A Multi-Hole Groove Gap Waveguide Directional Coupler based on Glide-Symmetric Holey EBG for E-Band Application

This paper presents a directional coupler in E-band based on recently introduced multi-layer waveguide transmission line. In this technology, by stacking several thin metal plates and creating a groove inside the structure, a transmission line is realized. To eliminate the field leakage via air gap between the metal layers, periodic holes on the metal plates are used to work as an Electromagnetic Band Gap (EBG) structure. The EBG holes have glide symmetry to obtain a wide band-gap from 50GHz to 100GHz. Then a multi-hole directional coupler based on the multi-layer gap waveguide and required transitions to standard WR-12 flange is designed and simulated. Different directional coupler with 20dB, 25dB, and 30dB coupling factor in the frequency range of 70GHz to 90GHz are designed and studied in this paper.