A Dual-Core Digitally Controlled Oscillator with a Switched Capacitor

This paper proposes a digitally controlled oscillator (DCO) using novel switched capacitor units. Compared with the traditional switched capacitor unit, the new unit reduces the device stress and improves the quality factor. To further reduce phase noise, the DCO uses a dual-core structure and replaces the traditional tail-current source transistor with a resistor. The proposed DCO is designed in 2Snm process, realizes a phase noise of-110.2dBc/Hz@1MHz at 28GHz, and the frequency modulation range is 27.1GHz-29.2GHz. It consumes 25mW under 0. 9V supply voltage for a figure of merit (FOM) of l85.2dB.