- This topic has 5 replies, 1 voice, and was last updated 13 years, 6 months ago by pix.
31st July 2007 at 10:09 #48465WInetGuest
Does power lines in first Fresnel zone has any impact on Rx level? There are like 6-10 power cables in distance of 1km from both antennas, directly in the line of sight. Thx for a reply.31st July 2007 at 22:01 #48466PixGuest
Interesting question !!
I can check tomorrow at work, but as far as i know :
the electromagnetic fields from the powerlines will not impact the propagation from the GSM antenna… the frequency should be about 50Hz (or 60Hz ? where do you live ?) anyway, it is very far from 900MHz !
the cables themselves can be considered as obstacles, which will create diffraction… but even ten cables in a row, it is still a very small amount of the signal that will hit them. So the amount of diffracted signal might be neglictible.
Furthermore, the cables are not really in the same scale (in terms of size) as the radio waves (gsm900 = 32cm, dcs1800 =16cm, a cable diameter = ?? cm) , so i’m not even sure there will be diffraction…1st August 2007 at 08:35 #48467WinetGuest
Thx Pix, you have cleared some of my doubts but what i had in mind was flexi hopper antennas not GSM. They will be working on 23GHz so the radio waves size is 1cm and the cable diameter is about the same size as well…..1st August 2007 at 16:41 #48468PixGuest
the problem is different then.. i don’t think it should impact the quality nor the level of the signal, but i can’t “prove” it.
no literature on IEEE about this ? or on the web ?9th August 2007 at 07:03 #48469ImranGuest
Normaly Power lines have no effect on the microwave.
We can even use the transmission towers for microwave usage also but do not make the transmission lines and microwave link parallel to one another because at high voltage transmission lines we have Corona effect which can interfere with the microwave. We can run the transmission lines and microwave propogation perpendicular to one another.9th August 2007 at 13:35 #48470pixGuest
thanks imran !