This paper presents an 11-15 GHz MMIC multifunction chip (MFC) with phase and amplitude control. The chip is based on the commonleg structure and comprises a phase shifter (PS), attenuator (ATT), T/R switch, gain compensation amplifiers (AMPs), driver stage AMPs and parallel control circuits. In the 11-15 GHz bandwidth, measurements show that the gain and saturation power (Psat) are higher than 21.5 dB and 26.5 dBm, while the efficiency is more than 30% in TX mode. In RX mode, the small signal gain is more than 10.2 dB, the NF is less than 9.8 dB, and output 1 dB power (OP1dB) is more than 8.5 dBm. The measured minimum RMS phase and amplitude errors are 1.7°and 0.45 dB, respectively.