Design of a 340 GHz GaN-Based Frequency Doubler with High Output Power

This paper presents a high-power 340 GHz frequency doubler based on GaN Schottky barrier diode (SBD) technology. The proposed frequency doubler consists of a pair of GaN SBDs chips, a quartz circuit, as well as the transition waveguides. To improve the power handling capabilities, a pair of GaN SBDs chips with six anodes in total is flip-chip mounted on the quartz circuit. The suspended microstrip line is employed in the circuit on quartz due to its low-attenuation characteristics at terahertz frequencies. To enhance the electrical performance of frequency doubler, low-loss transition structures are designed. The proposed frequency doubler shows a simulated output power of 300 mW with a conversion efficiency of 20% at 340 GHz.