A 220 GHz GaN‐based monolithic integrated frequency doubler delivering over 0.25 W output power

Abstract A 220 GHz GaN‐based monolithic integrated frequency doubler with high continuous‐wave output power has been developed. The doubler achieves improved heat dissipation by establishing the terahertz (THz) monolithic integrated circuit topology with GaN Schottky barrier diodes integrated on a high thermal conductivity SiC substrate. It features six anodes to enhance the power‐handling capabilities. A refractory Schottky metal stack is adopted for better thermal stability. The doubler realizes satisfactory performance by introducing the suspended microstrip and an all‐in‐one output structure. For verification, a prototype of the proposed frequency doubler was fabricated and tested. Measured results show that the proposed doubler produces a continuous‐wave output power of 255 mW at 220 GHz with an efficiency of 14.6%, exhibiting excellent potential for powerful THz sources.