Coupling Coefficient Matrix
For a matrix with entries Mij, i, j = 1,..., N, the coupling coefficient for row i and column j is given by the following equation:
This coefficient indicates how much flux in one coil is linked with the other coil.
If all the flux in one coil reaches the other coil, |k| = 1 (and coupling is 100%).
Inductors with |k| > 0.5 are tightly coupled. Inductors with |k| > 0.5 are loosely coupled.
The mutual inductance (M)
falls between 0 and (the geometric mean of the inductances).