A Terahertz GaN solid-state power amplifier on radial combining technique

Terahertz (THz) bands are considered to have various anticipated applications. Output power is an important factor determining the operating distance of THz systems, but it is very challenging to achieve high output power under current solid-state terahertz circuit technology. The paper first presents a four-way G-band radial combiner, which features high passive efficiency of 88% and compact size. Moreover, based on this radial combiner and in-house fabricated gallium nitride chips, a solid-state power amplifier prototype is further demonstrated. Measured results show that, the average saturated output power is 21.7 dBm across the 180-240 GHz band with a typical output power of 23.2 dBm at 189 GHz.