Mixer circuits are often used in, for example, transmitters and receivers. In, for example, a transmitter, there will often also be comprised an amplifier, usually a power amplifier. A drawback with power amplifiers is that they usually exhibit a transfer function which is non-linear. In order to compensate for such non-linearities in a power amplifier, a transmitter will therefore often comprise a “pre-distortion” circuit, i.e. a circuit which introduces non-linearities which are the inverse of the non-linearities exhibited by the power amplifier, so that the total transfer function of the transmitter is linearized.
A drawback of using pre-distortion circuits is that they are usually costly and have quite a complicated design.
USPTO Backgrounds
USPTO Backgrounds