Compact waveguide twist design fitting with interfacing waveguide cross sections

A novel twist solution is introduced providing high performance matching of two waveguides interfaces with an angular offset. It is based on a central angular step for the complete offset rotation in combination with double ridge waveguide transformer sections towards the waveguide interfaces¹. The transformer waveguide cross sections are directly fitting with the interface waveguides which accommodates with easy and low cost manufacturing in one piece by standard CNC milling techniques. It also facilitates integration and assembly issues within overall waveguide systems. It is shown that this approach provides high performance properties over more than 40% bandwidth for angular offsets up to 70 degree. A twist design at 28GHz has been realized to demonstrate the feasibility of the concept. To accommodate with the specific matching of two waveguides with perpendicular alignment, the approach has to be altered, i.e., the ridges of the transformer sections have to be considered with an appropriate offset from the center locations.