A reciprocity relation between the transmitting and the receiving properties of an antenna

Summary A reciprocity relation between the transmitting and the receiving properties of an antenna is derived. In the transmitting situation a certain part of the antenna, called source domain, is capable of carrying external currents, both of the electric and the magnetic type. In the receiving situation a plane electromagnetic wave is incident upon the antenna system.Whereas the customary way of deriving reciprocity relations in antenna theory starts with considering two separate antennas, the present method assumes a single antenna only.