Limitations and Optimization of Supergain End-Fire Arrays

In this paper, the possibility to optimize supergain end-fire arrays is numerically investigated. Firstly, the optimization problems in terms of directivity and gain are introduced. Then, infinitesimal-dipole based end-fire arrays have been optimized as a function of the number of elements and inter-element spacing. It is shown that, their radiation efficiency can be predicted and, for close inter-element spacing, even optimized to provide a higher gain than the one obtained with the classical directivity optimization methods. The numerical analysis is detailed and validated by full wave simulations in the case of three half-wavelength dipoles.