Characteristic modes and wire grid modeling

Modeling of the radiation and scattering properties of a conducting body using the wire-grid model is addressed. In particular, the convergence of the wire grid model (relative to the grid mesh size) is examined from the viewpoint of the characteristic modes associated with the body. A quantitative description of the wire grid structure is given. It allows a minimum grid size to be associated with a given error in the radiated or scattered power for an arbitrary body excitation. This enables the sensitivity of an initial design to small changes in the antenna or body shape to be determined. The examples presented use the wire grid structure for modeling the actual body, but the fundamental approach of using the characteristic modes to formulate and gain insight into the body radiation and scattering characteristics is applicable in general