Verify definition of circular polarization in Balanis.

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SUMMARY

The discussion centers on the definition of circular polarization as presented in Balanis' text, specifically regarding the phase relationship between the Ex and Ey components of the electric field. The user argues that Balanis incorrectly defines the rotation direction for circularly polarized waves propagating in the negative z direction, asserting that it should be classified as Right Hand Rotation (CCW) instead of Left Hand Rotation (CW). This claim is supported by derivations and references to Ulaby's "Engineering Electromagnetics," which corroborate the user's findings for propagation in the positive z direction. The discussion highlights the differing conventions between electrical engineers and physicists regarding circular polarization.

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yungman
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Attached is a scan of how Balanis define plane wave with circular polarization with Ey having a phase of +∏/2 respect to Ex component of the E field. I don't quite agree with the book. The second attachment is my derivation.

The definition of CW or CCW is with respect to direction of propagation come out of the paper as indicated in my notes ( point towards you!).

The book claimed for propagation in -ve z direction, if phase is +∏/2 (n=0), the rotation is CW which is Left Hand Rotation. And the book said if the propagation is in +ve z direction, the rotation reverse to CCW.

But as I proofed in my notes: For propagation in -ve z direction, the function is \cos(\omega{t}+kz+\frac{\pi}{2}). Which for t=0 and plot the wave along -z, maximum occur at kz+\frac{\pi}{2}\;=\;0\;\Rightarrow\; z=-\frac{\lambda}{4}. This is drawn in my notes. I showed the rotation of the E in CCW and is Right Hand Rotation for propagation in -ve z direction.

On the lower part of my notes for propagation in +ve z direction, the result is backed up by "Engineering Electromagnetics" by Ulaby. That it is CW and Left Hand Rotation. Based on all these, I cautiously say Balanis is wrong. Please check my work and tell me whether I am correct or not.

Thanks

Alan
 

Attachments

  • CP book.png
    CP book.png
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  • CP notes L.png
    CP notes L.png
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Last edited:
Science news on Phys.org
It's well known that electrical engineers and physicists define the sense of circular polarization oppositely. You are looking in one book from each camp.
 

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