Patent ID: 7038633

Claim:
An active antenna system (AS), said system comprising: a plurality of antenna elements (D); an exciter/receiver unit (ERU); a plurality of transmit/receive (T/R) modules (TRM 1 –TRMk); a feed and receive transmission network (R) connecting said ERU and said plurality of T/R modules; a plurality of antenna feeds (AF) connecting said T/R modules and said plurality of antenna elements; a beamforming unit (BFU), wherein said beamforming unit (BFU) controls the phase and amplitude of signals transmitted through each T/R module to produce a desired beamform from said plurality of antenna elements; a calibration unit (CU); a calibration network coupling said calibration unit (CU) and points on said antenna feeds (AF), wherein said calibration network comprises a plurality of alternative calibration nets (C 1 , C 2 . . . Cj), and wherein each T/R module comprises a switch (SM) for switching between alternative antenna feeds (A/F) and thereby between alternative calibration nets.