A low-power wide-band 20GHz VCO in 65nm CMOS

A 20GHz (centralized at 18.7GHz) voltage controlled oscillator (VCO) is implemented in standard 65nm CMOS technology. In the design process, several design optimizations including tail current source, cross-couples dimension and inductor selection, are done to achieve a good performance without additional area requirement. Through these techniques, the measured phase noise of -98dBc/Hz@1MHz achieved at 19.97 GHz and the figure of merit (FOM) is -176dBc/Hz. With the help of digital controlled switch array, tuning range is about 15%, from 17.36 to 20.15 GHz without much performance degradation. The total current is 4.6mA under the 1.3V supply voltage, including the buffer current consumption of 0.9mA. To our best knowledge, this is the minimum current consumption for VCO in this frequency band. The area of the core circuit is only 0.35 × 0.25mm².