EMI/EMC Shielding: Key to Protecting Military Devices and Personnel

EMI/EMC (electromagnetic interference/electromagnetic compatibility) shielding is used to give a device total protection from its outside environment and any potential interference that may affect its performance, which can be dangerous depending on the purpose of the equipment.

EMI/EMC shielding is particularly crucial for the DoD. Consequently, EMI/EMC shielding has become a common addition to military technology to allow defense personnel to protect sensitive equipment against interference.

For Army personnel, for example, scrambled or missing transmissions can put troops in harm’s way. Shielding prevents EMI from disrupting communications among devices.

EMI shielding in military flight systems helps prevent the shutdown of engines and scrambling of digital instruments.

Then there’s necessary EMI protection for military radio controllers/control panels. EMI shielding designs based on interference information help with this.

Even drones need EMI shielding. Flexible and lightweight shielding can isolate wireless gadgets from emitting or receiving signals.

One of the main principles in the design of EMI shielding is that you need to use conductive materials to form the barrier which will break the interference, and this is based on the idea of the Faraday cage.

This is the relatively simple aspect of shielding construction – but the more complicated element is that the device needs to be completely enveloped by the enclosure. This is not easy to achieve when access to the device itself is needed, and many shielding enclosures come in at least two parts for this reason.

The conductive continuity between these two parts must not be broken, otherwise the interference can find its way through the gap and the shielding will be rendered useless. This space is often filled by rubber seals in order to keep out environmental hazards such as water and dirt, but because EMI can pass through rubber this must also be enclosed in metal wire that maintains contact with both parts of the enclosure.

Usually, as long as any gaps left are under 3mm, effective shielding from EMI can still be maintained.

Want to learn more? Tonex offers Military EMI/EMC Training, a 3-day comprehensive course that covers the theory of EMC/EMI and all aspects of MIL-STD-461 and MIl-STD-464. Training also covers the basic math and the physics of EMI/EMC and the fundamentals of instrumentation, instruments, test setups and real measurements.

For more information, questions, comments, contact us.