PCB Level Shielding Effectiveness Evaluation in Near Field by Using Electromagnetic 3D Scanner

摘要

Shielding always play a main role in the effort to control electromagnetic interference of an electronic device. Metal shield cans had been widely used in electronic industry to ensure the compliance of products to Electromagnetic Compatibility (EMC) standard. The rapid growth of technology evolution urges wireless electronics devices to become thinner, smaller, and faster; they are operating in higher frequency, commonly up to Giga-Hertz. These smaller form factors make the PCB layout getting more compact and the spacing between components greatly reduced. These limitations earn a drawback that high frequency nature of the signals easily coupled among traces and components. Therefore, in this paper, a near field PCB-level shielding effectiveness evaluation method of small shield cans using a 3D Electromagnetic scanner is proposed. To verify the measurement result, a reliable simulation tools, Computer Simulation Technology (CST) Microwave Studio was applied. From the simulation and real measurement, decent and accurate results were obtained.