A 4-GHz LC-Based Voltage Controlled Oscillator & Frequency Divider for use in Neutrino Experiments

Inhalt:
A low power, low phase noise and wide tuning range 4GHz LC-based voltage controlled oscillator (VCO) to be used in a phase locked loop for neutrino experiments is presented. The design process should consider the limitations on the maximum tolerable jitter of the clock that is generated in the PLL. The presented structure consists of VCO block followed by two frequency dividers. To achieve a linear characteristic over a wide frequency range, the VCO uses NMOS varactors to control the frequency. The circuit is fabricated in a TSMC 65nm CMOS technology. The power consumption from 1.2V power supply excluding 50Omega buffer stage equals to 6.9mW. Measurement results provide -94dBc/Hz phase noise at 1MHz offset frequency from 1GHz carrier frequency. The circuit features a tuning range of 360MHz at the output of dividers for a control voltage range from 0 to 0.8V.