ABSTRACT

Cables are a major source of radiated emissions and receptors in electromagnetic coupling. The physical characteristics of a cable play a large role in its shielding effectiveness. Types of shielded cable are single braid, double braid, triple braid, two types of foil, braid and foil, conduit, semi rigid and flexible corrugated conduit. The shielding effectiveness of the coaxial cable against a magnetic field may be seen by comparing the shielded case to an unshielded cable. The lowest transfer impedance is with two layers of shielding, one the outside layer and the second the individual shield over the pairs of conductors. The coupling into a shielded or unshielded wire disconnected from ground and far removed from a ground plane. Maximum coupling occurs for a plane wave when the plane of incidence is coincident with the plane of the loop, with the magnetic field perpendicular to the plane of incidence.