Japanese Journal of Applied Physics
Microwave Properties of Y1Ba2Cu3O7-x Step-Edge Josephson Junction Series Arrays
Shuichi Yoshikawa, Keiichi Yamaguchi, Kunihiko Hayashi, Katsumi Suzuki Katsumi Suzuki, Youichi Enomoto
Abstract
Effects on microwave detection of a series-connected Josephson junction array are examined. The series-connected 10 step-edge Josephson junctions (10-SEJJs) are fabricated by Y1Ba2Cu3O7- x thin films on MgO substrates. Their responsivities as microwave broad-band detectors are evaluated by constructing microstrip circuits for measuring transmission and return power. 948 V/W is obtained at 17 K. This value is several times greater than 139 V/W of a single SEJJ at 17 K. Additionally, the return power from 10-SEJJs is less than that from the single SEJJ, as the bias current or the temperature increases. The small return power is attributed to the increase in the normal resistance of the SEJJ.