A transceiver system comprising: A. a transmit chain including: a signal generator for generating a baseband transmit signal; baseband I-Q amplification subsystem for providing baseband amplification of the baseband transmit signal; a direct-conversion subsystem for converting the baseband transmit signal to an RF transmit signal, and an RF transmit signal port; B. a receive chain including: an RF receive port for receiving an RF receive signal; a direct-conversion subsystem for converting the RF receive signal to a baseband receive signal; a baseband I-Q amplification subsystem for providing amplification of the baseband receive signal; a processor for processing of the baseband receive signal as required for the normal function of the transceiver, and C. a calibration subsystem including: a calibration RF signal generator for generating a calibration RF signal as a baseband transmit signal; a signal path for injecting the calibration RF signal from the RF transmit signal port to the RF receive signal port; a processor for processing the baseband receive calibration RF signal to form an observable indicator of I-Q imbalance; and a channel gain adjuster for varying the differential I-Q gain in the transmit and receive chains independently wherein the calibration RF signal includes a calibration cycle, and the calibration cycle determines transmitter I-Q gain settings which minimize an observable indicator while holding receive I-Q gain settings constant, and which in turn determines receiver I-Q gain settings which minimizes the observable indicator while holding the transmit I-Q gain settings constant. view more

A transceiver system according to claim 7, wherein the calibration RF signal includes a sampled phasor.