Impact of Number of Slots and Permittivity on EMI Shielding Effectiveness

Abstract

All electronics equipment and devices emit electromagnetic energy. The emitted energy creates electromagnetic interference to the nearby electronic equipment. Shielding is the only effective method of reducing this type of interference without disturbing and reducing the performance of complex electronic systems. Shielding cages usually have openings or slots to provide ventilation and enable access to electronic components placed inside the cage. In this chapter, the impact of dimension of the shielding cage and the number of slots in the shielding cage are investigated. Relative permittivity reflects the electrical characteristics. Its impact on shielding effectiveness is also analyzed in this chapter. Simulation results shows decrease in the shielding effectiveness with the increase in number of slots as well as increase in relative permittivity. In addition, the shielding effectiveness decreases with the increase in frequency.