Consider a passive lossless $n$-port as shown in "ig. P5.4. Show that it possesses a scattering matrix [S], referred to real terminations, which satisfies the same properties of Theorem 5.2 except that [S] is now an $n \times n$ matrix. In particular, show that the entries of $[S] \varepsilon$ defined by
(a) $S_{i t}=$ reflection coefficient of the one-port formed by closing all the other ports on their reference resistors.
(b) $S_{i j}(i \neq j)=$ transmission coefficient from port $j$ to port $i$ under reference terminating conditions.