Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105297
Yuhi Yokohama, T. Kodera
A novel microwave isolator operation based on non-reciprocal vectorial magnetic field cancellation in Magnet-less non-reciprocal Metamaterial (MNM) is proposed, analyzed, and its superiority to the previous concept is fully confirmed by prototype device. The field cancellation is realized by a traveling-wave ring resonator pair with structural perturbation in order to obtain asymmetric vectorial field excitation, which leads to vectorial field cancellation. Compared to the original design, isolation ratio (|S21|–|S12|) is improved from 10 to 35 dB with insertion loss of 2 dB.
{"title":"Transistor-loaded isolator based on both frustrated propagation and field cancellation mechanisms","authors":"Yuhi Yokohama, T. Kodera","doi":"10.23919/URSIGASS.2017.8105297","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105297","url":null,"abstract":"A novel microwave isolator operation based on non-reciprocal vectorial magnetic field cancellation in Magnet-less non-reciprocal Metamaterial (MNM) is proposed, analyzed, and its superiority to the previous concept is fully confirmed by prototype device. The field cancellation is realized by a traveling-wave ring resonator pair with structural perturbation in order to obtain asymmetric vectorial field excitation, which leads to vectorial field cancellation. Compared to the original design, isolation ratio (|S21|–|S12|) is improved from 10 to 35 dB with insertion loss of 2 dB.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115738451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105108
S. Priyadarshi, Q.‐H. Zhang, E. Thomas, L. Spogli, C. Cesaroni
TIDs are the large scale electron density perturbations that travel in the ionosphere and can be tracked by number of instruments, like incoherent scatter radar, ionosondes, HF Dopler system etc. They are believed to be the signature of atmospheric gravity wave in the high latitude ionosphere, which are generated due to geomagnetic activities [1].
{"title":"A study of traveling ionospheric disturbances and their associated scintillation behaviors at South Pole","authors":"S. Priyadarshi, Q.‐H. Zhang, E. Thomas, L. Spogli, C. Cesaroni","doi":"10.23919/URSIGASS.2017.8105108","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105108","url":null,"abstract":"TIDs are the large scale electron density perturbations that travel in the ionosphere and can be tracked by number of instruments, like incoherent scatter radar, ionosondes, HF Dopler system etc. They are believed to be the signature of atmospheric gravity wave in the high latitude ionosphere, which are generated due to geomagnetic activities [1].","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124578321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105300
J. Kovitz, Y. Rahmat-Samii
Integrating composite right/left-handed (CRLH) transmission lines into quadrature power dividers (QPDs) has demonstrated potential for enhanced bandwidth in circularly-polarized antenna applications. Despite the excitement about CRLH, optimal design strategies remain ambiguous, and previous work proposed varied embodiments of CRLH integrations but do not direct designers towards optimal designs strategies for QPDs. This paper investigates the necessity to integrate CRLH in both output paths of QPDs versus one output path. Our analysis reveals that there is no advantage from a dispersion perspective. Both analytical models and simulations agree with this conclusion, encouraging future users of this concept to employ a single CRLH line approach.
{"title":"Design strategies for metamaterial quadrature power dividers in CP antennas: Are two CRLH-loaded lines necessary?","authors":"J. Kovitz, Y. Rahmat-Samii","doi":"10.23919/URSIGASS.2017.8105300","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105300","url":null,"abstract":"Integrating composite right/left-handed (CRLH) transmission lines into quadrature power dividers (QPDs) has demonstrated potential for enhanced bandwidth in circularly-polarized antenna applications. Despite the excitement about CRLH, optimal design strategies remain ambiguous, and previous work proposed varied embodiments of CRLH integrations but do not direct designers towards optimal designs strategies for QPDs. This paper investigates the necessity to integrate CRLH in both output paths of QPDs versus one output path. Our analysis reveals that there is no advantage from a dispersion perspective. Both analytical models and simulations agree with this conclusion, encouraging future users of this concept to employ a single CRLH line approach.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114761019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105143
C. Estatico, A. Fedeli, M. Pastorino, A. Randazzo
Within the ever-growing field of electromagnetic imaging, inversion procedures are conventionally described in the mathematical framework of Hilbert spaces. Usually, the over-smoothing effects and oscillations that arise using a Hilbert-space formulation make the dielectric reconstruction of targets inaccurate. This problem is strongly reduced by the recent development of inversion techniques in Banach spaces. However, the selection of the Banach space norm parameter is critical for obtaining precise reconstructions, and no exact rules exist for this choice. To overcome this issue, an innovative approach in variable exponent Lebesgue spaces is proposed here, along with a preliminary numerical validation.
{"title":"An inverse scattering procedure in Lebesgue spaces with non-constant exponents","authors":"C. Estatico, A. Fedeli, M. Pastorino, A. Randazzo","doi":"10.23919/URSIGASS.2017.8105143","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105143","url":null,"abstract":"Within the ever-growing field of electromagnetic imaging, inversion procedures are conventionally described in the mathematical framework of Hilbert spaces. Usually, the over-smoothing effects and oscillations that arise using a Hilbert-space formulation make the dielectric reconstruction of targets inaccurate. This problem is strongly reduced by the recent development of inversion techniques in Banach spaces. However, the selection of the Banach space norm parameter is critical for obtaining precise reconstructions, and no exact rules exist for this choice. To overcome this issue, an innovative approach in variable exponent Lebesgue spaces is proposed here, along with a preliminary numerical validation.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114861115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105407
G. Venanzoni, M. Dionigi, C. Tomassoni, D. Eleonori, R. Sorrentino
We present a novel approach to fabricate microwave passive components using very cheap SLA 3D printing technology associated with copper electroplating of the resulting 3D plastic structures. Some test structures are presented showing the excellent performance of the process.
{"title":"3D printing of X band waveguide resonators and filters","authors":"G. Venanzoni, M. Dionigi, C. Tomassoni, D. Eleonori, R. Sorrentino","doi":"10.23919/URSIGASS.2017.8105407","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105407","url":null,"abstract":"We present a novel approach to fabricate microwave passive components using very cheap SLA 3D printing technology associated with copper electroplating of the resulting 3D plastic structures. Some test structures are presented showing the excellent performance of the process.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115059989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105258
G. Cheng, Yong Zhu, J. Grzesik
We propose an exact solution technique for lens and reflector shaping, which determines the surface geometry of a reflector or a lens excited by a single feed element based on the specified far field information. Otherwise stated, given a desired far field pattern over a specified solid angle range, a single-reflector/single-feed antenna system can be obtained analytically via a closed form, exact solution. There is no need whatsoever to invoke optimization algorithms. Given a required two-dimensional far field pattern, the surface of the reflector or lens, illuminated by a single feed, is generated via a closed form solution, a solution which satisfies Maxwell's equations and all relevant boundary conditions. For the purpose of demonstration, three reflector antennas, and one lens, each with a single feed, have been constructed based on three different far field contour beam patterns. In each such case, the CPU required to generate a thousand surface points amounted to just a few minutes of real time. Solution verification was carried out by analytic examples, software simulations, and hardware measurement. Four anal3itic examples, including the standard planar, parabolic, elliptical, and hyperbolic reflectors, are presented herein. Also confirmed with commercial software was the performance of a shaped reflector which provides a specific far field contour beam. Additionally, a dish antenna measurement verified the perfect reconstruction of the reflector surface from its measured near field pattern. Excellent correlations were obtained in all demonstration cases.
{"title":"Exact solutions for lens and reflector shaping","authors":"G. Cheng, Yong Zhu, J. Grzesik","doi":"10.23919/URSIGASS.2017.8105258","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105258","url":null,"abstract":"We propose an exact solution technique for lens and reflector shaping, which determines the surface geometry of a reflector or a lens excited by a single feed element based on the specified far field information. Otherwise stated, given a desired far field pattern over a specified solid angle range, a single-reflector/single-feed antenna system can be obtained analytically via a closed form, exact solution. There is no need whatsoever to invoke optimization algorithms. Given a required two-dimensional far field pattern, the surface of the reflector or lens, illuminated by a single feed, is generated via a closed form solution, a solution which satisfies Maxwell's equations and all relevant boundary conditions. For the purpose of demonstration, three reflector antennas, and one lens, each with a single feed, have been constructed based on three different far field contour beam patterns. In each such case, the CPU required to generate a thousand surface points amounted to just a few minutes of real time. Solution verification was carried out by analytic examples, software simulations, and hardware measurement. Four anal3itic examples, including the standard planar, parabolic, elliptical, and hyperbolic reflectors, are presented herein. Also confirmed with commercial software was the performance of a shaped reflector which provides a specific far field contour beam. Additionally, a dish antenna measurement verified the perfect reconstruction of the reflector surface from its measured near field pattern. Excellent correlations were obtained in all demonstration cases.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116797680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105159
M. Abdelhay, S. El-Khamy
In this paper, a compressive sensing approach for wide null steering in partially adaptive arrays is introduced. The proposed method imposes the wide nulls by canceling the whole sidelobes where the interference signals arrive. The problem is first formulated and relaxed to obtain a convex programming problem. The relaxed problem is then solved using iterative re-weighted minimization algorithm to enhance the sparsity in the final solution. Simulations were conducted for one and two wide nulls steering in small and large linear arrays. Results show that the proposed algorithm is capable of steering the required nulls with small number of perturbed array elements.
{"title":"A new compressed sensing based approach for null steering of linear arrays by perturbing minimum number of elements","authors":"M. Abdelhay, S. El-Khamy","doi":"10.23919/URSIGASS.2017.8105159","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105159","url":null,"abstract":"In this paper, a compressive sensing approach for wide null steering in partially adaptive arrays is introduced. The proposed method imposes the wide nulls by canceling the whole sidelobes where the interference signals arrive. The problem is first formulated and relaxed to obtain a convex programming problem. The relaxed problem is then solved using iterative re-weighted minimization algorithm to enhance the sparsity in the final solution. Simulations were conducted for one and two wide nulls steering in small and large linear arrays. Results show that the proposed algorithm is capable of steering the required nulls with small number of perturbed array elements.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"444 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123937008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105366
Y. Soldo, P. de Matthaeis, D. L. Le Vine
RFI (Radio-Frequency Interference) in the 1400–1427 MHz band degrades the quality of measurements made by satellite missions such as SMAP (Soil Moisture Active/Passive), Aquarius and SMOS (Soil Moisture and Ocean Salinity). A technique is presented here to estimate the location on the ground of RFI sources using SMAP measurements. The results of this technique have been validated against data derived by other means.
{"title":"Localization of L-band RFI sources from SMAP data","authors":"Y. Soldo, P. de Matthaeis, D. L. Le Vine","doi":"10.23919/URSIGASS.2017.8105366","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105366","url":null,"abstract":"RFI (Radio-Frequency Interference) in the 1400–1427 MHz band degrades the quality of measurements made by satellite missions such as SMAP (Soil Moisture Active/Passive), Aquarius and SMOS (Soil Moisture and Ocean Salinity). A technique is presented here to estimate the location on the ground of RFI sources using SMAP measurements. The results of this technique have been validated against data derived by other means.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124017480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8104493
Mingliang Tao, Feng Zhou
Radio frequency interference (RFI) is a major issue for synthetic aperture radar (SAR), and would affect the image quality and image interpretation. The majority of existing methods are applied on each azimuth echoes along range direction with the assumption that bandwidth of RFI is less than that of SAR. However, if SAR echoes are contaminated by ultra wide-band RFI, i.e., the bandwidth of RFI is relatively larger than the transmitted signal, traditional methods would fail due to large signal loss. In this paper, we discussed the characteristics of ultra wide-band RFI, and proposed a mitigation method using nonnegative matrix factorization along azimuth direction. The experimental results indicate the effectiveness of the proposed method.
{"title":"Correction of ultra wide-band radio frequency interference in SAR data using nonnegative matrix factorization","authors":"Mingliang Tao, Feng Zhou","doi":"10.23919/URSIGASS.2017.8104493","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8104493","url":null,"abstract":"Radio frequency interference (RFI) is a major issue for synthetic aperture radar (SAR), and would affect the image quality and image interpretation. The majority of existing methods are applied on each azimuth echoes along range direction with the assumption that bandwidth of RFI is less than that of SAR. However, if SAR echoes are contaminated by ultra wide-band RFI, i.e., the bandwidth of RFI is relatively larger than the transmitted signal, traditional methods would fail due to large signal loss. In this paper, we discussed the characteristics of ultra wide-band RFI, and proposed a mitigation method using nonnegative matrix factorization along azimuth direction. The experimental results indicate the effectiveness of the proposed method.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"461 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125849404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-08-01DOI: 10.23919/URSIGASS.2017.8105415
Yue Zhao, B. Ai, Dan Fei, Yiru Liu, Nan Li
Beamforming is a signal processing technique in which multiple antennas are used to weight the signals so that they can be added constructively in the desired direction, and destructively in the interference direction. In this paper, adaptive beamforming based on subband decomposition structure is investigated in smart antenna arrays and the performance of the proposed adaptive beamforming scheme is analyzed. An efficient subband structure with the reduced sampling rate of signal is given, which leads to the great reduction of computation complexity. Simulation results indicate that the adaptive beamforming based on subband structure works well and has comparative performance to the conventional fullband algorithms.
{"title":"Adaptive beamforming based on subband structure in smart antennas","authors":"Yue Zhao, B. Ai, Dan Fei, Yiru Liu, Nan Li","doi":"10.23919/URSIGASS.2017.8105415","DOIUrl":"https://doi.org/10.23919/URSIGASS.2017.8105415","url":null,"abstract":"Beamforming is a signal processing technique in which multiple antennas are used to weight the signals so that they can be added constructively in the desired direction, and destructively in the interference direction. In this paper, adaptive beamforming based on subband decomposition structure is investigated in smart antenna arrays and the performance of the proposed adaptive beamforming scheme is analyzed. An efficient subband structure with the reduced sampling rate of signal is given, which leads to the great reduction of computation complexity. Simulation results indicate that the adaptive beamforming based on subband structure works well and has comparative performance to the conventional fullband algorithms.","PeriodicalId":377869,"journal":{"name":"2017 XXXIInd General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125897185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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