Antenna coupling in multi active multi passive port topologies

The electromagnetic (EM) coupling between pairs of antennas in a system comprised of μ active RF ports and M passive ones is expressed under arbitrary complex terminations by obtaining the effective transfer function between the active ports using Mason´s rule. Unlike a previous approach where the mutual impedance matrix of N+M dimensions is collapsed to N dimensions, the proposed approach directly estimates the effective coupling from the reference scattering parameters and the complex terminations.