Superconducting Narrowband Filter for Receiver of Weather Radar

Tamio KAWAGUCHI  Noritsugu SHIOKAWA  Kohei NAKAYAMA  Takatoshi WATANABE  Tatsunori HASHIMOTO  Hiroyuki KAYANO  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E92-C   No.3   pp.296-301
Publication Date: 2009/03/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E92.C.296
Print ISSN: 0916-8516
Type of Manuscript: INVITED PAPER (Special Section on Recent Progress in Superconducting Analog Devices and Their Applications)
Category: 
Keyword: 
superconducting filter,  weather radar,  microstrip line,  

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Summary: 
We have developed a high-temperature superconducting (HTS) filter with narrow bandwidth characteristic for receiver of weather radar in order to reduce interference between adjacent radar channels. To realize a filter with which a narrow bandwidth and low insertion loss are compatible, resonators with high unloaded Q (Qu) value are required. Hairpin microstrip resonators with 1.5 times wavelength were adopted to suppress the radiation loss and achieve a high Qu value. The developed HTS filter has 8-pole quasi-elliptic function response for sharp skirt characteristic. The measured frequency response of the developed filter shows center frequency of 5370 MHz, insertion loss of 2.04 dB and maximum return loss of 15 dB, which agrees with the designed responses.