High-frequency multiplier based on GaN planar Schottky barrier diodes

In this letter, we report GaN planar Schottky barrier diodes (SBDs) with the DC and RF performance. The air-bridge structure is adopted to reduce the parasitic parameters. The cut-off frequency (f
_c
) of the diode with an anode diameter of 5 μm is calculated to be 655 GHz at zero bias. By using four anodes series GaN SBDs chip, a frequency tripler with a peak output power of 2.1 mW at 103.5 GHz is demonstrated for the first time.