Determination of the coupling model of common mode chokes using a TEM cell

Filter design heavily depends on magnetic inter-component couplings. To determine the magnetic coupling, i.e. the mutual inductance between two components, it is necessary to define a coupling model, in order to figure out to which extent a component catches the magnetic field. The coupling model of complex components, such as common mode chokes, cannot be established directly from geometry because of the number of ports, the possible modes (common and differential) and the magnetic material. This paper presents a procedure to determine the coupling model of common mode chokes using a TEM (Transverse ElectroMagnetic) cell.