- #1
FrankJ777
- 140
- 6
Hi, I'm hoping somebody can help me understand something. I'm studying transmission lines and I'm confused about SWR and standing waves on a transmission line. According to my book the voltage on the transmision line is the super position of an incident and reflected voltage wave given by:
V[itex]_{(z)}[/itex] = V[itex]^{+}_{0}[/itex] ( e[itex]^{-jBz}[/itex] + [itex]\Gamma[/itex] e[itex]^{jBz}[/itex])
I can see how this produces a standing wave with voltage minimums and maximums at fixed points every λ/2. What I'm confused about is why the voltage is not represented as a function of time. From what I thought I understood about the phasor representation of the voltage we dropped the factor e[itex]^{jωt}[/itex] in our notation, but that it's understood that it's still there and the wave is still a funtion of time and frequency (jωt). So my questions are these. Are standing waves also a function of time and frequency, and if so would they be traveling waves? It seems that according to my text the min and max points are at fixed distances, so it seems that the voltage wave doesn't travel. So what happened to time and frequency?
Thanks to anyone who can set me straight.
V[itex]_{(z)}[/itex] = V[itex]^{+}_{0}[/itex] ( e[itex]^{-jBz}[/itex] + [itex]\Gamma[/itex] e[itex]^{jBz}[/itex])
I can see how this produces a standing wave with voltage minimums and maximums at fixed points every λ/2. What I'm confused about is why the voltage is not represented as a function of time. From what I thought I understood about the phasor representation of the voltage we dropped the factor e[itex]^{jωt}[/itex] in our notation, but that it's understood that it's still there and the wave is still a funtion of time and frequency (jωt). So my questions are these. Are standing waves also a function of time and frequency, and if so would they be traveling waves? It seems that according to my text the min and max points are at fixed distances, so it seems that the voltage wave doesn't travel. So what happened to time and frequency?
Thanks to anyone who can set me straight.