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 mu m 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 mm(2). 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 mu W from 1 V voltage supply with an active area of 0.173 mm(2).