High-temperature superconducting filter using self-embedding asymmetric stepped impedance resonator with wide stopband performance and miniaturized size

• 来源期刊: 中国物理B（英文版）
• 关键词: high-temperature superconducting bandpass filter microstrip filter wide stopband
• 年，卷（期）: 2017,（10）
• 页码范围: 477-482
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/26/10/108502

摘要

In this study,a novel self-embedding asymmetric stepped impedance resonator (SE-ASIR) topology is proposed.By embedding asymmetric stepped impedance resonators in themselves,circuit sizes of ASIRs can be reduced effectively,while the ability to control spurious modes of ASIRs remains.Therefore,SE-ASIRs are suitable for being used to design filters with wide stopbands and miniaturized sizes.Furthermore,the construction process of the SE-ASIR is described in detail,and an equivalent model of the SE-ASIR is proposed.For demonstration,a high-temperature superconducting bandpass filter centered at 1112 MHz is designed and fabricated.The measured result agrees well with the simulation result and shows that the out-of-band rejection is better than 60 dB up to 4088 MHz,which is about 3.7 times the center frequency.The filter circuit size is 31 mm × 13 mm or 0.28λg × 0.12λg,where λg is the guided wavelength at 1112 MHz.