How do ferrite beads achieve anti-interference effect?

Ferrite magnetic beads are a kind of anti-interference components with rapid development. They are cheap and easy to use, and have a significant effect on filtering high-frequency noise. Interference refers to damage to the reception of useful signals. Anti jamming refers to the system or technology used to counter any interference of communication or radar operation.

Therefore, anti-interference components and anti-interference equipment generally refer to the equipment that can prevent electromagnetic interference acting on the equipment along the power line through the antenna input end, the shell of the equipment and the power line.

In the field of communication, signals are physical quantities that represent messages. For example, electrical signals can represent different messages through the changes of amplitude, frequency and phase. Interference refers to damage to the reception of useful signals. Interference generally consists of the following two kinds: crosstalk: the coupling phenomenon between two signal lines in electronics. Radio interference: the act of destroying communication and preventing radio signals by sending radio signals to reduce the signal-to-noise ratio.

Ferrite is a magnetic material, which will produce magnetic saturation due to excessive current, and the permeability will drop sharply. Magnetic beads specially designed in structure should be used for high current filtering, and its heat dissipation measures should also be paid attention to.

Ferrite magnetic beads can not only be used in power circuits to filter out high-frequency noise (DC and AC output), but also can be widely used in other circuits, and its volume can be made very small.

Especially in digital circuits, because the pulse signal contains high-frequency harmonics, which is also the main source of high-frequency radiation of the circuit, it can play the role of magnetic beads in this occasion. Ferrite magnetic beads are also widely used in noise filtering of signal cables.