How does a wave with circular polarization behave?

[lambjx]

does an em wave with circular polarization behave like a coil, i.e. do perpendicular electromagnetic fields join internally? I am very confused on this subject

 

[kuruman]

Summary:: how does a wave with circular polarization behave?

does an em wave with circular polarization behave like a coil, i.e. do perpendicular electromagnetic fields join internally? I am very confused on this subject

Watch this video. It's short and informative. Pay attention to the green arrow representing the resultant.

 

[lambjx]

Watch this video. It's short and informative. Pay attention to the green arrow representing the resultant.

so if I understand correctly, in the conductor that receives the circular wave, its electrons have a circular motion? similar to that of a reel?

 

[kuruman]

so if I understand correctly, in the conductor that receives the circular wave, its electrons have a circular motion? similar to that of a reel?

No. There is no conductor. The electromagnetic wave is a disturbance that propagates in vacuum. The net electric field vector characterizing this disturbance rotates in space as the wave propagates. If the wave is incident on a conductor the electrons will accelerate opposite to whatever direction the electric field points.

 

[lambjx]

No. There is no conductor. The electromagnetic wave is a disturbance that propagates in vacuum. The net electric field vector characterizing this disturbance rotates in space as the wave propagates. If the wave is incident on a conductor the electrons will accelerate opposite to whatever direction the electric field points.

therefore the electrons incident on the conductor do not follow a rotating path, but go up and down always changing direction ??

 

[Ibix]

therefore the electrons incident on the conductor do not follow a rotating path, but go up and down always changing direction ??

There are no electrons in an EM wave, so there are no electrons incident on anything. There's no conductor in your OP either - are you trying to consider the effect of an EM wave incident on a plane conductive surface?

 

[lambjx]

There are no electrons in an EM wave, so there are no electrons incident on anything. There's no conductor in your OP either - are you trying to consider the effect of an EM wave incident on a plane conductive surface?

guys i know that there are no electrons in an em wave, i just wanted to say if a circularly polarized em wave, when it hits a surface in this case can be flat, can generate a movement of electrons or ions, circular. I ask because I have seen that the helix antennas have a coil configuration

 

[lambjx]

There are no electrons in an EM wave, so there are no electrons incident on anything. There's no conductor in your OP either - are you trying to consider the effect of an EM wave incident on a plane conductive surface?

since with a linearly polarized wave the electrons of the receiving material have a linear movement, I cannot understand how the electrons of the receiving material can behave with a circular wave

 

[kuruman]

This is my response to the PM you sent me. Your thread started with a vague question

how does a wave with circular polarization behave?

I believe that particular question was answered in posts #2 and #4. Following these posts, you started talking about electrons in a conductor. If your question is about helical antennas, then perhaps this Wikipedia article might help.

I am not an antenna person, but if you refine your question and be more specific about what you want to know, then perhaps you might get a more comprehensive answer if you post in the Electrical Engineering forum.

 

[sophiecentaur]

guys i know that there are no electrons in an em wave, i just wanted to say if a circularly polarized em wave, when it hits a surface in this case can be flat, can generate a movement of electrons or ions, circular. I ask because I have seen that the helix antennas have a coil configuration

A good way to look at circularly polarised em waves to to think in terms of (very common) transmitting aerials that can produce CP. Take two dipoles, mounted at right angles (along x and y axes). Feed them with two RF signals (same frequency of course) in such a way that the two signals are in quadrature (90° phase difference). If you go along the z axis the signals will add together to produce circular polarisation. The direction of the E field sweeps around the z axis at the same frequency as the separate signals from the two dipoles.
If the dipoles are fed in phase, the resultant will be plane polarised at 45° to x and y. It's just a matter of vector addition of the two E fields.
When an em wave hits a metal surface, the electrons do not 'move' significantly because the drift velocity is a matter mm per second and the oscillations will be in MHz or faster.

A helical antenna does have currents flowing along the helix but the actual movement of electrons is still vanishingly small.

However, in the Ionosphere, the free electrons can be regarded as moving significant distances because there are so few of them, compared within a metal and, in the presence of the Earth's magnetic field and the low density plasma up there, the electrons can be considered to actually move in ellipses when the incoming wave is linearly polarised. The medium is Birefringent.