Broadside Coupling High-Temperature Superconducting Dual-Band Bandpass Filter

Yuta TAKAGI  Kei SATOH  Daisuke KOIZUMI  Shoichi NARAHASHI  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E96-C   No.8   pp.1033-1040
Publication Date: 2013/08/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E96.C.1033
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
bandpass filters,  dual-band,  resonator filters,  broadside coupling,  high-temperature superconducting,  YBCO,  

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Summary: 
This paper proposes a novel high-temperature superconducting dual-band bandpass filter (HTS-DBPF), that employs a broadside coupling structure, in which quarter-wavelength resonators are formed on opposite sides of each substrate. This structure provides a dual-band operation of the BPF and flexibility, in the sense of having a wide range in selecting two center passband frequencies of the HTS-DBPF. This paper employs the ratio of the lower and higher center passband frequencies, α, as a criterion for evaluating the flexibility. The obtained α ranges are from 1 to 4.7, which are the widest for DBPFs for mobile communications applications, to the best knowledge of the authors. This paper presents a 2.4-/2.9-GHz band HTS-DBPF, as an experimental example, using a YBCO film deposited on an MgO substrate. The measured frequency responses of the HTS-DBPF agree with the electromagnetic simulated results. Measurement and simulation results confirm that the proposed filter architecture is effective in configuring a DBPF that can set each center passband frequency widely.