A 4.6GHz PLL with automatic frequency calibration based on multiple-pass ring oscillator

In English A good-performance high-frequency Phase Locked
Loop using a ring oscillator is described. A Voltag e Controlled
Oscillator with automatic calibration of frequency fluctuated by
proce ss and tempe rature variations is propo sed. The VCO
adopts new multiple-pass loop to improve frequency with
unchangeable stages (phases). The circuit is implemented with
TSMC O. I8um standard CMOS technology and power supply is
1.8V. Cadence and Matlab tools are both used to present
credible transistor and behavior simulation results .