How do ferrites reduce signal loss in long-distance transmission lines?

Ferrites reduce signal loss in long-distance transmission lines primarily by serving as load coils.1

In the context of materials science, ceramic ferrites are highly valued for their high electrical resistance, which is significantly greater than that of magnetic metals. This high resistivity is achieved during processing by oxidizing the grain boundaries to create resistive internal layers.21

This property is critical because it minimizes the occurrence of eddy currents—unwanted electrical currents induced by rapidly fluctuating magnetic fields—which otherwise dissipate signal energy as heat. By effectively suppressing these eddy currents, ferrites allow for more efficient signal transmission, particularly in telecommunications and high-frequency applications.21