Accession Number : ADA336217

Title :   Applied Mathematical Problems in Modern Electromagnetics.

Descriptive Note : Final rept. 1 Jul 94-30 Jun 97,

Corporate Author : NEW JERSEY INST OF TECH NEWARK

Personal Author(s) : Kriegsmann, G. A. ; Luke, J. H. ; Hile, C. V.

PDF Url : ADA336217

Report Date : 20 NOV 1997

Pagination or Media Count : 7

Abstract : A hybrid method has been developed which efficiently models a large cavity constructed of a waveguide with a flanged opening at one end that couples it to free space. This method uses adiabatic mode theory to describe the electromagnetic fields in the waveguide (single mode) which is slowly changing and shorted at the far end. A finite difference scheme is used to describe the scattered electromagnetic fields in the exterior. This infinite region is truncated using a non-absorbing boundary condition. (2) A methodology has been developed to extend the above results to more realistic applications. Specifically S-Matrix theory is used to take into account discontinuities in the guide, such as an iris or another flanged outlet. This methodology holds for multi-mode waveguides. (3) Analysis of numerical errors for the FDTD method for pulse propagation in a dispersive media have been substantially refined and extended to the appended integral equation approach. (4) A substantially more efficient alternative to the FDTD method for dispersive media has been developed in one spatial dimension for homogeneous materials. Preliminary exploration of extensions to inhomogeneous materials (including material interfaces) and higher dimensions has begun.

Descriptors :   *ELECTROMAGNETIC FIELDS, *WAVEGUIDES, *APPLIED MATHEMATICS, FINITE DIFFERENCE THEORY, HYBRID SYSTEMS, INTEGRAL EQUATIONS, ADIABATIC CONDITIONS, ELECTROMAGNETIC PULSES, S MATRIX.

Subject Categories : Electricity and Magnetism
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE