Mixed coupling structure for the cross coupling of comb-line filters

摘要

A mixed coupling structure is proposed for the cross coupling of a comb-line filter. The proposed structure consists of an electric coupling probe and a magnetic coupling window, and the coupling required for the cross coupling of a cross-coupled filter can be achieved with much easier tuning capability than the structure with only an electric probe. A four-pole comb-line filter is designed and fabricated with the use of the proposed structure, and showed good filter response.