A 15-pole high temperature superconductor filter for radar applications

Abstract

This paper presents a compact and high first harmonic frequency resonator. The characteristics of this resonator are theoretically analyzed. A highly selective 15-pole Chebyshev high temperature superconducting ultra-high frequency narrowband filter for radar applications was fabricated by using this resonator. The filter has a center frequency of 495MHz and a fractional bandwidth of 1%. The first harmonic frequency is more than 3.3 times the fundamental frequency. The measured filter shows excellent selectivity, better than 85 dB/1 MHz skirt slopes, and more than 85 dB of rejection at 497.5 MHz from the band edge. The filter was fabricated on a 2 inch YBCO thin film with a 0.5 mm thick MgO substrate. The experimental results are consistent with the simulations.

Design of compact HTS bandpass filter operating above 100K by using dual-mode resonators with high selectivity

“…To fulfil the requirement of wide stopband characteristics, an interdigital capacitance structure can be employed to suppress the harmonic [4][5][6]. In [5], 15-order resonators are introduced to realize steep shirts, while suffering from relatively large circuit sizes. Miniature BPFs can also be developed with multi-mode resonator structures [7,8].…”

A 12-pole VHF band high selective high temperature superconducting filter

“…Half-wavelength resonator is widely used in HTS filter design. Numerous high order and excellent performance HTS filters are reported with half-wavelength resonators [3][4][5][6][7][8][9][10][11][12][13], but most of them are in the microwave range. It is difficult to realize higher order filter at VHF band for the large size of resonator.…”