Design of a wide tuning range VCO using an active inductor

This paper presents a wide tuning range CMOS voltage controlled oscillator suitable for radio frequency operation. The major advantage of this structure is the absence of on-chip inductor, thus reducing significantly the chip area. Measurements results using a 0.35 mum CMOS process from AMS have shown a wide tuning range of 84% of the 915 MHz central frequency and a phase noise around -90 dBc/Hz at 500 kHz offset from the carrier. The power consumption is reduced to less than 10 mW from a 3.3 V supply.