In the analysis of isolation between two antennas, it is well known that the matching of both antennas affects the isolation. To remove the effect of antenna matching, Optenni Lab can calculate the so-called “electromagnetic isolation”. This means that at each frequency, two antenna ports are simultaneously conjugate matched while the others are terminated with given impedances.
For two-port systems, the electromagnetic isolation gives the worst-case isolation; the obtained isolation is always better than this due to impedance mismatch. The concept of electromagnetic isolation is used in, for example, the analysis of MIMO and diversity antennas.