IEEE Standard Definitions of Terms for Antennas

In 1969, IEEE Standard 145 was published as a list of basic terms of antenna theory and practice. That document treated antenna gain as a fundamental property, with impedance and polarization as independent properties. The definitions of gain, directivity, impedance, and polarization were worded to emphasize this independence. Various other significant groups of terms were also defined, such as the regions of the electromagnetic field of an antenna, the terms relating to cross section, the tracking antenna techniques, and the idealized radiators.