Half Mode Substrate Integrated Waveguide (HMSIW) Directional Filter

A double-loop directional filter is described and realized in this work by using a novel guided-wave structure called half mode substrate integrated waveguide (HMSIW), which retains the attractive performances of substrate integrated waveguide (SIW) with a nearly half reduction in size compared to the original SIW version. The demonstrated filter is designed at 12 GHz with less than 3.2 dB insertion loss for a 250-MHz bandwidth, and the minimum insertion loss is 1.5 dB. It presents low insertion loss, high power capacity in planar compact configuration with a standard PCB fabrication process.