Approximation of the Active Reflection Coefficient in Phased Arrays via the Concept of Reaction

Antenna array performance is often significantly influenced by the mutual coupling between the antenna elements. This influence is commonly completely neglected, if only the array factor is taken into account during antenna design and optimization, which can lead to serious errors in the prediction of the array performance. A precise calculation of the mutual coupling requires full-wave simulations whose costs are often prohibitive during design. In this work we present a low-computational-cost alternative for approximating the mutual coupling based on the reaction integral and the Huygens principle. For an exemplary 5 ×5 planar array, it is shown that our method provides a good first-order approximation of the active reflection with reasonable computational overhead.