On the available diversity gain from different dual-polarized antennas

• Published in: IEEE journal on selected areas in communications Vol. 19; no. 2; pp. 287 - 294
• Main Authors: Lindmark, B., Nilsson, M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2001; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna radiation patterns; Antennas; Apertures; Azimuth; Base stations; Correlation; Dipole antennas; Dipoles; Diversity methods; Gain; Mobile antennas; Mobile communication; Mobile communication systems; Patch antennas; Polarization; Power generation; Stations
• DOI: 10.1109/49.914506
• ISSN: 0733-8716

Dual-polarized antennas are traditionally characterized in terms of port-to-port isolation and co- and cross-polar radiation patterns. For base station antennas in a mobile communications system, the critical parameter is instead the far-field coupling between the two channels. In a mobile communication system, base station antennas with a nominal /spl plusmn/45/spl deg/ to vertical linear polarization are commonly used. Such antennas are difficult to design with constant polarization characteristics in azimuth. We calculate the antenna output power correlation and diversity gain under Rayleigh fading conditions and different values of the environment cross-polar discrimination. Two different antennas are compared: a dual-polarized aperture coupled patch and a slanted dipole configuration, both over an infinite groundplane. We show that the aperture coupled patch provides lower output correlation and higher diversity gain than the slanted dipoles in all investigated cases.