Help: Effect of Proximity to 3G Ants Performance

I have two 3G ceramic antennas operating in 850, 1900, and 2100 MHz band that are mounted in vertical and horizontal plane to compensate polarization diversity. Two antennas are 10 mm apart. I heard that when antennas stay closer than lambda/2, there will be a coupling effect deducts antenna performance.

But how does the coupling effect impact on antenna performance?

If there is other effects of antenna proximity, please tell me. I know that two antennas should stay apart more than lambda/2, but with limited space I can't do that. So I would like to get suggestions about the effect that will happen to antennas. How to measure that effect? Can I measure ISOLATION between two antennas? If yes, please advice me.

I appreciate every comments.

Bill

Is my question too difficult or not clear? Anyone can help me??? Thank you in advance.

Just search the net for "Antenna Near Field" and you will get thousands of answers.

http://www.home.agilent.com/upload/cmc_upload/All/NSI-near-far.pdf

Have to think to the antenna coupling, the same situation when you have two coupled LC resonators (some RF basics), because an antenna basically is an LC resonant circuit.

More or less coupling between LC circuits (antennas in your case) will generate more or less influence one to each other, but especially in terms of tuning and loading. In case of coupled antennas also the EM fields are changed, resulting different antenna patterns.