Accession Number : ADA303261

Title :   FD-TLM Simulation of Josephson Junction Logic Circuits.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Sentelle, Christopher G.

PDF Url : ADA303261

Report Date : 1995

Pagination or Media Count : 136

Abstract : Josephson junction integrated circuits are capable of operating at clock frequencies from 1 to 100 GHz. At these frequencies, analysis of signal propagation delay, crosstalk, dispersions, radiation, and reflections must be included to determine proper response of the circuit. Much effort is required in simulating high frequency behavior, where the cross sectional dimensions of conductors are comparable to the signal wavelength, with conventional circuit simulation methods as SPICE. A simulation method capable of modeling high frequency behavior by solving Maxwell's curl equations, the finite difference transmission line matrix method (FD-TLM), is modified to model JJ logic circuits and provide simultaneous time domain three dimensional full wave electromagnetic field and JJ device analysis. The FD-TLM method is further extended to model superconducting quantum interference devices (SQUIDs). Techniques for simulation and simulation results for a Josephson Atto-Weber switch (JAWS), a two-junction superconducting quantum interference device (SQUID), and a modified variable threshold logic (MvTL) gate are provided. Interconnection lengths are kept intentionally short so the FD-TLM simulations can be validated by conventional, low frequency, quasi-static analysis. The general behavior observed in FD-TLM simulation and good agreement with quasistatic conventional circuit simulation validate the FD-TLM method.

Descriptors :   *LOGIC CIRCUITS, *JOSEPHSON JUNCTIONS, THRESHOLD EFFECTS, THESES, TRANSMISSION LINES, INTEGRATED CIRCUITS, PROBLEM SOLVING, FINITE DIFFERENCE THEORY, RESPONSE, CROSS SECTIONS, BROADBAND, CIRCUIT INTERCONNECTIONS, DELAY, MAXWELLS EQUATIONS, CROSSTALK, MATRIX THEORY.

Subject Categories : Electricity and Magnetism
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE