A Design Method to Realize Manufacture-Friendly Millimeter-Wave Folded Substrate Integrated Waveguide Bandpass Filters

Abstract

A design method for manufacture-friendly millimeter-wave (mm-Wave) folded substrate integrated waveguide (FSIW) bandpass filters (BPFs) is proposed in this brief. Based on conventional magnetic post-wall iris structure, etched parallel rectangular slots and an incompletely folded structure are introduced to serve as internal coupling structures. A design method is proposed to achieve lower fabrication errors and reduce the sensitivity to them by optimizing the coupling structures, thus, increasing the performance robustness. Then, an FSIW BPF based on the multilayer printed circuit board (PCB) is designed at Ka-band using the proposed method, and a conventional FSIW BPF is also designed as a reference. Both the two FSIW BPFs are fabricated, measured, and compared to confirm the effectiveness of the proposed method. The designed BPF using the proposed method exhibits a higher simulation-to-fabrication performance accuracy compared to the regular one, thus, should be a promising candidate for mm-wave applications.