A UHF-Band Narrow-Band HTS Bandpass Filter With Wide Stopband Using Interdigital Structure

摘要

In this paper, a novel resonator with modified interdigital fingers and vertical meander line is proposed. This resonator has a high first spurious frequency and is suitable for the design of a narrow-band filter with a wide stopband. A compact narrow-band six-pole high-temperature superconducting filter at the ultrahigh-frequency band is successfully designed and fabricated with this resonator. The measured out-of-band rejection is better than 75 dB up to 2600 MHz, which is as high as 5.2 times of the fundamental frequency.