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
Previously, fast computational methods based on directly thinning the matrix of method of moments (MoM), such as impedance matrix localization (IML), wavelet expansions, and reduced expansion and field testing (REFT), have been introduced. In this paper, we propose a simpler approach to thin the MoM matrix by using the concept of measured equation of invariance (MEI). This approach is referred to as matrix decomposition by MEI (MDMEI). A little effort is required to add the resulting method to any of a variety of MoM programs for solving problems of wire antennas, and conducting object scattering.
{"title":"A new approach to decompose MoM matrix to sparse matrices by using the concept of MEI method","authors":"Y. Liu, K. Lan, K. Mei, Y.M. Song, W. Y. Zhao","doi":"10.1109/APS.1999.789432","DOIUrl":"https://doi.org/10.1109/APS.1999.789432","url":null,"abstract":"Previously, fast computational methods based on directly thinning the matrix of method of moments (MoM), such as impedance matrix localization (IML), wavelet expansions, and reduced expansion and field testing (REFT), have been introduced. In this paper, we propose a simpler approach to thin the MoM matrix by using the concept of measured equation of invariance (MEI). This approach is referred to as matrix decomposition by MEI (MDMEI). A little effort is required to add the resulting method to any of a variety of MoM programs for solving problems of wire antennas, and conducting object scattering.","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":"8 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":"115832411","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 dual gridded reflector antenna has been analyzed taking account of multiple interactions between front and rear reflectors. The results show that the computed co-pol contour is in good agreement with the measured data. However, although the minimum C/X (co/cross pol) value in the coverage area is predicted, the C/X contour is not. The analysis of the C/X contour is a subject for further investigation.
{"title":"An analysis of a dual gridded reflector antenna","authors":"H. Luh, R. Hsu, B.S. Lee","doi":"10.1109/APS.1999.789511","DOIUrl":"https://doi.org/10.1109/APS.1999.789511","url":null,"abstract":"A dual gridded reflector antenna has been analyzed taking account of multiple interactions between front and rear reflectors. The results show that the computed co-pol contour is in good agreement with the measured data. However, although the minimum C/X (co/cross pol) value in the coverage area is predicted, the C/X contour is not. The analysis of the C/X contour is a subject for further investigation.","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":"1 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":"124383979","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 results on numerical simulation of ceramic, multilayer capacitors (CMC) using the finite difference time domain (FDTD) technique. An efficient approach is demonstrated in which the CMC is represented within the FDTD grid by a combination of transmission lines and lumped elements. Two methods of compensating for the induced numerical parasitics are shown.
{"title":"FDTD modeling of ceramic multi-layer capacitors using lumped equivalent models","authors":"T. Weller, N. Dib, B. Lakshminarayanan","doi":"10.1109/APS.1999.789502","DOIUrl":"https://doi.org/10.1109/APS.1999.789502","url":null,"abstract":"This paper presents results on numerical simulation of ceramic, multilayer capacitors (CMC) using the finite difference time domain (FDTD) technique. An efficient approach is demonstrated in which the CMC is represented within the FDTD grid by a combination of transmission lines and lumped elements. Two methods of compensating for the induced numerical parasitics are shown.","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":"84 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":"114361002","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 present paper deals with the transient fields transmitted and reflected through the interface between the air and ground. Excitation for the electromagnetic fields is produced by a vertically oriented impulsive electric dipole. The ground medium has arbitrary permittivity and permeability, but it is restricted to be lossless. Mathematical formulation of the problem is given for the magnetic vector potential, whose solution is derived in a new approach without using the frequency domain formulation. The main emphasis here is to derive simple expressions for transient vector potential and electromagnetic fields.
{"title":"A new time domain analysis of vertical dipole in the vicinity of a planar dielectric interface","authors":"G. Rafi, R. Moini, R. Faraji-Dana","doi":"10.1109/APS.1999.789433","DOIUrl":"https://doi.org/10.1109/APS.1999.789433","url":null,"abstract":"The present paper deals with the transient fields transmitted and reflected through the interface between the air and ground. Excitation for the electromagnetic fields is produced by a vertically oriented impulsive electric dipole. The ground medium has arbitrary permittivity and permeability, but it is restricted to be lossless. Mathematical formulation of the problem is given for the magnetic vector potential, whose solution is derived in a new approach without using the frequency domain formulation. The main emphasis here is to derive simple expressions for transient vector potential and electromagnetic fields.","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":"11 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":"114395872","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}
It is foreseen that suburban areas and countryside will be covered by low-Earth-orbit mobile satellite communications (LEO-MSAT). In order to make LEO-MSAT commercially viable, its mobile terminal must be designed as a consumer product that is low-cost, light-weight, small-in-size, and robust. This is a tall order to be fulfilled because the mobile terminal for LEO-MSAT is more complex than its counterparts for GEO-MSAT although the former has a lower power rating. Comparing with a DBS antenna, a MSAT antenna must be equipped with a steerable main-beam for tracking the satellite position, preferably it is an automatic tracking system. Moreover, the antenna must be low-cost, high-gain, high-efficiency, small-in-size, and preferable low-profile. To this end, an innovative antenna that satisfies most of the aforementioned requirements has been conceived. The innovative antenna is an array comprising two to three antennas. Each antenna itself comprises a coaxial transmission line protruded from a ground plane. In this paper, an accurate analytical technique is developed for studying and designing the element of the novel LEO-MSAT antenna array, the multi-slot coaxial line antenna. The calculated and experimental radiation patterns show that the technique is successful.
{"title":"A coaxial multi-slot antenna used for LEO-MSAT","authors":"Z.M. Xie, E. Yung, R. Chen, Y.F. Han","doi":"10.1109/APS.1999.789298","DOIUrl":"https://doi.org/10.1109/APS.1999.789298","url":null,"abstract":"It is foreseen that suburban areas and countryside will be covered by low-Earth-orbit mobile satellite communications (LEO-MSAT). In order to make LEO-MSAT commercially viable, its mobile terminal must be designed as a consumer product that is low-cost, light-weight, small-in-size, and robust. This is a tall order to be fulfilled because the mobile terminal for LEO-MSAT is more complex than its counterparts for GEO-MSAT although the former has a lower power rating. Comparing with a DBS antenna, a MSAT antenna must be equipped with a steerable main-beam for tracking the satellite position, preferably it is an automatic tracking system. Moreover, the antenna must be low-cost, high-gain, high-efficiency, small-in-size, and preferable low-profile. To this end, an innovative antenna that satisfies most of the aforementioned requirements has been conceived. The innovative antenna is an array comprising two to three antennas. Each antenna itself comprises a coaxial transmission line protruded from a ground plane. In this paper, an accurate analytical technique is developed for studying and designing the element of the novel LEO-MSAT antenna array, the multi-slot coaxial line antenna. The calculated and experimental radiation patterns show that the technique is successful.","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":"72 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":"114838238","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}
Inflatable technology has been identified as a potential solution to the problem of achieving small mass, high packaging efficiency, and reliable deployment for future NASA spaceborne synthetic aperture radar (SAR) antennas. Presently, there exists a requirement for a dual-polarized L-band SAR antenna with an aperture size of 10 m/spl times/3 m, a center frequency of 1.25 GHz, a bandwidth of 80 MHz, electronic beam scanning, and a mass of less than 100 kg. The work presented is part of the ongoing effort to develop such an inflatable antenna array.
{"title":"A dual-polarized microstrip subarray antenna for an inflatable L-band synthetic aperture radar","authors":"M. Zawadzki, J. Huang","doi":"10.1109/APS.1999.789134","DOIUrl":"https://doi.org/10.1109/APS.1999.789134","url":null,"abstract":"Inflatable technology has been identified as a potential solution to the problem of achieving small mass, high packaging efficiency, and reliable deployment for future NASA spaceborne synthetic aperture radar (SAR) antennas. Presently, there exists a requirement for a dual-polarized L-band SAR antenna with an aperture size of 10 m/spl times/3 m, a center frequency of 1.25 GHz, a bandwidth of 80 MHz, electronic beam scanning, and a mass of less than 100 kg. The work presented is part of the ongoing effort to develop such an inflatable antenna array.","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":"88 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":"116786935","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 synthetic aperture method (SAM) application to subsurface scanning data is discussed in the paper. SAM is known to be one of the most powerful techniques of electromagnetic sounding data processing. The advantages of SAM include the universality of its algorithm and the high resolution capability that it can produce. Images of non-dissipative and low-absorbing media can be efficiently treated with this technique. The applicability of SAM to the processing of data collected from media having non-negligible conductivity is rather limited. It is necessary to note, that such a conductivity is relevant in all moist soils. Thus, SAM needs a modification that will permit to take into account a distortion of the sounding impulse in a conducting medium. A modification of SAM that enables one to take into account the shape of the radiated impulse at a given depth is discussed. Also, two methods of estimation of this shape are proposed: 1. Rough estimation of the transfer function of the medium using its material parameters; 2. Shape pulse estimation using the FDTD technique.
{"title":"Probe pulse shape estimation in synthetic aperture method","authors":"V. Kovalenko","doi":"10.1109/APS.1999.788303","DOIUrl":"https://doi.org/10.1109/APS.1999.788303","url":null,"abstract":"The synthetic aperture method (SAM) application to subsurface scanning data is discussed in the paper. SAM is known to be one of the most powerful techniques of electromagnetic sounding data processing. The advantages of SAM include the universality of its algorithm and the high resolution capability that it can produce. Images of non-dissipative and low-absorbing media can be efficiently treated with this technique. The applicability of SAM to the processing of data collected from media having non-negligible conductivity is rather limited. It is necessary to note, that such a conductivity is relevant in all moist soils. Thus, SAM needs a modification that will permit to take into account a distortion of the sounding impulse in a conducting medium. A modification of SAM that enables one to take into account the shape of the radiated impulse at a given depth is discussed. Also, two methods of estimation of this shape are proposed: 1. Rough estimation of the transfer function of the medium using its material parameters; 2. Shape pulse estimation using the FDTD technique.","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":"40 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":"117010628","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 physical modeling method for the calculation of characteristic high-frequency electromagnetic parameters of small conformal arrays is introduced. The antenna array model is based on the interaction between special antenna elements composed of electrically small dipoles and loop antennas and allows for the calculation of generic mutual coupling effects inside the antenna array. Also, a pattern synthesis method based on the projection of cylindrical sector waves onto the antenna array elements is described. Numerical results for arrays of cylindrical sector geometry and commonly used beam shapes are presented and the calculated coupling effects inside the antenna array are analyzed. The results are compared to data measured at a practical antenna array.
{"title":"A polarimetric antenna model for small conformal arrays including mutual coupling effects","authors":"P. Knott, C. von Winterfeld","doi":"10.1109/APS.1999.789273","DOIUrl":"https://doi.org/10.1109/APS.1999.789273","url":null,"abstract":"A physical modeling method for the calculation of characteristic high-frequency electromagnetic parameters of small conformal arrays is introduced. The antenna array model is based on the interaction between special antenna elements composed of electrically small dipoles and loop antennas and allows for the calculation of generic mutual coupling effects inside the antenna array. Also, a pattern synthesis method based on the projection of cylindrical sector waves onto the antenna array elements is described. Numerical results for arrays of cylindrical sector geometry and commonly used beam shapes are presented and the calculated coupling effects inside the antenna array are analyzed. The results are compared to data measured at a practical antenna array.","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":"250 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":"123670926","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}
Lijun Zhang, Nicolaos G. Alexopoulos, Eli Yablonovitch
The effect of using a superstrate PBG material on a microstrip line fed slot antenna is investigated. The PBG material is composed of periodic metallic blocks inside a host dielectric material with high material permittivity, and exhibits a complete bandgap at the design frequency of the slot antenna. Simulation results show that by adding the PBG layer as a superstrate, radiation in the E-plane near the endfire direction is suppressed, while radiation in the H-plane is enhanced.
{"title":"Microstrip line fed slot antenna with PBG superstrate","authors":"Lijun Zhang, Nicolaos G. Alexopoulos, Eli Yablonovitch","doi":"10.1109/APS.1999.788334","DOIUrl":"https://doi.org/10.1109/APS.1999.788334","url":null,"abstract":"The effect of using a superstrate PBG material on a microstrip line fed slot antenna is investigated. The PBG material is composed of periodic metallic blocks inside a host dielectric material with high material permittivity, and exhibits a complete bandgap at the design frequency of the slot antenna. Simulation results show that by adding the PBG layer as a superstrate, radiation in the E-plane near the endfire direction is suppressed, while radiation in the H-plane is enhanced.","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":"114 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":"124069704","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}
Previously, a dielectric resonator antenna (DRA) including circularly polarized DRA (CP-DRA) has been studied by many researchers, since it can be used as an efficient radiator in the high frequency region. A new type of CP-DRA element fed by an asymmetric cross-slot is proposed here. This type of CP-DRB is probably one of the simplest devices for producing circular polarization at or near the millimeter-wave region. This paper presents the radiation properties of a new type of CP-DRB element together with the design technique of a DRA array composed of a pair of CP-DRAs. In order to evaluate the performance, some DRA elements and its arrays were fabricated and tested at X-band. The 3-dB axial-ratio bandwidth obtained from this new type of DRA array was about 20% at X-band, and it had an extremely broadband performance compared to that of a normal array antenna. Therefore, the DRA array proposed here is considered to be an effective model as a broadband circularly polarized array.
{"title":"Array antenna composed of circularly polarized dielectric resonator antennas","authors":"M. Haneishi, Bing Wu","doi":"10.1109/APS.1999.789128","DOIUrl":"https://doi.org/10.1109/APS.1999.789128","url":null,"abstract":"Previously, a dielectric resonator antenna (DRA) including circularly polarized DRA (CP-DRA) has been studied by many researchers, since it can be used as an efficient radiator in the high frequency region. A new type of CP-DRA element fed by an asymmetric cross-slot is proposed here. This type of CP-DRB is probably one of the simplest devices for producing circular polarization at or near the millimeter-wave region. This paper presents the radiation properties of a new type of CP-DRB element together with the design technique of a DRA array composed of a pair of CP-DRAs. In order to evaluate the performance, some DRA elements and its arrays were fabricated and tested at X-band. The 3-dB axial-ratio bandwidth obtained from this new type of DRA array was about 20% at X-band, and it had an extremely broadband performance compared to that of a normal array antenna. Therefore, the DRA array proposed here is considered to be an effective model as a broadband circularly polarized array.","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":"150 1 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":"125883334","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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