| 摘要 |
Methods and apparatus for dynamically compensating for signal variations in communications transmitters employing switch-mode PAs. An exemplary method includes first identifying a predetermined signal characteristic in an input signal applied to an input of a switch-mode PA. A modulated signal produced at the output of the switch-mode PA containing the identified signal characteristic is then sampled at approximately the same time the identified signal characteristic appears at the output of the switch-mode PA, to generate a digital sample representing an actual value of the identified signal characteristic. An error signal representing the extent to which the actual value deviates from an expected value is then generated. Finally, the DC level and/or gain of the input signal to the switch-mode PA is modified to reduce the error. By reducing the error in this manner, signal variations that adversely affect the accuracy of the switch-mode PA output signal are dynamically compensated for.
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