Novel types of narrow band filters based on the newly introduced gap waveguide technology are presented in this paper. The proposed filters have a central frequency of 35 GHz with approximately 1% fractional bandwidth. The filter resonators are composed of two separate plates and are manufactured by milling metallic blocks. The gap between the two metallic plates eliminates the need for electrical contact between them. This feature allows the resonators to be stacked in different layers. The filtering function is realized by producing a coupling between the stacked resonators. The measurement results of the manufactured filters are in good agreement with full-wave simulations, even without any tuning or adjustments.Index Terms-Direct coupled resonators, filter, gap waveguide, groove gap waveguide (GGW), ridge gap waveguide (RGW), stacked layer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.