Low power, high linearity multi-mode downconversion mixer for SDR

A low-power, high linearity and wideband passive mixer for SDR is presented The passive mixer employs the improved current-reuse Gm stage, combines source degeneration with MGTR to extend the linearity region while enhance the IIP 3 performance Measured results show the design achieves a good linearity even though the power of input RF signal is up to -14dBm (V pp is about 160mV, consider the balun's voltage gain and insert loss). The passive mixer achieves 10.7-13.8 dBm IIP 3 , IIP2 > 44dB, and 13.7dB NF under 13dB Max conversion gain at 900MHz. Implemented in 65nm CMOS process, the mixer core die area is 0.2mm 2 , and consumes 6.7mA from a 1.2V supply.