ANTENNA, a device for radiating or absorbing radio waves. There are two general classes of antennae, the condenser and the coil. The condenser type consists of an elevated horizontal aerial, together with a connection to the ground or to a network of wires near the ground, called a counterpoise. The coil type consists of a few turns of wire wound around a vertical frame which, for broadcast reception, may be 2 or 3f t. square.