On the real-time calibration of a six-port receiver (SPR) by averaging the received QPSK signals

In this paper, a new approach to the real-time calibration of a six-port receiver (SPR) by averaging the received QPSK signals is proposed. At first, the S-parameters/Qi points of the six-port are calculated from the average of the outputs of the six-port power detectors, and then calibration parameters of the six-port receiver are computed. Simulations on SPW verified this proposed approach. Error analysis with nonideal QPSK standard signals used in the calibration procedure is also performed. This proposed method of calibration has a clear physical meaning, and gives accurate calibration coefficients, even for very poor-quality six-port junctions.