Characteristic Performance of L-Band Waveguide BPF Made of Substrate Integrated Structure

This paper proposed a compact bandpass filter (BPF) based on Substrate Integrated Waveguide (SIW) for GPS applications. The purpose of using SIW was to produce a filter size that was as concise as possible but still maintained the performance of the filter. The proposed compact SIW-BPF design was made using 2 layers of FR4 epoxy dielectric substrate with a thickness of 1.6mm each. To produce a narrow bandwidth response, several metallic vias were arranged in the center of the filter. The results of the characterization showed that the proposed compact SIW BPF design had a center frequency of 1.575 GHz, in accordance with GPS applications. The fabrication results showed that the bandwidth of the proposed SIW-BPF was in the vicinity of the L-band frequency spectrum.