A Review of Antenna Analysis Using Characteristic Modes

Characteristic modes can be used to solve many radiation and scattering problems involving fully conducting structures. The basic concept is to use eigenvalues and eigenvectors of the characteristic mode equations of a certain topology, and to use these eigenmode currents to control the radiating structure's behavior. This is accomplished by understanding the overall reflection and radiation characteristics across the operating frequency band. More specifically, characteristic modes are effective for example in determining the best location for the excitation of a radiating structure. In this paper, a comprehensive overview is provided to the different studies and their results obtained for different antennas that are based on the characteristic mode analysis method. A future perspective is given regarding the potential of this method in antenna analysis and design.