A stereolithography 3-D printed Ka-band H-plane quasi-planar waveguide magic-T using slow-wave corrugations

A Äa-band H-plane quasi-planar rectangular waveguide magic-T is presented in this paper. The magic-T is based on an H-plane waveguide 3-dB directional coupler exploiting slow-wave corrugations on the narrow walls of one of the waveguide arms. These corrugations contribute to an additional phase shift of 90° in this waveguide arm. The magic-T is fabricated with ceramic-filled resin by employing stereolithography 3-D printing technique, which is followed by an electroless nickel/copper plating process to metallize its entire surface. The 3-D printed magic-T has little redundant structural material, a light weight (19.5 g), and good mechanical strength as well as thermal handling capability. This work exemplifies an effective method of fast and assembly-free prototyping multi-port waveguide passive devices.