Equivalent Transmission Line Models for the Analysis of Edge Effects in Finite Connected and Tightly Coupled Arrays

In this paper, we present an analysis of the edge effects in wideband connected arrays of slots and dipoles. Due to the strong mutual coupling between the elements, these arrays can support the propagation of guided waves along their surface. Such waves arise from the edges of the finite array and can be especially detrimental to the performance, since they can travel within the array without geometrical spreading. In this paper, we introduce Green's function-based equivalent transmission line models to describe the propagation of the guided waves. The elements' active impedances are represented as periodic loads on these transmission lines. The equivalent models can be used as a simple and convenient tool to control and minimize the edge effects. Finite array simulations of relevant array structures are discussed. The evidence is that the active impedance and the interelement capacitance can be tuned to attenuate and reflect the edge-born waves.