Broadband detection properties of EuBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// array junctions

We have fabricated EuBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Josephson junction arrays of two different sizes to improve detection output and microwave coupling between junctions and an rf source. The arrays contain three weak link grain boundary junctions made on an MgO bicrystal substrate. It is demonstrated that both the junction array configuration and smaller junction size are effective in improving microwave coupling and hence in increasing the responsivity. The best responsivity obtained is 1085 V/W for broadband detection at 11.9 GHz.<
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