Design of Riblet-type couplers for Ka band applications

The full-wave modeling and design of short-slot Riblet waveguide couplers are addressed in this contribution. These types of directional couplers are commonly used by their compact size in comparison with other waveguide configurations. The main features of the Riblet coupler are discussed and its modeling with different input/output excitations is described. Two different designs are shown, with either rectangular waveguide input/output ports or coaxial interfaces. The expected simulated results of two manufactured prototypes operating at 19 GHz are compared with their experimental measurements.