Design of continuously tunable superconducting filter with semiconductor varactors. Issue 4 (April 2014)

• Record Type: Journal Article
• Authors: Suo, Guannan; Zhang, Guoyong; Cao, Bisong; Guo, Xubo; Wei, Bin; Zhang, Xiaoping; Feng, Cheng; Ying, Zhijun; Shang, Zhaojiang
• Is Part Of: Microwave and optical technology letters. Volume 56:Issue 4(2014:Apr.)
• Page Start: 775
• Page End: 777
• Publication Date: 2014-04
• Subjects: Microwaves -- Periodicals; Optics -- Periodicals; 621
• DOI: 10.1002/mop.28239
• Languages: English
• ISSNs: 0895-2477

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>This article presents a four‐pole continuously tunable high‐temperature superconducting combline filter at L band on MgO substrate. Gallium Arsenide varactors are used as tuning elements in the filter. Additional varactors are used to tune the external quality factor of the input and output couplings. A shorted U‐shape secondary coupling line is introduced to match the desired couplings so as to maintain a good return loss in the entire tuning range. The four‐pole filter achieves a tuning range of 11.5% from 983.85 to 1103.6 MHz. The insertion loss is 0.46 dB at 1103.6 MHz with the bias of 9 V. The unloaded quality factor of the resonators in the four‐pole filter is estimated to be 710 at 1077.6 MHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:775–777, 2014</p> </abstract>