An RF-to-BB-Current-Reuse Wideband Receiver With Parallel N-Path Active/Passive Mixers and a Single-MOS Pole-Zero LPF

Abstract

N-path passive-mixer- first receivers suffer from a tight tradeoff between noise figure (NF), line arity and power due to no RF gain. This paper describes an extensively-current-reuse wideband receiver exploiting parallel N-path active/passive mixers. The key features are: 1) a stacked RF -to-BB front-end with an 8-path active mixer realizing RF ampli fication, har- monic-recombination (HR) downconversion and BB filtering in the current domain for better linearity a nd power ef ficiency; 2) a feedforward 8-path passive mixer enabling LO-de fined input impedance matching without exte rnal components, while offering frequency-translated bandpass filtering and noise cancelling; 3) a single-MOS pole-zero low-pass filter (LPF) permitting both RF and BB filtering at low voltage headroom consumption, while easing the tradeoff between the in-/out-of-band linearity, and 4) a BB-only two-stage HR amplifier boosting the third and fifth harmonic rejec- tion ratios (HRR 3,5) with low hardware intricacy. Measurements over the TV bands (0.15 to 0. 85 GHz) manifest favorable NF (4.6 0.9 dB) and out-of-band IIP2/IIP3 (+61/+17.4 dBm) at small power (10.6 to 16.2 mW) and area (0.55 mm 2). The HRR 2-6 are > 51 dB without any calibra tion or tuning. The ultimate out-of-band P–1dB is > +2.5 dBm. The BB stopband rejection is > 86 dB at 150 MHz offset.