PHASED ARRAY ANTENNA SYSTEM WITH MULTIPLE BEAMS

摘要

A phased array antenna system with multiple beams incorporates a CDMA base station (32) with multiple ports 34₁ to 36_N for positive and negative polarisation signals connected to ports 40₁ to 42_N of an antenna assembly (44). The antenna assembly (44) is single stack and multi-port, and it provides multiple antenna beams with polarisation diversity and different vertical angles of electrical tilt which are fixed or variable. It is suitable for 3G mobile radio using CDMA. Different antenna beams may carry groups of data channels distinguished either by different channelisation process coding or by different scrambling process coding. An operator may use two or more beams simultaneously. Control of angle of electrical tilt of antenna beams may be implemented by introducing variable relative delay between signals associated with different antenna ports A(+) and B(+) and feeding them to a signal splitting and combining network providing antenna element signals.