A novel array using microstrip elements for mobile satellite communications is presented. The cylindrical patch array consists of 18 circularly polarized microstrip patches, arranged around an inclined cylinder. The radiation elements were modified to reduce their resonant size, thus allowing for a compact array. A high-gain beam was achieved. It was electronically steered in azimuth for satellite tracking. A 10 dBic gain was achieved over elevation angles from 10 degrees to 50 degrees for a bandwidth of 1530 to 1660.5 MHz, ideal for mobile satellite coverage in Canada.<>
{"title":"Microstrip antenna array for mobile satellite communications","authors":"A. Petosa, P. Strickland, J. Wight","doi":"10.1109/APS.1992.221890","DOIUrl":"https://doi.org/10.1109/APS.1992.221890","url":null,"abstract":"A novel array using microstrip elements for mobile satellite communications is presented. The cylindrical patch array consists of 18 circularly polarized microstrip patches, arranged around an inclined cylinder. The radiation elements were modified to reduce their resonant size, thus allowing for a compact array. A high-gain beam was achieved. It was electronically steered in azimuth for satellite tracking. A 10 dBic gain was achieved over elevation angles from 10 degrees to 50 degrees for a bandwidth of 1530 to 1660.5 MHz, ideal for mobile satellite coverage in Canada.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114903458","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 9.5-mm-long dipole antenna was printed on the LiNbO/sub 3/ substrate where a Mach-Zehnder interferometer had been formed from an optical waveguide. An equivalent circuit of the sensor was created to calculate the sensitivity and the frequency response, and the circuit parameters were obtained using the moment method and were also measured. The measured sensitivity and frequency response of the antenna closely agree with the calculated values. The measured frequency response is almost flat from 100 Hz to 2.5 GHz.<>
{"title":"A small wideband antenna printed on the same LiNbO/sub 3/ substrate as the integrated optical modulator","authors":"N. Kuwabara, T. Ideguchi, R. Kobayashi","doi":"10.1109/APS.1992.221831","DOIUrl":"https://doi.org/10.1109/APS.1992.221831","url":null,"abstract":"A 9.5-mm-long dipole antenna was printed on the LiNbO/sub 3/ substrate where a Mach-Zehnder interferometer had been formed from an optical waveguide. An equivalent circuit of the sensor was created to calculate the sensitivity and the frequency response, and the circuit parameters were obtained using the moment method and were also measured. The measured sensitivity and frequency response of the antenna closely agree with the calculated values. The measured frequency response is almost flat from 100 Hz to 2.5 GHz.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115214441","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 approaches (which were applied to a parallel plate waveguide) for including thin material sheets in the finite-difference time-domain (FDTD) technique are compared. The first approach by J.G. Maloney and G.S. Smith (see IEEE Trans. Antennas Propag., vol.AP-40, no.3, 1992) uses a special FDTD cell to handle the sheet. Throughout the cell the component of the electric field tangential to the sheet is assumed to be constant. However, the component of the electric field normal to the sheet assumes different constant values in the sheet and in the space adjacent to the sheet. The discontinuity of the normal component of the electric field at the surface of the sheet allows for the presence of surface charge. In the second approach by P.A. Tirkas and K.R. Demarest (see IEEE Trans. Antennas Propag., vol.AP-39, no.9, p.1338, 1991) the component of the electric field tangential to the sheet is also assumed to be constant, but the component of the electric displacement normal to the sheet is assumed to vary linearly across the cell. This makes the normal component of the electric field jump by the ratio of the dielectric constants at the surface of the sheet. There are some subtle differences in the two approaches; these may make one prefer one of the approaches over the other for a particular application.<>
{"title":"A discussion of efficient methods for including thin material sheets in the FDTD technique","authors":"J. Maloney, G.S. Smith","doi":"10.1109/APS.1992.221538","DOIUrl":"https://doi.org/10.1109/APS.1992.221538","url":null,"abstract":"Two approaches (which were applied to a parallel plate waveguide) for including thin material sheets in the finite-difference time-domain (FDTD) technique are compared. The first approach by J.G. Maloney and G.S. Smith (see IEEE Trans. Antennas Propag., vol.AP-40, no.3, 1992) uses a special FDTD cell to handle the sheet. Throughout the cell the component of the electric field tangential to the sheet is assumed to be constant. However, the component of the electric field normal to the sheet assumes different constant values in the sheet and in the space adjacent to the sheet. The discontinuity of the normal component of the electric field at the surface of the sheet allows for the presence of surface charge. In the second approach by P.A. Tirkas and K.R. Demarest (see IEEE Trans. Antennas Propag., vol.AP-39, no.9, p.1338, 1991) the component of the electric field tangential to the sheet is also assumed to be constant, but the component of the electric displacement normal to the sheet is assumed to vary linearly across the cell. This makes the normal component of the electric field jump by the ratio of the dielectric constants at the surface of the sheet. There are some subtle differences in the two approaches; these may make one prefer one of the approaches over the other for a particular application.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125222244","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 three-dimensional vector boundary condition that applies to the surface of the scatterer is used to formulate a novel 3-D OSRC (on-surface radiation condition) based on Wilcox's (1956) asymptotic expansion, for solving electromagnetic scattering from a perfectly conducting body. The numerical results of the current distribution on conducting spheres with different sizes are in good agreement with the exact solution.<>
{"title":"Application of three-dimensional vector OSRC to electromagnetic scattering","authors":"Z. Chen, W. Zhang","doi":"10.1109/APS.1992.221475","DOIUrl":"https://doi.org/10.1109/APS.1992.221475","url":null,"abstract":"A three-dimensional vector boundary condition that applies to the surface of the scatterer is used to formulate a novel 3-D OSRC (on-surface radiation condition) based on Wilcox's (1956) asymptotic expansion, for solving electromagnetic scattering from a perfectly conducting body. The numerical results of the current distribution on conducting spheres with different sizes are in good agreement with the exact solution.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"13 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120834916","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 small-scale study to evaluate the principal modes of propagation for an experimental, beyond-the-horizon UHF link is presented. The propagation channel was characterized statistically in several ways. The data collected exhibited characteristics of both troposcatter and diffraction modes of propagation, with heavy influence from anomalies such as aircraft reflections and ducting. The movement of weather fronts through the region influences the runways used by aircraft, and thus the degree of fading due to aircraft. Weather fronts also influenced the principal mode and characteristics of propagation. The correlation between meteorological conditions and the degree of fading observed was biased by the heavy air traffic and the large beamwidth receiver antenna used.<>
{"title":"A PC-based UHF propagation study in an urban environment","authors":"J. Grimmer, S. Laxpati","doi":"10.1109/APS.1992.221636","DOIUrl":"https://doi.org/10.1109/APS.1992.221636","url":null,"abstract":"A small-scale study to evaluate the principal modes of propagation for an experimental, beyond-the-horizon UHF link is presented. The propagation channel was characterized statistically in several ways. The data collected exhibited characteristics of both troposcatter and diffraction modes of propagation, with heavy influence from anomalies such as aircraft reflections and ducting. The movement of weather fronts through the region influences the runways used by aircraft, and thus the degree of fading due to aircraft. Weather fronts also influenced the principal mode and characteristics of propagation. The correlation between meteorological conditions and the degree of fading observed was biased by the heavy air traffic and the large beamwidth receiver antenna used.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127093195","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 order to obtain a solution of a canonical problem in closed form, a planar structure is considered. The first part of the structure is an infinitesimally thin perfectly conducting halfplane, while the second one consists of a wire-mesh halfplane. The wire mesh is described by the equivalent sheet impedance operator, derived by K.F. Casey (1981), which is valid when the mesh dimensions are small in comparison with the wavelength. The diffraction of an obliquely incident plane wave is studied by means of a Wiener-Hopf technique. The cases of transverse-electric and transverse-magnetic incidence are considered.<>
{"title":"Low frequency electromagnetic penetration of loaded apertures; a canonical case","authors":"V. Daniele, M. Gilli","doi":"10.1109/APS.1992.221738","DOIUrl":"https://doi.org/10.1109/APS.1992.221738","url":null,"abstract":"In order to obtain a solution of a canonical problem in closed form, a planar structure is considered. The first part of the structure is an infinitesimally thin perfectly conducting halfplane, while the second one consists of a wire-mesh halfplane. The wire mesh is described by the equivalent sheet impedance operator, derived by K.F. Casey (1981), which is valid when the mesh dimensions are small in comparison with the wavelength. The diffraction of an obliquely incident plane wave is studied by means of a Wiener-Hopf technique. The cases of transverse-electric and transverse-magnetic incidence are considered.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127294605","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}
Summary form only given. To aid in standardizing the transmission/reflection (T/R) method, the National Institute of Standards and Technology (NIST) organized a nationwide intercomparison of permittivity measurements in the 50 MHz to 187 GHz frequency range. The T/R method involves calculation of relative permittivity ( in /sub r/) and permeability ( mu /sub r/) from transmitted and reflected scattering parameters measured by a network analyzer. Three sample kits have been circulated among fifteen participating organizations. Each kit will be circulated to five different participants. All three sample kits contain four materials with in /sub r/ ranging from approximately 5 to 20, and one sample kit contains a fifth, high-permittivity sample with in /sub r/ somewhere between 35 and 60. Measurement results are compared with each other and with high-accuracy cavity resonator measurements made by NIST. The commonly implemented Nicholson/Ross algorithm is shown to be less accurate and much more unstable than the Baker-Jarvis algorithm, especially when the sample is longer than a half wavelength.<>
只提供摘要形式。为了使传输/反射(T/R)方法标准化，美国国家标准与技术研究所(NIST)组织了一项全国性的50mhz至187ghz频率范围内介电常数测量值的比较。T/R法是根据网络分析仪测量的透射散射和反射散射参数计算相对介电常数(in /sub R /)和磁导率(mu /sub R /)。15个参加组织分发了三个样品包。每个工具包将分发给五位不同的参与者。所有三个样品套件包含四种材料，其in /sub r/范围约为5至20，其中一个样品套件包含第五种高介电常数样品，其in /sub r/范围在35至60之间。测量结果相互比较，并与NIST高精度腔谐振器测量结果进行了比较。通常实现的Nicholson/Ross算法被证明比Baker-Jarvis算法更不准确，更不稳定，特别是当样本长于半波长时。
{"title":"Intercomparison of permittivity measurements using the transmission/reflection method in 7-MM COAX","authors":"E. Vanzura","doi":"10.1109/APS.1992.221548","DOIUrl":"https://doi.org/10.1109/APS.1992.221548","url":null,"abstract":"Summary form only given. To aid in standardizing the transmission/reflection (T/R) method, the National Institute of Standards and Technology (NIST) organized a nationwide intercomparison of permittivity measurements in the 50 MHz to 187 GHz frequency range. The T/R method involves calculation of relative permittivity ( in /sub r/) and permeability ( mu /sub r/) from transmitted and reflected scattering parameters measured by a network analyzer. Three sample kits have been circulated among fifteen participating organizations. Each kit will be circulated to five different participants. All three sample kits contain four materials with in /sub r/ ranging from approximately 5 to 20, and one sample kit contains a fifth, high-permittivity sample with in /sub r/ somewhere between 35 and 60. Measurement results are compared with each other and with high-accuracy cavity resonator measurements made by NIST. The commonly implemented Nicholson/Ross algorithm is shown to be less accurate and much more unstable than the Baker-Jarvis algorithm, especially when the sample is longer than a half wavelength.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124833508","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 reflection coefficient for the dispersive boundary condition (DBC) is formulated. A one-way dispersive boundary condition is generalized and developed. The behavior of the reflection coefficients for second- and third-order DBCs is shown.<>
{"title":"Consideration of a one-way dispersive boundary condition (DBC) for the FD-TD method","authors":"Bi Zhiqiang, J. Litva","doi":"10.1109/APS.1992.221932","DOIUrl":"https://doi.org/10.1109/APS.1992.221932","url":null,"abstract":"The reflection coefficient for the dispersive boundary condition (DBC) is formulated. A one-way dispersive boundary condition is generalized and developed. The behavior of the reflection coefficients for second- and third-order DBCs is shown.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123287853","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}
Due to the instability of absorbing boundary conditions, numerical solutions spuriously grow as computations proceed; sooner or later, numerical errors override actual solutions. It has been found that the higher the order of the absorbing boundary condition applied, the stronger the instability. In the present work, it is shown that the instability originates from the computer roundoff error in the process of calculating boundary values. This error is further accumulated as the computation goes on. Numerical examples illustrate the instability caused by boundary conditions, and examine the way to suppress the instability.<>
{"title":"Investigation on the stability of absorbing boundary conditions for the time-domain finite-difference method","authors":"J. Fang","doi":"10.1109/APS.1992.221879","DOIUrl":"https://doi.org/10.1109/APS.1992.221879","url":null,"abstract":"Due to the instability of absorbing boundary conditions, numerical solutions spuriously grow as computations proceed; sooner or later, numerical errors override actual solutions. It has been found that the higher the order of the absorbing boundary condition applied, the stronger the instability. In the present work, it is shown that the instability originates from the computer roundoff error in the process of calculating boundary values. This error is further accumulated as the computation goes on. Numerical examples illustrate the instability caused by boundary conditions, and examine the way to suppress the instability.<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123294440","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 procedure has been developed for the optimal adjustment of the primary reflector surface of an antenna. This procedure, when applied to the haystack radio telescopic antenna, involves the iterative adjustment of standoffs and shear studs, expanders, and cable guide offsets in the back of the panels. Optimal adjustments are selected to minimize the resulting surface RMS of the antenna, subject to the constraints of loss of precompression across expanders. It has been demonstrated that the procedure can be used effectively to improve the surface RMS of the haystack antenna to the goal of less than 200 micron (8 mil).<>
{"title":"Optimal surface adjustment of haystack antenna","authors":"M. Zarghamee, J. Antebi","doi":"10.1109/APS.1992.221816","DOIUrl":"https://doi.org/10.1109/APS.1992.221816","url":null,"abstract":"A procedure has been developed for the optimal adjustment of the primary reflector surface of an antenna. This procedure, when applied to the haystack radio telescopic antenna, involves the iterative adjustment of standoffs and shear studs, expanders, and cable guide offsets in the back of the panels. Optimal adjustments are selected to minimize the resulting surface RMS of the antenna, subject to the constraints of loss of precompression across expanders. It has been demonstrated that the procedure can be used effectively to improve the surface RMS of the haystack antenna to the goal of less than 200 micron (8 mil).<<ETX>>","PeriodicalId":289865,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1992 Digest","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123414049","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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