Shielding Effectiveness Test

Shielding Effectiveness Test

Shielding effectiveness testing is essential to determine a material’s or enclosure’s capacity to block radio frequency and electromagnetic signals. It can be used to achieve one of three objectives. The first one is to confine RF signals within the container of a device, which is a requirement for product certification. The second one is to protect the device from external EMI. The third one is to ensure that all RF energy is confined within the container and external RF signals are isolated. 

The test method depends on the size and make-up of the sample, and it can be conducted on material samples, enclosed equipment, and complete facilities. Two EMC test chambers are connected and share a wall, with the sample safely positioned in the window on the common wall. An antenna for broadcasting is placed in one chamber and an antenna for receiving in the other. 

Testing electronic devices is done inside an EMC test chamber, where the device is powered and operated. The receiving antenna records EMI produced by the device, and then signals are sent to test for any unacceptably negative effects on the device. 

Cable shielding is another important aspect of the assessment. Depending on the material used, thickness, shielded volume, and frequency of the fields, the amount of reduction in radio waves, electromagnetic fields, and electrostatic fields will vary. The size, shape, and orientation of apertures in a shield to an incident electromagnetic field also affect the effectiveness of the shielding. 

Overall, assessing shielding effectiveness is a vital step for many industries to ensure the safety and reliability of their products and facilities.