A Self Oscillating Current-Reuse Image Reject Mixer for Ultra Low Power Receivers

This paper presents the analysis and design of an NB-IoT compliant Current-reuse self-oscillating quadrature downconversion mixer (CR-SOM). A modified Hartley Image Reject (IR) Receiver front end employing high-side LO injection is discussed. The SOM is designed and laid out in 65nm CMOS technology and oscillates at 2.8GHz while consuming 1.8mW. Post-layout results indicate a conversion gain of -14.3dB, noise figure of 11.6dB and phase noise of -85.4dBc/Hz at a 200kHz offset from the carrier. The quadrature output amplitude and phase errors fall under 0.02dB and 0.1°, respectively and the entire circuit occupies an area of 0.09mm2.