Monolithic integrated GaN-based 120 GHz frequency doubler on sapphire

Abstract

In this work, a novel monolithic integrated frequency doubler in D-band was designed and fabricated on sapphire substrate. A 120 GHz solid-state source gallium nitride (GaN) planar Schottky barrier diode (SBD) chain integrating with microstrip circuitry was achieved and analyzed. The continuous mode output power of the prototype device reaches 35.6 mW at 120 GHz with an efficiency of 8.9%. The characteristics of GaN SBDs and monolithic integrated heat dissipation are discussed and analyzed. Our results announce the success of exploring a novel avenue toward frequency multipliers in GaN materials solid-state sources, which greatly simplifies the assembly, and improves assembly accuracy and the scale of integration possible for terahertz applications.