A low-phase-noise ring oscillator with coarse and fine tuning in a standard CMOS process
粗调和细调相结合的标准CMOS低噪声环形压控振荡器

A low phase noise wideband ring oscillator with coarse and fine tuning techniques implemented in standard 65nm CMOS process is presented. Direct frequency modulation in the ring oscillator is analyzed and switched capacitor array is introduced for lower VCO-gain to suppress this effect. Two-dimensional stacked MOM-capacitor with high density was adopted as switched capacitor to make the proposed ring VCO compatible with standard CMOS process. The designed ring VCO exhibits output frequency from 480MHz to 1100MHz, resulting a tuning range of 78%, and the measured phase noise is -120dBc/Hz@1MHz at 495MHz output. The VCO core consumes 3.84mW under 1.2V supply voltage, the corresponding FOM is -169dBc/Hz.