IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)最新文献
An insulated linear antenna consists of a metallic, cylindrical conductor covered by a concentric sheath of dielectric with relative permittivity /spl epsiv//sub ri/. Insulated antennas are almost always used in an ambient medium, such as soil, seawater, or biological tissue, whose electrical properties are quite different from those of the insulation; that is, either the relative permittivity /spl epsiv//sub re/ or the conductivity /spl sigma//sub e/, of the external medium is much greater than that of the insulation. The purpose of this paper is to establish the range of validity for the transmission line theory for the insulated monopole antenna to produce accurate results. This is accomplished by comparing results from the transmission line theory with accurate calculations made with the finite-difference time-domain (FDTD) method.
{"title":"On the accuracy of the transmission line theory for the insulated linear antenna","authors":"T. Hertel, G.S. Smith","doi":"10.1109/APS.1999.789427","DOIUrl":"https://doi.org/10.1109/APS.1999.789427","url":null,"abstract":"An insulated linear antenna consists of a metallic, cylindrical conductor covered by a concentric sheath of dielectric with relative permittivity /spl epsiv//sub ri/. Insulated antennas are almost always used in an ambient medium, such as soil, seawater, or biological tissue, whose electrical properties are quite different from those of the insulation; that is, either the relative permittivity /spl epsiv//sub re/ or the conductivity /spl sigma//sub e/, of the external medium is much greater than that of the insulation. The purpose of this paper is to establish the range of validity for the transmission line theory for the insulated monopole antenna to produce accurate results. This is accomplished by comparing results from the transmission line theory with accurate calculations made with the finite-difference time-domain (FDTD) method.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131135565","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}
The ARISE (Advanced Radio Interferometry between Space and Earth) program, part of future scientific and communications missions, are designed to test the concept of using very large reflector antennas in space. The antenna dimensions are targeted from 10 m to 25 m and beyond. Frequencies covering L-band through W-band are being considered. Among these challenging missions, the ARISE program is projected to utilize a 25 m dual offset Gregorian optics operating from 8 GHz to 86 GHz. The objective of this mission is to create a space-based VLBI system (integrated with ground based antennas) for high resolution mapping of the black holes.
{"title":"ARISE: a challenging 25-m space antenna design","authors":"R. Hoferer","doi":"10.1109/APS.1999.788232","DOIUrl":"https://doi.org/10.1109/APS.1999.788232","url":null,"abstract":"The ARISE (Advanced Radio Interferometry between Space and Earth) program, part of future scientific and communications missions, are designed to test the concept of using very large reflector antennas in space. The antenna dimensions are targeted from 10 m to 25 m and beyond. Frequencies covering L-band through W-band are being considered. Among these challenging missions, the ARISE program is projected to utilize a 25 m dual offset Gregorian optics operating from 8 GHz to 86 GHz. The objective of this mission is to create a space-based VLBI system (integrated with ground based antennas) for high resolution mapping of the black holes.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130740812","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}
Satellite mobile communications is a key link in the chain of infrastructure of global communications. A ground mobile antenna with broad frequency band, transiently steerable sharp-beam, miniaturized and low profiled structure, is specifically required for various vehicle systems. As a elemental assemblage of the active array antenna system with spatial power combining, a broadband 4/spl times/2 sub-array is developed in advance by using broadband U-slotted microstrip patch radiators and broadband stripline feed network. The main performances of this sub-array are: 23.24% bandwidth for VSWR/spl les/2:1; the beamwidth is stable within the operating band (12.25-14.50 GHz) with (30-32)/spl deg/ in the E-plane and (15-14)/spl deg/ in the H-plane. The slightly higher side-lobe-level may be suppressed by the factor of the whole array; the cross-polar-level in the E-plane is very good, but deteriorated in the H-plane at the high end of the frequency band, which may be improved by replacing the feed type.
{"title":"A broadband sub-array of U-slotted patches for Ku-band active antenna system","authors":"W. Zhang, S. Jeon, S.P. Lee, N. Myung","doi":"10.1109/APS.1999.789383","DOIUrl":"https://doi.org/10.1109/APS.1999.789383","url":null,"abstract":"Satellite mobile communications is a key link in the chain of infrastructure of global communications. A ground mobile antenna with broad frequency band, transiently steerable sharp-beam, miniaturized and low profiled structure, is specifically required for various vehicle systems. As a elemental assemblage of the active array antenna system with spatial power combining, a broadband 4/spl times/2 sub-array is developed in advance by using broadband U-slotted microstrip patch radiators and broadband stripline feed network. The main performances of this sub-array are: 23.24% bandwidth for VSWR/spl les/2:1; the beamwidth is stable within the operating band (12.25-14.50 GHz) with (30-32)/spl deg/ in the E-plane and (15-14)/spl deg/ in the H-plane. The slightly higher side-lobe-level may be suppressed by the factor of the whole array; the cross-polar-level in the E-plane is very good, but deteriorated in the H-plane at the high end of the frequency band, which may be improved by replacing the feed type.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133566137","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}
The finite element solution of the vector Helmholtz equation is more difficult than that of the scalar one. Absorbing boundary conditions (ABCs) that were developed earlier for the vector wave equation were complex. In this work we develop a series of simple operators for the finite element solution of the three-dimensional vector wave equation. Unlike the methodologies adopted earlier namely that of developing operators by manipulating the vector field and thus obtaining boundary conditions that involve the vector field itself we develop operators that can be applied on the scalar field components of the vector field.
{"title":"Finite element implementation of Bayliss-Turkel boundary operators in the three-dimensional vector wave equation","authors":"O. Ramahi","doi":"10.1109/APS.1999.789184","DOIUrl":"https://doi.org/10.1109/APS.1999.789184","url":null,"abstract":"The finite element solution of the vector Helmholtz equation is more difficult than that of the scalar one. Absorbing boundary conditions (ABCs) that were developed earlier for the vector wave equation were complex. In this work we develop a series of simple operators for the finite element solution of the three-dimensional vector wave equation. Unlike the methodologies adopted earlier namely that of developing operators by manipulating the vector field and thus obtaining boundary conditions that involve the vector field itself we develop operators that can be applied on the scalar field components of the vector field.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132714192","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}
In some applications construction of reflector antennas require assembling smaller panels and conforming them to reflector surfaces, a process, which naturally leave gaps between the panels. Consequently, characterization of performance from these gaps, though small in terms of wavelength, becomes an important issue in antenna analysis and design. In this paper, the dual reflector antenna performance is quantified in terms of gain reduction, sidelobe structures, surface currents, etc., in order to visualize the effects of gaps on the antenna patterns.
{"title":"Characteristics of dual reflector antennas with gaps placed on the subreflector: MoM and PO analysis","authors":"B. Khayatian, Y. Rahmat-Samii","doi":"10.1109/APS.1999.789277","DOIUrl":"https://doi.org/10.1109/APS.1999.789277","url":null,"abstract":"In some applications construction of reflector antennas require assembling smaller panels and conforming them to reflector surfaces, a process, which naturally leave gaps between the panels. Consequently, characterization of performance from these gaps, though small in terms of wavelength, becomes an important issue in antenna analysis and design. In this paper, the dual reflector antenna performance is quantified in terms of gain reduction, sidelobe structures, surface currents, etc., in order to visualize the effects of gaps on the antenna patterns.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127829386","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}
This paper presents a simple broadband dual-polarized microstrip antenna with only three layers. The input impedance bandwidth (VSWR<2) of 25% is achieved with the double resonance technique, in which the resonant frequencies of the patch and the coupling slot are tuned near to each other. Proper positioning of the coupling slots and the use of a thin, medium permittivity substrate results in high isolation (>40 dB) between the ports and thus acceptable cross polarization (better than -20 dB). The geometry, return loss, and the isolation of a single antenna element and the radiation pattern of a four-element linear array are presented. These antennas were designed for the European DBS-band 10.70-12.75 GHz.
{"title":"Simple broadband dual-polarized aperture-coupled microstrip antenna","authors":"S. Hienonen, A. Lehto, A. Raisanen","doi":"10.1109/APS.1999.789535","DOIUrl":"https://doi.org/10.1109/APS.1999.789535","url":null,"abstract":"This paper presents a simple broadband dual-polarized microstrip antenna with only three layers. The input impedance bandwidth (VSWR<2) of 25% is achieved with the double resonance technique, in which the resonant frequencies of the patch and the coupling slot are tuned near to each other. Proper positioning of the coupling slots and the use of a thin, medium permittivity substrate results in high isolation (>40 dB) between the ports and thus acceptable cross polarization (better than -20 dB). The geometry, return loss, and the isolation of a single antenna element and the radiation pattern of a four-element linear array are presented. These antennas were designed for the European DBS-band 10.70-12.75 GHz.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"227 5257 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134495409","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}
The Advanced Synthetic Aperture Radar (ASAR) is a major instrument on board ENVISAT-1. The next Earth observation mission of the European Space Agency. It will represent a sensor of paramount importance for the remote sensing community because of its enhanced flexibility with respect to the existing SARs in the AMI on board ERS-1 and ERS-2. The unique combination of different spatial resolutions, incidence angles, swath width sizes and polarisation diversity will offer an increased number of operational modes tailored for a large set of scientific and operational applications. Among the innovative design features of this radar are the use of an active antenna concept for tailoring the transmit and receive elevation beams to different mode geometries, a digital generation waveform technique for obtaining variable time-bandwidth products and a block adaptive quantization compression scheme. In this paper, the ASAR antenna is described and the development status is presented.
{"title":"ESA's ground breaking synthetic aperture radar: the ENVISAT-1 ASAR active antenna","authors":"R. Torres, C. Buck, J. Guijarro, J. Suchail","doi":"10.1109/APS.1999.788235","DOIUrl":"https://doi.org/10.1109/APS.1999.788235","url":null,"abstract":"The Advanced Synthetic Aperture Radar (ASAR) is a major instrument on board ENVISAT-1. The next Earth observation mission of the European Space Agency. It will represent a sensor of paramount importance for the remote sensing community because of its enhanced flexibility with respect to the existing SARs in the AMI on board ERS-1 and ERS-2. The unique combination of different spatial resolutions, incidence angles, swath width sizes and polarisation diversity will offer an increased number of operational modes tailored for a large set of scientific and operational applications. Among the innovative design features of this radar are the use of an active antenna concept for tailoring the transmit and receive elevation beams to different mode geometries, a digital generation waveform technique for obtaining variable time-bandwidth products and a block adaptive quantization compression scheme. In this paper, the ASAR antenna is described and the development status is presented.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"21 Suppl 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133856600","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}
Two-dimensional adaptive multiscale moment method (AMMM) is presented for discussing the scattering from thin perfectly conducting plates. The EFIE is directly discretized based on the tensor product of the triangular basis by the Galerkin method. We present the formula of the linear equations for the two-dimensional multiscale basis. From one scale to another scale, the initial guess can be predicted according to the properties of the multiscale technique. AMMM can reduce automatically the size of the linear equation so as to improve the efficiency of the conventional moment method. Several numerical results are presented, which demonstrate that AMMM is a useful method to analyze the scattering problems from perfectly conducting plates.
{"title":"Two-dimensional adaptive multiscale moment method for analysis of scattering from a perfectly conducting plate","authors":"Chaowei Su, T. Sarkar","doi":"10.1109/APS.1999.789150","DOIUrl":"https://doi.org/10.1109/APS.1999.789150","url":null,"abstract":"Two-dimensional adaptive multiscale moment method (AMMM) is presented for discussing the scattering from thin perfectly conducting plates. The EFIE is directly discretized based on the tensor product of the triangular basis by the Galerkin method. We present the formula of the linear equations for the two-dimensional multiscale basis. From one scale to another scale, the initial guess can be predicted according to the properties of the multiscale technique. AMMM can reduce automatically the size of the linear equation so as to improve the efficiency of the conventional moment method. Several numerical results are presented, which demonstrate that AMMM is a useful method to analyze the scattering problems from perfectly conducting plates.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133720747","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}
A half-wave stacked patch antenna was developed for sufficient bandwidth and cross-polarization separation for the wideband radio channel sounding. To further reduce the cross-polar level, a concept of dielectric feed was developed, which electromagnetically resembles the aperture feed. The increase of the cross-polar discrimination was 2.6 dB in the prototype.
{"title":"Half-wave stacked patch antenna with dielectric feed","authors":"V. Voipio, J. Ollikainen, P. Vainikainen","doi":"10.1109/APS.1999.789309","DOIUrl":"https://doi.org/10.1109/APS.1999.789309","url":null,"abstract":"A half-wave stacked patch antenna was developed for sufficient bandwidth and cross-polarization separation for the wideband radio channel sounding. To further reduce the cross-polar level, a concept of dielectric feed was developed, which electromagnetically resembles the aperture feed. The increase of the cross-polar discrimination was 2.6 dB in the prototype.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115328385","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}
A method is proposed for predicting the radiation pattern of rectangular apertures on a finite rectangular ground plane. This method includes an accurate description of single, double and vertex diffraction mechanisms. The first step of the analysis is the full-wave estimation of the aperture field. To this end, the external and the internal regions are separated by replacing each aperture with a metallic plug with equivalent magnetic currents on its external and internal sides; these currents are of equal amplitude and of opposite sign to ensure the continuity of the electric tangential field through the aperture. Then, an integral equation is formulated, that represents the continuity of the tangential H-field through the apertures. To solve the internal-external coupling, the external flange is initially treated as an infinite ground plane. After the determination of the magnetic currents, these currents are considered as radiating on the finite ground plane. For the sake of simplicity, but without loss of generality, a single horn is considered. The internal region of the corrugated horn is analyzed by using a generalized admittance matrix method.
{"title":"Pattern distortion for corrugated horns open-ended on a finite ground plane","authors":"M. Albani, P. Focardi, A. Freni, S. Maci","doi":"10.1109/APS.1999.789263","DOIUrl":"https://doi.org/10.1109/APS.1999.789263","url":null,"abstract":"A method is proposed for predicting the radiation pattern of rectangular apertures on a finite rectangular ground plane. This method includes an accurate description of single, double and vertex diffraction mechanisms. The first step of the analysis is the full-wave estimation of the aperture field. To this end, the external and the internal regions are separated by replacing each aperture with a metallic plug with equivalent magnetic currents on its external and internal sides; these currents are of equal amplitude and of opposite sign to ensure the continuity of the electric tangential field through the aperture. Then, an integral equation is formulated, that represents the continuity of the tangential H-field through the apertures. To solve the internal-external coupling, the external flange is initially treated as an infinite ground plane. After the determination of the magnetic currents, these currents are considered as radiating on the finite ground plane. For the sake of simplicity, but without loss of generality, a single horn is considered. The internal region of the corrugated horn is analyzed by using a generalized admittance matrix method.","PeriodicalId":391546,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115577869","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}
IEEE Antennas and Propagation Society International Symposium. 1999 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.99CH37010)
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