We live in a world of technology where the majority of the population make regular use of multiple electronic devices such as laptops, cell phones, tablets and TV’s. Each electrical or electronic device has the potential to emit electromagnetic radiation and this radiation, in addition to the natural sources of electromagnetic radiation means that there is an ever increasing exposure to electromagnetic fields. It is invisible, we cannot see it, we cannot hear it but we may become aware of its presence as interference. If a cell phone for example is placed beside equipment such as speakers, we may hear a buzz or crackling from the speaker. This interference can be a nuisance but it can also have the potential to cause damage to equipment, cause it to function less effectively or render it useless. It becomes a much more serious problem if the electromagnetic fields cause difficulty for vital equipment such as life support machines in hospitals, security equipment or aviation equipment.
The interference is known as electromagnetic interference or EMI.
There are regulations in place for the manufacturers of devices which means that devices have to be able to withstand a certain amount of EMI without becoming damaged or disabled and in addition, the emissions from devices have to also be controlled. The process by which devices can work alongside each other is known as electromagnetic capability (EMC).
A process known as electromagnetic shielding is employed to allow devices to have that capability and metals such as copper, stainless steel, aluminium and zinc are employed for that purpose using a variety of techniques.
EMI shielding is applied to various devices and care is taken to prevent the escape of EM energy not only into the environment but into the circuitry of the appliance itself. Consideration is often given to shielding the circuitry as well as the enclosure itself. Shielding is not visible as it is incorporated as part of the device within the internal system or outer casing.
In our path through life, we encounter many technologies and sophisticated examples of EMI shielding, consider the following 5 examples
Aeroplanes have to be able to communicate with the ground via sophisticated electronic equipment. A malfunction could have very serious consequences.
Vehicles are using more and more sophisticated pieces of electronics and the electronic components have to be protected from each other to prevent malfunction.
Life saving equipment and state of the art technological advances are evident throughout hospitals. Shielding has to be employed using a variety of techniques to protect the vital and very expensive pieces of technology. A malfunction could be life threatening.
Our devices such as laptops, cell phones and tablets contain shielding and that is becoming more and more essential as manufacturers continue to add more and more features into the equipment. The features involve circuitry and components which have to be shielded from each other to avoid damage to the device.
Military / Defence Equipment
Highly effective shielding techniques are employed in this sector to ensure our security and safety. Measures have to be taken to protect sensitive data.
Most manufacturers of equipment will now consider EMI shielding early on in the design process and are coming up with increasingly sophisticated methods of shielding using various materials and techniques. As our use of technology increases so does the need for better and more innovative shielding techniques.