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RF loss in air - RF Cafe Forums
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| tbob
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Post subject: RF loss in air
Posted: Thu Aug 25, 2005 5:56 pm
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Does anyone know the formula to calculate the RF
power loss in air from a transmitting antenna to
a specified distance away from the antenna? Lets
say I am transmiting 100 watts into a unity gain
antenna, 400MHz. What will be the power level (in
watts, dB, or uV) 100 meters away.
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Kirt Blattenberger
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Post subject: Path Loss Equations
Posted: Thu Aug 25, 2005 10:30 pm
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| Site Admin |
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Joined: Sun Aug 03, 2003
2:02 pm
Posts: 308
Location: Erie, PA
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_________________ - Kirt Blattenberger
RF Cafe Progenitor & Webmaster
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IR |
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Post subject:
Posted: Fri Aug 26, 2005 5:12 am
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| Site Admin |
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Joined: Mon Jun 27, 2005
2:02 pm
Posts: 373
Location: Germany
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Hello tbob,
The Frii's formula which is given
in linear terms can be also calculated in dB:
Lpath=32.5+20log (F)+20log (D)-Gtx-Grx
Where:
F- frequency in MHz
D- Distance
in Km
_________________
Best regards,
-
IR
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Guest |
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Post subject:
Posted: Fri Aug 26, 2005 11:41 am
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Thanks to both of you for your help. I'll have to
visit this forum more often.
Bob - RF Test
Engineer
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Posted 11/12/2012
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