Concerning the influence of the resonator structures on the quality factor and design of an ultra-narrowband superconducting filter

Abstract

The influence of the resonator structures on the quality factor is simulated and discussed. A six-pole ultra-narrowband superconducting filter is designed using twin-spiral resonators with a high quality factor and fabricated. The measured results show a high performance.

Compact ultra-narrowband superconducting filter using N-spiral resonator with open-loop secondary coupling structure*

“…Twin-spiral and twin spiral-in-spiral-out resonators have been employed to design filter with ultra-narrow bandwidth. [9][10][11][12][13][14][15][16] Tao et al proposed modified twin-spiral and twin spiral-in-spiral-out resonators to realize weak couplings and designed two compact ultranarrowband filters with FBWs of 0.08% [12] and 0.18% [14] in S band. Moreover, another inspiring method that adding secondary coupling structures between resonators to reduce coupling has also been investigated.…”