Pub Date : 1986-06-08DOI: 10.1109/APS.1986.1149593
K. Lee, J. Herper
INTRODUCTION Identification of principal and noise eigenvalues in the eigenvalue/vector decomposition of a covariance matrix is an essential part of superresolution techniques such as MUSIC and PEGS (1). Target counting is decided directly by the number of principal eigenvalues chosen from the total set of eigenvalues. The resultant resolution pattern can be affected by the appearance of spurious peaks or the disappearance of real peaks if the eigenvalues are not properly identified. Curvefit methods customarily adopted to discriminate principal from noise eigenvalues fail when targets are so close that there is no significant slope change in the transition from noise eigenvalues to the least principal eigenvalue. Once the boundary between principal and noise eigenvalues is blurred, a superresolution technique based on the eigenvalue/vector decomposition of a covariance matrix loses its resolution capability.
{"title":"A tight threshold for noise eigenvalues in superresolution","authors":"K. Lee, J. Herper","doi":"10.1109/APS.1986.1149593","DOIUrl":"https://doi.org/10.1109/APS.1986.1149593","url":null,"abstract":"INTRODUCTION Identification of principal and noise eigenvalues in the eigenvalue/vector decomposition of a covariance matrix is an essential part of superresolution techniques such as MUSIC and PEGS (1). Target counting is decided directly by the number of principal eigenvalues chosen from the total set of eigenvalues. The resultant resolution pattern can be affected by the appearance of spurious peaks or the disappearance of real peaks if the eigenvalues are not properly identified. Curvefit methods customarily adopted to discriminate principal from noise eigenvalues fail when targets are so close that there is no significant slope change in the transition from noise eigenvalues to the least principal eigenvalue. Once the boundary between principal and noise eigenvalues is blurred, a superresolution technique based on the eigenvalue/vector decomposition of a covariance matrix loses its resolution capability.","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127476006","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 : 1986-06-08DOI: 10.1109/APS.1986.1149611
P. Bielli, D. Bresciani, S. Contu, G. Crone
{"title":"A Ku/Ka band dichroic subreflector development","authors":"P. Bielli, D. Bresciani, S. Contu, G. Crone","doi":"10.1109/APS.1986.1149611","DOIUrl":"https://doi.org/10.1109/APS.1986.1149611","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124370212","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 : 1986-06-08DOI: 10.1109/APS.1986.1149694
C. Chen, Y. Choung, D. Palma
{"title":"A compact multi-flare horn design for spacecraft reflector antenna","authors":"C. Chen, Y. Choung, D. Palma","doi":"10.1109/APS.1986.1149694","DOIUrl":"https://doi.org/10.1109/APS.1986.1149694","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122458206","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 : 1986-06-08DOI: 10.1109/APS.1986.1149673
J. Coughlin, A. Krall, D. Jablonski
{"title":"A comparison of the continuous gaussian antenna with the discrete binomial array","authors":"J. Coughlin, A. Krall, D. Jablonski","doi":"10.1109/APS.1986.1149673","DOIUrl":"https://doi.org/10.1109/APS.1986.1149673","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131541546","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 : 1986-06-08DOI: 10.1109/APS.1986.1149749
W. Scott, Glenn S. Smith
A procedure is developed for measuring the complex dielectric permittivity of a material over a broad range of frequencies using a monopole antenna. No restrictions are placed on the electrical size of the antenna. The antenna is calibrated one time by measuring the input admittance in a standard medium with known permittivity, such as air. Next, the admittance is measured with the antenna immersed in a material with unknown permittivity. These two sets of admittances are then used to determine the permittivity of the material. As an application of the procedure, the complex permittivity of the alcohol 1-butanol and saline solutions were measured using a cylindrical monopole antenna. The measured permittivities are in good agreement with those determined by previous investigators.
{"title":"Dielectric spectroscopy using monopole antennas of general electrical length","authors":"W. Scott, Glenn S. Smith","doi":"10.1109/APS.1986.1149749","DOIUrl":"https://doi.org/10.1109/APS.1986.1149749","url":null,"abstract":"A procedure is developed for measuring the complex dielectric permittivity of a material over a broad range of frequencies using a monopole antenna. No restrictions are placed on the electrical size of the antenna. The antenna is calibrated one time by measuring the input admittance in a standard medium with known permittivity, such as air. Next, the admittance is measured with the antenna immersed in a material with unknown permittivity. These two sets of admittances are then used to determine the permittivity of the material. As an application of the procedure, the complex permittivity of the alcohol 1-butanol and saline solutions were measured using a cylindrical monopole antenna. The measured permittivities are in good agreement with those determined by previous investigators.","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"57-58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120981176","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 : 1986-06-08DOI: 10.1109/APS.1986.1149737
J. Kiang, J. Kong, D. Shnidman
In applying the method of moments to solve the EM scattering problems, it is necessary to solve a large matrix when the dimension of the scatterer is larger than several wavelengths. Tremendous amount of computer CPU time will be spent on solving the matrix equation. When only the far field properties such as scattering cross section is of interest, we can use the sparse matrix technique to reduce the amount of compucation. In this paper, some algorithms are compared to solve the sparse matrix. The Gaussian elimina$ion algorithm, Cholesky decomposition algorithm, several versions of conjugate gradient methods are used. The number of multiplications and divisions(fl0ps) are counted for comparing the efficiency of these algorithms. The effect of the nonzero element positions to the efficiency is also studied by defining the clustering index.
{"title":"Comparison of algorithms to solve sparse matrix in EM scattering problem","authors":"J. Kiang, J. Kong, D. Shnidman","doi":"10.1109/APS.1986.1149737","DOIUrl":"https://doi.org/10.1109/APS.1986.1149737","url":null,"abstract":"In applying the method of moments to solve the EM scattering problems, it is necessary to solve a large matrix when the dimension of the scatterer is larger than several wavelengths. Tremendous amount of computer CPU time will be spent on solving the matrix equation. When only the far field properties such as scattering cross section is of interest, we can use the sparse matrix technique to reduce the amount of compucation. In this paper, some algorithms are compared to solve the sparse matrix. The Gaussian elimina$ion algorithm, Cholesky decomposition algorithm, several versions of conjugate gradient methods are used. The number of multiplications and divisions(fl0ps) are counted for comparing the efficiency of these algorithms. The effect of the nonzero element positions to the efficiency is also studied by defining the clustering index.","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129959869","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 : 1986-06-08DOI: 10.1109/APS.1986.1149685
D. Cohoon
{"title":"A mathematical model of the interaction of monochromatic light-frequency electromagnetic radiation with the eye permitting computer-aided. noninvasive assessment of visual acuity and an analysis of the effect of chemical and other stressors on the spread function","authors":"D. Cohoon","doi":"10.1109/APS.1986.1149685","DOIUrl":"https://doi.org/10.1109/APS.1986.1149685","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130004313","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 : 1986-06-08DOI: 10.1109/APS.1986.1149637
Changsik Kim, A. Rhoden
{"title":"Radiation pattern analysis of coaxial cavity feed horn","authors":"Changsik Kim, A. Rhoden","doi":"10.1109/APS.1986.1149637","DOIUrl":"https://doi.org/10.1109/APS.1986.1149637","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127064577","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 : 1986-06-08DOI: 10.1109/APS.1986.1149688
D. Jenn
{"title":"Scattering from an array of thin wires parallel to a rectangular ground plane","authors":"D. Jenn","doi":"10.1109/APS.1986.1149688","DOIUrl":"https://doi.org/10.1109/APS.1986.1149688","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134033164","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 : 1986-06-08DOI: 10.1109/APS.1986.1149646
A. Konrad
{"title":"A differential equation formulation for radiation problems based on the continuity gauge instead of the Lorentz gauge","authors":"A. Konrad","doi":"10.1109/APS.1986.1149646","DOIUrl":"https://doi.org/10.1109/APS.1986.1149646","url":null,"abstract":"","PeriodicalId":399329,"journal":{"name":"1986 Antennas and Propagation Society International Symposium","volume":" 15","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1986-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132159669","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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