A fast analytical method has been proposed for predicting the shielding effectiveness (SE) and resonances of an apertured enclosure with an interior enclosure. Under the concept of electromagnetic topology, the monitor point and the walls are treated as nodes, and the space between them is treated as tubes. The propagation relationships at tube level and reflection relationships at node level are derived as the propagation matrix. After modeling the front wall of the interior enclosure as a junction between two waveguides, an equivalent circuital model of the enclosures is derived. The front wall and the window structure in front of the adjacent space of the interior enclosure are considered as a three-port scattering matrix. Then we can use the extended BLT equations to calculate the voltage response at each node. Results from the proposed method are compared with those from the numerical method, and the results have a good agreement while it can dramatically save calculation time.

A fast analytical method for predicting the shielding effectiveness (SE) and resonances of a parallelly–serially cascaded triple enclosure was proposed. Under the concept of electromagnetic topology, the observation points and the walls are treated as nodes and the space between them as tubes. An equivalent circuit model of the enclosures is derived in which the apertures on the front and rear walls of the two parallelly cascaded sub-enclosures are considered as a pair of three-port networks. To predict the SE at a particular monitoring point, we introduce the position factor. The results of the proposed method have a good agreement with the numerical methods while it is much faster. The proposed method can help in determining SE for cascaded enclosures. We can also find that the resonance effect affects each subenclosure through the apertures, which must be carefully considered inpractice.

A fast analytical method for predicting the shielding effectiveness (SE) of heterotypic enclosures was proposed. By applying the concept of electromagnetic topology, the observation points and the walls are treated as nodes, and the space between them as tubes. Equivalent circuit models of the enclosures are derived in which the aperture on the front wall are considered as a two-port network and so is the shape of the discontinuous part, which resembles a window structure. Then, the expressions of the total voltage components can be obtained using the extended Baum-Liu-Tesche (BLT) equation. Three different types of heterotypic enclosures are proposed to validate the method. Compared with numerical simulation, the proposed method can reduce the computation time from 1000 s for numerical algorithms to a few hundred milliseconds while maintaining a very close accuracy.

A hybrid algorithm method for predicting the shielding effectiveness (SE) of apertured enclosure with an arbitrary inner window was proposed. By applying the concept of electromagnetic topology, equivalent circuit models of the enclosures are derived. The equivalent impedance of the arbitrary inner windows are calculated by a full-wave method. Then, the shielding effectiveness can be obtained using the extended BLT equation. Compared with full wave numerical simulation, the proposed method can reduce the computation time from 1000 seconds to 100 seconds while maintaining a very close accuracy.