A Voltage Controlled Oscillator with Tuning Gain Linearization and Automatic Frequency Calibration
Mingzhi Yan, Xinlin Xia, Xiao Lei Han, Lingqi Min, Yanjie Wang · 2025
A voltage-controlled oscillator (VCO) with automatic frequency calibration (AFC) and a linearized tuning gain (Kvco) for the phase noise optimization of the phase-locked loop (PLL) frequency synthesizer is presented in this paper. The proposed AFC module possesses a recalibration function to eliminate the impact of supply voltage and temperature (VT) variations on the PLL spurs. Designed in 40-nm CMOS LP process, the post-layout simulation results show that VCO achieves a frequency tuning range of$4. 51\sim 5.39$GHz (17.58%), with the variation of the Kvco less than 9.01% across$0.2 \sim 0.9 ~\mathrm{V}$tuning range in each single frequency band. At 4.8 GHz, the phase noise is -124.6 dBc/Hz@lMHz, and the figure of merit (FoM) is 186.6 dBc/Hz@1MHz. The power consumption is less than 16 mW under 1.1 V supply voltage. With an 80 MHz reference, the calibration time for the AFC ranges from 2.75 to 13.75$\mathrm{\mu}\mathrm{ s}$.