W-band monolithic frequency doubler using vertical GaAs varactor diode with n/sup +/ buried layer

A W-band monolithic frequency doubler was designed and fabricated using a vertical GaAs varactor diode that has an n + buried layer and uses a mesa isolation process. An output power of 30 mW was obtained from this chip at 93 GHz with a conversion efficiency of 12%. This is believed to be the first reported W-band monolithic varactor diode frequency doubler