LTE antenna omnidirectional two frequencies

[magicfoot]

My LTE router is used in different areas and uses different mobile cell operators. One operator's LTE signal is at 800MHz and the other is on 2600MHz.

What is involved in choosing one omnidirectional antenna for LTE to suit both of these frequencies? Should one maybe use two different monopoles operating at 0.25 wavelength to get the best result? I am currently using a 20cm long monopole antenna on the routerand feel I can improve the signal quality in remote areas by using a correctly sized antenna. Has anyone tried this?

 

[vfone]

This is a collinear omni-directional antenna, which give you some gain:
https://www.amazon.com/Omni-Directional-800-2600MHz-Indoor-Antenna-Shipping/dp/B01CMWUAR6

Or this one, with higher gain. This support MIMO, but you can use only one connector for dual-band operation:
https://www.amazon.com/12dBi-Outdoor-Dome-Antenna-800-2600MHz/dp/B06XFHH43B

Probably these antennas are from China, and perhaps you can find them on other sites also..

 

[magicfoot]

This is a collinear omni-directional antenna, which give you some gain:
https://www.amazon.com/Omni-Directional-800-2600MHz-Indoor-Antenna-Shipping/dp/B01CMWUAR6

Or this one, with higher gain. This support MIMO, but you can use only one connector for dual-band operation:
https://www.amazon.com/12dBi-Outdoor-Dome-Antenna-800-2600MHz/dp/B06XFHH43B

Probably these antennas are from China, and perhaps you can find them on other sites also..

>>>>>>>>>>>>>>>
Thank you for the direction about the collinear and the other hooded antenna. I have several thousand routers deployed and this makes the collinear an economic choice for the general all-directional implementation when compared to the dome antenna. I actually deploy a curly collinear off-the-shelf antenna with the pack and the proportional segments are not at all 1/4 wavelengths(for LTE bands), but they work OK . I have tried a variety of omni-directional antennas and they are all pretty much the same, irrespective of whether the transmission is at 800 or 2600 MHz. As long as there is some signal available, and no noise, I suspect even a short piece(15cm) of steel coat-hanger antenna would work satisfactorily as an omni-antenna at all LTE frequencies. There seems to be no obviously dominant solution to the choice of a low cost omni-antenna for LTE use at multiple frequency bands in the non-ideal or urban environment.

 

[vfone]

If you look to an (unknown) encapsulated whip antenna you don't know what is exactly inside. Could be just a wire, a helix antenna, a collinear antenna, etc.
But collinear antenna is the only one that gives the highest omnidirectional gain.
Is not an easy job designing a collinear antenna. The dimensions of the elements should be λ/2 and not λ/4. The λ/2 dimensions need to be slightly adjusted to get the maximum gain and required bandwidth.