Design and Loss Reduction of Multiple-Zeros Dual-Band Bandpass Filter Using SISL

This brief proposed a dual-band bandpass filter (DBBPF) topology realized on substrate integrated suspended line (SISL) platform. In this topology, separated electric and magnetic coupling paths (SEMCP) is firstly applied between two different filter bands to generate additional zeros for better skirt selectivity. The proposed filters, featured with self-packaging advantage, use hybrid spiral structure to realize different electric and magnetic coupling scheme for dual-band, compact size and multiple transmission zeros. In addition, loss reduction approach to reduce both substrate and metal losses is used to achieve insertion loss reduction.