Single and dual mode cavities based on defected bed of nails structure for ridge gap waveguide

A single mode dielectric cavity and a dual mode cavity are proposed and studied for newly introduced ridge air gap waveguide. These cavities are realized by creating defects in periodic structure of EBG surface made of bed of conducting nails, which are used in ridge air gap and groove gap waveguides. These cavities and resonators are used to realize some filters. As an example, a dual bandstop notch filter is designed and simulated. In addition, a narrow bandpass filter is designed, fabricated, and measured using the proposed cavities in the X-band.