Unwanted
frequency components resulting from
the interaction of two or more spectral
components passing through a device with
nonlinear behavior (e.g., mixer, amplifier).
The unwanted components are related to
the fundamental components by sums and
differences of the fundamentals and various
harmonics, e.g. f1 ± f2, 2f1 ± f2, 2f2 ± f1
, 3f1 ±