A Mixer-First Receiver with Enhanced Matching Bandwidth by Using Baseband Reactance-Canceling LNA

A mixer-first receiver (RX) with enhanced matching bandwidth (BW) is proposed. The enhanced matching BW is achieved by exploiting the input reactance (negative capacitance) exhibited in resistive feedback voltage-voltage low-noise amplifiers (LNAs), to create a second-order baseband impedance without any power or noise penalty. The technique is analyzed based on a linear time-invariant (LTI) model. An integrated 8-phase mixer-first RX prototype was fabricated in the TSMC 65-nm CMOS process as a proof of concept. The RX is capable of broadband operation and achieves wideband <-10-dB matching of 40 MHz, with 36-dB RX gain, noise figure (NF) of 2.2-4.2 dB, B1dB of 14.5 dBm, out-of-band (OOB) IIP3 of 33 dBm, and 1-dB NF degradation for 5-dBm blocker power, at a frequency range of 0.5-2 GHz.