A 3.7-6.5GHz 8-Phase N-Path Mixer-First Receiver with LO Overlap Suppression Achieving <5dB NF and >5dBm OOB B1dB

This paper presents an 8-phase N-path mixer-first receiver in 45nm SOI operating from 3.7-6.5GHz. The receiver implements an LO overlap suppression technique to relax the LO duty-cycle requirement for such mixers, allowing 8-phase 25% duty-cycle LO to realize 8-phase operation at higher frequencies. The prototype receiver achieves a noise figure of 2.4-4.7dB while consuming 89-135mW. The out-of-band (OOB) blocker 1dB compression point (B1dB) is >5dBm and OOB IIP3 is >+28dBm. The receiver allows 22-43dB third-order harmonic rejection (HR3) without any calibration, and up to 72dB HR3 with proper recombination weighting in DSP.