ABSTRACT
A negative result denotes attenuation rather than
amplification. A negative gain is thus equivalent
to an attenuation (or loss). If desired, the formulae
may be adapted to produce a positive result for
attenuation simply by inverting the ratios, as
shown below:
where Ap, Av, or Ai is the power, voltage or
current gain (or loss) expressed in decibels, Pin
and Pout are the input and output powers, Vin and
Vout are the input and output voltages, and Iin and
Iout are the input and output currents. Again note
that the powers, voltages or currents should be
expressed in the same units/multiples (e.g. Pin and
Pout should both be expressed in W, mW, µW or
nW).
