An ideal amplifier would be a totally linear device, but real amplifiers are only linear within limits.
When the signal drive to the amplifier is increased, the output also increases until a point is reached where some part of the amplifier becomes saturated and cannot produce any more output; this is called clipping, and results in distortion.
In most amplifiers a reduction in gain takes place before hard clipping occurs; the result is a compression effect, which (if the amplifier is an audio amplifier) sounds much less unpleasant to the ear. For these amplifiers, the 1 dB compression point is defined as the input power (or output power) where the gain is 1 dB less than the small signal gain. Sometimes this nonlinearity is deliberately designed in to reduce the audible unpleasantness of hard clipping under overload.
Ill effects of nonlinearity can be reduced with negative feedback.
Linearization is an emergent field, and there are many techniques, such as feedforward, predistortion, postdistortion, in order to avoid the undesired effects of the non-linearities.
When the signal drive to the amplifier is increased, the output also increases until a point is reached where some part of the amplifier becomes saturated and cannot produce any more output; this is called clipping, and results in distortion.
In most amplifiers a reduction in gain takes place before hard clipping occurs; the result is a compression effect, which (if the amplifier is an audio amplifier) sounds much less unpleasant to the ear. For these amplifiers, the 1 dB compression point is defined as the input power (or output power) where the gain is 1 dB less than the small signal gain. Sometimes this nonlinearity is deliberately designed in to reduce the audible unpleasantness of hard clipping under overload.
Ill effects of nonlinearity can be reduced with negative feedback.
Linearization is an emergent field, and there are many techniques, such as feedforward, predistortion, postdistortion, in order to avoid the undesired effects of the non-linearities.
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