05-09-2011, 03:44 PM
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Join Date: May 2011
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Since nobody answered me I tried to compute the gain myself, but I've reached a dead end again.
I found that the unknown gain of an antenna can be computed with the formula:
Gain [dBi] = ReferenceGain [dBi] + (MeasuredLevel [dBm] - ReferenceLevel [dBm] )
The notations are:
Gain - unknown gain (of laptop or phone antenna)
ReferenceGain - gain of a reference antenna
MeasuredLevel - signal strength (in dBm) from the antenna of unknown gain
ReferenceLevel - signal strength (in dBm) from the reference antenna, measured in the same conditions as MeasuredLevel
I've used a reference antenna with a 3 dBi gain.
My values are:
ReferenceGain = 3 dBi
MeasuredLevel = -75 dBm
ReferenceLevel = -39 dBm
and after the computations the gain is Gain=-33 dBi (negative gain !!!)
I don't think these results are correct.
Can someone tell me what am I doing wrong?
Or even better can someone tell be the gain of these antennas?