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 increasing use of short-range radio links for applications such as ward or home based physiological monitoring creates the need for a better knowledge and understanding of the indoor propagation environment. The work presented concerns a body-worn, cross-band UHF transponder used for physiological signaling within single-room environments. A modified image-based ray-tracing algorithm is used to calculate the fading characteristics for a link under the worst case condition, when the direct path between the source and chest-mounted receiver is obstructed by the body itself. The approach adopted utilizes a FDTD-generated radiation pattern of a realistic adult-male body model, incorporating the directional gains into the three-dimensional indoor ray-tracing algorithm. A description of the biomedical transponder is followed by details of the computational technique; path loss and small area fading results are then presented for a 76 m/sup 2/ area representing a hospital ward. The cumulative distribution function (CDF) results were found to be characteristically bi-modal and this novel feature is investigated in more detail.
{"title":"Body-obstructed fading characteristics of an in-ward 2.45 GHz biomedical telecommand link","authors":"W. Scanlon, G. C. Crumley, N. Evans","doi":"10.1109/APS.1999.789158","DOIUrl":"https://doi.org/10.1109/APS.1999.789158","url":null,"abstract":"The increasing use of short-range radio links for applications such as ward or home based physiological monitoring creates the need for a better knowledge and understanding of the indoor propagation environment. The work presented concerns a body-worn, cross-band UHF transponder used for physiological signaling within single-room environments. A modified image-based ray-tracing algorithm is used to calculate the fading characteristics for a link under the worst case condition, when the direct path between the source and chest-mounted receiver is obstructed by the body itself. The approach adopted utilizes a FDTD-generated radiation pattern of a realistic adult-male body model, incorporating the directional gains into the three-dimensional indoor ray-tracing algorithm. A description of the biomedical transponder is followed by details of the computational technique; path loss and small area fading results are then presented for a 76 m/sup 2/ area representing a hospital ward. The cumulative distribution function (CDF) results were found to be characteristically bi-modal and this novel feature is investigated in more detail.","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":"5 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":"130822235","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}
P. Irazoqui-Pastor, E. Swanson, C. Short, J. Bernhard
This work describes a design and analysis tool that evaluates real-world diversity system performance by accounting for the effects of chassis integration on antenna characteristics. The method allows qualitative comparisons of antenna systems and is both numerically efficient and highly versatile. Theoretical, simulated, and measured antenna characteristics with a variety of diversity processing schemes can be incorporated in the analysis. Results using measured antenna characteristics are presented.
{"title":"An analysis and design tool for evaluation of integrated antenna diversity systems in portable wireless devices","authors":"P. Irazoqui-Pastor, E. Swanson, C. Short, J. Bernhard","doi":"10.1109/APS.1999.788367","DOIUrl":"https://doi.org/10.1109/APS.1999.788367","url":null,"abstract":"This work describes a design and analysis tool that evaluates real-world diversity system performance by accounting for the effects of chassis integration on antenna characteristics. The method allows qualitative comparisons of antenna systems and is both numerically efficient and highly versatile. Theoretical, simulated, and measured antenna characteristics with a variety of diversity processing schemes can be incorporated in the analysis. Results using measured antenna characteristics 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":"131297580","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 concept of optical elements using diffraction is quite an old one; for instance, Fresnel's zone plate dates from about 1830. The elements of the diffraction quasioptics (EDQ) are intended for transformation of incident wavefronts into the required ones. The EDQ operation principle is based on creation of specifically chosen discrete phase delays over the wave front. There are three main types of EDQ (by the principle of disposition with respect to the propagation direction of the electromagnetic wave): transverse (made mainly on a flat surface), longitudinal-transverse (made on an arbitrary curvilinear surface) and longitudinal (representing a system of screens located along the direction of the electromagnetic wave propagation). The EDQ can operate both in the "transmission regime" and the "reflection regime". According to the application the EDQ can be of amplitude (binary) and phase inversion type. The main physical properties of the EDQ are surveyed in the present work. Different systems based on the EDQ are considered as well.
{"title":"New class microwave antennas, based on the elements of the diffraction quasioptics: advantages and applications","authors":"I. Minin, O. Minin","doi":"10.1109/APS.1999.789424","DOIUrl":"https://doi.org/10.1109/APS.1999.789424","url":null,"abstract":"The concept of optical elements using diffraction is quite an old one; for instance, Fresnel's zone plate dates from about 1830. The elements of the diffraction quasioptics (EDQ) are intended for transformation of incident wavefronts into the required ones. The EDQ operation principle is based on creation of specifically chosen discrete phase delays over the wave front. There are three main types of EDQ (by the principle of disposition with respect to the propagation direction of the electromagnetic wave): transverse (made mainly on a flat surface), longitudinal-transverse (made on an arbitrary curvilinear surface) and longitudinal (representing a system of screens located along the direction of the electromagnetic wave propagation). The EDQ can operate both in the \"transmission regime\" and the \"reflection regime\". According to the application the EDQ can be of amplitude (binary) and phase inversion type. The main physical properties of the EDQ are surveyed in the present work. Different systems based on the EDQ are considered as well.","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":"12 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":"125440188","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}
We have modeled a two-dimensional periodic structure by a two-dimensional impedance surface. The scattering of waves by such an impedance surface is rigorously formulated as a three-dimensional boundary-value problem, including the coupling between the TE and TM polarized waves. Numerical examples are given to illustrate physical phenomena associated with the structure.
{"title":"Scattering of plane waves by two-dimensional periodic impedance surface","authors":"R. Hwang, S. Peng","doi":"10.1109/APS.1999.788328","DOIUrl":"https://doi.org/10.1109/APS.1999.788328","url":null,"abstract":"We have modeled a two-dimensional periodic structure by a two-dimensional impedance surface. The scattering of waves by such an impedance surface is rigorously formulated as a three-dimensional boundary-value problem, including the coupling between the TE and TM polarized waves. Numerical examples are given to illustrate physical phenomena associated with the structure.","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":"126669270","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 large class of scattering and propagation problems can be reduced to a system of dual series equations. This system of equations can be rigorously solved in an efficient manner by the method based on the Riemann-Hilbert problem. Although the presence of an edge introduces some distinctive features, it was pointed out that the Riemann-Hilbert approach explicitly accounted for the singularity of the fields near the edge. In the present work, the dual series equations for a gyrotropic circular rod covered with metal strip are solved by the modified method for the Riemann-Hilbert problem.
{"title":"The scattering of an E-polarized plane wave from a metal strip on a ferrite circular rod","authors":"K. Yashiro, N. Guan, S. Ohkawa","doi":"10.1109/APS.1999.789260","DOIUrl":"https://doi.org/10.1109/APS.1999.789260","url":null,"abstract":"A large class of scattering and propagation problems can be reduced to a system of dual series equations. This system of equations can be rigorously solved in an efficient manner by the method based on the Riemann-Hilbert problem. Although the presence of an edge introduces some distinctive features, it was pointed out that the Riemann-Hilbert approach explicitly accounted for the singularity of the fields near the edge. In the present work, the dual series equations for a gyrotropic circular rod covered with metal strip are solved by the modified method for the Riemann-Hilbert problem.","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":"41 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":"126733792","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 primary objective of developments in wireless communications systems is to increase the density of subscribers simultaneously served by the system. Another major objective is to provide services where high rates of data transmission are needed. This can be achieved by extending the multiple access scheme and by improving channel modulation and coding. There are two major approaches to the multiple access scheme problem-the code division multiple access (CDMA) and the spatial division multiple access (SDMA). Their implementation calls for the use of smart antennas not only at the base station site, but also at the terminals, where antennas of an improved design are recommended. However, the functioning of smart antennas is still far from being well defined, and in this context a variety of concepts have been examined. This paper presents some results of our investigations into terminal antennas with improved properties of their radiation patterns. We focused on two properties-the optimized shape of the radiation pattern and the scanning of the main beam. These properties are needed to suppress interference. Furthermore, owing to the achieved antenna directivity it is feasible to suppress the scattered waves and to decrease intersymbol interference, which is a prerequisite to achieve a high data transmission rate. Unfortunately, each terminal antenna design must comply with the tough miniaturization requirements.
{"title":"Planar handset antennas with electronically steerable parameters","authors":"P. Kabacik, A. Kucharski","doi":"10.1109/APS.1999.788369","DOIUrl":"https://doi.org/10.1109/APS.1999.788369","url":null,"abstract":"The primary objective of developments in wireless communications systems is to increase the density of subscribers simultaneously served by the system. Another major objective is to provide services where high rates of data transmission are needed. This can be achieved by extending the multiple access scheme and by improving channel modulation and coding. There are two major approaches to the multiple access scheme problem-the code division multiple access (CDMA) and the spatial division multiple access (SDMA). Their implementation calls for the use of smart antennas not only at the base station site, but also at the terminals, where antennas of an improved design are recommended. However, the functioning of smart antennas is still far from being well defined, and in this context a variety of concepts have been examined. This paper presents some results of our investigations into terminal antennas with improved properties of their radiation patterns. We focused on two properties-the optimized shape of the radiation pattern and the scanning of the main beam. These properties are needed to suppress interference. Furthermore, owing to the achieved antenna directivity it is feasible to suppress the scattered waves and to decrease intersymbol interference, which is a prerequisite to achieve a high data transmission rate. Unfortunately, each terminal antenna design must comply with the tough miniaturization requirements.","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":"77 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":"126230264","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 aperture-coupled hemispherical dielectric resonator antenna with a thick ground plane is studied. The effects of the ground plane thickness on the resonant frequency, impedance bandwidth, and front-to-back radiation ratio are presented.
{"title":"On the aperture-coupled dielectric resonator antenna using a thick ground plane","authors":"K. Leung, Z. Chen, K. Luk, E. Yung","doi":"10.1109/APS.1999.789386","DOIUrl":"https://doi.org/10.1109/APS.1999.789386","url":null,"abstract":"The aperture-coupled hemispherical dielectric resonator antenna with a thick ground plane is studied. The effects of the ground plane thickness on the resonant frequency, impedance bandwidth, and front-to-back radiation ratio 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":"18 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":"126457348","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}
Tom T. Taylor founded the science of low sidelobe high efficiency distributions while at Hughes Aircraft (Culver City) in the 1950s. The present author takes pleasure in reviewing briefly his seminal contributions. References may be found in Hansen (1998).
{"title":"Contributions of T.T. Taylor to array synthesis","authors":"R. Hansen","doi":"10.1109/APS.1999.789268","DOIUrl":"https://doi.org/10.1109/APS.1999.789268","url":null,"abstract":"Tom T. Taylor founded the science of low sidelobe high efficiency distributions while at Hughes Aircraft (Culver City) in the 1950s. The present author takes pleasure in reviewing briefly his seminal contributions. References may be found in Hansen (1998).","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":"13 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":"126546639","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}
Analytical expressions based on uniform theory of diffraction (UTD) are widely used in ray-tracing simulation tools for the diffraction problem. Although these theories predict the fields accurately in the far-field region for simple problems, it is difficult, if not impossible, to extend the analysis to find diffraction coefficients for wedges composed of dielectric and imperfectly conducting materials. In fact, the classical problem of diffraction from an infinite lossless dielectric wedge has not been solved analytically. In the past, we demonstrated the successful application of the FDTD method to numerically obtain diffraction coefficients for an infinite PEC wedge. In this paper, we use the FDTD method in a similar approach in order to find the electromagnetic field in the shadowing region of the inhomogeneous wedge. We further extend the FDTD approach to analyze parameter sensitivity for the diffracted fields from 2-D inhomogeneous material wedges representing practical cases, such as corners of different buildings with different type of inhomogeneities. This approach, in principle, can be extended to calculate the power in the shadowing region in three dimensions.
{"title":"Numerical studies of diffraction by 2-D homogeneous and inhomogeneous dielectric wedges","authors":"D. Demetriou, G. Stratis","doi":"10.1109/APS.1999.789352","DOIUrl":"https://doi.org/10.1109/APS.1999.789352","url":null,"abstract":"Analytical expressions based on uniform theory of diffraction (UTD) are widely used in ray-tracing simulation tools for the diffraction problem. Although these theories predict the fields accurately in the far-field region for simple problems, it is difficult, if not impossible, to extend the analysis to find diffraction coefficients for wedges composed of dielectric and imperfectly conducting materials. In fact, the classical problem of diffraction from an infinite lossless dielectric wedge has not been solved analytically. In the past, we demonstrated the successful application of the FDTD method to numerically obtain diffraction coefficients for an infinite PEC wedge. In this paper, we use the FDTD method in a similar approach in order to find the electromagnetic field in the shadowing region of the inhomogeneous wedge. We further extend the FDTD approach to analyze parameter sensitivity for the diffracted fields from 2-D inhomogeneous material wedges representing practical cases, such as corners of different buildings with different type of inhomogeneities. This approach, in principle, can be extended to calculate the power in the shadowing region in three dimensions.","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":"122222470","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}
Accurate and efficient techniques for analyzing linear transient wave phenomena are of significant interest to many disciplines. Although integral equation based methods for analyzing two-dimensional (2D) transient phenomena have been studied extensively in the past they all suffer from a high computational complexity, which limits their application to practical problems. To accelerate the integral equation based analysis of three dimensional transient scattering phenomena, our group developed the three-dimensional plane wave time domain (PWTD) algorithm (Ergin et al., 1998). In this paper, we extend our previous work from three to two dimensions and propose a novel 2D PWTD algorithm that relies on a diagonal translation operator for the efficient evaluation of 2D wave fields. When used in conjunction with a marching-on-in-time (MOT) scheme, this algorithm drastically accelerates the integral equation based analysis of 2D transient scattering phenomena.
准确而有效地分析线性瞬态波现象的技术是许多学科的重要兴趣。虽然基于积分方程的二维瞬态现象分析方法在过去已经得到了广泛的研究，但它们都具有较高的计算复杂度，这限制了它们在实际问题中的应用。为了加速基于积分方程的三维瞬态散射现象分析，本课题组开发了三维平面波时域(PWTD)算法(Ergin et al.， 1998)。在本文中，我们将之前的工作从三维扩展到二维，并提出了一种新的二维PWTD算法，该算法依赖于对角平移算子来有效地评估二维波场。当该算法与MOT (marching-on- time)方案结合使用时，可大大加快基于积分方程的二维瞬态散射现象分析。
{"title":"A diagonal translation operator for the fast evaluation of two-dimensional transient wave fields","authors":"M. Lu, J. Wang, A. A. Ergin, A. Michielssen","doi":"10.1109/APS.1999.789561","DOIUrl":"https://doi.org/10.1109/APS.1999.789561","url":null,"abstract":"Accurate and efficient techniques for analyzing linear transient wave phenomena are of significant interest to many disciplines. Although integral equation based methods for analyzing two-dimensional (2D) transient phenomena have been studied extensively in the past they all suffer from a high computational complexity, which limits their application to practical problems. To accelerate the integral equation based analysis of three dimensional transient scattering phenomena, our group developed the three-dimensional plane wave time domain (PWTD) algorithm (Ergin et al., 1998). In this paper, we extend our previous work from three to two dimensions and propose a novel 2D PWTD algorithm that relies on a diagonal translation operator for the efficient evaluation of 2D wave fields. When used in conjunction with a marching-on-in-time (MOT) scheme, this algorithm drastically accelerates the integral equation based analysis of 2D transient scattering phenomena.","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":"15 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":"122247404","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)
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：