A summary of the transmitting and receiving properties of antennas

An expression for the electric field radiated by an arbitrary current distribution is given, which leads to a straightforward characterization of an antenna by a complex vector called the equivalent length. All classical transmitting parameters-such as the radiated power density, power intensity, radiation resistance, directional gain, and gain-are simple functions of the equivalent length. The same is true for the receiving parameters: induced voltage, available power, equivalent surface, and antenna factor. Eliminating the equivalent length between the gain and an equivalent surface provides a simple, direct, and general proof of the fundamental relation for antennas