Search

In this study, we propose a novel resonator that is composed of a modified spiral with an embedded interdigital capacitor. A large ratio of the first spurious frequency to the fundamental resonant frequency is obtained, which is suitable for the design of filters with wide stopbands, and the circuit size is considerably reduced by embedding the interdigital structure in the spiral. For demonstration, a compact four-pole high temperature superconducting (HTS) filter with a center frequency of 568 MHz is designed and fabricated on double-sided YBCO film with a size of 11.4 mm × 8.0 mm. The filter measurement shows excellent performance with an out-of-band rejection level better than 60.9 dB up to 3863 MHz. [ABSTRACT FROM AUTHOR]

In this paper, we present a compact quint-band superconducting filter operating at 2.4, 3.5, 4.7, 5.3, and 5.9 GHz. Matching junctions with different impedance branch lines are used to connect a dual-band sub-filter with a tri-band sub-filter and to reduce the channel interactions. The quint-band filter design is divided into two sections to determine the controllable frequencies and bandwidths, while ensuring compact size and reducing design complexity. The filter is fabricated on double-sided YBCO film deposited on an MgO substrate with a size of 26 mm × 19 mm. The measured results match well with the simulations. [ABSTRACT FROM AUTHOR]