On Computing the Mutual Coupling Between Two Antennas

The calculation of mutual coupling usually demands intense computations, especially for large aperture antennas placed in the near-field region of each other. In this article, the validity of an integral coupling formula is evaluated to demonstrate its utilizations where an efficient method for computing mutual coupling is most required. The integral coupling formula is used to compute the mutual coupling between two antennas in the near-field and far-field regions. The formula demonstrates fast and accurate computing properties based on typically available information such as 3-D vector far-field patterns and antenna configurations. Based on the coupling formula, a comprehensive evaluation is performed with respect to diverse antenna configurations, computation time, accuracy, and different polarizations. The expanded applicability of the formula is also examined through an antenna configuration, which includes a circular polarization selective surface (CPSS) structure to reduce the level of mutual coupling.