Harmonic Distortion of Nonlinear Transfer Functions

coefficients

c

1

0

c

2

0

clipping

If a sinusoidal signal is applied to a linear system, the output is a sine wave with the same frequency. Output signals at other frequencies are observed as well for nonlinear systems. This Demonstration considers nonlinear input signals of the form

y=x+

c

1

2

x

+

c

2

3

x

, in which

x

is a sine wave with frequency 1 kHz and amplitude 1. The figures show the output

y

and its magnitude spectrum obtained from the DFT (discrete Fourier transform). Depending on the coefficients

c

1

and

c

2

and the settings for clipping, the output has spectral components at either even or odd multiples of the first harmonic.