Question

3. In the transmission line of Fig.P.1, RL = 20 = 50 2, and Ry =75 2. Determine and plot the voltage at the load resistor as functions of time for (4 1/v) by constructing appropriate voltage reflection diagrams: Referring to the figure, closing the switch launches a voltage wave whose value is found trough simple voltage division, ig. P.2 may serve as a guidline on how to plot the voltage at the load. 11 ating Zo RL =0 ==1 Fig. P.1 transmission line 137 31 Hv 0 Fig. P.2 2 Voltage reflection diagram

Answer 1

Sci Transmission line voltage equation V= vote & vo 12 Where a length V = Vote (+iB)2 + vó é (actiß)2 > Incident voltage Reflected Voltage it travell 20 mt from load then 2=-20 20 Incident voltage Amplitude Amplitude = vote ^ (Imercase) Reflected voltage Amplitude (decrease) at load a=0 Amplitude mot (for incident wave) Increase in Amplitude Amplitude llo-Cfor reflected waves Decrease in Amplitude = In phase Angle it is change of ie B2 = 3.483X 20 200 - e -200 +32 z 69. 66 had.

2L RL = 50 20 = 50 p=2L-20 1elyeso 2L+20 VSWR Ite an l-e perfectly matched transmission line there is no Teflection of voltage at load resistance. RL=20=500 Rg = 7552

t=0 R2=202502 Rg = 75.2 IRL 20 Zil Zo Source voltage reflection coelbicient = fg=Rg-20 Rg+20 75-50 75+50 202 Trans time =T= h seconds Incident voltage = vita vg. zo (Rg+20) vg 50 75750 Vit T- = 0.48g - 27 Vi=truit = oxvit=o 1127 3TH -- 414 vat = Tg vizo vą = TL v2 t=0 Vg * = Jg vq zo t t l O Tg 0.419 Vittur, 0,4 g t velvil T 31 51 voltage at land