Compact single-channel rotary joint using ridged waveguide sections for phase adjustment

A new design for single-channel waveguide rotary joints for high-power applications is presented. In order to obtain correct signal phase conditions along the ring and, at the same time, reduce the diameter of the rotary joint, tapered ridged waveguide sections are introduced. Design guidelines with respect to general transmission characteristics, H-plane aperture couplers, and ridge waveguide analysis are presented. Measurements of a 9.05-GHz prototype show less than 1-dB insertion loss over a 250-MHz bandwidth and, hence, verify the design concept.