A Novel Compact Dual-Mode Substrate Integrated Waveguide Cavity based Bandpass Filter for WLAN Applications

In this paper, a dual-mode bandpass filter based on substrate integrated waveguide (SIW) is presented. Initially, a SIW cavity is designed at higher frequency range. The stepped impedance resonator (SIR) slots are embedded as a slot on the top of the cavity structure. Four SIR slots are etched on the top surface of the cavity which helps to eliminate the higher resonating modes of the cavity. The pass band is centered at 4.7 GHz to pass the WLAN band. The resonating slots generated dual mode characteristics with excellent selectivity. The stop band characteristic of the proposed filter is also satisfactory for mitigation of higher order modes. The proposed structure is EM-simulated to verify the theoretical analysis.