Mutual Coupling of Antennas With Overlapping Minimum Spheres Based on the Transformation Between Spherical and Plane Vector Waves

Mutual coupling in finite arrays of antennas with strongly overlapping minimum spheres is quickly calculated by computing the general translation matrix between spherical modes. This obtained using transformation properties and plane vector waves. Although this approach less efficient than classical one, which based on addition theorems, it allows to overcome well-known limitation theorems that requires nonintersecting spheres. Symmetry relations are provided for coefficients greatly increase speed computation matrix. By reflection transmission submatrices generalized scattering a antenna array, accurate results S-parameters radiation patterns arrays, comparison commercial software or purely numerical in-house full-wave method. For purpose, different types hemispheres an array environment ground used, such as apertures, monopoles, cavity-backed patch antennas, dielectric resonator antennas.