antenna operating at 2.5 GHz are shown, proving the correctness of the described design technique. |
| 44. | Ilona Piekarz; Jakub Sorocki; Krzysztof Wincza; Slawomir Gruszczynski Coupled-Line Sensor With Marchand Balun as RF System for Dielectric Sample Detection Journal Article IEEE Sensors Journal, 16 , pp. 88-96, 2016. @article{10.1109/JSEN.2015.2476957, title = {Coupled-Line Sensor With Marchand Balun as RF System for Dielectric Sample Detection}, author = {Ilona Piekarz and Jakub Sorocki and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/abstract/document/7243302}, doi = {10.1109/JSEN.2015.2476957}, year = {2016}, date = {2016-01-01}, journal = {IEEE Sensors Journal}, volume = {16}, pages = {88-96}, abstract = {A novel nondestructive method for effective permittivity measurement and detection of sample's permittivity change in microwave frequency range has been proposed, utilizing a Marchand balun and a coupled-line sensor. The out-of-phase excited coupled-line section is used to obtain high sensitivity on the covering sample, which can be as narrow as the spacing between coupled strips. Formulas describing balanced to unbalanced impedance transformation of a Marchand balun have been provided, hence the proposed method requires only one-port measurement to determine effective permittivity in a wide frequency range. The proposed setup has been theoretically and experimentally investigated. The obtained measurement results proved the usefulness of the proposed approach for dielectric sample detection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel nondestructive method for effective permittivity measurement and detection of sample's permittivity change in microwave frequency range has been proposed, utilizing a Marchand balun and a coupled-line sensor. The out-of-phase excited coupled-line section is used to obtain high sensitivity on the covering sample, which can be as narrow as the spacing between coupled strips. Formulas describing balanced to unbalanced impedance transformation of a Marchand balun have been provided, hence the proposed method requires only one-port measurement to determine effective permittivity in a wide frequency range. The proposed setup has been theoretically and experimentally investigated. The obtained measurement results proved the usefulness of the proposed approach for dielectric sample detection. |
| 43. | Artur Rydosz; Erwin Maciak; Krzysztof Wincza; Slawomir Gruszczynski Microwave-based sensors with phthalocyanine films for acetone, ethanol and methanol detection Journal Article Sensors and Actuators B: Chemical, 237 , pp. 876 - 886, 2016, ISSN: 0925-4005. @article{10.1016/j.snb.2016.06.168, title = {Microwave-based sensors with phthalocyanine films for acetone, ethanol and methanol detection}, author = {Artur Rydosz and Erwin Maciak and Krzysztof Wincza and Slawomir Gruszczynski}, url = {http://www.sciencedirect.com/science/article/pii/S0925400516310292}, doi = {10.1016/j.snb.2016.06.168}, issn = {0925-4005}, year = {2016}, date = {2016-01-01}, journal = {Sensors and Actuators B: Chemical}, volume = {237}, pages = {876 - 886}, abstract = {The utilization of novel comb copolymer phthalocyanine (Pc) thin films as sensitive layers for microwave gas sensors at room temperature under exposure to various volatile organic compounds are presented. The microwave gas sensors are based on an interdigital capacitor fabricated in a microstrip line technique with adequate layers and dimensions. The developed sensors were tested for acetone, ethanol and methanol in the range of 0–200ppm with special emphasis to the range of 0–25ppm. The presented sensors will be used as a part of a microsystem for exhaled breath analysis, i.e. diabetes biomarkers detection. All the measurements are carried out at room temperature. The obtained results confirmed the possibility of utilization the microwave Pc-based sensors for exhaled acetone measurements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The utilization of novel comb copolymer phthalocyanine (Pc) thin films as sensitive layers for microwave gas sensors at room temperature under exposure to various volatile organic compounds are presented. The microwave gas sensors are based on an interdigital capacitor fabricated in a microstrip line technique with adequate layers and dimensions. The developed sensors were tested for acetone, ethanol and methanol in the range of 0–200ppm with special emphasis to the range of 0–25ppm. The presented sensors will be used as a part of a microsystem for exhaled breath analysis, i.e. diabetes biomarkers detection. All the measurements are carried out at room temperature. The obtained results confirmed the possibility of utilization the microwave Pc-based sensors for exhaled acetone measurements. |
| 42. | Kamil Staszek; Krzysztof Wincza; Slawomir Gruszczynski Rigorous Approach for Design of Differential Coupled-Line Directional Couplers Applicable in Integrated Circuits and Substrate-Embedded Networks Journal Article Scientific Reports, 6 , 2016. @article{10.1038/srep25071, title = {Rigorous Approach for Design of Differential Coupled-Line Directional Couplers Applicable in Integrated Circuits and Substrate-Embedded Networks}, author = {Kamil Staszek and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://www.nature.com/articles/srep25071}, doi = {10.1038/srep25071}, year = {2016}, date = {2016-01-01}, journal = {Scientific Reports}, volume = {6}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 41. | Krzysztof Wincza; Kamil Staszek; Izabela Slomian; Slawomir Gruszczynski Scalable Multibeam Antenna Arrays Fed by Dual-Band Modified Butler Matrices Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 1287-1297, 2016. @article{10.1109/TAP.2016.2521888, title = {Scalable Multibeam Antenna Arrays Fed by Dual-Band Modified Butler Matrices}, author = {Krzysztof Wincza and Kamil Staszek and Izabela Slomian and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7393531}, doi = {10.1109/TAP.2016.2521888}, year = {2016}, date = {2016-01-01}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {64}, pages = {1287-1297}, abstract = {A concept of dual-band multibeam antenna arrays that allows for efficient utilization of a common aperture has been proposed. The presented antenna arrays allow for achieving N-independent beams pointing at N different directions at higher frequency and N-independent beams at lower frequency pointing at N/2 different directions and having two orthogonal polarizations. As feeding networks, novel modified Butler matrices (BMs) have been proposed in which directional couplers having different properties in two frequency ranges have been for the first time utilized. To confirm the theoretical analysis, a dual-band multibeam antenna array fed by a modified 4 × 4 BM has been developed operating in 2.4 and 5.2 GHz frequency ranges.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A concept of dual-band multibeam antenna arrays that allows for efficient utilization of a common aperture has been proposed. The presented antenna arrays allow for achieving N-independent beams pointing at N different directions at higher frequency and N-independent beams at lower frequency pointing at N/2 different directions and having two orthogonal polarizations. As feeding networks, novel modified Butler matrices (BMs) have been proposed in which directional couplers having different properties in two frequency ranges have been for the first time utilized. To confirm the theoretical analysis, a dual-band multibeam antenna array fed by a modified 4 × 4 BM has been developed operating in 2.4 and 5.2 GHz frequency ranges. |
| 40. | Krzysztof Wincza; Slawomir Gruszczynski Series-Fed Dual-Band Dual-Polarized Antenna Lattice Fed by Slot-Coupled Power Dividers Journal Article IEEE Antennas and Wireless Propagation Letters, 15 , pp. 1065-1068, 2016. @article{10.1109/LAWP.2015.2492606, title = {Series-Fed Dual-Band Dual-Polarized Antenna Lattice Fed by Slot-Coupled Power Dividers}, author = {Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/7393531}, doi = {10.1109/LAWP.2015.2492606}, year = {2016}, date = {2016-01-01}, journal = {IEEE Antennas and Wireless Propagation Letters}, volume = {15}, pages = {1065-1068}, abstract = {A series-fed dual-band dual-polarized antenna lattice has been proposed. It has been shown that it is possible to feed two separate antenna arrays having the frequency ratio f2/f1 ≈ 2 that are integrated within a common aperture with the use of a series feeding network along both x- and y-axes. To achieve that, a concept of slot-coupled power dividers has been employed and a series feeding network allowing simultaneously for frequency separation and appropriate signal distribution in both frequency ranges has been proposed. The presented concept has been verified by measurements of the manufactured circularly polarized series-fed antenna lattice operating at 2.4- and 5.3-GHz frequency ranges.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A series-fed dual-band dual-polarized antenna lattice has been proposed. It has been shown that it is possible to feed two separate antenna arrays having the frequency ratio f2/f1 ≈ 2 that are integrated within a common aperture with the use of a series feeding network along both x- and y-axes. To achieve that, a concept of slot-coupled power dividers has been employed and a series feeding network allowing simultaneously for frequency separation and appropriate signal distribution in both frequency ranges has been proposed. The presented concept has been verified by measurements of the manufactured circularly polarized series-fed antenna lattice operating at 2.4- and 5.3-GHz frequency ranges. |
| 39. | Kamil Staszek; Slawomir Gruszczynski; Krzysztof Wincza Six-Port Reflectometer Providing Enhanced Power Distribution Journal Article IEEE Transactions on Microwave Theory and Techniques, 64 , pp. 939-951, 2016. @article{10.1109/TMTT.2016.2518681, title = {Six-Port Reflectometer Providing Enhanced Power Distribution}, author = {Kamil Staszek and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://ieeexplore.ieee.org/document/7393874}, doi = {10.1109/TMTT.2016.2518681}, year = {2016}, date = {2016-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {64}, pages = {939-951}, abstract = {A six-port reflectometer providing an improved power distribution is proposed. The developed six-port network allows for a significant enhancement of the measurement accuracy without increasing the complexity of the reflectometer's network. The proposed six-port has been theoretically analyzed, designed in a stripline technique with the use of single-section coupled-line directional couplers, and fabricated. For the experimental verification, the developed six-port has been utilized in reflection coefficient measurements in a wide frequency range, 2.5-3.5 GHz. The obtained results are very close to the reference values measured using a vector network analyzer. Furthermore, the same measurements have been performed utilizing the classical six-port reflectometer operating within the same frequency range. The comparison clearly shows that the proposed six-port reflectometer provides a significantly higher measurement accuracy with respect to the classical solutions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A six-port reflectometer providing an improved power distribution is proposed. The developed six-port network allows for a significant enhancement of the measurement accuracy without increasing the complexity of the reflectometer's network. The proposed six-port has been theoretically analyzed, designed in a stripline technique with the use of single-section coupled-line directional couplers, and fabricated. For the experimental verification, the developed six-port has been utilized in reflection coefficient measurements in a wide frequency range, 2.5-3.5 GHz. The obtained results are very close to the reference values measured using a vector network analyzer. Furthermore, the same measurements have been performed utilizing the classical six-port reflectometer operating within the same frequency range. The comparison clearly shows that the proposed six-port reflectometer provides a significantly higher measurement accuracy with respect to the classical solutions. |
| 38. | Izabela Slomian; Slawomir Gruszczynski; Krzysztof Wincza Symmetrical series-fed dual-polarised microstrip antenna lattice with odd number of radiating elements Journal Article IET Microwaves, Antennas & Propagation, 10 , pp. 701-708, 2016. @article{10.1049/iet-map.2015.0645, title = {Symmetrical series-fed dual-polarised microstrip antenna lattice with odd number of radiating elements}, author = {Izabela Slomian and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://ieeexplore.ieee.org/document/7393874}, doi = {10.1049/iet-map.2015.0645}, year = {2016}, date = {2016-01-01}, journal = {IET Microwaves, Antennas & Propagation}, volume = {10}, pages = {701-708}, abstract = {A concept of symmetrical microstrip antenna lattice having an odd number of radiating elements has been proposed. In the presented antenna array, all radiating elements are connected in series along both X and Y axes, which allows for generation of dual polarisation and for reduction of dissipation losses in the feeding network. The proposed approach extends the idea of the previously developed antenna lattice, in which an even number of radiating elements has been considered. This study presents the design procedure for the proposed concept, which is confirmed by simulations and measurements of the developed 5 × 5 antenna lattice operating at 5.4 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A concept of symmetrical microstrip antenna lattice having an odd number of radiating elements has been proposed. In the presented antenna array, all radiating elements are connected in series along both X and Y axes, which allows for generation of dual polarisation and for reduction of dissipation losses in the feeding network. The proposed approach extends the idea of the previously developed antenna lattice, in which an even number of radiating elements has been considered. This study presents the design procedure for the proposed concept, which is confirmed by simulations and measurements of the developed 5 × 5 antenna lattice operating at 5.4 GHz. |
| 37. | Jakub Sorocki; Kamil Staszek; Ilona Piekarz; Krzysztof Wincza; Slawomir Gruszczynski Application of RH and LH sections for reduction of coupling coefficients in two-section asymmetric directional couplers Journal Article International Journal of Microwave and Wireless Technologies, 8 (3), pp. 559–565, 2016. @article{sorocki_staszek_piekarz_wincza_gruszczynski_2016, title = {Application of RH and LH sections for reduction of coupling coefficients in two-section asymmetric directional couplers}, author = {Jakub Sorocki and Kamil Staszek and Ilona Piekarz and Krzysztof Wincza and Slawomir Gruszczynski}, doi = {10.1017/S1759078715000410}, year = {2016}, date = {2016-01-01}, journal = {International Journal of Microwave and Wireless Technologies}, volume = {8}, number = {3}, pages = {559–565}, publisher = {Cambridge University Press}, abstract = {A method allowing for reduction of coupling coefficients required for realization of two-section asymmetrical coupled-line directional couplers has been proposed. It has been shown that by connecting uncoupled left-handed and right-handed transmission lines between two coupled-line sections one can obtain greater design flexibility of the resulting circuit, simultaneously with the coupling reduction in coupled-line sections. Moreover, the proposed circuit features the properties of two-section asymmetric directional couplers offering wide operational bandwidth. The theoretical analysis has been verified by measurements of a 3 dB directional coupler operating at the center frequency f0 = 1.5 GHz having coupling imbalance δC = ±0.4 dB and bandwidth 0.75–2.3 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A method allowing for reduction of coupling coefficients required for realization of two-section asymmetrical coupled-line directional couplers has been proposed. It has been shown that by connecting uncoupled left-handed and right-handed transmission lines between two coupled-line sections one can obtain greater design flexibility of the resulting circuit, simultaneously with the coupling reduction in coupled-line sections. Moreover, the proposed circuit features the properties of two-section asymmetric directional couplers offering wide operational bandwidth. The theoretical analysis has been verified by measurements of a 3 dB directional coupler operating at the center frequency f0 = 1.5 GHz having coupling imbalance δC = ±0.4 dB and bandwidth 0.75–2.3 GHz. |
| 36. | Serge Soula; Oscar van der Velde; Joan Montanya; Martin Fullekrug; Andrew Mezentsev; Janusz Mlynarczyk Characteristics of lightning flashes generating sprites above storms Journal Article E3S Web of Conf., 12 , pp. 02001, 2016. @article{refId0, title = {Characteristics of lightning flashes generating sprites above storms}, author = {Serge} {Soula and Oscar} {van der Velde and Joan} {Montanya and Martin} {Fullekrug and Andrew} {Mezentsev and Janusz} {Mlynarczyk}, url = {https://doi.org/10.1051/e3sconf/20161202001}, doi = {10.1051/e3sconf/20161202001}, year = {2016}, date = {2016-01-01}, journal = {E3S Web of Conf.}, volume = {12}, pages = {02001}, abstract = {Sprites are Transient Luminous Events (TLEs) that can extend vertically from 40 to 90 km and horizontally over several tens of km to form clusters of individual or multiple column or/and carrot-shaped luminous elements. They can even extend over more than 100 km in the form of sequential luminous emissions that are called “dancing sprites”. Their optical detection and other parameters describing the storm and the lightning activity associated allow us to understand the conditions of their production and their links with the lightning activity. Our observations confirm some characteristics of the sprites and put forward others: (i) the sprites are essentially produced above the stratiform region of the Mesoscale Convective Systems after positive cloud-to-ground lightning flashes that produce large Charge Moment Change (CMC), with a shorter delay if the impulsive CMC (iCMC) is larger. (ii) The dancing sprites reflect the timing and the location of the successive lightning strokes that generate them. (iii) The sprite elements can be shifted from the stroke location when their delay is large. (iv) Bright sprites produce current signatures in ELF radiation a few milliseconds (<5 ms) after the positive strokes that generate them.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sprites are Transient Luminous Events (TLEs) that can extend vertically from 40 to 90 km and horizontally over several tens of km to form clusters of individual or multiple column or/and carrot-shaped luminous elements. They can even extend over more than 100 km in the form of sequential luminous emissions that are called “dancing sprites”. Their optical detection and other parameters describing the storm and the lightning activity associated allow us to understand the conditions of their production and their links with the lightning activity. Our observations confirm some characteristics of the sprites and put forward others: (i) the sprites are essentially produced above the stratiform region of the Mesoscale Convective Systems after positive cloud-to-ground lightning flashes that produce large Charge Moment Change (CMC), with a shorter delay if the impulsive CMC (iCMC) is larger. (ii) The dancing sprites reflect the timing and the location of the successive lightning strokes that generate them. (iii) The sprite elements can be shifted from the stroke location when their delay is large. (iv) Bright sprites produce current signatures in ELF radiation a few milliseconds (<5 ms) after the positive strokes that generate them. |
| 35. | Janusz Mlynarczyk; József Bór; Andrzej Kulak; Martin Popek; Jerzy Kubisz An unusual sequence of sprites followed by a secondary TLE: An analysis of ELF radio measurements and optical observations Journal Article Journal of Geophysical Research: Space Physics, 120 (3), pp. 2241-2254, 2015. @article{10.1002/2014JA020780, title = {An unusual sequence of sprites followed by a secondary TLE: An analysis of ELF radio measurements and optical observations}, author = {Janusz Mlynarczyk and József Bór and Andrzej Kulak and Martin Popek and Jerzy Kubisz}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JA020780}, doi = {10.1002/2014JA020780}, year = {2015}, date = {2015-01-01}, journal = {Journal of Geophysical Research: Space Physics}, volume = {120}, number = {3}, pages = {2241-2254}, abstract = {Abstract We present an extraordinary case of sprites in rapid succession—four sprite clusters in only 400 ms—followed by a secondary jet. Simultaneous ELF and optical observations, as well as lightning data, enabled us to thoroughly document this unique event. Locations of the transient luminous events (TLEs) were triangulated using video recordings from Nydek (Czech Republic) and Sopron (Hungary). We found that sprites were displaced up to 70 km from their parent lightning. The current moment waveform and charge moment changes associated with the event were reconstructed from the ELF electromagnetic signature recorded at the Hylaty station (Poland) by a new method. The results suggest that both a short-delayed and a long-delayed sprite were generated by a single positive cloud-to-ground discharge that had an intense continuing current. It had an unusual progression and lasted 200 ms. A large increase in the current moment during the development of a massive carrot sprite provides evidence in favor of sprite current. Our results also support the formation of an electric environment hypothesized to be necessary for the generation of the secondary TLEs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract We present an extraordinary case of sprites in rapid succession—four sprite clusters in only 400 ms—followed by a secondary jet. Simultaneous ELF and optical observations, as well as lightning data, enabled us to thoroughly document this unique event. Locations of the transient luminous events (TLEs) were triangulated using video recordings from Nydek (Czech Republic) and Sopron (Hungary). We found that sprites were displaced up to 70 km from their parent lightning. The current moment waveform and charge moment changes associated with the event were reconstructed from the ELF electromagnetic signature recorded at the Hylaty station (Poland) by a new method. The results suggest that both a short-delayed and a long-delayed sprite were generated by a single positive cloud-to-ground discharge that had an intense continuing current. It had an unusual progression and lasted 200 ms. A large increase in the current moment during the development of a massive carrot sprite provides evidence in favor of sprite current. Our results also support the formation of an electric environment hypothesized to be necessary for the generation of the secondary TLEs. |
| 34. | Joanna Kozakiewicz; Andrzej Kulak; Janusz Mlynarczyk Analytical modeling of Schumann resonance and ELF propagation parameters on Mars with a multi-layered ground Journal Article Planetary and Space Science, 117 , pp. 127 - 135, 2015, ISSN: 0032-0633. @article{10.1016/j.pss.2015.05.019, title = {Analytical modeling of Schumann resonance and ELF propagation parameters on Mars with a multi-layered ground}, author = {Joanna Kozakiewicz and Andrzej Kulak and Janusz Mlynarczyk}, url = {http://www.sciencedirect.com/science/article/pii/S0032063315001646}, doi = {10.1016/j.pss.2015.05.019}, issn = {0032-0633}, year = {2015}, date = {2015-01-01}, journal = {Planetary and Space Science}, volume = {117}, pages = {127 - 135}, abstract = {Two electrically conductive planetary spheres, the ionosphere and the ground, form a spherical waveguide. Within such a planetary cavity a phenomenon called Schumann resonance (SR) can occur. It is a resonance of extremely low frequency (ELF) electromagnetic waves. The resonance parameters are strongly related to the electromagnetic properties of the cavity. On Mars, as there is no liquid water at the planetary surface, the ground has a low conductivity. In such a situation, ELF waves penetrate into the planetary subsurface up to many kilometers depth. To examine the influence of low-conductivity grounds on ELF propagation, we have introduced a recently developed analytical method, which enables to estimate the propagation parameters and explicate their dependence of the ground properties. Since the presented model is fully analytical, it is computationally efficient and can be very useful in finding inverse solutions. To demonstrate the potential of the method, we present the relationship between individual ground properties and the parameters of Schumann resonance. The obtained results indicate that Martian exploration performed by one ELF station located at the planetary surface can reveal, along with the properties of the ionosphere, the existence of liquid water under the Martian surface.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two electrically conductive planetary spheres, the ionosphere and the ground, form a spherical waveguide. Within such a planetary cavity a phenomenon called Schumann resonance (SR) can occur. It is a resonance of extremely low frequency (ELF) electromagnetic waves. The resonance parameters are strongly related to the electromagnetic properties of the cavity. On Mars, as there is no liquid water at the planetary surface, the ground has a low conductivity. In such a situation, ELF waves penetrate into the planetary subsurface up to many kilometers depth. To examine the influence of low-conductivity grounds on ELF propagation, we have introduced a recently developed analytical method, which enables to estimate the propagation parameters and explicate their dependence of the ground properties. Since the presented model is fully analytical, it is computationally efficient and can be very useful in finding inverse solutions. To demonstrate the potential of the method, we present the relationship between individual ground properties and the parameters of Schumann resonance. The obtained results indicate that Martian exploration performed by one ELF station located at the planetary surface can reveal, along with the properties of the ionosphere, the existence of liquid water under the Martian surface. |
| 33. | M Mrózek; J Mlynarczyk; D S Rudnicki; W Gawlik Circularly polarized microwaves for magnetic resonance study in the GHz range: Application to nitrogen-vacancy in diamonds Journal Article Applied Physics Letters, 107 (1), pp. 013505, 2015. @article{10.1063/1.4923252, title = {Circularly polarized microwaves for magnetic resonance study in the GHz range: Application to nitrogen-vacancy in diamonds}, author = {M Mrózek and J Mlynarczyk and D S Rudnicki and W Gawlik}, url = {https://doi.org/10.1063/1.4923252}, doi = {10.1063/1.4923252}, year = {2015}, date = {2015-01-01}, journal = {Applied Physics Letters}, volume = {107}, number = {1}, pages = {013505}, abstract = {The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85%; it is possible to address the specific spin states of a diamond sample using a low power microwave generator. The circuit may be applied to a wide range of magnetic resonance experiments with a well-controlled polarization of microwaves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85%; it is possible to address the specific spin states of a diamond sample using a low power microwave generator. The circuit may be applied to a wide range of magnetic resonance experiments with a well-controlled polarization of microwaves. |
| 32. | Zenon Nieckarz; Piotr Baranski; Janusz Mlynarczyk; Andrzej Kulak; Jan Wiszniowski Comparison of the charge moment change calculated from electrostatic analysis and from ELF radio observations Journal Article Journal of Geophysical Research: Atmospheres, 120 (1), pp. 63-72, 2015. @article{10.1002/2014JD022289, title = {Comparison of the charge moment change calculated from electrostatic analysis and from ELF radio observations}, author = {Zenon Nieckarz and Piotr Baranski and Janusz Mlynarczyk and Andrzej Kulak and Jan Wiszniowski}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JD022289}, doi = {10.1002/2014JD022289}, year = {2015}, date = {2015-01-01}, journal = {Journal of Geophysical Research: Atmospheres}, volume = {120}, number = {1}, pages = {63-72}, abstract = {AbstractWe compare the results of two methods of calculation of the charge moment change (CMC, also called the dipole moment change) of the cloud-to-ground lightning discharges. The first method uses multistation ground-based measurements of the E field change for the purpose of the lightning flash location and charge analysis. Our six stations, called the Local Lightning Detection Network (LLDN), were set up in the Warsaw region. The second method is based on measurements of the horizontal magnetic field component of electromagnetic waves generated by atmospheric discharges in the ELF (extremely low frequency) range. Our ELF station is equipped with two magnetic antennas, east-west and north-south and is located in a sparsely populated area of the Bieszczady Mountains in Poland (49.19°N, 22.55°E). We present and discuss the results obtained by both methods, focusing on the negative return stroke (RS) and the return stroke with continuing current (RS and CC) lightning discharges. Results show a good correlation between the CMC obtained by the two methods. For the negative RS and CC and RS the correlation coefficient is equal to +0.50 and +0.80, respectively.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AbstractWe compare the results of two methods of calculation of the charge moment change (CMC, also called the dipole moment change) of the cloud-to-ground lightning discharges. The first method uses multistation ground-based measurements of the E field change for the purpose of the lightning flash location and charge analysis. Our six stations, called the Local Lightning Detection Network (LLDN), were set up in the Warsaw region. The second method is based on measurements of the horizontal magnetic field component of electromagnetic waves generated by atmospheric discharges in the ELF (extremely low frequency) range. Our ELF station is equipped with two magnetic antennas, east-west and north-south and is located in a sparsely populated area of the Bieszczady Mountains in Poland (49.19°N, 22.55°E). We present and discuss the results obtained by both methods, focusing on the negative return stroke (RS) and the return stroke with continuing current (RS and CC) lightning discharges. Results show a good correlation between the CMC obtained by the two methods. For the negative RS and CC and RS the correlation coefficient is equal to +0.50 and +0.80, respectively. |
| 31. | Izabela Slomian; Krzysztof Wincza; Slawomir Gruszczynski Conical-Beam Circularly-Polarized Microstrip Antenna Array for Ceiling Mount Doppler Sensors Journal Article International Journal of Information and Electronics Engineering, 5 , pp. 88-92, 2015. @article{10.7763/IJIEE.2015.V5.508, title = {Conical-Beam Circularly-Polarized Microstrip Antenna Array for Ceiling Mount Doppler Sensors}, author = {Izabela Slomian and Krzysztof Wincza and Slawomir Gruszczynski}, url = {http://www.ijiee.org/index.php?m=content&c=index&a=show&catid=50&id=553}, doi = {10.7763/IJIEE.2015.V5.508}, year = {2015}, date = {2015-01-01}, journal = {International Journal of Information and Electronics Engineering}, volume = {5}, pages = {88-92}, abstract = {A conical-beam circularly-polarized microstrip antenna array composed of four square-shaped radiating elements has been proposed. In the presented antenna array all of radiating elements are fed with equal-amplitude and in-phase signals and the excitation signal is guided to the center of the array through the via, to achieve both appropriate polarization properties and the conical radiation pattern. The paper includes the design details as well as simulation and measurement results of the manufactured antenna array designated for ceiling mount Doppler sensors operating at 10.5 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A conical-beam circularly-polarized microstrip antenna array composed of four square-shaped radiating elements has been proposed. In the presented antenna array all of radiating elements are fed with equal-amplitude and in-phase signals and the excitation signal is guided to the center of the array through the via, to achieve both appropriate polarization properties and the conical radiation pattern. The paper includes the design details as well as simulation and measurement results of the manufactured antenna array designated for ceiling mount Doppler sensors operating at 10.5 GHz. |
| 30. | Piotr Kaminski; Izabela Slomian; Krzysztof Wincza; Slawomir Gruszczynski Fully Integrated, Multipurpose Low-Cost K-Band FMCW Radar Module with Sub-Milimeter Measurement Precision Journal Article International Journal of Information and Electronics Engineering, 5 , pp. 74-78, 2015. @article{10.7763/IJIEE.2015.V5.505, title = {Fully Integrated, Multipurpose Low-Cost K-Band FMCW Radar Module with Sub-Milimeter Measurement Precision}, author = {Piotr Kaminski and Izabela Slomian and Krzysztof Wincza and Slawomir Gruszczynski}, url = {http://www.ijiee.org/index.php?m=content&c=index&a=show&catid=50&id=550}, doi = {10.7763/IJIEE.2015.V5.5058}, year = {2015}, date = {2015-01-01}, journal = {International Journal of Information and Electronics Engineering}, volume = {5}, pages = {74-78}, abstract = {A design of a low-cost K-band FMCW radar module with integrated microstrip antenna arrays and onboard digital signal processing has been presented. The radar utilizes antenna arrays with series feeding network which minimizes dissipation losses and allows for realization of high-gain antennas. The radar’s microcontroller unit is able to perform complete signal processing at real time which makes the presented sensor suitable for fully autonomous operation. Moreover, the presented radar module is capable of performing interferometric measurements. The interferometric capability of the developed unit allows for measurements of object displacement with precision on the order of tens of micrometers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A design of a low-cost K-band FMCW radar module with integrated microstrip antenna arrays and onboard digital signal processing has been presented. The radar utilizes antenna arrays with series feeding network which minimizes dissipation losses and allows for realization of high-gain antennas. The radar’s microcontroller unit is able to perform complete signal processing at real time which makes the presented sensor suitable for fully autonomous operation. Moreover, the presented radar module is capable of performing interferometric measurements. The interferometric capability of the developed unit allows for measurements of object displacement with precision on the order of tens of micrometers. |
| 29. | Kamil Staszek; Slawomir Gruszczynski; Krzysztof Wincza Measurement Accuracy Enhancement in Six-Port Reflectometers Journal Article IEEE Microwave and Wireless Components Letters, 25 , pp. 553-555, 2015. @article{10.1109/LMWC.2015.2440784, title = {Measurement Accuracy Enhancement in Six-Port Reflectometers}, author = {Kamil Staszek and Slawomir Gruszczynski and Krzysztof Wincza}, url = {https://ieeexplore.ieee.org/document/7131578}, doi = {10.1109/LMWC.2015.2440784}, year = {2015}, date = {2015-01-01}, journal = {IEEE Microwave and Wireless Components Letters}, volume = {25}, pages = {553-555}, abstract = {A new algorithm improving measurement accuracy in six-port reflectometers, applicable also for arbitrary multiport reflectometers, is proposed. The developed procedure does require neither additional measurements nor modifications of the measuring system. The introduced weighting coefficients allow for enhancement of the measurement accuracy using the same power measurements as in classic solutions. The proposed theory has been confirmed experimentally by the measurements of reflection coefficient within a wide frequency range 2-4 GHz.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new algorithm improving measurement accuracy in six-port reflectometers, applicable also for arbitrary multiport reflectometers, is proposed. The developed procedure does require neither additional measurements nor modifications of the measuring system. The introduced weighting coefficients allow for enhancement of the measurement accuracy using the same power measurements as in classic solutions. The proposed theory has been confirmed experimentally by the measurements of reflection coefficient within a wide frequency range 2-4 GHz. |
| 28. | Ilona Piekarz; Jakub Sorocki; Krzysztof Wincza; Slawomir Gruszczynski Modeling and performance improvement of folded coupled lines in miniaturized Quasi-lumped directional couplers Journal Article International Journal of RF and Microwave Computer-Aided Engineering, 25 (1), pp. 1-9, 2015. @article{10.1002/mmce.20817, title = {Modeling and performance improvement of folded coupled lines in miniaturized Quasi-lumped directional couplers}, author = {Ilona Piekarz and Jakub Sorocki and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/mmce.20817}, doi = {10.1002/mmce.20817}, year = {2015}, date = {2015-01-01}, journal = {International Journal of RF and Microwave Computer-Aided Engineering}, volume = {25}, number = {1}, pages = {1-9}, abstract = {ABSTRACT An efficient modeling method for folded coupled inductors for application in quasi-lumped directional couplers designed in both symmetric and asymmetric structures has been proposed. The presented model takes into account the deteriorative effects which occur when coupled inductors realized as electrically short coupled-lines matched to the high impedance standard are folded into, for example, meander or spiral pattern. The deteriorative influence of coupled-lines' folding on the performance of the resulting directional coupler has been modeled as additional lumped inductors and capacitors on the schematic diagram of a quasi-lumped directional coupler's subsection. Moreover, it has been shown that this deteriorative influence can be substantially minimized when values of lumped elements constituting the directional coupler are appropriately changed. The proposed design procedure has been experimentally verified by measurements of two 3-dB single-section directional couplers designed in symmetric and asymmetric structures as quasi-lumped couplers with folded coupled inductors. The measurement results show a good agreement with both circuit and electromagnetic analysis which proves the correctness and usefulness of the presented methods. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:1–9, 2015.}, keywords = {}, pubstate = {published}, tppubtype = {article} } ABSTRACT An efficient modeling method for folded coupled inductors for application in quasi-lumped directional couplers designed in both symmetric and asymmetric structures has been proposed. The presented model takes into account the deteriorative effects which occur when coupled inductors realized as electrically short coupled-lines matched to the high impedance standard are folded into, for example, meander or spiral pattern. The deteriorative influence of coupled-lines' folding on the performance of the resulting directional coupler has been modeled as additional lumped inductors and capacitors on the schematic diagram of a quasi-lumped directional coupler's subsection. Moreover, it has been shown that this deteriorative influence can be substantially minimized when values of lumped elements constituting the directional coupler are appropriately changed. The proposed design procedure has been experimentally verified by measurements of two 3-dB single-section directional couplers designed in symmetric and asymmetric structures as quasi-lumped couplers with folded coupled inductors. The measurement results show a good agreement with both circuit and electromagnetic analysis which proves the correctness and usefulness of the presented methods. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:1–9, 2015. |
| 27. | Michał Dyrda; Andrzej Kulak; Janusz Mlynarczyk; Michał Ostrowski Novel analysis of a sudden ionospheric disturbance using Schumann resonance measurements Journal Article Journal of Geophysical Research: Space Physics, 120 (3), pp. 2255-2262, 2015. @article{10.1002/2014JA020854, title = {Novel analysis of a sudden ionospheric disturbance using Schumann resonance measurements}, author = {Michał Dyrda and Andrzej Kulak and Janusz Mlynarczyk and Michał Ostrowski}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014JA020854}, doi = {10.1002/2014JA020854}, year = {2015}, date = {2015-01-01}, journal = {Journal of Geophysical Research: Space Physics}, volume = {120}, number = {3}, pages = {2255-2262}, abstract = {AbstractA spherical cavity between Earth and the lower ionosphere forms a global resonator for Extremely Low Frequency electromagnetic waves. Constant thunderstorm activity leads to the formation of a resonance field in the cavity, known as the Schumann resonance. Solar flare generated Sudden Ionospheric Disturbances (SID) modify the ionosphere affecting the ground-based radio communication systems. They are also expected to modify radiowave propagation in the cavity. In this paper, the Schumann Resonance spectral decomposition method is used for the first time to study the cavity resonance frequencies during the SID accompanying a strong X2.1 solar flare. We analyzed rapid changes in the frequencies and Q factors of the first five resonance modes using a 5 min timescale. The observed frequency shifts were compared to the ionizing solar flare fluxes in the UV, X-ray, and high-energy γ rays.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AbstractA spherical cavity between Earth and the lower ionosphere forms a global resonator for Extremely Low Frequency electromagnetic waves. Constant thunderstorm activity leads to the formation of a resonance field in the cavity, known as the Schumann resonance. Solar flare generated Sudden Ionospheric Disturbances (SID) modify the ionosphere affecting the ground-based radio communication systems. They are also expected to modify radiowave propagation in the cavity. In this paper, the Schumann Resonance spectral decomposition method is used for the first time to study the cavity resonance frequencies during the SID accompanying a strong X2.1 solar flare. We analyzed rapid changes in the frequencies and Q factors of the first five resonance modes using a 5 min timescale. The observed frequency shifts were compared to the ionizing solar flare fluxes in the UV, X-ray, and high-energy γ rays. |
| 26. | Jakub Sorocki; Ilona Piekarz; Krzysztof Wincza; Slawomir Gruszczynski Pseudo-highpass filters based on semi-distributed balanced composite right/left-handed unit cells Journal Article Journal of Electromagnetic Waves and Applications, 29 (16), pp. 2171-2177, 2015. @article{10.1080/09205071.2015.1078748, title = {Pseudo-highpass filters based on semi-distributed balanced composite right/left-handed unit cells}, author = {Jakub Sorocki and Ilona Piekarz and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://www.tandfonline.com/doi/abs/10.1080/09205071.2015.1078748}, doi = {10.1080/09205071.2015.1078748}, year = {2015}, date = {2015-01-01}, journal = {Journal of Electromagnetic Waves and Applications}, volume = {29}, number = {16}, pages = {2171-2177}, abstract = {In this study, the design of high selectivity, pseudo-highpass filters is presented. The proposed circuits utilize a novel semi-distributed-element composite right/left-handed unit cell (UC) composed of sections of transmission lines and a lumped capacitor. By proper balancing the structure, a very broad operation band can be obtained. Moreover, a single-layer microstrip realization is possible making the UC well suitable for low-cost filter realization. The proposed concept has been experimentally verified by the design and measurements of an exemplary pseudo-highpass filter.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, the design of high selectivity, pseudo-highpass filters is presented. The proposed circuits utilize a novel semi-distributed-element composite right/left-handed unit cell (UC) composed of sections of transmission lines and a lumped capacitor. By proper balancing the structure, a very broad operation band can be obtained. Moreover, a single-layer microstrip realization is possible making the UC well suitable for low-cost filter realization. The proposed concept has been experimentally verified by the design and measurements of an exemplary pseudo-highpass filter. |
| 25. | Jakub Sorocki; Ilona Piekarz; Krzysztof Wincza; Slawomir Gruszczynski Right/Left-Handed Transmission Lines Based on Coupled Transmission Line Sections and Their Application Towards Bandpass Filters Journal Article IEEE Transactions on Microwave Theory and Techniques, 63 (2), pp. 384-396, 2015. @article{10.1080/09205071.2015.1078748b, title = {Right/Left-Handed Transmission Lines Based on Coupled Transmission Line Sections and Their Application Towards Bandpass Filters}, author = {Jakub Sorocki and Ilona Piekarz and Krzysztof Wincza and Slawomir Gruszczynski}, url = {https://ieeexplore.ieee.org/document/6985681}, doi = {10.1109/TMTT.2014.2378283}, year = {2015}, date = {2015-01-01}, journal = {IEEE Transactions on Microwave Theory and Techniques}, volume = {63}, number = {2}, pages = {384-396}, abstract = {Novel metamaterial structures featuring left-handed (LH) and composite right/left-handed (CRLH) character are presented. The proposed unit cells utilize sections of coupled transmission lines. It is shown that by taking advantage of the coupling between transmission lines an additional degree of freedom is achieved, and therefore, the design process of artificial transmission lines is more flexible. The general behavior of each of the proposed circuits is presented and analyzed. Moreover, the design equations are formulated and the design process of each unit cell is described. The usefulness and validity of the proposed unit cells are illustrated and verified by the design and measurements of compact artificial transmission line sections utilizing the presented structures. Moreover, possible applications are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Novel metamaterial structures featuring left-handed (LH) and composite right/left-handed (CRLH) character are presented. The proposed unit cells utilize sections of coupled transmission lines. It is shown that by taking advantage of the coupling between transmission lines an additional degree of freedom is achieved, and therefore, the design process of artificial transmission lines is more flexible. The general behavior of each of the proposed circuits is presented and analyzed. Moreover, the design equations are formulated and the design process of each unit cell is described. The usefulness and validity of the proposed unit cells are illustrated and verified by the design and measurements of compact artificial transmission line sections utilizing the presented structures. Moreover, possible applications are discussed. |
| 74. | Ionospheric D Region Remote Sensing Using ELF Sferic Group Velocity Journal Article Geophysical Research Letters, 45 (23), pp. 12,739-12,748, 2018. |
| 73. | Liquids Permittivity Measurement Using Two-Wire Transmission Line Sensor Journal Article IEEE Sensors Journal, 18 (18), pp. 7458-7466, 2018. |
| 72. | Low-Cost Microwave Vector System for Liquid Properties Monitoring Journal Article IEEE Transactions on Industrial Electronics, 65 (2), pp. 1665-1674, 2018. |
| 71. | Low-Loss Directional Filters Based on Differential Band-Reject Filters With Improved Isolation Using Phase Inverter Journal Article IEEE Microwave and Wireless Components Letters, 28 (4), pp. 314-316, 2018. |
| 70. | On the Series of +CG Lightning Strokes in Dancing Sprite Events Journal Article Journal of Geophysical Research: Atmospheres, 123 (19), pp. 11,030-11,047, 2018. |
| 69. | Six-Port Calibration Utilizing Matched Load and Unknown Calibration Loads Journal Article IEEE Transactions on Microwave Theory and Techniques, 66 (10), pp. 4617-4626, 2018. |
| 68. | Wideband Nine-Port Reflectometer Journal Article International Journal of Electronics and Telecommunications, 64 (1), 2018. |
| 67. | Wideband three-section symmetrical coupled-line directional coupler operating in differential mode Journal Article IEEE Microwave and Wireless Components Letters, 28 (6), pp. 488-490, 2018. |
| 66. | Globally coherent short duration magnetic field transients and their effect on ground based gravitational-wave detectors Journal Article Classical and Quantum Gravity, 34 (7), pp. 074002, 2017. |
| 65. | Assessment of Unusual Gigantic Jets observed during the Monsoon season: First observations from Indian Subcontinent Journal Article Scientific Reports, 7 , pp. 16436, 2017. |
| 64. | Broadband Multibeam Antenna Arrays Fed by Frequency-Dependent Butler Matrices Journal Article IEEE Transactions on Antennas and Propagation, 65 (9), pp. 4539-4547, 2017. |
| 63. | Dancing sprites: Detailed analysis of two case studies Journal Article Journal of Geophysical Research: Atmospheres, 122 (6), pp. 3173-3192, 2017. |
| 62. | Design of low-loss directional couplers with compensated coupled-line sections in suspended microstrip technique Journal Article International Journal of RF and Microwave Computer-Aided Engineering, 27 (8), pp. e21125, 2017. |
| 61. | Folded Single-Layer 8 × 8 Butler Matrix Journal Article Journal of Electromagnetic Waves and Applications, 31 (14), pp. 1386-1398, 2017. |
| 60. | Frequency-Selective Feeding Network Based on Directional Filter for Constant-Beamwidth Scalable Antenna Arrays Journal Article IEEE Transactions on Antennas and Propagation, 65 (8), pp. 4346-4350, 2017. |
| 59. | Impedance transforming directional couplers with increased achievable transformation ratio Journal Article International Journal of Microwave and Wireless Technologies, 9 (3), pp. 509–513, 2017. |
| 58. | Measurement uncertainty analysis and design of a broadband four-port reflectometer Journal Article IET Microwaves, Antennas & Propagation, 11 (15), pp. 2162-2167, 2017. |
| 57. | Microwave Sensors for Dielectric Sample Measurement Based on Coupled-Line Section Journal Article IEEE Transactions on Microwave Theory and Techniques, 65 (5), pp. 1615-1631, 2017. |
| 56. | Six-port microwave system for volatile organic compounds detection Journal Article Sensors and Actuators B: Chemical, 245 , pp. 882 - 894, 2017, ISSN: 0925-4005. |
| 55. | The Accuracy of Radio Direction Finding in the Extremely Low Frequency Range Journal Article Radio Science, 52 (10), pp. 1245-1252, 2017. |
| 54. | Tunable multiport system for measurement of two-port scattering parameters Journal Article International Journal of Microwave and Wireless Technologies, 9 (1), pp. 99–112, 2017. |
| 53. | Broadband coupled-line directional couplers with high impedance transformation ratio Journal Article International Journal of Microwave and Wireless Technologies, 9 (7), pp. 1473–1480, 2017. |
| 52. | Ultra-Wideband Dual-Line Multiprobe Reflectometer Journal Article IEEE Transactions on Microwave Theory and Techniques, 65 (4), pp. 1324-1333, 2017. |
| 51. | Subtraction of correlated noise in global networks of gravitational-wave interferometers Journal Article Classical and Quantum Gravity, 33 (22), pp. 224003, 2016. |
| 50. | A broadband capacitive sensing method for label-free bacterial LPS detection Journal Article Biosensors and Bioelectronics, 75 , pp. 328 - 336, 2016, ISSN: 0956-5663. |
| 49. | Broadband Balun Circuits Composed of Impedance Transforming Directional Couplers and LH Transmission-Line Sections Journal Article International Journal of Information and Electronics Engineering, 6 , pp. 147-150, 2016, ISSN: 2010-3719. |
| 48. | Broadband Integrated 8×8 Butler Matrix Utilizing Quadrature Couplers and Schiffman Phase Shifters for Multibeam Antennas With Broadside Beam Journal Article IEEE Transactions on Microwave Theory and Techniques, 64 , pp. 2596-2604, 2016. |
| 47. | Broadband scalable antenna arrays with constant beamwidths fed by frequency-selective networks Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 2936–2943, 2016. |
| 46. | Circularly Polarized Switched-Beam Antenna Arrays With Reduced Sidelobe Level Journal Article IEEE Antennas and Wireless Propagation Letters, 15 , pp. 1213-1216, 2016. |
| 45. | Composite right/left-handed leaky-wave antenna with adjustable radiation bandwidth Journal Article Journal of Electromagnetic Waves and Applications, 30 , pp. 1054-1063, 2016. |
| 44. | Coupled-Line Sensor With Marchand Balun as RF System for Dielectric Sample Detection Journal Article IEEE Sensors Journal, 16 , pp. 88-96, 2016. |
| 43. | Microwave-based sensors with phthalocyanine films for acetone, ethanol and methanol detection Journal Article Sensors and Actuators B: Chemical, 237 , pp. 876 - 886, 2016, ISSN: 0925-4005. |
| 42. | Rigorous Approach for Design of Differential Coupled-Line Directional Couplers Applicable in Integrated Circuits and Substrate-Embedded Networks Journal Article Scientific Reports, 6 , 2016. |
| 41. | Scalable Multibeam Antenna Arrays Fed by Dual-Band Modified Butler Matrices Journal Article IEEE Transactions on Antennas and Propagation, 64 , pp. 1287-1297, 2016. |
| 40. | Series-Fed Dual-Band Dual-Polarized Antenna Lattice Fed by Slot-Coupled Power Dividers Journal Article IEEE Antennas and Wireless Propagation Letters, 15 , pp. 1065-1068, 2016. |
| 39. | Six-Port Reflectometer Providing Enhanced Power Distribution Journal Article IEEE Transactions on Microwave Theory and Techniques, 64 , pp. 939-951, 2016. |
| 38. | Symmetrical series-fed dual-polarised microstrip antenna lattice with odd number of radiating elements Journal Article IET Microwaves, Antennas & Propagation, 10 , pp. 701-708, 2016. |
| 37. | Application of RH and LH sections for reduction of coupling coefficients in two-section asymmetric directional couplers Journal Article International Journal of Microwave and Wireless Technologies, 8 (3), pp. 559–565, 2016. |
| 36. | Characteristics of lightning flashes generating sprites above storms Journal Article E3S Web of Conf., 12 , pp. 02001, 2016. |
| 35. | An unusual sequence of sprites followed by a secondary TLE: An analysis of ELF radio measurements and optical observations Journal Article Journal of Geophysical Research: Space Physics, 120 (3), pp. 2241-2254, 2015. |
| 34. | Analytical modeling of Schumann resonance and ELF propagation parameters on Mars with a multi-layered ground Journal Article Planetary and Space Science, 117 , pp. 127 - 135, 2015, ISSN: 0032-0633. |
| 33. | Circularly polarized microwaves for magnetic resonance study in the GHz range: Application to nitrogen-vacancy in diamonds Journal Article Applied Physics Letters, 107 (1), pp. 013505, 2015. |
| 32. | Comparison of the charge moment change calculated from electrostatic analysis and from ELF radio observations Journal Article Journal of Geophysical Research: Atmospheres, 120 (1), pp. 63-72, 2015. |
| 31. | Conical-Beam Circularly-Polarized Microstrip Antenna Array for Ceiling Mount Doppler Sensors Journal Article International Journal of Information and Electronics Engineering, 5 , pp. 88-92, 2015. |
| 30. | Fully Integrated, Multipurpose Low-Cost K-Band FMCW Radar Module with Sub-Milimeter Measurement Precision Journal Article International Journal of Information and Electronics Engineering, 5 , pp. 74-78, 2015. |
| 29. | Measurement Accuracy Enhancement in Six-Port Reflectometers Journal Article IEEE Microwave and Wireless Components Letters, 25 , pp. 553-555, 2015. |
| 28. | Modeling and performance improvement of folded coupled lines in miniaturized Quasi-lumped directional couplers Journal Article International Journal of RF and Microwave Computer-Aided Engineering, 25 (1), pp. 1-9, 2015. |
| 27. | Novel analysis of a sudden ionospheric disturbance using Schumann resonance measurements Journal Article Journal of Geophysical Research: Space Physics, 120 (3), pp. 2255-2262, 2015. |
| 26. | Pseudo-highpass filters based on semi-distributed balanced composite right/left-handed unit cells Journal Article Journal of Electromagnetic Waves and Applications, 29 (16), pp. 2171-2177, 2015. |
| 25. | Right/Left-Handed Transmission Lines Based on Coupled Transmission Line Sections and Their Application Towards Bandpass Filters Journal Article IEEE Transactions on Microwave Theory and Techniques, 63 (2), pp. 384-396, 2015. |