Belevitch's theorem
Belevitch's theorem is a theorem in electrical network analysis due to the Russo-Belgian mathematician Vitold Belevitch. The theorem provides a test for a given S-matrix to determine whether or not it can be constructed as a lossless rational two-port network.
Lossless implies that the network contains only inductances and capacitances – no resistances. Rational implies that the network consists solely of discrete elements.The theorem
For a given S-matrix of degree ;
Belevitch's theorem states that, represents a lossless rational network if and only if,
