A current distortion parameter for characterizing coupling of antennas

Abstract

A current distortion parameter for characterizing the coupling of antennas is proposed, which is based on the difference between the current distributions with and without the coupling. The parameter describes the influence of the mutual coupling between antennas on the current distribution comprehensively, and thus, it can act as a supplement to S parameters for the mutual coupling characterization and the decoupling structure evaluation. The current distortion parameter can also assess a coupling effect caused by a non-free-space environment on the antenna current and indicates the sensitivity of the antenna to the non-free-space environment. Several examples, including two thin dipole antenna arrays, two printed dipole antennas with a decoupling structure, an array of two patch antennas, and a thin dipole antenna with a metallic bar, demonstrate the usefulness of the current distortion parameter for the antennas coupling investigation.