Question

All transmission line section in figure, have a characteristic impedance $R_0+j_0$. The input imprdance $Z_{in}$ equals

• A. $\frac{3}{2}{R}_0$
• B. $\frac{2}{3}{R}_0$
• C. $R_0$
• D. $2R_0$

Answer 1

The correct option is C $R_0$

Ans : (b)

For $\lambda /4$ line

$Z_{i{n}_1}=\frac{Z_{01}^2}{Z_{L_1}}=\frac{R_0^2}{R_0/2}=2R_0$

For $\lambda /2$ line

$Z_{i{n}_2}=Z_{L_2}=2R_0$

$For\lambda /8line$

$Z_L=\left(Z_{i{n}_1}\right)\left|\right|\left(Z_{i{n}_2}\right)$

$Z_L=\left(2R_0\right)\left|\right|\left(2R_0\right)$

$Z_L=R_0$

$For\lambda /8line$

$Z_{in}=Z_0\left[\frac{Z_L+j{Z}_0}{Z_0+j{Z}_L}\right]$

$Z_{in}=R_0\left[\frac{R_0+j{R}_0}{R_0+j{R}_0}\right]=R_0$