A study of calibration method for six-port direct conversion receivers including nonlinear circuits

摘要

A six-port receiver can restore the original modulated signal by calculating the detected power and system parameters of the six-port circuit. The system parameters were determined at each frequency in advance. The six-port receiver has an advantage in the point that the user can select the frequency arbitrarily, but there is a problem of nonlinear distortion because we use diode detectors for power detection. We proposed a novel compensation method for distortion of multi-port nonlinear circuit. We performed computer simulation and experiment at frequency 1.9, 2.45, and 5.85GHz, also we evaluate the accuracy by constellation pattern and EVM (Error Vector Magnitude) value.