This paper describes a J-band (15 GHz) transceiver MMIC with image rejection that has been designed for RADAR T/R module applications. The MMIC consists of a switched attenuator, an LNA, a Transmit/Receive switch, an image rejection mixer and a local oscillator buffer amplifier. The size of the MMIC is 6.48 mm by 4.47 mm. In receive mode the MMIC has a conversion gain in excess of 10 dB with less than 1 dB of ripple and noise figure less than 4 dB across a 10 GHz to 16.5 GHz band. The Input P1dB is –13 dBm. In transmit mode the conversion gain is –12 dB with an input P1dB of +15 dBm. The Transceiver MMIC was fabricated using the GMMT, 0.25 m m, H40 pHEMT process. This is believed to be the first integrated transceiver MMIC designed specifically for this frequency band.