EM Shielding of Conductive Spherical Shell

Electromagnetic shielding represents the process of reducing the electromagnetic (EM) field by blocking the field using barriers made of conductive and/or magnetic materials. The exact purpose of EM shielding is to protect devices from the undesirable coupling between interior and exterior space of the device.

In this application note we are focused on shielding which is performed by enclosing the area under protection by a conducting shell. As analytical solution for spherical shell is well known as MIE series result. In order to achieve significant reduction of interference field inside the shell, thickness of its walls would be few times larger than skin depth. The field on outer surface of the shell is much larger than field on inner surface, so EM simulation must be carried out rigorously.

Results presented in the application note show that WIPL-D software package can be used for very accurate analysis of electromagnetic shielding problems. Almost perfect agreement between simulated and analytical results is obtained for problems with shielding efficiency of more than 260 dB. All the models described here are simulated at standard desktop PC with low number of unknowns, in just a few seconds.

Section: EMC

For full version of the document, please check the following pdf.