RUGGED IQ RECEIVER BASED RF GAIN MEASUREMENTS

摘要

A method and apparatus for measuring a complex gain of a transmit path are disclosed. During a test mode, an IQ to radio frequency modulator modulates a quadrature RF carrier signal using a quadrature test signal. An RF to IQ down-converter down-converts a down-converter RF input signal to provide a quadrature down-converter output signal using the quadrature RF carrier signal. The down-converter RF input signal is based on the quadrature test signal and the gain of the transmit path. A digital frequency converter frequency converts the quadrature down-converter output signal, providing an averaged frequency converter output signal, which is a quadrature direct current signal representative of an amplitude of the quadrature test signal and the gain of the transmit path. Therefore, a measured gain of the transmit path is based on the amplitude of the quadrature test signal and averaged frequency converter output signal.