A subthreshold down converter optimized for super-low-power applications in MICS Band

This paper presents a super low power MICS band receiver front-end down converter on 65 nm CMOS for Bionic Eye or other implantable biomedical devices. This down converter, including a low-noise amplifier (LNA) and a quadratrue mixer, consumes a mere 500-μA DC current under 1-V supply. With a small differential local oscillation (LO) swing of 300 mV, it provides a voltage conversion gain of 34 dB with a noise figure of 7 dB, while a -27.5-dBm IIP3 is obtained. In order to achieve super low power, current-reuse structure is adopted and all transistors are operated in subthreshold region. A noise figure optimization technique is developed for optimal on-chip power matching for the subthreshold cascode LNA. Circuits level issues and techniques are also discussed.