A W-Band Power Combined Amplifier Based on the Waveguide Coupler With Spoof Surface Plasmon Polaritons

In this letter, a W-band power combiner is proposed by exploiting the 3-dB branching waveguide directional couplers and GaN power amplifiers. In the framework, a novel waveguide coupler is realized through an integrated load based on the spoof surface plasmon polaritons (SSPPs), which can effectively realize the absorption of the reflected electromagnetic wave and ensure the high isolation of the output ports. For application and verification, the electromagnetic energy divided by the directional coupler is linked to the grounded coplanar waveguide (GCPW) utilizing waveguide E-plane probes, and the quasi-TEM modes of the wave are attached to the power amplification monoliths using gold wire for energy amplification. Lastly, the two enhanced electromagnetic energy signals are combined by the directional coupler to generate a high-power output electromagnetic wave signal. Experimental results demonstrate that, in the frequency range of 85–100 GHz, the power combiner achieves a maximum output power of approximately 3 W and an average combining efficiency of 84.5%. The proposed prototype possesses the merits of high-temperature tolerance and low-implementation difficulty, which may facilitate further advancements in solid-state devices.