Applied Physics Letters
Eye-diagram and scattering parameter characterization of superconducting and gold coplanar transmission lines
J. Kruse, W.H. Chang, D.R. Scherrer, Milton Feng, M. J. Scharen, Albert Humirang Cardona, Roger J. Forse
Abstract
We report the gigahertz experimental results of time and frequency performance on YBCO high-temperature superconductor and gold coplanar transmission lines. An on-wafer direct probing measurement system was used to collect data at cryogenic temperatures on both YBCO and gold coplanar lines. The insertion loss of the 6 cm lines at a frequency of 2.5 GHz was measured to be −0.03 dB for the superconducting line compared to −10.4 dB for the gold line at 80 K. Eye-diagram measurements were performed on the packaged lines and show the correlation between the insertion loss of the line and the attenuation of a pseudorandom bit sequence. The measured eye height was 170 mV for the YBCO compared to 90 mV for a gold line at 1 Gbit/s and a temperature of 77 K for the packaged 6 cm lines.