Does this waveform plot at t=0 look correct for the reflected wave and the summation (standing wave)?

 

Hi,

What method are you using for the calculations? You could show that here. That would help.
Is it a worked out transmission line equation or something else.

 

I'm doing this in matlab.

%Waveform Frequency (Hz)
F = 2;
%Transmission line length (m)
L = 1;
%Speed of travel (m/s)
v = 1;
%Amplitude (peak-Volts)
A = 1;
%Transmission line
x = [0:0.01:L];
%Wavelength
wavelength = 1/F;
%Angular frequency
angfreq = 2*pi*F;
%Time value
t = 1;
%Phase constant
phasecont = 2*pi/wavelength;

%Source wavefrom formula
ysrc = A.*sin(phasecont.*x-angfreq.*t);
%Reflected waveform formula
yref = A.*sin(phasecont.*(L-x)-angfreq.*t);
%Summation waveform formula
ysum = ysrc+yref;

%Plot the waveforms
figure()
subplot(211)
plot (x,ysrc)
xlabel('Length along line (m)')
ylabel('Amplitude (V)')
title('Source and reflected wave')
hold on
plot (x,yref)
grid minor
legend('source', 'reference')

subplot(212)
plot (x,ysum)
xlabel('Length along line (m)')
ylabel('Amplitude (V)')
title('Summation of each point along the x axis')
axis([0 1 -1 1])%Set x,y axis
grid minor

 

Hello again,

I dont work with matlab, but that code looks generic especially with those three formulas so we could simply talk about the formulas as they would graph about the same way in any software environment.

So first, where did you get those formulas? Did you come up with them yourself of get them from a book or something? I ask because proving this really means proving the formulas are correct, but you can also ask yourself what happens at the end of the line to the current and voltage and the fact that the wave must continue to be a sinusoidal wave. You can also try different line lengths and see what you get.

Since there are other ways to go about this, i would want to ask you how you would go about proving this? That would take us in a direction that would help you in the best way. It may help if you stated what kinds of problems you did in the past with transmission lines.

Transmission lines are a beautiful part of nature. It's like having a small part of the universe right in your very own hands