An explicit relation between mutual coupling and the pattern of an antenna array

The effect of mutual coupling among the elementary antennas comprising an array in producing the radiation pattern of the array antenna is explicitly evaluated via a scattering formalism based on spherical modes. A relation between the coupling matrix of an -element array, considered as a dissipative -port, and the complex radiation pattern of the array antenna is obtained in terms of patterns associated with the elementary antennas. While the elementary patterns required are, in general, not those produced by each element when isolated from all others, for an array composed of (canonical) minimum scattering-antennas (e. g. dipoles) just these conventional patterns of the isolated elements are involved.