A 10-pole quasi-elliptic bandpass filter （BPF） with a relatively wide passband in the very high frequency （VHF） band was de- signed and fabricated using YBCO thin films deposited on both sides of a LaAIO3 substrat...A 10-pole quasi-elliptic bandpass filter （BPF） with a relatively wide passband in the very high frequency （VHF） band was de- signed and fabricated using YBCO thin films deposited on both sides of a LaAIO3 substrate. Single-spiral resonators were modified to generate strong coupling and reduce the parasitic coupling, We analysed the coupling polarities between the modi- fied resonators. Two pairs of attenuation poles were introduced in the filter for sharp cut-off response. The measurements showed that the filter has a centre frequency of 255.8 MHz, fractional bandwidth of about 12.3%, insertion loss of smaller than 0.265 dB, and the return loss in the passband of better than 17.5 dB, in zood a^reement with computer simulations.展开更多
基金supported by the External Cooperation Program of theChinese Academy of Sciences (Grant No. GJHZ1007)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KJCX2-YW-W16)
文摘A 10-pole quasi-elliptic bandpass filter （BPF） with a relatively wide passband in the very high frequency （VHF） band was de- signed and fabricated using YBCO thin films deposited on both sides of a LaAIO3 substrate. Single-spiral resonators were modified to generate strong coupling and reduce the parasitic coupling, We analysed the coupling polarities between the modi- fied resonators. Two pairs of attenuation poles were introduced in the filter for sharp cut-off response. The measurements showed that the filter has a centre frequency of 255.8 MHz, fractional bandwidth of about 12.3%, insertion loss of smaller than 0.265 dB, and the return loss in the passband of better than 17.5 dB, in zood a^reement with computer simulations.
