Low-power and high-linearity CMOS parametric passive mixers for millimeter wave applications

A low-power CMOS mmWave passive mixer based on a novel LO shaping technique using non-linear transmission line (NLTL) is proposed. The mixer employs a non-return-to-zero (NRZ) capacitive loaded sampling structure. The LO signal is reshaped by an NLTL before it is applied to the mixer, which alleviates the tradeoff between the mixer gain and linearity and decreases the noise figure (NF). The NLTL is constructed using series inductors and shunt varactors. It boosts the LO swing and re-shapes the LO pulses to have higher amplitude, narrower pulses, and sharper edges, resulting in higher gain, better linearity, and lower noise figure. Two mixers, one operated at 60GHz and the other at 120GHz, are designed using 65nm CMOS process. The simulation results show single-sideband NF of 5.9dB and 6.8dB, IP1dB of 0.9dBm and 1.4dBm, and a power gain of 1.2dB and 1dB, for the 60GHz and 120GHz mixers, respectively. Both mixers require a 0dBm LO input level and do not consume DC power.