Scattering Analysis of an Unequal-Length Dipole Array in the Presence of Mutual Coupling [Antenna Applications Corner]

The scattering behavior of a phased array depends on its design parameters, feeding network, and the platform over which it is mounted. In this paper, the total scattered field from an unequal-length dipole array is analyzed towards controlling the radar cross section (RCS) of the array. The mutual-coupling effect between the dipole elements is taken into account. The RCS of a non-skewed linear dipole array is analytically estimated by computing the signal reflections at each level of the antenna system. The closed-form formulation for the RCS estimation of the dipole array is separately presented for both series and parallel feeding networks. An attempt has been made to explain the variations observed in the RCS patterns corresponding to different configurations of unequal length dipole arrays arbitrarily arranged. The effects on the array's RCS of optimizing the lengths of the dipoles and of other parameters are discussed. It is shown that the appropriate choice of the lengths of the dipoles can contribute towards the reduction of the array's RCS.