A New Passive CMOS Mixer With LO Shaping Technique for mmWave Applications

A mmWave (mmW) passive mixer topology based on a novel LO waveform-shaping technique using non-linear transmission line (NLTL) is proposed. The NLTL is constructed using series inductors and shunt varactors. It boosts the LO signal swing and reshapes the LO waveform to have higher amplitude and narrower pulses, resulting in higher gain, better linearity, and lower Noise Figure (NF) of the mixer. Mixers operating at 60 GHz are designed and implemented using 65 nm CMOS process. Simulation results show the mixer with the proposed technique obtains an NF of 5.5 dB, an input-referred P
_{1 dB}
(IP
_{1 dB}
) of 0 dBm, and a voltage conversion gain of 1.2 dB with 0 dBm LO signal and zero dc power consumption. Silicon measurement results show that the proposed LO shaping technique improves the conversion gain by 2.5 dB and the IP
₁
dB by 3 dB.