A Low-Power Class-C Voltage-Controlled Oscillator With Robust Start-Up and Compact High-Q Capacitor Array

This brief presents a class-C voltage-controlled oscillator (VCO) that ensures a robust start-up with low phase noise and high power efficiency. The proposed start-up scheme, which uses a voltage converter that operates according to the output state, relieves the start-up difficulty by supplying a time-varying bias voltage to the core transistors and allows the VCO to operate in an optimal state. ...