A C-band monolithic silicon-bipolar low-power low-IF WLAN receiver

This paper presents the design, implementation and measurements of a monolithic low-IF receiver compliant with the main 5 GHz WLAN standards. It consists of a low-noise preamplifier, that is simultaneously noise and power matched to the RF source, two matched active single-balanced mixers and two polyphase filters used to generate LO quadrature signals and provide image rejection. Realized in a 47 GHz-ft commercial BiCMOS technology, the circuit exhibits 25 dB of conversion gain, 35 dB of IRR, 8.9 dB of NF, -12.5 dBm and -19 dBm of iIP3 and P1 dB respectively. To the knowledge of the authors this is the first monolithic implementation of a low-IF C-band receiver achieving sufficient IRR over the three U-NII bands. Power consumption is 19 mW.