Utilization of Loaded Stripline Technology in Hybrid Substrate Integrated Waveguide Filters

This article introduces hybrid substrate integrated waveguide filters incorporating stripline loading. The filter boasts a compact size, complete enclosure, and good out-of-band rejection. A half-wavelength stripline with a metallized blind hole, is skillfully incorporated between two Substrate Integrated Waveguide (SIW) cavities. This integration serves to elevate the filter order and introduce additional transmission zeros (TZs) without necessitating extra dimensions. To validate this approach, we initially designed a third-order hybrid filter, followed by a fifth-order hybrid filter.