This is one the main characteristics to determine when designing or
choosing an amplifier. This is a measure of the increase (or decrease in
case of negative gain) the amplitude of the input signal.
Representation:
There
are a few different ways to represent amplifier gain. One of the more
common way among beginners & hobbyists, specially for DC or small
signals, is to describe gain as the ratio of input vs output amplitude:
Gain = Vout/Vin, Where both input & output are either voltage or current (amperage).
Another
way to represent amplifier gain is using a logarithmic decibel scale
(dB). This representation is calculated using the ratio of input/output
powers using the formula:
Gain = 10log(Pout/Pin)
Utility of gain:
There
are countless applications & uses for amplifiers, since in the
electronics world most signals we get from sensors or transmission lines
is very small. There are also other times when not the amplitude of the
signal is required but its power to transform into useful work, like
when powering a motor, transmitting a radio signal & displaying an
image on a screen.
How to calculate:
The
specifics of how much gain can an amplifier have depend heavily on the
components or circuits used, as well as the topology (configuration) of
the amplifier. You can have a better understanding of the formulas used
for each component & configuration by going to the specific page.
