中国物理B ›› 2017, Vol. 26 ›› Issue (5): 58503-058503.doi: 10.1088/1674-1056/26/5/058503

• RAPID COMMUNICATION • 上一篇    

A high-temperature superconducting filter withcontrollable transmission zero

Tianqi Gao(高天琪), Bin Wei(魏斌), Yong Heng(衡勇)   

  1. 1 State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China;
    2 Beijing Institute of Electronic System Engineering, Beijing 100854, China
  • 收稿日期:2017-03-14 出版日期:2017-05-05 发布日期:2017-05-05
  • 通讯作者: Bin Wei E-mail:weibin@mail.tsinghua.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 61371009) and the Chinese Ministry of Science and Technology (Grant No. 2014AA032703).

A high-temperature superconducting filter withcontrollable transmission zero

Tianqi Gao(高天琪)1, Bin Wei(魏斌)1, Yong Heng(衡勇)2   

  1. 1 State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China;
    2 Beijing Institute of Electronic System Engineering, Beijing 100854, China
  • Received:2017-03-14 Online:2017-05-05 Published:2017-05-05
  • Contact: Bin Wei E-mail:weibin@mail.tsinghua.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 61371009) and the Chinese Ministry of Science and Technology (Grant No. 2014AA032703).

摘要:

This paper presents a novel microstrip feedline structure to introduce an extra and controllable transmission zero (TZ) with high rejection for a narrowband filter. This structure loads a reconfigurable capacitor at the end of the input feedline without changing the main structure of the filter. The capacitor is recognized by a 2-bit inter-digital capacitor array. The asymmetrical microstrip feedline structure is suitable for multiple-pole filter designs. A low-loss six-pole high-temperature superconducting bandpass filter with a reconfigurable TZ is designed and fabricated. The center frequency of the filter is 5.22 GHz with TZ at the lower stopband. The TZ can be tuned among four different states. The out-of-band rejection at the TZ frequency is higher than 90 dB, and the insertion loss is lower than 0.92 dB. The measured results are consistent with the simulations.

关键词: superconducting, narrowband filter, transmission zero

Abstract:

This paper presents a novel microstrip feedline structure to introduce an extra and controllable transmission zero (TZ) with high rejection for a narrowband filter. This structure loads a reconfigurable capacitor at the end of the input feedline without changing the main structure of the filter. The capacitor is recognized by a 2-bit inter-digital capacitor array. The asymmetrical microstrip feedline structure is suitable for multiple-pole filter designs. A low-loss six-pole high-temperature superconducting bandpass filter with a reconfigurable TZ is designed and fabricated. The center frequency of the filter is 5.22 GHz with TZ at the lower stopband. The TZ can be tuned among four different states. The out-of-band rejection at the TZ frequency is higher than 90 dB, and the insertion loss is lower than 0.92 dB. The measured results are consistent with the simulations.

Key words: superconducting, narrowband filter, transmission zero

中图分类号:  (Superconducting devices)

  • 85.25.-j