1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184)最新文献_第5页

A field/polarization diversity antenna for portable phones 一种用于移动电话的场/极化分集天线

1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184) Pub Date : 1998-11-01 DOI: 10.1109/APWC.1998.730671

W. Young, B. Belzer, R. Olsen

{"title":"A field/polarization diversity antenna for portable phones","authors":"W. Young, B. Belzer, R. Olsen","doi":"10.1109/APWC.1998.730671","DOIUrl":"https://doi.org/10.1109/APWC.1998.730671","url":null,"abstract":"The design of a two-element field/polarization diversity antenna for portable phones is considered. The antenna consists of a dipole terminated with a parallel loop capacitor combination. The antenna has a single feed at a point on the loop opposite the junction, and does not require external combining circuitry. The capacitor creates a phase shift between the dipole and loop currents, thereby greatly reducing the probability of deep nulls when the antenna is deployed in the vicinity of a fixed reflector, where standing wave patterns occur. Theoretical and simulation studies based on multiple incident plane wave fields are used to quantify antenna diversity gain in the presence of a fixed reflector. Simulation results are presented for three antenna types: a dipole antenna, a loop-dipole antenna without a capacitor, and the loop-dipole antenna with capacitor. The simulation results are verified by field measurements on an automated outdoor test range, where the incidence angle and distance from the reflector are varied. Both the simulation and field test results show that the loop-dipole-capacitor design provides a substantial diversity gain over the standard dipole antenna and over the loop-dipole antenna without the capacitor.","PeriodicalId":246376,"journal":{"name":"1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127037570","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

Indoor ISM band multipath fading: frequency and antenna diversity 室内ISM波段多径衰落:频率和天线分集

1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184) Pub Date : 1998-11-01 DOI: 10.1109/APWC.1998.730626

J. Colburn, M. Jensen, Y. Rahmat-Samii

引用次数: 9

A physical-statistical time-series model for the mobile-satellite channel 移动卫星信道的物理统计时间序列模型

1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184) Pub Date : 1998-11-01 DOI: 10.1109/APWC.1998.730624

C. Tzaras, S. Saunders, B. Evans

引用次数: 10

Adaptive transmit antenna 自适应发射天线

1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184) Pub Date : 1900-01-01 DOI: 10.1109/APWC.1998.730638

R. Dybdal, S. J. Curry

{"title":"Adaptive transmit antenna","authors":"R. Dybdal, S. J. Curry","doi":"10.1109/APWC.1998.730638","DOIUrl":"https://doi.org/10.1109/APWC.1998.730638","url":null,"abstract":"Adaptive techniques are commonly used to protect receiving antennas from interference. However, adaptive techniques have not been applied to transmitting antennas. An example of adaptively controlling a transmitting antenna is described. This adaptive transmit antenna concept was motivated by requirements for future personal communication systems. These antennas require broad antenna coverage to avoid antenna pointing requirements. This broad-coverage antenna requirement unavoidably results in multipath susceptibility that degrades communication performance. Rake receivers provide adaptive equalization and adaptive antenna element combining are well-known techniques to reduce multipath degradation for receiving systems. However, the performance of the transmit antenna remains degraded by multipath signals. Since the receive and transmit frequencies are separated, the adaptive receive combinations differ from those needed in the transmit case. This new adaptive transmit antenna provides a means to reduce multipath interference in the transmit case. Multipath distortions on transmission reduce the isolation between multiple users in CDMA systems, which is a well-known limit on overall system capacity.","PeriodicalId":246376,"journal":{"name":"1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications (Cat. No.98EX184)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122230866","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