Why are shields used in electrical cable?
In addition to the benefit of protection against damage to cable components from cable motion and use, proper shielding is essential to many applications as it can keep out unwanted external interference. In many applications, electromagnetic interference (EMI) is a threat to signal integrity. Shield quality is of particular importance in small signal or high frequency applications where a slight variation can have significant impact. All electrical cable will radiate energy to, and pick up energy from, its surroundings. As such, shielding can also be used to contain the electromagnetic energy radiated by a cable, which can protect nearby sensitive components.
