Shielding performance of a metallic rack used for telecommunication equipments: FIT modeling and measurements

The ever growing increase in speed of digital signals has made more difficult the achievement of conformity about limits emissions. It often happens that to verify the requirements of standards on these emissions the use of a metallic enclosure is necessary: in this way the power radiated by the system is reduced. The effect on radiated emission due to the presence of a slot on the frontal part of a metallic rack used for telecommunication equipment is studied both by dedicated experiments and by simulations. An internal source represented by a loaded monopole antenna is used to investigate the shielding behavior of the rack. A simplified model of the antenna source is presented and a good agreement over a frequency range up to 1 GHz is achieved between measured results and simulated results