In our increasingly interconnected and electronic-driven world, Electromagnetic Interference (EMI) is everywhere. Since EMI can impact all kinds of functions, causing device malfunction, data loss, and other similar issues, the importance of electromagnetic interference (EMI) shielding cannot be overstated. EMI shielding is crucial for protecting PCBs of sensitive electronic components and systems from different device interference. Whether you're developing cutting-edge communication devices, medical equipment, or industrial machinery, ensuring that your products are resistant to EMI is vital for their performance and reliability.
Having said this, in order to ensure the effectiveness of EMI shielding, it is important to test its effectiveness in the design and manufacturing process. It involves a series of evaluations to determine how well a material or enclosure can block or attenuate electromagnetic interference. There are several methods and best practices in place for testing EMI shielding effectiveness, which determines the ability of material and enclosures to block electromagnetic and radio frequency (RF) signals. Would you like to know about a few of the popularly used methods to test EMI shielding effectiveness? Read the post to know.
Popular Methods of EMI Shielding Effectiveness Testing
The EMI shielding effectiveness is evaluated by measuring the EMI and RF signal attenuation on a shield under different conditions. Here are the major types of EMI shielding effectiveness tests:
- Shielded Room Test: Requiring two shielded rooms with a wall between them, this test measures the effectiveness of shielding materials or enclosures in a controlled environment. These rooms can be designed in different dimensions with very high attenuation values, providing accurate results for various frequency ranges.
- Shielded Box Test: Performed within a completely sealed box with a cut-out portion to insert the shielding material, this test helps to measure all transmitted and received emissions. Widely chosen to test frequencies less than 500 megahertz. The method also measures the difference between internal and external EMI..
- Coaxial Transmission Line Test: Designed to measure lane-wave field electromagnetic wave radiation in planar material, this test follows the specifications of the ASTM D4935 standard to test frequencies between 30 MHz and 1.5 GHz.
- Open Field Test: This specific test, which is designed to simulate normal usage conditions for electronics, allows for measurements of radiated field strength and conductive emissions. The test aims to replicate the real-use conditions, for instance, the test is conducted by placing the testing equipment in an open area without other electrical devices nearby.
Different EMI Shielding Effectiveness Standards
With the growing importance of electronic devices in every aspect of our lives, governments worldwide have implemented strict regulations to ensure these devices meet minimum EMI shielding standards. Industries such as military and defense, aerospace, medical, and automotive have established stringent regulations and standards to ensure the EMI shielding effectiveness of electronic equipment. Manufacturers regularly test their devices against standards set by organizations like the IEC, ASTM, IEEE, and MIL to guarantee compliance with these EMI shielding requirements.
- ASTM D4935: This standard suggests the methods for measuring the shielding effectiveness of flat, planar materials in the frequency range of 30 MHz to 1.5 GHz.
- MIL-DTL-83528: This military specification outlines the requirements for conductive elastomeric shielding gaskets used for EMI suppression.
- MIL-STD-461: Extensively used in defense and aerospace sectors, this standard defines the requirements for controlling EMI emissions and susceptibility characteristics of electronic, electrical, and electromechanical equipment.
- IEEE 299-2006: This IEEE standard is used to evaluate the performance of shielded rooms, cabinets, and other enclosures that are specifically created to block electromagnetic interference.
- IEC 61000-5-7: This testing standard is applicable for testing the EMI shielding effectiveness of empty enclosures.
Ensuring the effectiveness of EMI shielding is essential for the reliable performance of sensitive devices in our electronic driven world. This is where XGR Technologies' SnapShot® board-level shields stand out in the marketplace. These shields have undergone rigorous testing and have consistently outperformed traditional EMI shields, making them the ideal choice for applications requiring the highest levels of protection against electromagnetic interference.
