A wireless communication unit is described that includes a transceiver; at least one antenna port operably coupled to the transceiver via at least one antenna switch; a radio frequency part of the transceiver that includes at least one tuneable radio frequency (RF) component; and a test signal generator for generating an RF test signal for receiver calibration. The radio frequency part includes a coupler located between the at least one tuneable RF component and the at least one antenna switch for coupling the RF test signal to or from the radio frequency part for calibration.