Accurate Modeling of the Electromagnetic Field of Loop-Coupled Shielded Enclosures with Apertures

In this contribution we analyze the problem of the electromagnetic field radiated from apertures in metallic enclosures, fed by a coaxial cable, such as, for example, in PC environments. In particular, we develop an accurate model of the entire structure, including the coaxial line-loop-cavity coupling. The analysis is developed by means of two different methods, the Transmission Line Matrix (TLM) method and the Integral Equation (IE) method. The former is particularly suited to the modeling of arbitrarily shaped and complex structures, the latter is a rigorous approach based on the equivalence principle and leading to an integral equation formulation that is solved by the Method of Moments (MoM) approach. Theoretical results are compared with experimental ones showing very good agreement. The evaluation of the reflection coefficient and the input impedance of the structure (coaxial line-enclosure) leads to an equivalent circuit formulation, which is highly helpful for the engineering design of the entire structure.