Front-to-back ratio for UHF antenna
In article t,
"Ralph Mowery" wrote:
"Bishoop" wrote in message
(snip)
10 or 12db of forward gain goes NOT equal 10 "times" the received signal
strength.
Then what do you think it is equal to ?
Well, 10dB of gain is a 10x increase in absolute signal, but 12dB of
gain would be about 16x the signal.
dB = 10 * log(S1/S2)
where S1 and S2 are the absolute strengths of two signals you're
finding the dB of difference between.
The regular absolute-value scale and logarithmic scale of dB "cross" at
the factor of 10; so 10dB = 10x, but that's the only place that's true
(at least, I think it is, off the top of my head).
-Kadin.
|