Sub‐mW cognitive CMOS frequency down‐converter for internet of things

In this study, a suitable sub-mW frequency down converter for internet of things is presented. It is based on a single balanced switched transconductance mixer driven by a current-reuse LC voltage controlled oscillator (LC-VCO). For cognitive radio demonstration, the frequency converter is implemented with a tunable low-noise amplifier (LNA) in 0.13 µm standard complementary metal oxide semiconductor (CMOS) technology. Post-layout simulations return a gain conversion of 27 dB with a single-sideband noise figure of 8 dB (LNA included) for a consumption of 0.97 mW under a voltage supply of 1.2 V and an active area of 0.4 mm2. The stand-alone LC-VCO prototype exhibits a measured phase noise of −102 dBc/Hz at 1 MHz offset while showing −114 dBc/Hz in the post-layout simulation. The LC-VCO measured power consumption is only 260 µW from 1 V voltage supply with an active area of 0.173 mm2.