摘要 |
A circuit and method for applying a dynamically varying collector voltage to a power amplifier is presented. A desired output power is determined, and an input and output power of a power amplifier are measured. A processor determines, for the measured input power and the desired output power, a collector voltage. The processor controls the input power to the power amplifier using the desired output power, the measured output power, and the measured input power. The collector voltage is changeable even though the desired output RF power does not change, so the collector voltage is not fixed for a particular output RF power. Preferably, an algorithm in memory stores, for each desired output value, collector voltages for various conditions of input RF power. Collector current is maximally reduced where the collector voltages stored in memory are the lowest voltages that will meet power linearity requirements, such as may be imposed by CDMA.
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