Adaptive base-station antenna arrays

Adaptive antenna systems represent an area in which considerable development efforts and field trials are being conducted to increase capacity in mobile communication networks. Ericsson has developed array antennas for use in the 900, 1800 and 1900 MHz frequency bands. Thanks to microstrip patch elements, Butler matrices, and several dual-polarized beams, these antennas yield high antenna gain and excellent spatial efficiency. The authors describe adaptive antenna hardware and configurations as well as measured results from work on adaptive base-station antennas.