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4x4 antenna help

Posted: Tue Nov 24, 2020 10:11 am
by tbenz
Hi - I purchased a 4x4 MIMO antenna this summer in anticipation of getting a 5G modem with 4x4 MIMO capabilities. Plans have changed. Considering that all 3 carrier towers are close to each other and aligned very closely from my location, I'd like to use this 4x4 antenna with 2 different 2x2 modems on 2 different carriers. Not knowing a whole bunch about this I have a few questions that hopefully you could help me with:

-Looking at the specs of this antenna, is this possible? ( https://qu.wireless.com/downloads/Datas ... MO-4x4.pdf )
-Is this just 4 identical antennas arranged in a cross-polarized fashion or is it a group of individual frequency-specific antennas?
-None of the 4 cables exiting the antenna are labeled. How would I figure out which cable goes where?

Thanks for your help!

Re: 4x4 antenna help

Posted: Fri Nov 27, 2020 1:02 pm
by Viper67857
According to the specs, all 4 antennas are on vertical polarity... I would expect significant cross-talk between 2 modems on this antenna. I doubt it would even work well on a single 4x4 modem, especially with such low gain. To put it bluntly, that anteena is probably trash..

Re: 4x4 antenna help

Posted: Fri Nov 27, 2020 1:10 pm
by tbenz
Well that's a bummer. I might take it apart then. See if there's anything that can be done. Thanks Viper!

Re: 4x4 antenna help

Posted: Fri Nov 27, 2020 9:43 pm
by R1250GSA
From the specs of the antenna, it does not appear to be that future proofed for 5G, being 700-2700.
The current market is providing 600-3800 as the more future forward frequency range.

I am a bit skeptical of 4x4 MIMO, as LTE likes spatially diverse antennas, by at least half a meter, so a 4x4 is a mix of compromises; cost, space to mount, and aesthetics.

You also have a chicken and egg situation. Since you already have an antenna(assuming you can not return), get your router and modem going.
With this, you will have some real data points and know if the 4x4 works or needs replacing.

Re: 4x4 antenna help

Posted: Sat Nov 28, 2020 6:44 am
by tbenz
Since I don't have a modem capable of 4x4 yet, I'll experiment with a 2x2 modem
Thanks

Re: 4x4 antenna help

Posted: Sun Mar 07, 2021 3:54 am
by Iridium
R1250GSA wrote: Fri Nov 27, 2020 9:43 pm I am a bit skeptical of 4x4 MIMO, as LTE likes spatially diverse antennas, by at least half a meter, so a 4x4 is a mix of compromises; cost, space to mount, and aesthetics.
Is that true for polarized 4x4 MIMO also?

Because on the Poynting youtube channel, there is a video about antenna spacing, and they say that if the antenna is polarized, it's not needed to space them.
Well he was speaking about 2x2 MIMO antennas, but a 4x4 antenna is also polarized (+/-22.5° each group of 2x2).

What's true, what's false?