“Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.” This is how the Wikipedia defines EMI. Electromagnetic radiation passes through the air. It interferes with the proper operation of various types of electrical equipments. This is precisely why EMI shielding is imperative. Circuits are designed in a way that lessens the amount of electromagnetic interference produced. Ideally, circuits should provide enough EMI shielding to endure electromagnetic interference from the surroundings. But this is not always possible or achievable. So an EMI shielding becomes all the more pertinent. As electromagnetic radiation is a wave, the EMI shielding can avert the wave if designed in the right way. Apart from keeping a thorough check on the emissions from the equipment, the shielding is adept in obstructing radiation that would probably affect the unit. Do you hear any noise from the speakers of your car when you’re getting a phone call? It’s a fairly common occurrence. It takes place because the radio of your car picks up some of the signal from your mobile phone. The very term ‘interference’ refers to how unwanted this phenomenon is.
Electrical equipments are used by the likes of police personnel in order to communicate. Besides, we have computers, radios and mobile phones which function at radio frequencies. Quite naturally, these equipments are very likely to suffer interface from another electrical apparatus. Thus, electrical appliances are invariably affected by EMI (electromagnetic interference) interface and RFI (radio-frequency interference) interface.
TEM radiation is the most prevalent of all. Approximately 75 percent of the total EMI interference results from the interference of the radiation that is released in this manner. One of the reasons responsible for this is the common tendency among consumers to purchase computer systems that perform and function at augmented, higher frequencies. In that case, shielding the radiation emitted from the processors working at an elevated frequency rate is easier said than done.
To protect our mobile phones and computers, manufacturers and designers leave no stone unturned to design the appliance in a way that minimises the physical dimensions. As the size is more compact, the weight is diminished. With the cost of the device remaining moderate, the efficiency attains an optimum level. The same goes with other radio communication appliances. The advantage of electromagnetic shielding lies in protecting equipments from the danger of radiation. Also, it inevitably leads to a direct and proportional boost to the circuit speed.
Shielding is all the more indispensable when it comes to small and thickly packaged and sensitized appliances. With EMI shielding, it is necessary to lessen the impact of umwanted signals. Also, it is seen that the electronic equipment is not harmed in any possible way. Both the absorption and reflection of radio signals is taken into account. The new appliances run on a combination of two approaches, namely source suppression and containment.