Analysis of High-Order Mutual Coupling Effect of Antenna Arrays Based on Infinitesimal Dipole Model

The infinitesimal dipole model (IDM) is a crucial method for analyzing the electromagnetic characteristics of antennas. This article proposes a new approach to analyzing the admittance matrix of an antenna array, incorporating high-order mutual coupling effect, based on the IDM. First, the radiating element is modeled as a group of infinitesimal dipoles. Second, the mutual admittance between two arbitrary radiating elements is calculated using the reaction theorem, considering only first-order coupling effect. Third, starting from the mechanism of multipole electromagnetic scattering in a typical two-element array, the admittance matrix that includes high-order coupling effect is derived in detail. Consequently, the admittance matrix for an N-element antenna array is obtained. Numerical and experimental cases are presented to validate the proposed method.