Analysis of the shielding performance of rectangular enclosure of metal structure with aperture covered with wire grid

A method of moment (MOM) solution for analyzing the electromagnetic shielding performance of rectangular metal enclosure with aperture covered with wire grid is presented. The concerned objects are modeled by using rectangular surface patches and the piece wise linear basic functions are used to expand the unknown electric currents on the surfaces of the cavity. The wire grid that covers the apertures is modeled as thin wire, and the unknowns are currents on the wire which is also modeled by piece wise linear basic functions. Using this method, the accurate value of shielding effectiveness of rectangular enclosure of metal structure with apertures covered with wire grid can be obtained quickly. Validation of the method is presented by comparing the results with those obtained by measurement. Finally, the shielding effectiveness of a protection cell in a substation is calculated as an application.