An LC-type voltage-controlled oscillator (VCO) and a push-push frequency doubler are presented for 20/40-GHz dual-band design in standard 0.13-μm CMOS. Combining the varactor with the transconductance-tuned regime, the VCO is realized to arrive at the range extension for high-frequency operation. In addition, a technique using sensitivity distribution is adopted to achieve linear tuning range. The VCO provides the tuning range of 19.8-22.6 GHz, and the measured phase noise at 21.2-GHz frequency is -105.7 dBc/Hz at a 1-MHz offset. The doubler following the VCO can provide twice the frequency over the tuning range and generate output with better fundamental rejection resulting from the notch characteristic. The measured phase noise of the doubler at 42.4-GHz frequency is -94.6 dBc/Hz at a 1-MHz offset while dissipating 8 mW in the whole circuit.