Cost Effective PCB Gap Waveguide Based on Broken Glide Symmetry

Gap waveguides can provide a cost-effective and low-loss solution for high frequency transmission line technologies. This paper introduces a novel electromagnetic bandgap structure for a gap waveguide operating across the entire E band, targeting automotive radar applications. The proposed concept is compatible with cost-effective FR4-based printed circuit boards, utilizing substrate-integrated hole unit cells. Broken glide-symmetric geometry is adopted in the proposed approach to reach wider stopbands and greater adaptability for larger gap sizes. The final design achieves an average transmission loss of 0.1 dB/cm within the 76 - 81 GHz frequency band.