Accurate wire-grid modelling of buried conducting cylindrical scatterers

Abstract

This work is focused on the wire-grid modelling of 2D (infinitely long) buried conducting objects. A circular cylinder is considered, embedded in a dielectric half-space and illuminated by a transverse magnetic monochromatic plane wave. The scattered near field is calculated by using the cylindrical-wave approach. This rigorous technique is briefly resumed in the paper, and its convergence properties in wire-grid modelling are discussed. Numerical results obtained for different wire-grid models are compared with the exact solution. It is shown that the well-known same-area criterion, in the considered cases, yields affordable results. However, it is not the optimum, and better results are obtained with a wire radius shorter than what was suggested by the rule.

Keywords:

• electromagnetic scattering
• buried objects
• cylindrical-wave approach
• wire-grid model
• same-area rule