Miniaturized Quadband High-Temperature Superconducting Bandpass Filter with a Wide Frequency Ratio

This paper presents a miniaturized quadband high-temperature superconducting (HTS) bandpass filter based on multistub-loaded resonator. Owing to the symmetrical structure of proposed resonator, odd- and even-mode analysis method can be used derive its resonance frequencies. First, frequency ratio between passbands may significantly changed by adjusting impedance fold spacing Moreover, exhibits well-controlled center frequencies bandwidths for four passbands, resulting in considerably enhanced design possibility filters. A low insertion loss within each band is obtained using HTS technology. Additionally, was etched an MgO substrate with thickness 0.5 mm combined YBCO thin films demonstration. The results were highly consistent those simulation, validating effectiveness viability method.