LAUSR

This letter presents a 300-GHz varactor doubler suitable for ultrahigh-speed wireless communications. The doubler employs balance configuration to enhance the second harmonic efficiently. The proposed varactor doubler realized in TSMC 40-nm CMOS can be integrated with other CMOS components to generate millimeter-wave signals at 300-GHz frequency band. At the pumping frequency of 150 GHz and input power of 10 dBm, the doubler results in an output power of −4.6 dBm at 300 GHz. The doubler consumes no dc power while it occupies a chip area of $0.53~\text {mm}^{2}$ including probe pads.