Standing Wave Pattern Animation (SWR)

Uniform plane wave traveling in the +z direction and normally incident on a medium interface at z=0. Only the electric field intensity is shown.
The top figure shows the incident (blue), reflected (red), incident+reflected (brown) and transmitted field in both media. In the bottom figure, the standing wave patterns created in both media are shown.

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[meyavuz]

This is expected. The total field is summation of two propagating modes and depending on the reflection amount, one can see such propagation behavior. Consider a case where the reflection is very small, then you would see the propagation of the total field in the +z direction in a much clearer way. However, the nodes and antinodes would always occur at the same spatial locations.

[meyavuz]

@Gilmourist Hi... At the interface, the "total" tangential E fields should be equal to each other, not the incident. Since in the first medium, the total field is summation of Eincident and Ereflection and in the second medium the total field is just the Etransmitted. You can also see this in the animation above.

[meyavuz]

They cannot be the same as long as the two media is different from each other. There are many reasons, e.g. the dielectric of the second medium is different so the wavelength is different which make the waves in the two media different already. If they were the same, then there would not be any reflection. If you are asking about the power, then consider the H field component (not shown here).

[Gilmourist]

Thanks. actually I was trying to understand why the incedent wave is E*e^-jkz while the reflected is E*e^jky, This helped! However, isn't the incedent and reflected supposed to always be equal at z=0?

[scroogemcduckenjoyer]

Kind of annoying that i would've understand a LOT more during my telecommunications engineering course if I watched this simple thing

[bhongusa]

@meyavuz
It looks like the "partial standing wave" in medium 1 (incident + reflected) is still propagating in the +z direction. How does one explain that? I thought that for partial reflections, the standing wave is still characterized by horizontally stationary nodes and antinodes. It's just that both the nodes and antinodes oscillate vertically with amplitudes Emin and Emax respectively, forming the SWR. I'm confused.

[rzkna]

what tools did you use for this animation?