Additively Fabricated 90° Waveguide Twist Integrated with Printed Circuit Board

The paper presents an implementation of a 90-deg twist for polarization rotation in a PCB-integrated air-filled waveguide. A recently developed stack-up that combines on-PCB microstrip line with additively fabricated waveguide by sharing the same ground plane on PCB for high integrated electronics applications is explored. The twist construction that maintains a constant-plane orientation of one of the walls with on-PCB metal is adopted. The concept was experimentally verified by fabrication and measurements of an exemplary twist in WR-42 waveguide geometry centered at f0 = 10.5 GHz. The results prove that two polarization orientations can be used in the integrated stack-up.