English title

This paper reports a four-pole microstrip high-temperature superconducting (HTS) band-pass filter with a quasi-elliptic function response. A microstrip filter configuration that allows a pair of transmission zeros to be placed at the band edges is described. The filter was fabricated using single-sided YB₂Cu₃O₇ superconducting thin film deposited on a LaAl₂O₃ single crystal substrate of size  by pulsed laser deposition. Very good experimental results were obtained when the filter cooled using liquid nitrogen. The minimum pass-band loss was measured to be approximately 0.5 dB. The pass-band width at points 1 dB down from the minimum loss point was 110 MHz for a center frequency of 3.25 GHz.