Understanding Polarization-Dependent Phase Shifts of Radio Waves

In summary, the video gave a good explanation of the phase shift, but the post provides more detail about the conditions that cause it.
  • #1
antrobot
7
0
I've seen this video:

There it is explained that an electromagnetic (here radio) wave has a phase shift if it was radiated in horizontal polarization, but it does not experience the phase shift when it was emitted vertically polarized when it gets reflected on the ground.
When reading up on phase shifts I didn't find anything in connection with polarization. But, I found that light will ALWAYS get reflected with a 180 degree phase shift when reflected on a denser medium. Therefore I am confused now, and don't understand if it is polarization dependent or not, and most importantly why?
 
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  • #2
Indeed, according to the Fresnel equations both the reflected components of the electric field parallel and perpendicular to the boundary get a 180 degree phase shift ("sign flip") when entering the denser medium. One has to be careful in interpreting the polarization vectors of the incoming, reflected, and transmitted wave trains! For a very clear treatment and careful discussion of the physics, see

https://www.physicsforums.com/kbibtex%3Afilter%3Aauthor=Joos, https://www.physicsforums.com/kbibtex%3Afilter%3Aauthor=Freeman: https://www.physicsforums.com/kbibtex%3Afilter%3Atitle=Theoretical%20Physics , https://www.physicsforums.com/kbibtex%3Afilter%3Aedition=3rd, https://www.physicsforums.com/kbibtex%3Afilter%3Apublisher=Dover%20Publications,%20Inc., https://www.physicsforums.com/kbibtex%3Afilter%3Ayear=1986
 
  • #3
Thank you for your answer, but I was not able to find that book online or in the library to read up on (for free). However, I actually think the reflection is indeed polarization dependent, just not exactly in the way it was explained in the video. I found this post:

https://www.physicsforums.com/threads/phase-shift-upon-reflection.799497/
which explains the exact conditions for the phase shift depending on p- and s-polarizations. These polarizations are defined with regard to the plane of incidence, and the conditions fall out of Fresnels equations. Following the logic of this post the p-polarized (in the video it actually does correspond to the vertical polarization) only experiences a phase shift if a certain condition is fulfilled (see the link for the conditions)! Also, common literature seems not to discuss this, which is why it is believed that there is always a phase shift, not depending on polarization.
 

Related to Understanding Polarization-Dependent Phase Shifts of Radio Waves

What is polarization-dependent phase shift?

Polarization-dependent phase shift refers to the change in the phase of a radio wave as it passes through a polarizing medium, such as an antenna or a polarizing filter. This shift is dependent on the orientation of the electric field of the wave with respect to the polarizing medium.

Why is it important to understand polarization-dependent phase shift?

Understanding polarization-dependent phase shift is crucial in the design and operation of communication systems, especially those that use polarized antennas. It allows for the optimization of signal transmission and reception, reducing interference and improving overall performance.

What factors affect polarization-dependent phase shift?

The primary factors that affect polarization-dependent phase shift are the angle of incidence of the radio wave, the properties of the polarizing medium, and the frequency of the wave. Other factors such as atmospheric conditions and the material composition of the medium can also play a role.

How can polarization-dependent phase shift be measured?

Polarization-dependent phase shift can be measured using specialized instruments such as polarimeters or vector network analyzers. These instruments measure the amplitude and phase of the transmitted and received signals, allowing for the calculation of the phase shift.

What are some practical applications of understanding polarization-dependent phase shift?

Understanding polarization-dependent phase shift has numerous practical applications, including in satellite communications, radar systems, and wireless networks. It is also essential in fields such as remote sensing, where precise measurements of the phase shift can provide valuable information about the properties of the medium being studied.

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