Element gain in phased array antennas

Three expressions for element realized gain are discussed: the traditional (port referenced) definition is particularly suited for radiation pattern measurement; another (current referenced) is just as precise and suited for computation; and the third (scalar) is devoid of polarization information. The port referenced and current referenced gains are equal in the infinite array case. The scalar gain is limited to planar arrays and the absence of grating lobes. Because the port referenced and current referenced gains are dependent on the polarization of the receive antenna, they sometimes are referred to as vector gains. The geometry of an infinite array of dipole antennas for which element gain was computed is shown. The vector, scalar, and ideal (scalar with reflected power set to zero) element realized gains are computed. The impact of an edge on the element realized gain is assessed by measurement and analysis.<>