An embodiment of the invention uses a
predistortion correction
signal to combination the modulated RF
signal by an
analog multiplier for
linearization of power amplifiers having nonlinear characteristics such as those used in
wireless RF transmitters. A
predistortion controller comprises a plurality of down
converters for retrieving both the ideal non-distorted information and the feedback distorted information, together with pre-stored digitally-indexed
predistortion information stored, for example, in a look-up table. The digitally-indexed information models nonlinear characteristics of the
high power amplifier, and is stored prior to
processing of pre-compensation in the power
amplifier. When the predistortion information is combined with the modulated RF
signal in the
analog multiplier, the result is a substantially linear
information transmission from the power
amplifier. In an embodiment of the
system, the modulated RF input signal and the feedback signal from PA output are down-converted, respectively, by analog devices, such as mixers, after which the analog
intermediate frequency (IF) signals are digitized by analog-to-digital
converters for digital predistortion correction
processing, followed by predistortion
processing performed by, for example, a DSP or
FPGA chip to generate a digital correction
control signal, which is then converted to an
analog signal by a digital-to-analog converter, followed by combining the analog correction signal with the RF modulated input signal to yield the input to the power
amplifier.