Cross-coupled band-pass filter using HTS microstrip resonators

Author

Min, B.C. ; Choi, Y.H. ; Kim, S.K. ; Oh, B.

Author_Institution

LG Electron. Inst. of Technol., Seoul, South Korea

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

485

Lastpage

488

Abstract

We have fabricated microstrip band-pass filters based on the quadruplet geometry using high-temperature superconductor. Every half-wavelength resonator in the filter consists of a loop-like inductor and two patch capacitors at both ends. The inductive coupling in between the loop-like inductors of non-adjacent resonators produces transmission zeros in the frequency response. The transmission zero can be allocated by changing the polarity and the strength of the cross coupling. We have designed a 9-pole filter for personal communication services (PCS) application using combination of a CAD tool and a full-wave analysis EM simulator. We have fabricated filters using double-sided YBa₂Cu₃O_7-δ (YBCO) thin films on LaAlO₃ substrates. The filter has 1.784 GHz center frequency, 11 MHz 3-dB bandwidth, and 0.8 dB insertion loss at 60 K. Due to the transmission zeros near the passband, the steep skirt characteristic is exhibited. The attenuation at 1 MHz away from the edge of the passband is -34 dB

Keywords

band-pass filters; barium compounds; elliptic filters; high-temperature superconductors; microstrip filters; microstrip resonators; microwave filters; resonator filters; superconducting filters; superconducting microwave devices; superconducting resonators; superconducting thin films; yttrium compounds; 0.8 dB; 1.784 GHz; 11 MHz; 60 K; CAD; LaAlO₃; LaAlO₃ substrate; PCS wireless communication; YBCO thin film; YBa₂Cu₃O₇; cross-coupled band-pass filter; frequency response; full-wave analysis electromagnetic simulation; half-wavelength resonator; high temperature superconductor; insertion loss; loop-like inductor; microstrip resonator; patch capacitor; quasi-elliptic filter; transmission zero; Band pass filters; Couplings; Filtering theory; High temperature superconductors; Inductors; Microstrip filters; Microstrip resonators; Passband; Personal communication networks; Resonator filters;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919388

Filename

919388