# Accession Number:

## AD0716494

# Title:

## Theory and Computation of Characteristic Modes for Conducting Bodies,

# Descriptive Note:

# Corporate Author:

## SYRACUSE UNIV N Y DEPT OF ELECTRICAL ENGINEERING

# Personal Author(s):

# Report Date:

## 1970-12-01

# Pagination or Media Count:

## 64.0

# Abstract:

A theory of characteristic modes for conducting bodies is developed starting from the operator formulation for the current. The mode currents form a weighted orthogonal set over the conductor surface, and the mode fields form an orthogonal set over the sphere at infinity. It is shown that the modes are the same ones introduced by Garbacz to diagonalize the scattering matrix of the body. Formulas for the use of these modes in antenna and scatterer problems are given. A procedure for computing the characteristic modes for bodies of arbitrary shape is developed, and applied to conducting bodies of revolution and to wire objects. Illustrative examples of the computation of characteristic currents and characteristic fields are given for a cone-sphere, a disk, and a wire arrow. Modal solutions using these modes are computed for representative antenna and scattering problems to illustrate convergence of the solution as the number of modes is increased. For electrically small and intermediate size bodies, only a few modes are needed to characterize the electromagnetic behavior of the body. Author

# Descriptors:

# Subject Categories:

- Electricity and Magnetism
- Radiofrequency Wave Propagation