WEAK-LINK ARRAY JUNCTIONS IN EUBA2CU3O7-X FILMS FOR MICROWAVE DETECTION

High temperature superconductors are eminently suitable for use in hig h frequency devices because of their large energy gap. We fabricated w eak link Josephson junctions connected in series. The junctions were c onstructed of EuBa2-Cu3O7-x (EBCO) superconducting thin films on bicry stal MgO substrates. We measured their microwave broadband detection ( video detection) characteristics. The responsivity (S(r)) of the junct ions depended on the bias current and their normal state resistance. T he array junctions were effective in increasing normal state resistanc e. We obtained a maximum S(r) of 22.6 [V/W].