Near Fields around Metallic Walls due to a Nearby Dipole Source with Applications to EMC

Abstract

This paper discusses the near field characteristics of a dipole source located near conducting metallic walls from an electromagnetic compatibility (EMC) point of view. An integral equation for a dipole source near a metallic wall is derived and solved by applying Galerkin’s method of moments (MoM). The results show that in the regions outside the dipole source, total electric near fields decrease gradually in magnitude with an increasing field point from the dipole source. But in the regions inside the dipole source, total electric near fields decrease rapidly with a dipole position of h≤ 0.3λ. For a dipole position of h≥0.7λ, the peaks and nulls of the total near electric field occur periodically in the regions inside the dipole source, and the fluctuation period is almost 0.5λ. The worst position for a receptor location is along the z-axis, and a range of a half-magnitude of the maximum near electric field in the principal H-plane is about two times broader than that of the principal E-plane. Experimental measurements are also presented to validate the theory.