antenna-theory.com

[Phelar]

Hi!

I've just started to read about mimo technology and antenna polarisation.

What i understand a mimo 2x2 system you want your two antennas in the same polarisation as the receiving/transmitting end. A cross polarisation, 45 deg. from the vertical plane. I´ve read that in urban terrain that this setup is preferable, but in open terrain you want the spatial spacing between the antennas but both in the vertical plane. This i dont understand if the opposite end has it's antennas in 90 degres polarisation, can someone explain this?

I also have a question about reflections.
Does the phase change or the polarisation change after reflections in urban terrain. If a RF from a 90 deg. polarised antenna reflects on a building, does it leave with the same polarisation?

Cheers!