Voltage Controlled Oscillator with Impedance Spectroscopy for Non-invasive Glucose Application

A new three-phase voltage controlled oscillator (VCO) implemented in TSMC 0.18 μm 1P6M CMOS process. The designed VCO consists of three single-ended current-reused VCOs coupled via a back gate coupling to reduce the power consumption for impedance spectroscopy sensor. Tuning range of VCO is 0.689 GHz, from 4.45 GHz to 5.14 GHz, while the control voltage was tuned from 0V to 1.8V and the VCO core power consumption is 4mW at the supply voltage of 1 V. The measured phase noise is -128.08 dBc/Hz at 1MHz offset frequency from 4.46 GHz. The VCO occupies a chip area of 1.000×0.772mm
²
and provides a figure of merit of -195.05 dBc/Hz setup in non-invasive glucose application.