Transmission of single-flux-quantum pulses along superconducting microstrip lines

The authors analyzed, designed, and tested drivers and receivers which make it possible to connect distant circuits of the rapid single-flux-quantum (RSFQ) logic/memory family by passive superconducting microstrip lines. Using these circuits implemented with a niobium trilayer fabrication technology, reliable transmission and reception of the SFQ pulses over distances up to 1 cm, with margins of bias currents as wide as +or-30%, have been demonstrated. The pulses can be passed along wide lines (20 mu m for 3.5 mu Nb-Al/sub 2/O/sub 3/-Nb Josephson junction technology) over such distances and can be picked up by the RSFQ receiver.>