Compact multiple electromagnetic band gap (EBG) cells based ultra wide band (UWB) filter with improved stop-band characteristics

Abstract

PurposeThe purpose of the study is – in Microwave filter design, the performances of passive components are deteriorated by parasitics at gigahertz (GHz) frequency range. A compact and multi-stack electromagnetic band gap (EBG) structure is proposed with improved stop band characteristics at GHz frequency range in this work. This paper proposes a new design for ultra wide band pass filter (resonator BPF) with periodically loaded one-dimensional EBG to achieve the harmonic suppression. This basic EBG structure is developed with combination of a signal strip and ground plane in the slotted section. The resonator BPF is loaded with one EBG, two EBG and three EBGs to improve the stop-band rejection.Design/methodology/approachThe proposed filter is with multi-stack EBG cell for achieving good pass band and stop bands performance. Circuit model is analyzed in Section 2. Section 3 discuses band pass filter loaded with one EBG. In Sections 4 and 5, filter with two and three EBG loaded resonators are discussed, respectively. Section 6 is concluded with comparison of simulation and measured results.FindingsThe stop-band rejection is 20 dB, 40 dB and 50 dB, respectively, in the frequency range of 6 GHz to 20 GHz. The simulation analysis is carried out with advanced system design software. To validate the simulation results, proposed structure is fabricated, and results are found to be in good agreement.Originality/valueThis paper accounts for designing resonator BPF, which has slow wave pass band and stop band characteristics. Second and third harmonics are suppressed using multi-stack EBG. Various stacks with basic designs are proposed and improved results have been demonstrated which is open for future research.