On Aug 30, 2009, at 3:00 PM, Orna Agmon Ben-Yehuda wrote:
If we stick to the air as our media, then you will need a unidirectional antenna. This is also an idealization, as an antenna which points to one direction, projects energy to the opposite direction as well, and there is also significant power loss to the sides.
Often it can be only omnidrectional in 2 dimensions and only if you want to power a circular area. If you want to power all the devices in your apartment for example, you can place an omnidirectional antenna in the center, or a narrower beam antenna in a corner. The advantages of a center one is obvious, you get more power in more all of the apartment. A corner antenna placed in the corner where the demand is greater, e.g. kitchen, laundry, etc and farthest from where the demand is the least, e.g. in a bedroom where you want lights, a clock and maybe a TV or radio has a distinct advantage in power levels output and the radiation the residents are exposed to.
This has a practical application in the world of computers as you want to place a WifI transmitter close to your computers if they are clustered and as far away as possible from anyone else's. So I place mine where they "leak" out of the building about 5 meters into a common entrance yard, but don't reach the street, instead of at the other end of the apartment where they would.
Either way, I have no desire to radiate WiFi, or if I could electrical power, down into the ground or up into my neighbor's or the street.
Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
