Environmental Engineering Reference
In-Depth Information
In conclusion, being
the second and third harmonic distortion
factors are
A more compact form of the second and third harmonic distortion
coefficients can be obtained considering that the return ratio, is usually
much greater than one. Hence, after normalising the amplifier terms
to
the amplifier gain
and the feedback terms
to the feedback linear
term,
(by defining
and
we get
By inspection of (7.32) and (7.33), it is apparent that feedback does not
reduce the nonlinearity of the feedback network. Thus, we cannot obtain an
amplifier having a nonlinearity lower than that of the feedback network, and
even small nonlinearity terms of the feedback networks cannot be neglected,
but they must be taken into account.
