In
antenna design theory, the phase center is the point from which the
electromagnetic radiation
In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength ...
spreads spherically outward, with the
phase
Phase or phases may refer to:
Science
*State of matter, or phase, one of the distinct forms in which matter can exist
*Phase (matter), a region of space throughout which all physical properties are essentially uniform
*Phase space, a mathematica ...
of the signal being equal at any point on the sphere. Apparent phase center is used to describe the phase center in a limited section of the
radiation pattern
In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the ''directional'' (angular) dependence of the strength of the radio waves from the antenna or other source.Constantine A. Balanis: " ...
.
If it is used in the context of an
antenna array
An antenna array (or array antenna) is a set of multiple connected antenna (radio), antennas which work together as a single antenna, to transmit or receive radio waves. The individual antennas (called ''elements'') are usually connected to a s ...
, one has to define a reference point from which the basevectors of the single elements are referred to.
The phase center may vary, depended on the beamforming algorithm. It produces the weight vector, that may vary over time depending on the geometrical setup as well as the receive conditions.
References
* J. D. Dyson, “Determination of the Phase Center and Phase Patterns of Antennas,” in Radio Antennas for Aircraft and Aerospace Vehicles, W. T. Blackband (ed.), AGARD Conference Proceedings, No. 15, Slough, England Technivision Services, 1967.
* Y. Y. Hu, “A Method of Determining Phase Centers and Its Applications to Electromagnetic Horns,” Journal of the Franklin Institute, Vol. 271, pp. 31–39, January 1961.
Antennas
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