antenna-theory.com

[sigsgt]

My question is this. I have to mount mobile mag antennas inside a building. But. The roofs are metal. I beleive that there might be some interference due to this. These are for mobile base stations. I know if they (the antennas) were mounted on top of the roof you can use the roof as a ground plain. Freq. 380-400 Mhz.

[pete463251]

I'm not sure what a mag antenna is.

However, if you are mounting antennas indoors, you will always get a lot of reflections off the wall, ceilings, floor, room objects, etc... So the roof won't be a huge problem (you could use the roof as aground plane if you mounted the antenna upside down on the roof, but you probably don't need to do that).

If you can get unobstructed line-of-site between your two communication systems, you will probably get decent communication. Otherwise you might have to move the antennas around till it works.

See
http://www.antenna-theory.com/definitions/multipath.php
http://www.antenna-theory.com/arrays/diversity.php