Highly Dispersive Ridge Gap Waveguide for mm-Wave Fast-Scanning Leaky-Wave Arrays

This communication explores the modification of a ridge-gap waveguide with the objective of attaining highly dispersive wave propagation. This new waveguide enables the design of leaky-wave arrays with a fast frequency-scanning rate. The modification entails the insertion of deep corrugations into the central ridge, which serves to enforce the slow-wave regime and augment the slope of the phase constant with respect to frequency. A design example of a linear shunt slot array based on this new waveguide has been proposed. With a relatively simple structure, a field of view of ±30° is covered within 1-GHz bandwidth. These results confirm the promising properties of the proposed waveguide for the design of backward-to-forward fast-scanning all-metal leaky-wave arrays in the millimeter-wave band.