definition of power gain

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eda_range

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wikipedia rf gain definition

What is exactly the power gain?
If input with power of -20dBm, get output with power of -12dBm, what is the power gain for this case?
thanks.
 

power gain is the ratio of an output power to an input power
 

eda_range
To answere your specific question, the power gain is -12dbm - (-20dbm) = 8db.
Regards,
Kral
 

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    eda_range

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-12 dBm -(-20 dBm) = 8 dB. That is the gain.

Or in other words:
-20 dBm = 0.01 mW = 10 uW
-12 dBm = 0.0631 mW = 63.1 uW
then the ratio is (63.1/10)= 6.31 which in dB is
10 log(6.31) = 8 dB.....

Do not get confuse with negative number, remember
is only a reference.....dBm ----> mW.....any negative
number only means that is less than 1 mW....that is all.
-20dBm is less power than -12dBm.....think about it in
terms of a long scale with a 0 on it in some place.
 

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    eda_range

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power gain = 10*log(Po/Pin) [dB]

voltage gain = 20*log(Vo/Vin) [dB]

NB. Log in base 10
 

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    eda_range

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Power gain = 20 log ( Vo/vi)
provided ip and o/p impedances are same.
 

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