Miniaturized HTS coplanar waveguide bandpass filters with highly packed meanderlines

Design and performance of miniaturized coplanar waveguide (CPW) bandpass filters (BPFs) using high T/sub c/ superconducting (HTS) films have been studied. In order to realize the miniaturized filters, we coupled highly packed meanderline half-wavelength resonators with interdigital gaps, where admittance inverters (J inverters) were made of interdigital gaps. The exact J values, susceptance slope parameters and the length of the resonators of the meanderline are calculated from the cascade matrix (K-matrix) and scattering matrix (S-matrix) obtained by the 2.5-dimensional electromagnetic field simulator (HP-Momentum). It is shown that the size of the filters can be greatly reduced by introducing CPW with highly packed meanderline geometry (center frequency 2 GHz, fractional band width 15 MHz, ripple 0.1 dB) packed within 10 mm square substrate. Simulated performance was in good agreement with the designed one.