Patent ID: 6229483
Filing Date: 2001-05-08
Classification: H01Q

Abstract:
A method of calibration at a group antenna system (11), said group antenna system comprising at least two transmitters (T1, . . . , TN), in which each transmitter comprises control means (91-1, . . . ,91-N; 93-1, . . . ,93-N) for controlling a complex amplification of each transmitter, and said group antenna system furthermore comprising at least two radiation elements (X1, . . . XN), the method comprising the steps of:a) supplying an input signal to the transmitters (T1, . . . ,TN); andb) transmitting output signals from the transmitters (T1, . . . ,TN), characterized in the steps of:c) transferring the output signals to the radiation elements (X1, . . . ,XN);d) generating control signals to the control means (91-1, . . . ,91-N; 93-1, . . . ,93-N) of the transmitters (T1, . . . ,TN) in dependence on time varying requested complex an amplifications and error signals associated with the transmitters, wherein the time varying requested complex amplifications correspond to a time varying antenna diagram for transmission, and the error signals indicate complex errors of the transmitters;e) generating a sum signal corresponding to a sum of the output signals while generating the control signals to the control means in accordance with step e); andf) generating the error signals in dependence on the input signal, the sum signal and the time varying requested complex amplifications.