Microwave Band-Pass Filtering Using Interacting Conducting Ring Resonators

This work presents an experimental investigation into a novel microwave band-pass filter architecture based on interacting conducting ring resonators. Leveraging the inherent resonant behavior of copper rings, the design achieves multiple narrow passbands within the 1–12 GHz frequency range. By systematically varying both the inter-resonator spacing and the number of rings, the study identifies an optimal configuration—particularly at an inter-ring distance of 6.75 mm—that maximizes the quality factor and transmission amplitude. Experimental results reveal distinct resonances at 2.2, 4.2, 6.6, 8.6, and 11.2 ± 0.2 GHz, corresponding to the fundamental and higher-order harmonic modes. The demonstrated filtering mechanism, characterized by compact size, tunable frequency response, and low insertion loss, offers a scalable solution for modern wireless communication systems. These findings indicate significant potential for integration into next-generation 5G and emerging 6G networks, providing a cost-effective alternative to conventional filter designs.