Development of new methods for predicting the bistatic electromagnetic scattering from absorbing shapes
Abstract
More accurate, reliable and efficient methods to calculate the bistatic scattering of electromagnetic fields from absorbing dielectric fields from absorbing dielectric objects were developed. While solution of 3D scattering problems has not been achieved, the methods developed provide, for the first time, finite element solutions of closed 3D electromagnetic fields free of the spurious solutions that have plagued previous procedures. These stable finite elements are defined in three varieties: (1) mixedorder rectangular parallelepiped elements, (2) edgebased tangential vector finite elements, and (3) derivative continuous elements. Each is shown to give only physically correct solutions. A new procedure, called the transfinite element method, is also presented for solution of open or unbounded electromagnetic scattering problems. This method provides a one step procedure to compute scattered fields in electromagnetics. The transfinite element method is applied only in 2D. Finally, a new high efficiency algorithm is proposed to compute electromagnetic scattering over a specified frequency range. In this algorithm, frequencies are selected adaptively to ensure a given accuracy in minimum computation time for the specified frequency range. The individual procedures are illustrated with a variety of examples.
 Publication:

Final Report
 Pub Date:
 January 1990
 Bibcode:
 1990cmu..reptS....C
 Keywords:

 Algorithms;
 Bistatic Reflectivity;
 Dielectrics;
 Electromagnetic Scattering;
 Finite Element Method;
 Computation;
 Electromagnetic Fields;
 Frequency Stability;
 Multistatic Radar;
 Prediction Analysis Techniques;
 Radiation Absorption;
 Time;
 Communications and Radar