YBCO microwave grain boundary mixer using a SrTiO/sub 3/ bicrystal substrate
R. Seed, Paul C. Dorsey, Hoton How +2 more
A microwave mixer was patterned on a microstrip transmission line of superconducting YBCO (YBa/sub 2/Cu/sub 3/O/sub 7-x/). The YBCO film was epitaxially laser deposited on a SrTiO/sub 3/ bicrystal substrate. A weak link was constructed by patterning a microbridge in the microstrip at the bicrystal boundary. Microwave signals at 9.000 GHz and 9.941 GHz were applied at the input of the microstrip line. An output intermediate frequency signal was observed at 941 MHz and was detected as the transmitted signal. The microbridge junction, which behaved as a resistively shunted Josephson junction (RSJ), was current biased slightly above the critical current I/sub c/. The mixer conversion loss was measured at the input and output ports of the device package. The mixing efficiency was determined at the device junction. This efficiency was compared with the calculated efficiency determined by numerical solution of the Josephson equation for the weak link junction.>
IEEE Transactions on Magnetics•Nov 1, 1993•4 citations