Simplified analysis for the initial design of rectangular waveguide cross-slot couplers

For the purpose of providing initial designs of waveguide cross-slot couplers, the authors present a simplified analysis of cross-slot coupling through the common broad wall of two rectangular waveguides. Straightforwardly implementable equations are presented which not only include a wide range of cross-slot dimensions but also the location as well as the rotation of the cross-slot in a coupler environment. Moreover, asymmetric coupler structures can be easily incorporated. Analyses of individual structures are verified by HFSS. Two examples of cross-slot waveguide couplers demonstrate the applicability of this technique for the initial design of waveguide cross-slot couplers.