EXAMPLE OF SELECTIVE SHIELDING
To eliminate pickup from the electric field, the loop could be shielded as shown below. However, this configuration allows shield current to flow, which will cancel the magnetic field as well as the electric field. To preserve the magnetic sensitivity of the loop, the shield must be broken to prevent the flow of shield current. This can be done as shown in Fig. C by breaking the shield at the top. The resulting antenna responds only to the magnetic filed component of an applied wave.