A Millimeter-Wave Mixer-First Receiver With LO Waveform Shaping Using Varactors

A mixer-first receiver is proposed, which uses an overlap-suppressed local oscillator (LO) signal for the mixer switching. A sinusoidal LO wave can be shaped into a sharper waveform by adding a second-harmonic component to the fundamental one. This is readily achieved by integrating accumulation MOS varactors with LO buffers. The receiver is implemented in a 28-nm bulk CMOS and achieves an input 1-dB gain compression power in the range of −12.6 to −14.3 dBm and a noise figure (NF) in the range of 8.4–9.6 dB at frequencies of 24–29 GHz while consuming 12.6-mW power.