A distortionless line has a characteristic impedance Z_{o}= 50[Ω] and a propagation constant γ = 0.01 + j 4.0[m^{-1}] at frequency f = 100[MHz] . Find R, L, G, C, and v_{p}.
From Eqs. (9-25c) and (9-25d), we have
\beta = \omega \sqrt{LC} (9-25c)\\ Z_{o} = \sqrt{\frac{L (R / L + j \omega )}{ C ( G / C + j \omega )} } =\sqrt{\frac{L}{C} } \text{(characteristic impedance)} (9-25d) \\ \beta = \omega \sqrt{LC} = 2\pi \times 10^{8} \sqrt{LC} = 4.0 \\ Z_{o} = \sqrt{L / C} = 50From the above equations we obtain
L = 318[nH/m]
C = 127[pF/m]
From Eq. (9-25b) we obtain
\alpha = G \sqrt{L / C} = R \sqrt{C/L} (9-25b)
\alpha = G \sqrt{L / C} = G Z_{o} = 0.01, and thus
G = 200[μS/m]
From the relation RC = GL we obtain
R = \frac{GL}{C} = \frac{200 \times 10^{-6} \times 318 \times 10^{-9}}{127 \times 10^{-12}} = 0.50 [\Omega / m]Phase velocity is therefore
v_{p} = \frac{\omega }{\beta } = \frac{2 \pi \times 10^{8}}{4} = 1.57 \times 10^{8} [m / s]