The condition for reciprocity for a two-port transmission network is expressed by
1
\(\left|\begin{array}{ll}\text{A} & \text{D} \\ \text{B} & \text{C}\end{array}\right|=1\)
2
\(\left|\begin{array}{ll}\text{A} & \text{C} \\ \text{B} & \text{D}\end{array}\right|=0\)
3
\(\left|\begin{array}{ll} \text{A} & \text{B} \\ \text{C} & \text{D} \end{array}\right|=0\)
4
\(\left|\begin{array}{ll}\text{A} & \text{B} \\ \text{C} & \text{D}\end{array}\right|=1\)