converting dBm to uV/m
On Wed, 28 Dec 2005 22:04:40 GMT, Owen Duffy wrote:
So, the lhs of your formulat is in units of
dBuV/m, and assumes AF=0dB/m and 1Hz bandwidth. AF depends on antenna
gain and frequency, and antenna / receiver R.
Sorry, whilst looking into the rhs I overlooked the 10^x/20... the lhs
is in uV/m... but the formula does assume an Antenna Factor of 0db/m
(and 1Hz bandwidth if talking about power densities).
Trying to find the minimal correction to your formula to make it work:
Field Strength (uV/m) = 10 ^ ( (107 + RxPwr + AF) / 20 )
Whe
o RxPwr is in dBm
o AF (=FS/Vin) includes matching effects and is in dB (1/m) (or dB/m
for short)
o same bandwidth applies to both sides for continuous spectra
For a matched antenna in a 50 ohm system under plane wave conditions:
AF=20*log(9.73/lambda/gain^0.5)
Owen
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