Statistical Analysis of Electric-Field Distribution and Radiation Characteristics From a Perforated Enclosure Excited by Built-In Devices

The electronic devices working inside the enclosure will affect the internal electromagnetic (EM) environment, and their radiated EM energy will also be coupled out through the apertures, which could affect the surrounding equipment. In this article, the built-in transmission line and printed circuit board are considered, respectively, to analyze their influence on the deterministic and statistical distribution of the internal EM environment at different frequencies and positions. Second, based on the radiation power of the built-in device, combined with the coupling cross-section of the aperture, the statistical method is used to quickly calculate the leaking power outward the perforated enclosure. Finally, a three-dimensional positioning system is developed to measure the statistical characteristics of the internal electric field and the outward radiation power, which are in good agreement with the calculation ones. It is revealed that when the device is working at a high frequency, the field modes excited simultaneously increases, the complexity of the EM environment increases, and the field distribution is complex and chaotic. The change of the frequency or position will cause drastic changes in the deterministic field distribution. However, from the probability density functions of the electric field, the position of the built-in device has little effect on the statistical characteristics.