General design aspects of integrated superconductor electronics

We discuss different wiring configurations and analyze their properties. We present our theoretical and experimental results about the influence of the line impedance to the operation of RSFQ circuits. The impedance matching between the connecting microstrip-lines and the JJ is a key issue for the correct operation. We performed circuit simulations and collected experimental data of correct and incorrect operating circuits to derive a design criteria. The critical reflection coefficient is 0.35 and the particular design must use a smaller value to ensure pulse transfer and a larger value for storage of SFQ pulses, respectively.