DocumentCode :
2346736
Title :
A field/polarization diversity antenna for portable phones
Author :
Young, William ; Belzer, Benjamin ; Olsen, Robert
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Washington State Univ., Pullman, WA, USA
fYear :
1998
fDate :
1-4 Nov 1998
Firstpage :
125
Lastpage :
128
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
Keywords :
antenna testing; capacitors; dipole antennas; diversity reception; electromagnetic wave polarisation; loop antennas; mobile antennas; reflector antennas; telephone sets; antenna diversity gain; automated outdoor test range; dipole antenna; field measurements; field/polarization diversity antenna; fixed reflector; loop-dipole antenna; loop-dipole-capacitor design; multiple incident plane wave fields; parallel loop capacitor; phase shift; portable phones; standing wave patterns; two-element antenna; Antenna feeds; Antenna measurements; Antenna theory; Capacitors; Circuit simulation; Dipole antennas; Diversity methods; Diversity reception; Polarization; Reflector antennas;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Antennas and Propagation for Wireless Communications, 1998. 1998 IEEE-APS Conference on
Conference_Location :
Waltham, MA
Print_ISBN :
0-7803-4955-5
Type :
conf
DOI :
10.1109/APWC.1998.730671
Filename :
730671
Link To Document :
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