Calculating surface current distribution in antenna array in the presence of mutual coupling by analytical solving of Pocklington’s integral equation

In this article, the current distribution of an antenna array in the presence of mutual coupling is calculated analytically by solving Pocklington’s integral equation. Blockpulse and Galerkin’s functions are used for numerical solving of Pocklington’s integral equation. In this work, the surface current distribution can be achieved for an antenna array in receiving mode, with any arbitrary structure and various numbers of elements. In all previous works, the authors have been tried to solve Pocklington’s integral equation for a single half dipole antenna in transmitting mode. Pocklington’s equation is somehow difficult to work with because of the singularity and existence of a sharp peak for a small value of wire’s radius. In order to calculate surface current distribution, for thin wires, singularity part is extracted from the kernel in aforementioned integral. Hence, the kernel is decomposed into singular and nonsingular parts. An inter-element mutual coupling effect between array elements and self-coupling for each element are assumed in this case. The validity of the proposed methodology is tested by numerical simulation results. The accuracy of the proposed method is evaluated by the multiple signal classification (MUSIC) algorithm for different scenarios to direction of arrival (DOA) estimation.