Miniaturized and optimized half mode SIW bandpass filter design integrating Hilbert cells as DGS

ABSTRACT This paper demonstrates a novel configuration of half mode substrate integrated waveguide HMSIW bandpass selective filter based on Hilbert cells as DGS. Two 50-Ohm conventional micro-strip are used as feed lines. The filter is designed and optimized using CST Software, Where a parametric study is used to optimize its geometric parameters. In our design, six periodic Hilbert cells are used, which are work collectively with three transverse slots to generate the desired resonance frequency. The used dielectric substrate is FR4 with a relative permittivity of 4.3. The proposed filter operates at the frequency of 3.25 GHz with an insertion loss about of −2 dB and a rejection extended from 1 GHz to 3.2 GHz and from 3.4 GHz to 7 GHz respectively for the lower and the higher sides with a level more than −35 dB. The filter is fabricated and measured, where the obtained measurements show a clear crystal similarity with the simulated results. The proposed filter is considered for TD LTE applications.