Using Aperture Impedance for Shielding Effectiveness Estimation of a Metallic Enclosure With Multiple Apertures on Different Walls Considering Higher Order Modes

In this paper, our previously published analytical method for calculation of shielding effectiveness (SE ) of a metallic enclosure with a centered aperture is extended to generalize the method for a much wider range of applications. The new extended analytic formulation considers an enclosure with centered and off-centered apertures on different enclosure walls and the monitoring point can be anywhere inside the enclosure. In addition, the incident field angle and the polarization angle are arbitrary and higher order modes are considered. An analytic discussion and an experimental setup are proposed for the validation of the new method. The proposed measurement setup can lead to a new SE measurement method for enclosures with arbitrary position apertures. In this measurement method, there is no need for antennas, reverberation chambers, etc. Another advantage of the proposed method is introducing a new figure of merit for shield evaluation. This new figure of merit is S11 of a two port microstrip line which is placed over the apertures.