New method to improve power handling capability for coplanar waveguide high-temperature superconducting filter

This paper proposes a new method for improving the power handling capability of a coplanar waveguide (CPW) high-temperature superconducting (HTS) filter. The noteworthy point of the proposed method is that it is based on the concept that the power handling capability is improved by reducing the maximum current density of the filter. Numerical investigations confirm that a CPW HTS filter using 100-Ω characteristic impedance resonators reduce the maximum current density compared to that using conventional 50-Ω resonators. A 5-GHz band, four-pole, CPW HTS filter is fabricated based on the proposed method. The fabricated filter has the third-order intercept point of 62 dBm at 60 K. This result indicates the effectiveness of the proposed method.