Je ziet dikwijls antennes voor 4G die onder 45° polarisatie werken, hoe zit dat in Belgie? Voor 3g is dit alleszins niet het geval denk ik? (Heb de mijne altijd verticaal gepolariseerd)

Some notes from pointing on physical spacing between 2 antennas for LTE:
The reason we need a physical spacing between the antennas, is to obtain some spatial de-correlation between the antennas. The spacing required to get good de-correlation is a function of the environment in which the antennas are placed, hence it is not possible to give an exact measurement between the antennas as the environment is not known. In a very built up environment where the wave will experience many reflections good spatial de-correlation can be achieved with the antennas moderately close to each other. In a rural environment the physical spacing would have to be greater in order to achieve the same de-correlation.
Typical spacing between the antennas should be ½ wavelength and 2 wavelengths:
At 900 MHZ the wavelength is 30 cm
At 1800 MHz the wavelength is 16 cm
At 2700 MHz the wavelength is 11 cm.
A good de-correlation between antennas is required so that each antenna is able to receive a different signal at the same frequency. If this is achieved then you can effectively double the throughput of the system with 2 antennas and with 3 antennas you can triple the throughput.