Electromagnetic interference (EMI), also called radio-frequency interference (RFI), is a disturbance generated by unwanted electrical signals. These unwanted signals can come from other electronic components or devices in the operating environment, or they may occur naturally, such as during lightning strikes. They can have harmful effects on equipment, reducing the performance of the equipment or even stopping it from functioning properly. EMI/RFI is a particular problem when it occurs in critical applications, including communication and military flight control systems, medical applications, and telecommunications.
Design engineers need a way to filter out the unwanted electrical signal, so it doesn’t harm additional components. In order to protect modern electronic systems from the abundance of EMI sources in today’s environments, a combination of approaches is implemented: shielding, filtering, and reduction of EMI at the source (if possible).
