Accuracy Analysis of Shielding Effectiveness of Enclosures With Apertures: A Parametric Study

An analytical formulation for calculating shielding effectiveness (SE) was developed by Robinson. This analytical method, compared with numerical methods, can obtain SE faster and needs less computer memory. However, its accuracy depends on the distance p, which is from the observation point to the aperture. In this paper, a reference distance p̅, which determines whether Robinson's method is precise has been introduced. We define that Robinson's method has a high accuracy if p <; p̅ but a low accuracy if p <; p̅. The relationship between the value of p̅ with all related parameters has been intensively studied. The approximate formulation for calculating p̅̅̅ has also been obtained with the data fitting method. The transmission-line matrix method (TLM) and the finite-element method (FEM) are used to test the approximate formulation. Based on the calculation and analysis in this paper, we can easily get the value of p̅ through bringing all related parameters into the approximate formulation. Therefore, when using Robinson's analytical method to predict SE, we can get precise SE by setting observation points at positions p <; p̅.