Design of compact high temperature superconducting dual-band filter using dual-composite right-/left-handed resonators

A compact high temperature superconducting dual-band band-pass filter (BPF) is presented based on compact dual-mode dual-composite right-/left-handed (D-CRLH) resonators in this article, which is composed of spiral coupled lines and meander lines. In addition, the equivalent circuit model and the admittance matrix are given to analyze the resonant characteristics of the designed D-CRLH resonator. Then, the proposed filter realizes the flexible controllability of the center frequencies and coupling coefficient of the two passbands, which greatly increases the design freedom of dual-band BPFs. Finally, the proposed filter was designed and etched on a 0.5-mm-thick MgO substrate with double-sided YBCO thin-films for demonstration. The measured results match the simulated ones well, indicating the feasibility of the proposed design method.