Elliptic-disc filters of high-T-c superconducting films for power-handlingcapability over 100 W

On the future digital communication system, distortion of transmitted signa ls should be eliminated as much as possible for high communication quality. However, the need to both minimize distortion of signal amplifiers and con tinue to provide good filtering protection can become difficult to achieve with conventional devices, In this paper, the RF coplanar circuit filter us ing elliptic-disc resonators is proposed and investigated, This proposition makes it possible to miniaturize power filter circuits and to realize high performance of power ability of high-temperature superconducting (HTS) fil ters. An end spread signal coupling electrodes is investigated in order to adjust the coupling degree between disc and feedline circuits and provide p roper characteristic impedance of circuit. Two-mode coupling operation in t he elliptic disc are then explained. Electromagnetic-held distribution chan ge caused by this mode coupling can protect current and heat concentration, and realize power-handling capability over 100 W. Finally, the design prin ciple of a multiple-disc filter is introduced for high performance of out-o f-band rejection and passband flatness, It has been confirmed that an ellip tic-disc resonator filter can bring out the excellent performance of HTS ma terials.