- This topic has 5 replies, 1 voice, and was last updated 13 years, 6 months ago by
pix.
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WInet
GuestHello,
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.
Pix
GuestInteresting 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…
Winet
GuestHI,
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…..
Pix
GuestWinet,
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 ?
Imran
GuestHi Winet.
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.pix
Guestthanks imran !
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