Automatic Calculation of Daily Ionospheric Current Systems
Abstract
A Josephson logic OR gate suitable for high speed logic circuits is proposed and tested. This gate has a structure modified from Variable Threshold Logic (VTL) to obtain large operating margin and small occupation area. The operating margin is calculated as + or - 19 percent for fan-out of 2, even with the critical current variation of + or - 20 percent. The circuit area is 40 x 60 sq microns. A chain of 5-stage OR gates was fabricated. The gates had Josephson junctions of 4-microns and 7-microns diameter made with Pb-alloy technology. The minimum gate delay of 9 ps was measured using a Josephson sampler.
- Publication:
-
Geophysical Journal International
- Pub Date:
- June 1968
- DOI:
- 10.1111/j.1365-246X.1968.tb05751.x
- Bibcode:
- 1985JaJAP..24L...1F
- Keywords:
-
- Gates (Circuits);
- Josephson Junctions;
- Logic Circuits;
- Logical Elements;
- Threshold Logic;
- Time Lag;
- Equivalent Circuits;
- High Speed;
- Superconductors;
- Switching Circuits;
- Electronics and Electrical Engineering