B. D. Manuilov, A. A. Kuznetsov

The mathematical model of plane finite dipole array placed over infinite perfectly conducting ground plane is proposed. The model based on scattering matrix technique includes antenna aperture and beam-forming multi-port network which consists of power distribution network and complex-weight two-port circuits controlling the amplitudes and phases of each individual element of antenna array. To shape multi-beam radiation pattern the matrix synthesis method with independent control of directions and amplitudes of beams is applied. The scattering matrix of antenna aperture is evaluated using the orthogonalization matrix of currents introduced by D.M. Sazonov and dipole input impedance matrix. The known representations of structural and antenna components of scattering cross-section are discussed. The correction of these representations is introduced for the case of arrays with multi-beam radiation patterns. It is shown that the form of structural component of the array scattering pattern does not depend on amplitude and phase distribution. However, to calculate the scattering pattern the orthogonalization matrix of currents should be taken into account. By certain conditions the structural component of array scattering pattern has diffraction maximums. Since the directivity of antenna array with multi-beam radiation pattern is less than for the antenna arrays with single-beam radiation pattern, the maximal values of antenna components of scattering cross-section by shaping of multi-lobe radiation patterns are less too. This effect may be accompanied by increase of structural components of scattering cross-section. The calculated 3-dimentional scattering patterns and maximal values of scattering cross-section components for 144-element array of dipoles are considered.