EMI Shielding Technology Applications in Defence Systems
As the defence industry continues to push the boundaries on advanced electronic systems and state-of-the-art communication devices, the requirements governing these programs must follow suit. Among the many technical requirements is Electromagnetic Compatibility, defined as the ability of a device to withstand both anticipated and unanticipated electronic interference (EMI) as well as minimise the interference being radiated.
It’s important to note that electromagnetic compatibility is a requirement across a variety of platforms in military technology including, but not limited to: missile and missile defence, ground vehicles, man-portable communication, electronic warfare/radar, stationary shelters, and avionics. Additionally, commercial technology such as aircraft and satellites often adopt military standards for electromagnetic shielding.
Missiles and missile defence
Innovation and improvements in war-fighting over the past several decades have led to the improvement of key weapons systems, most notably the missile defence arsenal. As weapons improve range, minimise collateral damage, and attempt to outpace anti-missile efforts, a greater focus has been placed on electronic controls and built-in fail-safe measures. These measures are developed to the highest EMI standards for the safety of military personnel, with elastomer gaskets and conductive paints serving to ensure weather sealing and minimisation of interference.
Ground vehicles
Humvees and tanks are built for durability in all environments, with the safety of the crew a top priority. To ensure proper function of the engine components, weapons systems, and data transmission, these vehicles must meet EMI standards. Expanded aluminium gaskets for turret and antenna mounts are just one example of shielding efforts on both the interior and exterior of the vehicle.
Man-portable communication
Defence research and development continues to optimise the gear used by servicemen and women, both in combat and support roles. The first line of communication is the direct unit carried by those who serve, whether built into helmets/headsets or carried in the form of hand-held devices. Each device is tested and retested, verifying that interference will not present hazards at the most inopportune times. EMI shielded displays on these devices ensure minimal interference with maximum information transmission.
Electronic warfare/radar
Radar and electronic warfare modules come in all sizes, from under-wing units on fighter jets to stationary units the size of a small island. Each unit, whether stationary or mobile, must pass stringent electronic emissions and susceptibility standards to ensure that billions of dollars of development and manufacturing yield the most advanced technology.
Stationary shelters
Ground control shelters have become mobile mission control hubs, storing a great deal of technology inside. EMI shielding caulks and compounds at the seams ensure that only the proper information is relayed as expected.
Avionics
Onboard electronics equipment such as flight recorders, navigation units, flight-control systems, and radios are perfect examples of components that must comply with EMI shielding specifications. These devices are mission-critical, with the slightest interference potentially causing communication delays or misinformation presented to the crew or ground control staffs. Commercial aircraft observe similar safety requirements while including additional electronics such as in-flight entertainment units that utilise custom shielded display units.
EMI shielding is a crucial consideration in the safe and effective operation of defence electronic systems. Nearly every device developed for military and aerospace applications must utilise gaskets, coatings, adhesives, or a variety of other sub-components in meeting rigorous military electronics standards. Additional technical information and specific metrics on defence requirements for electromagnetic compatibility can be found in MIL-STD 461G.