Nonlinear amplifier calibration system and methods

摘要

Apparatus and methods that compensate for the effects of gain and phase variations of a high power amplifier in the presence of multicarrier traffic. The calibration system and method impose negligible degradation to the multicarrier traffic processed by the high power amplifier. A calibration signal generator is used to generate a plurality of nondisrupting calibration signals, such as pseudorandom numbers, which are also summed and combined with the multicarrier traffic signals. The plurality of nondisrupting calibration signals are also combined to produce a combined nondisrupting calibration signal. Each of the nondisrupting calibration signals is selectively output and is combined with sampled versions of the amplified multicarrier traffic signals produced by the high power amplifier to despread them. The despread multicarrier traffic signals are then processed in a processor to generate signals indicative of total signal power, intermodulation power, and phase shift of the despread multicarrier traffic signals to determine a current operating point of the high power amplifier on its gain transfer curve. Gain and phase control signals are generated by a processor that are coupled to the gain control and phase control circuits to set the amplifier at its most desirable operating point.