Title :
A 60-GHz NbN single-flux quantum counter circuit
Author :
Spargo, John W. ; Cooper, James E. ; Kerber, George L. ; King, George R. ; Morris, Robert S. ; Toth, Andrew G.
Author_Institution :
Hughes Technol. Center, Carlsbad, CA, USA
fDate :
6/1/1991 12:00:00 AM
Abstract :
A Josephson binary counter using single-flux quanta transitions of DC SQUIDs (superconducting quantum interference devices) has been fabricated using an eight-level NbN-based process. High-speed binary division has been demonstrated at 4.2 K, with single-cell counting observed at 60 GHz using the Josephson voltage-to-frequency relationship. Count rate was primarily limited by conservative process and design rules. The counter was designed for operation at 4.2 K. At 8-10 K, the βL of the SQUIDs would not allow operation, though the junction characteristics were good
Keywords :
Josephson effect; counting circuits; niobium compounds; superconducting junction devices; superconducting logic circuits; 4.2 K; DC SQUIDs; Josephson binary counter; Josephson voltage-to-frequency relationship; NbN; binary division; count rate; design rules; junction characteristics; single-cell counting; single-flux quanta transitions; single-flux quantum counter circuit; Counting circuits; Flip-flops; Josephson junctions; Marine vehicles; Niobium; Process design; SQUIDs; Switches; Temperature; Voltage;
Journal_Title :
Solid-State Circuits, IEEE Journal of
