Using a Half-mode SIW Loaded with Slots to Realize a Compact UWB Bandpass Filter

This paper presents an ultra-wideband bandpass filter (UWB-BPF) based on a half-mode substrate-integrated waveguide (HMSIW) structure with a passband that spans from 4.12 to 11 GHz and has a center frequency of 7.56 GHz with a fractional bandwidth of 91%. Less than 0.3 dB of insertion loss was achieved through the passband, with the return loss being better than 19 dB. Two transmission zeros were generated, contributing to the 5.24 GHz out-of-band rejection. The proposed filter is compact, making it a good choice for space-constrained systems. In addition, a notch response has been utilized to comply with standards issued by applicable regulatory bodies, by blocking some bands located in the passband. Ansys EDT software was used to implement the design and determine the response of the proposed structure, while Keysight ADS was used to validate the results.