Patent ID: 7342445

Claim:
A radio frequency power amplifier circuit comprising: a constant envelope modulation providing circuitry; a power amplifier driver having a driver gain control input, a driver signal output, and a driver signal input coupled to the constant envelope modulation providing circuitry; a power amplifier having an amplifier input coupled to the driver signal output; an amplifier input signal sensor having an amplifier signal sensor output; an amplifier output power sensor coupled to the power amplifier to thereby sense variations in a power output value of the power amplifier; a power amplifier gain controller having a gain controller input coupled to a power variation detector output of the amplifier output power sensor and an output of the power amplifier gain controller is coupled to a power amplifier gain control input of the power amplifier; and a feedback circuit having an Radio Frequency signal input coupled to the amplifier signal sensor output, a reference input coupled to the power variation detector output of the amplifier output power sensor, and a feedback circuit output coupled to the driver gain control input, wherein, in operation, when the amplifier output power sensor senses the variations in the power output value, the power amplifier gain controller adjusts a gain setting of the power amplifier at the power amplifier gain control input and the feedback circuit adjusts a gain setting of the driver gain control input so that the constant envelope modulated radio frequency signal is within a linear operating region of the power amplifier, and wherein the gain settings of the power amplifier and power amplifier driver are concurrently adjusted until the power output value for the power amplifier is achieved.