ABSTRACT This paper presents design simulation and measurement of two compact and high performance UWB BPFs. Ansys EDT 2022R1 full‐wave simulator was used to design, analyze, optimize, and simulate the presented filters. The proposed filters employed substrate integrated waveguide (SIW) technology due its high‐quality performance and planar structure; furthermore, half‐mode SIW (HMSIW) helped in miniaturizing the structure into half. Spoof surface plasmon polaritons (SSPPs) concept was used to perturb the propagation modes of the SIW cavity so that slow‐wave propagation can be achieved. The SSPP structure consists of an S‐shaped groove with different sizes. The resultant structure that consists of HMSIW‐SSPP was utilized to develop the proposed BPFs. The proposed filters were designed and fabricated on Rogers RO3450B substrate. The first design exhibited a UWB frequency response ranging from 3.9 to 7.9 GHz, and the measured IL was 0.5 dB at the center frequency. The measured return loss (RL) was better than 14.5 dB over the operating band and fractional bandwidth (FBW) of 67.8%. Furthermore, a longitudinal slot was incorporated within the SSPP structure to enhance the FBW of the second proposed filter. It showed a UWB frequency response ranging from 4.4 to 10 GHz, where the measured IL was 0.54 dB at center frequency. The measured RL was better than 14 dB over the operating band with FBW of 77.8%. Compared to state‐of‐the‐art, the proposed concept showed superior FBW and IL performance and compact filters size of (0.28) and (0.41), respectively.
Al-Darraji et al. (Fri,) studied this question.