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IEEE Antennas and Propagation Society International Symposium 1997. Digest最新文献

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A novel impedance-tuned monopole antenna 一种新型阻抗调谐单极天线
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.631817
K. A. Wagner, S. Gearhart
{"title":"A novel impedance-tuned monopole antenna","authors":"K. A. Wagner, S. Gearhart","doi":"10.1109/APS.1997.631817","DOIUrl":"https://doi.org/10.1109/APS.1997.631817","url":null,"abstract":"The authors introduce the slot-tuned monopole antenna whose input impedance may be tuned using slots integrated within the antenna. The slots may be thought of as integrated coplanar-waveguide tuning stubs and may also be used to create a second impedance-tuned resonance. The ratio of the two impedance-tuned resonances can be adjusted by changing the dimensions of the antenna and slots. To illustrate the flexibility of the slot-tuned monopole antenna, two examples are presented. The first example shows how the insertion of a open circuited stub within the antenna can increase the resonant impedance of the monopole from approximately 35 /spl Omega/, which is typical to monopoles, to 50 /spl Omega/. The 50 /spl Omega/ input impedance is chosen because it is well matched to 50 /spl Omega/ coaxial lines. In actual applications, nearly any input impedance may be chosen. In the second example short and open circuited stubs were inserted in parallel and the dimensions of the antenna were adjusted to create an antenna with two impedance-tuned resonant frequencies with a frequency ratio of 1.5:1. For these tests, the antennas are fabricated on 10 mil thick substrate with /spl epsiv//sub r/=4. Simulations are performed using HP Momentum moment method software.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116030957","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}
引用次数: 2
Sequentially rotated phased array consisting of higher order mode elements 由高阶模元组成的顺序旋转相控阵
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.631560
M. Tanaka
{"title":"Sequentially rotated phased array consisting of higher order mode elements","authors":"M. Tanaka","doi":"10.1109/APS.1997.631560","DOIUrl":"https://doi.org/10.1109/APS.1997.631560","url":null,"abstract":"A circular or ring microstrip antenna with second or higher order mode excitation can form a conical pattern with the null at broadside and the beam peak at an elevation angle of about 45 degrees, and can be effectively applied as an element of conformal land mobile phased arrays for satellite communication. However, higher order mode microstrip antennas have a serious problem concerning axial ratio characteristics. The author proposes a method of designing a sequentially rotated array consisting of higher order mode elements in order to reduce axial ratio quality. This sequentially rotated array requires different rotation angles for different mode excitation, while the phase shift is independent of the mode excitation. The application of this sequentially rotated array to a phased array consisting of higher order mode elements is described.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122439458","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}
引用次数: 0
Experimental study of parasitically steered, fixed beam microstrip patch arrays 寄生导向固定波束微带贴片阵列的实验研究
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.631799
D. Gray, L. Shafai
{"title":"Experimental study of parasitically steered, fixed beam microstrip patch arrays","authors":"D. Gray, L. Shafai","doi":"10.1109/APS.1997.631799","DOIUrl":"https://doi.org/10.1109/APS.1997.631799","url":null,"abstract":"The linearly polarised single feed point Yagi microstrip patch array was previously developed from the concept of the thin wire Yagi-Uda array. It is possible to build either vertically polarised or horizontally polarised arrays. Both feed points of an array can be excited with the correct amplitude and phasing to produce circular polarisation. A Yagi microstrip patch array produces a mainlobe away from the zenith, and has the advantage of being planar for applications such as wireless office. The aim of this paper is to investigate the influence of various characteristics of the dielectric substrate upon array performance and to access the effects of reduction of the array size upon its behaviour. The collected experimental data will be useful for comparison to numerical simulations in future work. The linear polarised measurements were undertaken in the anechoic chamber at the University of Manitoba.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"321 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122732896","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}
引用次数: 6
Impedance image reconstruction using neural networks 基于神经网络的阻抗图像重建
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.631510
A. Nejatali, I. Ciric
{"title":"Impedance image reconstruction using neural networks","authors":"A. Nejatali, I. Ciric","doi":"10.1109/APS.1997.631510","DOIUrl":"https://doi.org/10.1109/APS.1997.631510","url":null,"abstract":"Impedance imaging can be used in a variety of practical applications, such as medical diagnosis, geological exploration, multicomponent fluid flow analysis, and quality control. We consider the electrical impedance imaging where the spatial conductivity distribution within the object is reconstructed based on the voltage-current relationship measured by using a system of electrodes located on the surface of the object. The solution of the associated inverse problem requires a substantial amount of computation. In this paper, we present a new neural network architecture, with a relatively simple and inexpensive hardware, that can be employed efficiently to solve this inverse problem.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122743343","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}
引用次数: 2
Experimental investigation of the effects of rough surface criterion and surface conductivity on radio links 粗糙表面准则和表面电导率对无线电链路影响的实验研究
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.625429
R. Mazzolin, J. Dahele
{"title":"Experimental investigation of the effects of rough surface criterion and surface conductivity on radio links","authors":"R. Mazzolin, J. Dahele","doi":"10.1109/APS.1997.625429","DOIUrl":"https://doi.org/10.1109/APS.1997.625429","url":null,"abstract":"The requirement for the calculation of microwave link path loss has received considerable attention over time. A number of path loss prediction algorithms based on theoretical calculations using idealized obstacles have been created, but usually actual measurements will deviate significantly from calculated values. Through the use of modern computing techniques, algorithms can benefit from the use of experimental data for better approximation of loss due to actual terrain features. This paper outlines the results of measurements taken involving the effects of rough surface criterion and surface conductivity on radio links.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122618467","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}
引用次数: 0
Smart antenna array for high data rate mobile communications 用于高数据速率移动通信的智能天线阵列
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.630159
F. Chin, M. Chia
{"title":"Smart antenna array for high data rate mobile communications","authors":"F. Chin, M. Chia","doi":"10.1109/APS.1997.630159","DOIUrl":"https://doi.org/10.1109/APS.1997.630159","url":null,"abstract":"A flexible experimental 12-element antenna array testbed was built for high data rate mobile communications and PCS applications. The supported simultaneous data sampling rate on 12 elements is about 3.5 MHz. A field trial was conducted to demonstrate performance improvement in terms of BER and SNR. Further experiments are currently being conducted to demonstrate multipath mitigation, interference suppression, range extension and capacity enhancement.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122891343","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}
引用次数: 3
PO analysis of depolarizing trihedral corners 退偏光三面角的PO分析
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.630142
C. Gennarelli, G. Riccio, G. Pelosi
{"title":"PO analysis of depolarizing trihedral corners","authors":"C. Gennarelli, G. Riccio, G. Pelosi","doi":"10.1109/APS.1997.630142","DOIUrl":"https://doi.org/10.1109/APS.1997.630142","url":null,"abstract":"In this paper, a physical optics (PO) model to analyze a loaded trihedral corner reflector (TCR) is developed and applied to predict the backscattering by a depolarizing TCR. Such a reflector, proposed by Jull and Michelson (1995), is obtained from the conventional triangular one by loading one of its interior faces with \"ad hoc\" chosen rectangular corrugations parallel to the z-axis. By generalizing the model developed in Corona et al. (1995, 1996), an anisotropic impedance boundary condition (IBC) is introduced to take into account the properties of such a corrugated surface. The proposed PO method uses the geometrical optics (GO) to evaluate the illuminating electric field related to the direct, singly and doubly reflected rays incident on each face and to determine in analytic form the shape of the corresponding lighted patches. Further improvements in the EM model can be introduced by augmenting PO calculation with contribution due to the diffraction from the edges.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114255309","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}
引用次数: 1
A planar L-band transportable antenna 一种平面l波段可移动天线
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.630186
N. Mcdonald
{"title":"A planar L-band transportable antenna","authors":"N. Mcdonald","doi":"10.1109/APS.1997.630186","DOIUrl":"https://doi.org/10.1109/APS.1997.630186","url":null,"abstract":"The establishment of an L-band mobile satellite communications system in Australia has created the need for an antenna suitable for transportable, semi-permanent and permanent installations. A new form of circularly polarised planar antenna has been developed for such applications. Mobile satellite communications systems are typically down-link limited, that is the link direction from satellite to the ground terminal is more critical than the uplink. Accordingly not only the antenna gain is important, but also its noise temperature. For transportable applications a good physical profile for packaging and transport is also essential. The particular requirements for the Australian system are a bandwidth of approximately 8% centered near 1600 MHz, right hand circular polarisation, and a system G/T of more than -14.0 dB/K.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114563591","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}
引用次数: 0
Multifunction personal and mobile SMM antenna for satellite communications systems 用于卫星通信系统的多功能个人和移动SMM天线
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.630187
J.J.H. Wang, J. Tillery
{"title":"Multifunction personal and mobile SMM antenna for satellite communications systems","authors":"J.J.H. Wang, J. Tillery","doi":"10.1109/APS.1997.630187","DOIUrl":"https://doi.org/10.1109/APS.1997.630187","url":null,"abstract":"There are a number of personal and mobile communications systems based on the use of microwave links relayed by Earth-orbiting satellites between small, low-cost Earth terminals using antennas of low directivity and broad beam aiming at the appropriate satellites. These satellite communications systems are now either deployed or in various stages of development and planning. For example, there are the AMSC geostationary satellites covering North America. There are the fully operational GPS systems of the US and GLONASS of Russia that both allow the determination of positioning on Earth with high accuracy. The bold and ambitious vision of linking people and businesses in the most remote corners of the globe by satellites, specifically the low-Earth-orbiting (LEO) satellites, which was considered by many as a dream, is now becoming reality. The ongoing Iridium project, a consortium led by Motorola, plans to have 66 LEO satellites carrying messaging, data, and voice services starting in 1998. This paper presents a preliminary design for the needed personal and mobile Earth-terminal antennas.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116614334","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}
引用次数: 3
Optical generation of a mHz linewidth microwave signal with a discriminator-aided phase-locked loop using two semiconductor lasers 用两个半导体激光器用鉴别器辅助锁相环产生mHz线宽微波信号
IEEE Antennas and Propagation Society International Symposium 1997. Digest Pub Date : 1997-07-13 DOI: 10.1109/APS.1997.631574
Z. Fan, M. Dagenais
{"title":"Optical generation of a mHz linewidth microwave signal with a discriminator-aided phase-locked loop using two semiconductor lasers","authors":"Z. Fan, M. Dagenais","doi":"10.1109/APS.1997.631574","DOIUrl":"https://doi.org/10.1109/APS.1997.631574","url":null,"abstract":"Optical beam forming and steering of RF phased array antenna offers interesting advantages over standard microwave techniques, including inherently low transmission losses, large bandwidth and light weight. One important challenge of such a system is to optically generate a microwave carrier with a well controlled frequency. Offset optical phase locking of two semiconductor lasers can be an effective technique to achieve this goal. In our experiment, two external cavity semiconductor lasers were phase locked by using a discriminator-aided optical phase-locked loop with enhanced acquisition range over previous approaches.","PeriodicalId":283897,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium 1997. Digest","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116823242","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}
引用次数: 2
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