Compact low loss millimeter wave 8-way radial waveguide power combiner

A compact low loss millimeter wave eight-way waveguide power combiner is proposed in this paper. The 8-way power combiner is designed based on a central radial waveguide surrounded by eight input rectangular waveguides. A output rectangular waveguide is connected with the radial waveguide by using coaxial probe. The overall size of the radial waveguide power combiner is about 5δ₀ × 5δ₀ × 0.5δ₀ (δ₀ is the operating wavelength). Within the operating band from 27.5 GHz to 31 GHz, the return loss for both input- and output-ports are lower than -10 dB, and the combining loss is less than 0.25 dB. The introduced eight-way power combiner has the merits of compact size, simple design, and low loss and is suitable for efficient power combining to achieve a high-power solid-state amplifier system.