Design of Dual-Band Bandpass Filters Based on Metal-Integrated Suspended Line Technology

This letter introduces two dual-band bandpass filters (BPFs) based on novel metal-integrated suspended line (MISL) technology. These filters are designed to operate simultaneously in both the C-band and Ku-band based on dual-mode MISL resonators with low loss. Unlike traditional coaxial designs, the proposed MISL-based dual-band filters offer a compact footprint and allow for greater flexibility in design and fabrication. To improve the attenuation between the two passbands, the mixed electric and magnetic couplings have been used to achieve controllable between-band transmission zeros (TZs). To validate the concept, two dual-band BPFs are designed, fabricated, and measured. The measured results of the filters align well with the simulated results, confirming the compact size and low-loss characteristics of the proposed designs.