In
electronics a
mixer or
frequency mixer is a
nonlinear electrical circuit that creates new frequencies from two signals applied to it. In its most common application, two signals at frequencies
f1 and
f2 are applied to a mixer, and it produces new signals at the sum
f1 +
f2 and difference
f1 -
f2 of the original frequencies, called
heterodynes. Other frequency components may also be produced in a practical frequency mixer.