High-Efficiency GaN/SiC Doubler Terahertz Monolithic Integrated Circuit at 175 GHz

A high-power, high-efficiency, 175 GHz frequency doubler terahertz monolithic integrated circuit (TMIC) in continuous wave (CW) mode has been fabricated using planar gallium nitride (GaN) Schottky barrier diodes (SBDs) on a SiC substrate. Heat dissipation is improved by adopting a high thermal conductivity SiC substrate. At room temperature, the GaN doubler has an output power exceeding 110 mW at 164 GHz to 181 GHz with an efficiency of 11 % to 20.6 % in CW mode. A 242 mW maximum output power with 20.2 % efficiency is obtained at 175 GHz. The results imply that a GaN-based monolithic integrated frequency doubler provides a viable means of obtaining high output power and high efficiency in CW mode.