A wide tuning 1.3 GHz LC VCO with fast settling noise filtering voltage regulator in 0.18 µm CMOS process

This paper presents a wide tuning LC voltage controlled oscillator (VCO) with integrated voltage regulator to minimize supply pushing. The integrated voltage regulator utilizes on-chip low-corner frequency noise filters to minimize the impact of regulator noise on VCO phase noise. One shot circuit is used with low-corner frequency noise filter to ensure fast settling. The VCO achieves current consumption of 15.9 mA with single integrated low-Q LC tank, tuning range of 620.8 MHz to 1384.5 MHz, phase noise of −128 dBc/Hz at 1 MHz offset from 1.3 GHz carrier at room temperature. With the noise filter, 9 dB improvement in phase noise is demonstrated in measurement. The frequency range can be extended to 38.8 MHz – 1384.5 MHz with integrated frequency dividers.