High‐order dual‐band superconducting filter with independently controllable passbands and wide stopband |
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Authors: | Xinxiang Lu Xubo Guo Chenjie Luo Bin Wei Liuwan Zhang Bisong Cao |
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Affiliation: | 1. Department of Physics and Electronic Engineering, Shaoxing University, Shaoxing, People's Republic of China;2. State Key Laboratory of Low‐Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, People's Republic of China |
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Abstract: | A stepped‐impedance‐stub loaded stepped‐impedance resonator (SISLSIR) is proposed to design a dual‐band bandpass filter. The even‐ and odd‐mode frequencies and the coupling strength of the proposed resonators can be independently designed and adjusted. A dual‐feedline structure is used to meet the required external couplings of the 2 passbands. Thus, both the center frequencies and the bandwidths of the 2 passbands can be independently controlled. A 6‐pole dual‐band filter with the passbands of 3300~3600 MHz and 4800~5000 MHz is successfully designed using the proposed method and fabricated with YBCO/MgO high‐temperature superconducting (HTS) wafer. The measured results of the filter exhibit high performance and match well with the simulations. The measured insertion losses are less than 0.2/0.3 dB, and the return losses are greater than 15/14 dB for the lower/upper passbands, respectively. The out‐of‐band rejection is greater than 68 dB up to 12 GHz. |
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Keywords: | dual‐band filter high‐temperature superconductor stepped‐impedance resonator stepped‐loaded resonator |
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