A Dual Band, Wide Tuning Range CMOS Voltage Controlled Oscillator for Multi-Band Radio

A novel multi-band VCO is presented, using a double-tuned, current-driven transformer load The dual frequency range oscillator (low band and high band), is based on the ON/OFF switching of current in the secondary port of the transformer. The concept is validated through measurement results from a fabricated prototype in 0.25 mum CMOS technology. The VCO has a measured tuning range of 1.94 to 2.55 GHz for the low-frequency band and 3.6 to 4.77 GHz for the high-frequency band. It draws a current of 1.0 mA from 1.8V supply with a measured phase noise of -116 dBc/Hz at 1 MHz offset from 2.55 GHz carrier. For the high frequency band, it draws 7.5 mA from the same supply with a phase noise of -106 dBc/Hz at 1 MHz offset from 4. 77 GHz carrier.