Finiteness effects in wideband connected arrays : analytical models to highlight the effects of the loading impedances

Most phased arrays are designed using infinite array theory, which does not account for edge effects. However, this approximation might not be adequate for the design of wideband arrays, for which truncation effects are more significant than in traditional narrow-band arrays. In particular, edge effects can be very severe in broadband connected arrays, since the inter-element connection facilitates the propagation of edge-born waves that can become dominant over large portions of the arrays. This paper presents a formulation based on Green's function for the analysis of finite connected arrays. We first rigorously derive the electric current distribution on the array with an efficient numerical solution. Later on, the introduction of a few simplifying assumptions allows the derivation of an analytical approximation for the current distribution. This latter provides meaningful insights in the induced dominant edge-wave phenomena.