Sponsored Links

Orientation of Poynting XPOL-1

mikeliuk

ULTIMATE Member
Recently I've positioned two Poynting omni-directional XPOL-1 to roughly optimize for various signal parameters and measured performance but without being aware of the connected mast at the time because I wasn't able to locate them having failed to realize they were displayed in hexadecimal instead of decimal.

The weird thing I found was that it was not optimal to point the front surface of the A-XPOL-0001-V2-21 and A-XPOL-0001-V2-41 towards the mast but instead to have their starboard side directed to the mast. Has anyone found similar? It's possible that this is due to their location in the loft rather than being outside with fewer proximate obstructions causing constructive and destructive interferences.

1677078234010.png

Compare to before using bundled antennas: https://www.ispreview.co.uk/talk/threads/teltonika-trb500.39316/page-2

1677078264732.png
 
I believe this is down to the radiation pattern of the antennas and I believe because they're +/- 45° polarised.

It makes them slightly directional. They're low gain regardless so the 3dB window isn't massively affected but the directivity is.
 
I think there's a document online that can be found searching for "Technical-Specification-A-XPOL-0001-V2.pdf" to see the radiation pattern (apparently below is how small it needs to be to be under the 120 KB size limit).

1677086432173.webp
 
Sponsored Links
Remember, there's 2 antennas inside that housing that are cross polarised - I think +/-45.

Whilst the individual antenna inside that housing radiation pattern in a vertical position may look like their datasheet, when you rotate them to +/-45 their radiation pattern also moves the same angle.

This makes the assembly slightly directional.

Screenshot_2023-02-22-22-49-48-049-edit_com.miui.notes.jpg
 
My current interpretation is the top four diagrams are looking down (horizontal section) at the mounted antenna, and the bottom four diagrams are looking from the side (vertical section/slice) so the shape of the volume is a torus with little radiated straight up into space or straight down into the ground.

I don't think polarisation impacts the radiation pattern. The classical view is that you have a photon with fields polarised a certain way but the line of travel is not impacted unless interacting with the air. The quantum perspective is you have a wave function per photon which propagates in the same way regardless of polarisation. I'll need to think a bit more to see if I have this last bit correct.

A nice reference for interpreting the radiation pattern diagrams: https://www.netxl.com/blog/antennas/radiation-patterns/
 
Last edited:
I don't think polarisation impacts the radiation pattern. The classical view is that you have a photon with fields polarised a certain way but the line of travel is not impacted unless interacting with the air. The quantum perspective is you have a wave function per photon which propagates in the same way regardless of polarisation. I'll need to think a bit more to see if I have this last bit correct.

I'm fairly sure this is correct.
Those gain plots and antenna gain figures are 99.9% of the time compared against an isotropic antenna. That is, an antenna with an isotropic radiation pattern i.e. radiation is equal in all directions.

So the fact that you've got a donut pattern means the pattern has already been effected.

So yeah polarisation effects the radiation pattern also. In fact if polarisation didn't effect the radiation pattern, MIMO would not be as efficient as there needs to be a discernable difference between the feeds for the base station to go, 'hey look, you've got more than 1 antenna, I can send you data to that one too and increase your throughput'

Here's a vertically polarised antenna. The radiation pattern is 360° to the antenna itself, torus shaped.
Screenshot_2023-02-23-07-05-38-171-edit_com.miui.notes.jpg


You then take that antenna, rotate it through 90° to a horizontal position you'll get this. Technically, this is now a partially directional antenna as the only useful part of the pattern goes forwards and backwards with little to the sides.
Screenshot_2023-02-23-07-05-38-171-edit_com.miui.notes~2.jpg
 
Top
Cheap BIG ISPs for 100Mbps+
Community Fibre UK ISP Logo
150Mbps
Gift: None
Virgin Media UK ISP Logo
Virgin Media £22.99
132Mbps
Gift: None
Vodafone UK ISP Logo
Vodafone £24.00 - 26.00
150Mbps
Gift: None
NOW UK ISP Logo
NOW £24.00
100Mbps
Gift: None
Plusnet UK ISP Logo
Plusnet £25.99
145Mbps
Gift: £50 Reward Card
Large Availability | View All
Cheapest ISPs for 100Mbps+
Gigaclear UK ISP Logo
Gigaclear £17.00
200Mbps
Gift: None
Community Fibre UK ISP Logo
150Mbps
Gift: None
Virgin Media UK ISP Logo
Virgin Media £22.99
132Mbps
Gift: None
Hey! Broadband UK ISP Logo
150Mbps
Gift: None
Youfibre UK ISP Logo
Youfibre £23.99
150Mbps
Gift: None
Large Availability | View All
Sponsored Links
The Top 15 Category Tags
  1. FTTP (6026)
  2. BT (3639)
  3. Politics (2721)
  4. Business (2439)
  5. Openreach (2405)
  6. Building Digital UK (2330)
  7. Mobile Broadband (2146)
  8. FTTC (2083)
  9. Statistics (1901)
  10. 4G (1816)
  11. Virgin Media (1764)
  12. Ofcom Regulation (1582)
  13. Fibre Optic (1467)
  14. Wireless Internet (1462)
  15. 5G (1407)
Sponsored

Copyright © 1999 to Present - ISPreview.co.uk - All Rights Reserved - Terms  ,  Privacy and Cookie Policy  ,  Links  ,  Website Rules