Engineering method for evaluation of shielding performance

The high frequency model for theoretical Shielding Effectiveness (SE) calculation becomes applicable as soon as structural imperfections become comparable to the wavelength, creating multiple leakage through the wall structure and thus this type of model is to take care of all the three regions of propagation pass. To aid the cost efficient and time saving installation of a shielded enclosure, a type of inexpensive and sufficiently accurate theoretical SE computation method, based on a circuit approach, is presented here for the microwave frequency range. Propagation of the electromagnetic waves inside and outside the shielding enclosure is modeled using well established modeling approaches. The waveguide model is applied here to treat each structural imperfection inside the shield region as a coupling slot. The method takes into account guaranteed tolerance and assembling technology used during the implementation stage, as well as the way the SE is evaluated during the acceptance test. Flexibility of the SE calculation method allows one to change the enclosure structural configuration, modify the measurement setup, and vary the construction materials.