IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229)最新文献_第3页

Graphical representations of radiation patterns of phased arrays using digital phase shifters 使用数字移相器的相控阵辐射图的图形表示

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.960070

M. Clénet, G. Morin

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引用次数: 3

Scaling and focusing of the Rotman lens 罗特曼透镜的缩放和聚焦

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.959838

Jaeheung Kim, F. Barnes

引用次数: 19

Design of radiofrequency coils for magnetic resonance imaging applications at high fields: technological and physical feasibility issues 高磁场磁共振成像应用射频线圈的设计:技术和物理可行性问题

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.958869

T. Ibrahim, R. Lee, B. Baertlein, P. Robitaille

{"title":"Design of radiofrequency coils for magnetic resonance imaging applications at high fields: technological and physical feasibility issues","authors":"T. Ibrahim, R. Lee, B. Baertlein, P. Robitaille","doi":"10.1109/APS.2001.958869","DOIUrl":"https://doi.org/10.1109/APS.2001.958869","url":null,"abstract":"In the field of medical magnetic resonance imaging (MRI), there has been a constant drive towards more powerful magnets and therefore higher operational frequencies. Imaging at higher fields has several benefits, so that images with much greater detail can be obtained using high field MRI systems with high static (B/sub 0/) field strength. Operation at high frequencies, however, adds significant technical challenges to the design of radiofrequency (RF) coils. We address the physics associated with RF coils and their electromagnetic interactions with biological tissue. This is accomplished by examining the B/sub 1/ field distribution and the RF power requirements between 135 MHz and 470 MHz. We also propose methods to optimize the B/sub 1/ field distribution at ultra high field (/spl ges/ 300 MHz). Using the finite difference time domain (FDTD) method, antenna array concepts are utilized to excite a volume head coil (TEM resonator) such that an optimal B/sub 1/ field distribution is achieved in the head. Input excitations with both variable phase and magnitude are evaluated for 2, 3, 4, 6, and 10 excitation ports in a 24-strut TEM resonator loaded with an 18-tissue anatomically detailed human head model. Finally, true phased array is implemented to modify the phase and magnitude of all the 24 possible ports in the 24-strut TEM resonator. By properly exciting each drive port, significantly improved B/sub 1/ field homogeneity was obtained.","PeriodicalId":159827,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124557544","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

Broadside parallel-plate slot antenna without dielectric 无电介质的宽边平行板槽天线

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.960144

M. Vera-Isasa, A. Álvarez, M. Sierra-Castañer, M. Sierra-Pérez

引用次数: 1

A study on pattern synthesis method for array-fed reflector antenna for advanced direct broadcasting satellites 先进直播卫星阵列馈电反射天线方向图合成方法研究

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.958916

S. Tanaka, T. Yamada, T. Murata, T. Nomoto, H. Matsumura

{"title":"A study on pattern synthesis method for array-fed reflector antenna for advanced direct broadcasting satellites","authors":"S. Tanaka, T. Yamada, T. Murata, T. Nomoto, H. Matsumura","doi":"10.1109/APS.2001.958916","DOIUrl":"https://doi.org/10.1109/APS.2001.958916","url":null,"abstract":"Satellite broadcasting services operated in the 12 GHz-band are currently provided in Japan. Furthermore, the technical development of areas such as future 21 GHz-band satellite broadcasting systems is also in progress. One of the major technical difficulties with the satellite broadcasting systems using such frequency bands is the large rain attenuation caused by heavy rainfall. A method for compensating for rain attenuation is necessary to avoid the interruption of broadcasting reception. We have been studying an advanced broadcasting satellite system having an on-board large-scale phased array antenna. This system can compensate for rain attenuation by increasing the radiation power over areas of heavy rainfall. The adaptive pattern synthesis technique of the phased array antenna makes it possible to reconfigure the radiation pattern (equivalent isotropically radiated power: EIRP) according to the distribution of rainfall on the service area. We describe the results of a basic study focused on (1) the radiation pattern requirements that systems such as broadcasting satellite systems with variable EIRIP will have to satisfy and, (2) pattern synthesis methods for an array-fed reflector antenna based on singular value decomposition (SVD).","PeriodicalId":159827,"journal":{"name":"IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130315006","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

Prediction and optimization of transient temperature fields in electromagnetic hyperthermia 电磁热疗瞬态温度场的预测与优化

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.958846

M. Kowalski, J. Jin

引用次数: 1

Numerical modeling and experimental study of a novel leaky wave antenna 一种新型漏波天线的数值模拟与实验研究

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.959440

E. Semouchkina, W. Cao, R. Mittra, G. Semouchkin, N. Popenko, I. Ivanchenko

引用次数: 3

A compact multiband terminal antenna 一种紧凑的多波段终端天线

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.959635

P. Kabacik

引用次数: 2

Coplanar patch antennas: principle, simulation and experiment 共面贴片天线:原理、仿真与实验

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.960119

K. Li, C.H. Cheng, T. Matsui, M. Izutsu

引用次数: 52

Grand challenges in analyzing EM band-gap structures: an FDTD/Prony technique based on the split-field approach EM带隙结构分析的重大挑战:基于分场方法的FDTD/ proony技术

IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229) Pub Date : 2001-07-08 DOI: 10.1109/APS.2001.959618

H. Mosallaei, V. Rahmat-Samii

引用次数: 7