S=\left[\begin{array}{cccc} 0.1 \angle 90^{\circ} & 0.8 \angle-45^{\circ} & 0.3 \angle-45^{\circ} & 0 \\ 0.8 \angle-45^{\circ} & 0 & 0 & 0.4 \angle 45^{\circ} \\ 0.3 \angle-45^{\circ} & 0 & 0

& 0.6 \angle-45^{\circ} \\ 0 & 0.4 \angle 45^{\circ} & 0.6 \angle-45^{\circ} & 0 \end{array}\right] (a) Lossless? Matrix must be unitary: (b) Reciprocal? (c) Return loss at port 1 with all other ports terminated. (d) Insertion loss and phase delay between port 2 and 4 all other ports terminated. (e) Reflection at port 1 if short circuit placed at port 3, other ports terminated.