Boundary Evaluation of the Maximum Coupling Obtained in EM Illumination Test with Different Polarization Direction

Abstract

In system-level high-altitude electromagnetic pulse (HEMP) illumination tests, it is common to perform the test in two orthogonal polarizations of the incident electric field. With the judgment standard of the electromagnetic norm, this paper evaluated, improved, generalized, and verified this method. The evaluated result shows that the maximum error of the maximum coupling in this method is less than 3 dB. Meanwhile, this method is improved by serving the 1.2 period of the larger coupling of the 2 illuminations as the maximum coupling. The maximum error can be controlled within 1.5 dB. Moreover, this method is generalized to non-orthogonal conditions. Expressions of the deviations of this method are strictly derived. Based on this method, the application and some extended thinking are discussed. At last, a current coupling test is designed and carried out to verify the methods and conclusions. The methods introduced in this paper can be applied to any linear system in the illumination test under approximate transverse electromagnetic (TEM) waves.