Ultra-low-power wideband NMOS LC-VCO design for autonomous connected objects

In this paper, a fully integrated sub threshold LC voltage controlled oscillator (VCO) is presented. A design methodology is also proposed to find the optimal parameters lowering the power consumption. This methodology has been applied to design oscillators for different frequency bands. Furthermore, an adaptive body biasing technique has been used to improve the startup constrains and allows a high immunity to PVT (process, voltage and temperature) variations . A VCO operating in 5 GHz ISM (Industrial, Scientific and Medical) band has been realized with the proposed methodology in 0.13 μm CMOS. It consumes only 468 μW from 0.39 V supply voltage. This makes it possible to meet the required specifications of autonomous connected objects and IoT applications. The measured oscillation frequency can be tuned from 5.14 to 5.44 GHz. The obtained phase noise is approximately equal to − 112 dBc/Hz in post-layout simulation (PLS) and − 104.5 dBc/Hz in measure.