HTS Coplanar Meander-Line Resonator Filters with a Suppressed Slot-Line Mode

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Authors

Colleges, School and Institutes

Abstract

The design and experimental results of a four-pole coplanar waveguide (CPW) quasi-elliptic filter using high-temperature superconductor (HTS) films are presented.. Quarter-wavelength meander-line resonators are used in the filter topology. Although the resonators are aligned in two lines, no bond-wire bridges are required to balance the ground planes in the design and measurement. The slot-line mode of the filter was shifted to be higher than its third harmonic. The filter is highly miniaturized. and the performance is significantly improved by the use of superconductors. The main. circuit of the filter only has an area of about 6.6 mm x 2.4 mm on a magnesium oxide substrate, coated with, 600-nm-thick YBCO HTS thin film on single side of the substrate. The 3-dB bandwidth is about 1.6% centered. at 2.95 GHz. The performance measured at 30 K, without any tuning, gives an insertion loss, of better than 0.4 dB and a return loss of about 12 dB in the passband. The first spurious mode is about triple the center frequency.

Details

Original languageEnglish
Pages (from-to)28-32
Number of pages5
JournalIEEE Transactions on Applied Superconductivity
Volume14
Issue number1
Publication statusPublished - 1 Mar 2004

Keywords

  • high-temperature superconductor (HTS), bandpass filter, meander line, microwave monolithic integrated circuits (MMIC), coplanar