Groove gap waveguide: A rectangular waveguide between contactless metal plates enabled by parallel-plate cut-off

This work presents a numerical study of a topology of gap waveguide referred to as groove-type gap waveguide, including dispersion diagrams and field distributions for different groove geometries. The main difference between this groove gap waveguide and the ordinary rectangular waveguides is that there is no need of electrical contact between upper and lower plate constituting the waveguide. This is a clear advantage at high frequencies when designing cavity filters and other components which require the fabrication of the waveguide based on two pieces and consequently requiring a large number of screws to ensure good conducting contact and avoid leakage.