A 1V Wide Tuning Range VCO for UHF DTV Tuner

This paper presents a low power wide tuning range 0.18 mum CMOS voltage-controlled oscillator. The VCO is oscillating at 1.5 times of the LO frequency to reduce the size of tank inductor. Capacitor bank switching is adopted to increase the VCO tuning range. To ensure oscillation at low frequency band, the bias current is adjusted automatically with respect to oscillation frequency. The frequency coverage of the CMOS VCO is from 675 MHz to 1275 MHz, and the tuning range is 62%. The operation supply voltage and power consumption of the VCO are 1V and 5 mW, respectively. The measured phase noise is - 98 dBc/Hz at 100 kHz offset.