An optimum superconducting ultra-wideband bandpass filter at VHF band

✍ Scribed by Wei Chen; Xubo Guo; Bisong Cao; Xiaoping Zhang; Bin Wei; Ying Zhang; Xinxiang Lu

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 175 KB
• Volume: 52
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.25571

✦ Synopsis

Abstract

A highly selective superconducting ultra‐wideband filter with a passband from 125 to 260 MHz is designed and demonstrated using a microstrip structure. The filter is designed according to a circuit model for an optimum short‐circuited stub transmission‐line filter and consists of 10 shunt short‐circuited stubs separated by connecting lines. The short‐circuited stubs are quarter‐wavelength long, and the connecting lines are half‐wavelength long. The filter is realized on two 3‐inch YBCO/LaAlO~3~ substrates, which are connected by two bonding wires. The short‐circuited stubs are grounded via two grounding pads that are attached to the box wall by a number of SiAl bonding wires. The measured results exhibit a selective filtering characteristic equivalent to a 19‐pole Chebyshev filter and a low insertion loss of less than 0.1 dB at center frequency without tuning. Furthermore, the experimental results of the filter are in good agreement with the simulated ones. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2639–2641, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25571