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
The paper summarizes the basic outcomes of the several years of research on the Fresnel zone plate lenses and antennas accomplished at the Eindhoven University of Technology (EUT). Added are also some results obtained at the Technical University of Vama (TUV) as an extension of the joint work on the subject between the EUT and the TUV initiated under a CEC/COST research contract. In this paper, we pay attention to the transmission Fresnel zone plates and Fresnel zone plate antennas only.
{"title":"Some developments in Fresnel zone plate lens antennas","authors":"H. Hristov","doi":"10.1109/APS.1999.789417","DOIUrl":"https://doi.org/10.1109/APS.1999.789417","url":null,"abstract":"The paper summarizes the basic outcomes of the several years of research on the Fresnel zone plate lenses and antennas accomplished at the Eindhoven University of Technology (EUT). Added are also some results obtained at the Technical University of Vama (TUV) as an extension of the joint work on the subject between the EUT and the TUV initiated under a CEC/COST research contract. In this paper, we pay attention to the transmission Fresnel zone plates and Fresnel zone plate antennas only.","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":"10 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":"116534100","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}
One critical problem that as aircraft may encounter during a flight is lightning. The effects of lightning can be roughly distinguished as direct and indirect. The direct effects are closely related to the points where the lightning arc enters and exits the aircraft. Examples of different effects include melting of the aircraft skin, puncture of nonconducting externally mounted parts and sparks in the fuel system. The indirect effects have to do with the magnetic and electric fields coupled to the interior of the aircraft. These can cause temporary upset or even permanent damage to the electronic equipment of the aircraft. The mechanisms through which this coupling can happen are resistive voltage drop on the airframe structure and through apertures, such as windows. Even with no apertures, the lightning current flowing in the metal wall of the airframe produces a non-zero magnetic field at the interior. This field together with the resistive voltage drop form the diffusion mechanism. In this paper the lightning current on a structure is modeled using FDTD. Then the diffusion mechanism is described for simple cylindrical structures and simulation results are shown. Finally, results on a Blackhawk helicopter structure excited with a lightning pulse are presented.
{"title":"Modeling of lightning effects on simple structures and helicopter airframes using FDTD","authors":"G. Ballas, C. Balanis","doi":"10.1109/APS.1999.789210","DOIUrl":"https://doi.org/10.1109/APS.1999.789210","url":null,"abstract":"One critical problem that as aircraft may encounter during a flight is lightning. The effects of lightning can be roughly distinguished as direct and indirect. The direct effects are closely related to the points where the lightning arc enters and exits the aircraft. Examples of different effects include melting of the aircraft skin, puncture of nonconducting externally mounted parts and sparks in the fuel system. The indirect effects have to do with the magnetic and electric fields coupled to the interior of the aircraft. These can cause temporary upset or even permanent damage to the electronic equipment of the aircraft. The mechanisms through which this coupling can happen are resistive voltage drop on the airframe structure and through apertures, such as windows. Even with no apertures, the lightning current flowing in the metal wall of the airframe produces a non-zero magnetic field at the interior. This field together with the resistive voltage drop form the diffusion mechanism. In this paper the lightning current on a structure is modeled using FDTD. Then the diffusion mechanism is described for simple cylindrical structures and simulation results are shown. Finally, results on a Blackhawk helicopter structure excited with a lightning pulse are 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":"6 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":"122598693","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}
Scattering of electromagnetic waves by homogeneous dielectric or finitely conducting bodies can be reduced to the solution of integral equations. In the simpler cases, only a single-integral-equation is needed, with no increase of required memory over scattering by a perfectly conducting body. In more complicated cases, this is not possible and two unknown boundary functions have to be defined on some of the interfaces. We decrease the required memory by changing the interface where two functions are used. We apply this method to strips on substrates, although more significant memory savings can be effected in three-dimensional problems. This method is extended to scattering from a strip on another strip on a substrate.
{"title":"Extensions of the single-integral-equation method","authors":"E. Marx","doi":"10.1109/APS.1999.789549","DOIUrl":"https://doi.org/10.1109/APS.1999.789549","url":null,"abstract":"Scattering of electromagnetic waves by homogeneous dielectric or finitely conducting bodies can be reduced to the solution of integral equations. In the simpler cases, only a single-integral-equation is needed, with no increase of required memory over scattering by a perfectly conducting body. In more complicated cases, this is not possible and two unknown boundary functions have to be defined on some of the interfaces. We decrease the required memory by changing the interface where two functions are used. We apply this method to strips on substrates, although more significant memory savings can be effected in three-dimensional problems. This method is extended to scattering from a strip on another strip on a substrate.","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":"37 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":"122796726","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}
Reflector antennas are very popular part of modern communication systems. Especially, large reflectors are important for point to point communication. Reflectors generally have a parabolic shape but spherical or circular shapes can also be used in scanning systems. Our interest is offset circular reflector with a directive feed. The offset reflectors have no aperture blockage and have asymmetrically shape main beam in one plane and in another perpendicular plane the beamwidth is very small. Therefore, as an example, these kind of offset circular reflectors have usage in navigational systems to scan the Earth from a aeroplane. In this study, the 2D offset circular reflector antenna is solved with an exact analytical-numerical technique with a guaranteed convergence and accuracy for all observation positions. For the same geometry, a physical optics (PO) solution is also generated and some comparisons are made with the exact solution. The exact and PO results are both obtained for E-polarization.
{"title":"Analysis of offset circular reflector antenna with a large aperture by complex source-dual series approach","authors":"T. Oğuzer","doi":"10.1109/APS.1999.789285","DOIUrl":"https://doi.org/10.1109/APS.1999.789285","url":null,"abstract":"Reflector antennas are very popular part of modern communication systems. Especially, large reflectors are important for point to point communication. Reflectors generally have a parabolic shape but spherical or circular shapes can also be used in scanning systems. Our interest is offset circular reflector with a directive feed. The offset reflectors have no aperture blockage and have asymmetrically shape main beam in one plane and in another perpendicular plane the beamwidth is very small. Therefore, as an example, these kind of offset circular reflectors have usage in navigational systems to scan the Earth from a aeroplane. In this study, the 2D offset circular reflector antenna is solved with an exact analytical-numerical technique with a guaranteed convergence and accuracy for all observation positions. For the same geometry, a physical optics (PO) solution is also generated and some comparisons are made with the exact solution. The exact and PO results are both obtained for E-polarization.","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":"92 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":"122983936","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}
An improved numerical procedure based on the Gabor series representation of the scattered field in front of a cylinder positioned in a focused beam system was used to reconstruct the scattering radiation pattern for plane wave illumination. The analysis was based on the assumption that the electric fields between the lenses can be described by fundamental Gaussian beams. The algorithm reduces significantly the required angular data measurements to reconstruct the scattering radiation pattern in comparison to a previous procedure based on an FFT algorithm. The information obtained on the scattering pattern helps to refine the calculations of the scattering analysis for large space frame radomes.
{"title":"An improved scattering analysis of arbitrary shaped cylinders in a focused beam system using Gabor representation","authors":"R. Shavit","doi":"10.1109/APS.1999.789259","DOIUrl":"https://doi.org/10.1109/APS.1999.789259","url":null,"abstract":"An improved numerical procedure based on the Gabor series representation of the scattered field in front of a cylinder positioned in a focused beam system was used to reconstruct the scattering radiation pattern for plane wave illumination. The analysis was based on the assumption that the electric fields between the lenses can be described by fundamental Gaussian beams. The algorithm reduces significantly the required angular data measurements to reconstruct the scattering radiation pattern in comparison to a previous procedure based on an FFT algorithm. The information obtained on the scattering pattern helps to refine the calculations of the scattering analysis for large space frame radomes.","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":"28 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":"114135608","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 criterion for the diversity effectiveness of a multi-antenna arrangement on a car is derived. This number of equivalent decorrelated antennas being effective is evaluated by turntable antenna measurements as a basis for computer simulated virtual drives in a Rayleigh wave propagation scenario. The comparison of a variety of antenna arrangements shows that even compact antenna systems on a car window provide high diversity effectiveness.
{"title":"Optimization of the antenna-diversity-effectiveness of complex FM-car-antenna systems","authors":"H. Lindenmeier, J. Hopf, L. Reiter, R. Kronberger","doi":"10.1109/APS.1999.788366","DOIUrl":"https://doi.org/10.1109/APS.1999.788366","url":null,"abstract":"A criterion for the diversity effectiveness of a multi-antenna arrangement on a car is derived. This number of equivalent decorrelated antennas being effective is evaluated by turntable antenna measurements as a basis for computer simulated virtual drives in a Rayleigh wave propagation scenario. The comparison of a variety of antenna arrangements shows that even compact antenna systems on a car window provide high diversity effectiveness.","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":"103 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":"114176125","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 advent of fast algorithms in computational electromagnetics has permitted the solution of integral equations with an unprecedented number of unknowns. This is the consequence of the development of the fast multipole algorithms (FMA) and the multilevel fast multipole algorithms (MLFMA). Such algorithms allow a matrix-vector multiplication to be performed in O(NlogN) operations or less for many scattering problems. Moreover, the memory requirements of these methods are O(NlogN), or almost matrix free. Using the fast matrix-vector multiplications in an iterative solver, problems for integral equations involving millions of unknowns have been solved previously. One of the most important mathematical formulas in FMA is the addition theorem. In the numerical implementation of the addition theorem, the infinite series should be truncated. The error analysis for the truncation error in the scalar Green's functions has been done by many researchers. In this paper, the error analysis for the truncation error in the multipole expansion of vector Green's functions is given.
{"title":"Error analysis for the truncation of multipole expansion of vector Green's functions","authors":"Jiming Song, W. C. Chew","doi":"10.1109/7260.933781","DOIUrl":"https://doi.org/10.1109/7260.933781","url":null,"abstract":"The advent of fast algorithms in computational electromagnetics has permitted the solution of integral equations with an unprecedented number of unknowns. This is the consequence of the development of the fast multipole algorithms (FMA) and the multilevel fast multipole algorithms (MLFMA). Such algorithms allow a matrix-vector multiplication to be performed in O(NlogN) operations or less for many scattering problems. Moreover, the memory requirements of these methods are O(NlogN), or almost matrix free. Using the fast matrix-vector multiplications in an iterative solver, problems for integral equations involving millions of unknowns have been solved previously. One of the most important mathematical formulas in FMA is the addition theorem. In the numerical implementation of the addition theorem, the infinite series should be truncated. The error analysis for the truncation error in the scalar Green's functions has been done by many researchers. In this paper, the error analysis for the truncation error in the multipole expansion of vector Green's functions is given.","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":"9 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":"114286272","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}
Fresnel zone plates are planar devices with lens-like focusing properties. The planar structure makes a zone plate easy to construct and provides lower absorption loss and weight. This paper reports on the Fresnel zone plates to be constructed from metal. Typically in the past, zone plates have been fabricated from dielectric material. In addition to the advantages mentioned earlier, metallic zone plates can be machined or cast directly into sectoral horns.
{"title":"Metallic zone plates for sectoral horns","authors":"D. Black, C. Nguyen","doi":"10.1109/APS.1999.789418","DOIUrl":"https://doi.org/10.1109/APS.1999.789418","url":null,"abstract":"Fresnel zone plates are planar devices with lens-like focusing properties. The planar structure makes a zone plate easy to construct and provides lower absorption loss and weight. This paper reports on the Fresnel zone plates to be constructed from metal. Typically in the past, zone plates have been fabricated from dielectric material. In addition to the advantages mentioned earlier, metallic zone plates can be machined or cast directly into sectoral horns.","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":"14 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":"114492496","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 methods of controlling the input impedance of a microstrip end-fed patch antenna are investigated. Using a 4 GHz reference antenna, the variations of input impedance and radiation patterns are compared, for (a) changing the feed positions to the non-radiating edge against (b) changing the width of a normal fed patch antenna. An expression for finding the necessary width for the last case is given using the results of the analysis.
{"title":"Methods of controlling the input impedance of a microstrip patch antenna","authors":"M. Chryssomallis, C. Christodoulou","doi":"10.1109/APS.1999.789310","DOIUrl":"https://doi.org/10.1109/APS.1999.789310","url":null,"abstract":"Two methods of controlling the input impedance of a microstrip end-fed patch antenna are investigated. Using a 4 GHz reference antenna, the variations of input impedance and radiation patterns are compared, for (a) changing the feed positions to the non-radiating edge against (b) changing the width of a normal fed patch antenna. An expression for finding the necessary width for the last case is given using the results of the analysis.","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":"54 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":"114580896","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}
Expanded Gaussian-Laguerre modes provides a more accurate and simple method to analyze the beam-waveguide (BWG) system. Using the propagated mode set and multiplication of the matrices for the BWGs factors, output field patterns with cross-polarized fields can be derived. A Q-band (33-50 GHz) BWG system which has two flat mirrors and two elliptic mirrors for a satellite Earth station antenna is designed. The characteristics of a corrugated conical horn for feeding to the BWG and the output beam patterns of the BWG system are simulated and compared with measured values.
{"title":"Design of Q-band beam-waveguide system for the satellite communication Earth antenna","authors":"Taeho Son, Dong-Jin Lee, P. Uslenghi","doi":"10.1109/APS.1999.789238","DOIUrl":"https://doi.org/10.1109/APS.1999.789238","url":null,"abstract":"Expanded Gaussian-Laguerre modes provides a more accurate and simple method to analyze the beam-waveguide (BWG) system. Using the propagated mode set and multiplication of the matrices for the BWGs factors, output field patterns with cross-polarized fields can be derived. A Q-band (33-50 GHz) BWG system which has two flat mirrors and two elliptic mirrors for a satellite Earth station antenna is designed. The characteristics of a corrugated conical horn for feeding to the BWG and the output beam patterns of the BWG system are simulated and compared with measured values.","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":"67 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":"117015106","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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