On generalizations of the maximum power transfer problem

The necessary conditions for maximum power transfer to the outputs of a multiport are discussed. The condition Z = Z
0
^*
is sufficient. A solution to this problem is not generally unique, because the matrix Z must satisfy the matrix equation Z(Z
0
+ Z
0
^*
)
^-1
E
0
= - Z
0
(Z
0
+ Z
0
^*
)
^-1
E
0
+ E
0
. When the power transfer is maximum, only the total power of the equivalent sources is equally divided between the "passive" multiport and the ports.