Easily Fabricable Gap Waveguide Based on Inverted V-Shaped Groove Glide-Symmetric EBG Structure

In this letter, we propose a new structure to reduce the manufacturing complexity of gap waveguides. This design improves manufacturing efficiency while maintaining excellent performance and higher reliability. The electromagnetic band gap (EBG) unit cell consists of two identical but oppositely oriented V-shaped grooves on two metal plates. The width of the grooves matches the milling tool’s diameter, allowing the grooves to be machined in a single lateral pass, which enhances machining efficiency. Compared to traditional designs, the proposed structure eliminates metal pins, thereby improving reliability. At a gap g of 0.03 mm, the proposed EBG structure achieves a stopband covering the entire W-band. We validated the performance of the structure through simulation and prototype fabrication. Test results show that the gap waveguide with the proposed structure achieves outstanding transmission and isolation performance. The measured unit length insertion loss is −0.075 dB/cm in W-band.