IEEE 145-1973

This standard is a comprehensive revision and extension of the previous Standard Definitions of Terms of Antennas. It is assumed in this standard that an antenna is a passive linear reciprocal device. Thus, where a definition implies the use of an antenna in a transmitting situation, its use in a receiving situation is also implicit unless specifically stated otherrewise. When an antenna or group of antennas is combined with circuit elements that are active, nonlinear, or nonreciprocal, the combination is regarded as a system which includes an antenna. Examples of such cases are an adaptive antenna system and a signalprocessing antenna system; the complete conical- scanning, monopulse, and compound interferometer systems also fall in this category.



Revision Standard - Superseded. 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.