Evaluation of shielding effectiveness of slotted enclosures by internal stirring

This paper presents a new technique for evaluation of a slotted enclosure shielding effectiveness (SE). The enclosure under test is equipped with a built-in, rotating, conductive stirrer, and the SE is determined for discrete angles of the stirrer position. The stirrer is used for modeling different internal arrangements of the enclosure and for approximation of the `worst case´ of the shielding performance. An experimental model and a numerical one are analyzed. The computations are carried out in an open space and the experiments are carried out in a GTEM cell. The results of computations and measurements are compared.