Relation between diagram correlation factors and s-parameters of multiport antenna with arbitrary feeding network

Antenna diversity demands a sufficiently low diagram correlation factor p. A universal relation between p and the scatter parameters of a multiport antenna is derived for arbitrary numbers of ports and radiating elements. It is shown that the diagram correlation factor depends significantly on the number of ports. While for a two-port antenna a vanishing correlation factor can be achieved with port matching only, this is not possible for multiport antennas with port numbers greater than two.