Understanding the fundamental radiating properties of antennas with characteristic mode analysis

Characteristic mode analysis (CMA) is a useful design tool that equips antenna designers with a non-brute force way of systematically extracting the radiating properties of a structure. These properties are presented by CMA in the form of eigenvalues and eigenvectors, i.e. the solution of a generalised eigenvalue equation that is formulated from the MoM impedance matrix. An important aspect to note at this stage, is that the eigenvalue equation can be solved without taking into account the effect of sources. Only the geometrical properties of the structure are considered.