GATE ECE 2006 | Question: 30

Question

A two-port network is represented by $\text{ABCD}$ parameters given by

$$ \left[\begin{array}{c} \mathrm{V}_1 \\ \mathrm{I}_1 \end{array}\right]=\left[\begin{array}{ll} \mathrm{A} & \mathrm{B} \\ \mathrm{C} & \mathrm{D} \end{array}\right]\left[\begin{array}{c} \mathrm{V}_2 \\ -\mathrm{I}_2 \end{array}\right] $$

if port-$2$ is terminated by $\text{R}_\text{L},$ then input impedance seen at port-$1$ is given by

• A. $\frac{\mathrm{A}+\mathrm{BR}_{\mathrm{L}}}{\mathrm{C}+\mathrm{DR}_{\mathrm{L}}}$
• B. $\frac{\mathrm{AR}_{\mathrm{L}}+\mathrm{C}}{\mathrm{BR}_{\mathrm{L}}+\mathrm{D}}$
• C. $\frac{\mathrm{DR}_{\mathrm{L}}+\mathrm{A}}{\mathrm{BR}_{\mathrm{L}}+\mathrm{C}}$
• D. $\frac{\mathrm{B}+\mathrm{AR}_{\mathrm{L}}}{\mathrm{D}+\mathrm{CR}_{\mathrm{L}}}$