A Phase Noise Minimization Of Cmos Vcos Over Wide Tuning Range And Large Pvt Variations

An automatic amplitude control circuit to minimize the phase noise of a LC-VCO is proposed and implemented by a 0.18-mu m CMOS process. The phase noise lower than -90dBc/HZ at 100kHz offset is achieved over a wide tuning range (from 2.2GHz to 2.8GHz) under large process (Delta V-th = +/- 100mV), temperature (from -350 degrees C to 85 degrees C), and power supply (from 1.8V to 3V) variations.