US Patent 8674874 Method and device for calibrating an array antenna

A method for calibrating an array antenna having a plurality of branches includes generating a test signal using a pseudo-random sequence assigned to one of the plurality of branches for each of the plurality of branches; adding the test signals to a useful signal of the antenna so as to form a summed signal emitted via the array antenna; receiving the summed signal with a receiver antenna; correlating the received summed signal with a replica of the pseudo-random sequence so as to produce a correlation result; estimating a characteristic of one of the plurality of branches by processing the correlation result; and calibrating the antenna based on the estimated characteristic.