A wide tuning range 11.8 GHz ring oscillator VCO with temperature and process compensation

This paper presents a novel ring based voltage controlled oscillator (VCO) with a wide tuning range (0.6-11.8) GHz. The design implements a new technique that servos the Phase Locked Loop (PLL) control voltage to compensate for PVT variations. By adjusting the size of the VCO´s voltage controlled resistors (VCRs), the VCO achieves a wide frequency range without adversely impacting the stability or the natural frequency of the PLL. The KVCO variation is less than 3.9. The design was simulated and extracted in 90nm CMOS technology, uses a 1.2V supply, and consumes a maximum power of 22 mW.