A 1.8 GHz–2.4 GHz SAW-Less Reconfigurable Receiver Frontend RFIC in 65nm CMOS RF SOI

Abstract

This paper presents a tunable single-ended two-port switched-RC 8-path filter followed by a low-noise amplifier (LNA). The 8-path filter is driven by a novel on-chip tunable 8-phase LC oscillator. The integrated multi-phase oscillator is tunable from 1.8 GHz–2.4 GHz; enabling the tuning of the center frequency of the 8-path filter and consequently the receiver frontend. The architecture of the receiver frontend is of filter-first type, where the 8-path filter precedes the LNA; similar to the current state-of-the-art RF frontend circuits in mobile wireless devices, where the SAW/BAW filter precedes the LNA. The circuit exhibits an end-to-end power gain (S21) of 12.2 dB, and an out-of-band rejection of 23 dB at 80 MHz from the center frequency while maintaining better than −15dB of in-band S11 and S22. In-band and out-of-band IIP3 of −3.4dBm and +13.4dBm, respectively, are measured. Power consumption is 31.6mW for the 8-path filter+LNA while it is 64.4mW when the 8-phase oscillator is included. The circuit is fabricated in a 65nm CMOS RF SOI process, and occupies an active area of 0.59mm2 for the n-path filter+LNA and 5mm2 when the 8-phase oscillator is included.