Hard–Soft Groove Gap Waveguide Based on Perpendicularly Stacked Corrugated Metal Plates

A new electromagnetic band gap (EBG) structure based on the soft and hard surfaces for gap waveguide (GW) technology is introduced in this article. The proposed EBG structure consists of a soft surface and a hard surface in parallel with a gap between them, where the ridges/corrugations of the two surfaces are perpendicular to each other or with an angle near 90°. Compared with the contactless bed of nails EBG, the most widely used EBG structure in GW technology, the structural strength of the new EBG structure is increased significantly, which makes it very suited for high-frequency applications. Another advantage is that with the varying of the angle between the ridges/corrugations of the two surfaces, the stopband shifts in a wide frequency band, which makes the stopband tunable after the EBG is fabricated. The stopband performance of the proposed EBG is investigated. Straight and bended groove GWs (GGW) employing this new EBG are designed, manufactured and tested. The isolation performance with different columns of ridges/corrugations is also tested. The measured results show the proposed GGWs have excellent transmission performance.