A 12-pole VHF band high selective high temperature superconducting filter. (16th November 2020) - Yu, Xiao
Abstract: A 12-pole VHF band high temperature superconducting (HTS) filter with a spiral quarter-wavelength resonator is introduced. The coupling characteristics of the proposed resonator, cross structure and external quality factor is analyzed in detail. The HTS filter is fabricated on a 3-inch-diameter double-sided DyBa2 Cu3 O7 HTS thin film with a LAO substrate and measured with a low-temperature test system at 77 K. The measured filter has a center frequency of 119.93 MHz and a 1-dB passband of 10.04 dB. Due to the introduction of transmission zeros, the rectangular coefficient (BW60dB /BW1dB ) of the measured filter is about 1.20, which shows excellent selectivity. The measured results are in good agreement with the simulated ones.