A 2.4/5 GHz Dual-Band VCO using a Variable Inductor and Switched Resonator

A dual-band, low phase noise, low power and small sized voltage-controlled oscillator (VCO) with a variable inductor and switched resonator is described. The dual-band VCO operated near 2.4 GHz and 5 GHz with a phase noise of -120 and -121 dBc/Hz at a 1 MHz offset and a tuning range of 250 MHz and 1.2 GHz, respectively. The power consumption was 1.5/1.8 mW for 2.4/5 GHz operations. The total size the VCO was only 1.06 mm², which was achieved by using one inductor which was connected with a switch to give good dual-band operation and performance.