Open AccessImproved modal method of moments technique to compensate the effect of wall dimension in shielding effectiveness evaluation
Author(s) -
Nobakhti Marzieh,
Dehkhoda Parisa,
Tavakoli Ahad
Publication year - 2014
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2012.0103
Subject(s) - enclosure , method of moments (probability theory) , aperture (computer memory) , reflection (computer programming) , electromagnetic shielding , optics , modal , wavelength , acoustics , physics , mathematical analysis , mathematics , materials science , engineering , computer science , electrical engineering , statistics , quantum mechanics , estimator , polymer chemistry , programming language
In the conventional modal method of moments (MoM) method, when shielding effectiveness (SE) of a rectangular enclosure is the goal, it is assumed that the incident wave is reflected from an infinite wall. This assumption makes the results inaccurate specifically at low frequencies where the wall size is not large compared to the illumination wavelength. In this study, the mentioned reflected wave is corrected by considering the reflection from a box without any aperture. To obtain the reflected wave from the box, an induced electric current on the metallic surface is assumed. Using Rao Wilton Glisson basis functions along with free space Green's function, the unknown electric currents and consequently the reflected wave are calculated. The results are compared with full wave numerical methods. A very good agreement is observed between the results and it is shown that for lower frequencies the proposed method has more accuracy rather than the modal MoM itself specifically for an enclosure with a very large aperture.