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I would appreciate it if you could check my assumptions regarding the application of antennas in my design, which usually involve cellular and Wi-Fi technologies. Sometimes, I come across parameters such as antenna polarization. Typically, it's linear polarization, but for certain antennas, it's specified as horizontal or vertical polarization. I have several questions:

  1. Am I correct in understanding that for UHF wireless signals, polarization might not be as critical because the signal undergoes multiple reflections from different surfaces, which can alter its polarization?
  2. If I choose a 1/4 wavelength signal antenna, do I need to provide a good conductive ground surface to facilitate the mirror effect of the antenna?
  3. Is the mirror effect for the antenna occur when a signal is reflected from the ground, causing a phase change that resonates with the non-reflected part of the signal?
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  • \$\begingroup\$ (1) Polarization (random), if occurring, is a problem at any frequency (2) No, (3) No. As you can see, you get better answers when you ask questions that don't easily fall into yes or no answers. Concentrate on making improvements to (2) and (3) if you want more information. I could also have said "no" to q1 of course. This is a Q and A site. \$\endgroup\$
    – Andy aka
    Nov 6, 2023 at 20:42
  • \$\begingroup\$ @Andy aka, Do I understand correctly that depending on how I position, for example, a dipole antenna in space, its polarization will depend on it? If my statement is true, then I don't understand how the datasheet ( productfinder.pulseelectronics.com/api/open/part-attachments/… ) can state that the dipole antenna has a vertical polarization. \$\endgroup\$
    – Andr
    Nov 6, 2023 at 20:50
  • \$\begingroup\$ You are using a monopole though so I don't see the relevance. \$\endgroup\$
    – Andy aka
    Nov 6, 2023 at 20:57

1 Answer 1

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  1. Antenna polarization can be described as horizontal, vertical or circular rotation (left and right). It doesn't really matter what transmitter frequency is chosen at the UHF frequency you have chosen, keep the same receiver polarization.

  2. Yes for a theoretical examination of antenna radiation

  3. A ground or any other object that reflects the transmitted wave will have a different (i.e. longer) path to travel to the receiver. At the receiving antenna the waves add. The additional distance of the reflected wave means that there will be a phase difference between the two waves. This is the phase difference will add or subtract from the non-reflected wave.

If the object is moving (i.e. an aeroplane) the phase difference will vary relatively rapidly. This impact on the signal strength can be described as 'flutering'.

Terms such as resonates is not applicable.

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