Colpitts-based Folded Self-oscillating Mixer

This paper proposes a low-power single-stage single-balanced radio frequency (RF) front-end receiver in which a high performance Colpitts based self-oscillating mixer (SOM) is folded at the output of a cascode low-noise amplifier (LNA). Since the cascode LNA is used in the front-end, the proposed SOM has good reverse isolation from the oscillator output to the RF input. Using a 65 nm CMOS technology, the proposed SOM is optimized for the best phase noise performance. Targeted for WLAN frequency band application, the proposed SOM oscillates at around 2.4 GHz and achieves the phase noise of -77 dBc/Hz, -100 dBc/Hz, and -120 dBc/Hz at 10 kHz, 100 kHz, and 1 MHz offset frequency, respectively. The simulated voltage conversion gain is about 44 dB. The double side-band (DSB) noise figure (NF) is about 6.8 dB at 1 MHz intermediate frequency (IF). The SOM cell consumes 755 μW de power from a 1-V supply.