A 60 GHz CMOS VCO Using a Fourth-Order Resonator

In this letter, a 60 GHz voltage-controlled oscillator (VCO) implemented in the 90 nm CMOS process is presented. By using a fourth-order LC resonator, the proposed VCO oscillates at its second pole frequency to achieve high speed operation with fully differential output phases and a wide tuning range with a larger size of varactors. The measured oscillation frequencies of the proposed VCO are from 58.76 to 63.94 GHz corresponding to an 8.44% tuning range. The measured phase noise is -91.53 dBc/Hz at 1 MHz frequency offset for the highest output frequency. The core circuit consumes 7.2 mW power from a 1.2 V dc supply.