Dual-Band Unit Cell of EBG Structure for Printed Gap Waveguide

A dual electromagnetic gap (EBG) is realized by a unit cell of three substrates sandwiched between two metal plates. The unit cell consists of two stacked dielectric substrates topped by an aired substrate below the top metallic plate. The unit cell consists of a large mushroom patch on the bottom grounded substrate etched on its top and connected to the lower metal plane by a conducting via. The intermediate substrate has four smaller mushroom patches of total size smaller or equal to the bottom patch, and each is connected to the lower patch by conducting vias. The total size of the one-unit cell is 1.8mm. The unit cell is designed to achieve two stop band gaps; one is for the lower band for 13–24 GHz and another for the upper band 34–44 GHz. Inserting a so-called printed ridge perturbing the periodicity creates propagating modes within the EBG bands, guiding the electromagnetic waves between the upper conductor and the ridge and suppressing them elsewhere. The simulated results are presented. They could have the potential to be used for various dual-band applications.