Mats H. Andersson

Antennas with Fast Beam Steering for High Spectral Efficiency in Broadband Cellular Systems

New mobile broadband high bit rate services will require significantly better spectral efficiency than traditional mobile voice and low bit rate services to reach a mass market. Radio base station antennas with fast beam steering in elevation and/or azimuth can significantly improve the carrier to interference ratio and hence the spectral efficiency. The carrier to interference ratio improvement of using fast beam steering in elevation is estimated using a two cell model. Electrically steerable base station antennas suitable for fast beam steering have been designed and built. The antennas are travelling wave microstrip patch arrays with varactor diode based phase shifters between the elements. The phase shifters are chosen to have very fast response time to allow beam steering on a per time slot basis