A Switched-Capacitor RF Receiver Exploiting MOS Parametric Amplification to Reduce NF
Switched-capacitor (SC) radio frequency (RF) receivers based on N-path sampling mixers are near ideal software-defined radios with some of the most desirable properties like clock-tunable high-Q bandpass filtering upfront, high linearity, and high blocker tolerance. This paper presents a gain-embedding technique to reduce the noise figure (NF) in switched-capacitor RF receivers. The proposed technique is based on a MOS capacitor based parametric amplifier. Measurement results of a prototype SC receiver in CMOS 180 nm technology are presented. The receiver is tunable from 0.2-to-0.95 GHz. The receiver has a conversion gain of 41 dB and a noise figure of 3.1 dB at 800 MHz. Measurement results show > 10 dB reduction in NF with the embedded parametric gain.