Design and Performance of an Ultra-Narrowband Superconducting Filter at UHF Band

A stepped impedance spiral resonator suitable for high-temperature superconducting (HTS) filter with bandwidth narrower than 0.5% is presented. An eight-pole demonstration HTS filter is developed with a central frequency of 650 MHz and a bandwidth of 0.3%. The measurements show that the insertion loss is less than 0.3 dB, and the return loss is better than 16 dB. The filter has out-of-band rejections of 65 dB at 2 MHz below the passband and 80 dB at 2 MHz above the passband, respectively.

[1]  E. M. Jones,et al.  Microwave Filters, Impedance-Matching Networks, and Coupling Structures , 1980 .

[2]  Jia-Sheng Hong,et al.  Microstrip cross-coupled trisection bandpass filters with asymmetric frequency characteristics , 1999 .

[3]  Young Hwan Choi,et al.  A compact narrowband HTS microstrip filter for PCS applications , 1999, IEEE Transactions on Applied Superconductivity.

[4]  M. Barra.  Miniaturized superconducting planar filters for telecommunication applications , 2004 .

[5]  Jia-Sheng Hong,et al.  Narrowband high temperature superconducting filter for mobile communication systems , 2004 .

[6]  Jiasheng Hong,et al.  Coupled Resonator Circuits , 2001 .

[7]  Jia-Sheng Hong,et al.  Microstrip filters for RF/microwave applications , 2001 .

[8]  Frederick Huang,et al.  Ultra-compact superconducting narrow-band filters using single- and twin-spiral resonators , 2003 .

[9]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[10]  Sheng Luo,et al.  A high-performance ultra-narrow bandpass HTS filter and its application in a wind-profiler radar system , 2006 .

[11]  Bisong Cao,et al.  Design and performance of a compact forward-coupled HTS microstrip filter for a GSM system , 2002 .

[12]  Fei Li,et al.  High Temperature Superconducting Microwave Filters for Applications in Mobile Communication, Satellite Receiver and Wind-Profile Radar , 2007, 2007 International Kharkov Symposium Physics and Engrg. of Millimeter and Sub-Millimeter Waves (MSMW).