Design of Gysel power combiners in E-plane rectangular waveguides

The design of 5-port power combiners using the Gysel-type architecture in full E-plane rectangular waveguide is presented. It exploits the high power handling capabilities of empty metallic waveguides and the achievable bandwidth of operation that Gysel combiners provide when compared to traditional combiners. The proposed new design takes into account the different requirements on the power handling capability of the terminating loads and their waveguide ports. This leads to having different port heights at the isolated ports, based on the need to handle certain power levels in the isolated ports in cases of phase and amplitude imbalance between inputs. The new realization is proposed in full E-plane rectangular waveguide topology for compactness, ease of fabrication, efficient full-wave analysis, and tailored power handling capabilities. A proof of concept Gysel combiner at X-band was designed, fabricated and tested, demonstrating excellent test results without any tuning: a combining loss of better than 0.5 dB over a 25% fractional bandwidth with a very compact volume of 1.2 lambda(0) x 1.7 lambda(0) x 1.9 lambda(0).