Patent ID: 8299852

Claim:
A method of varying a gain of an amplifier having a first signal coupled to an input of the amplifier, by varying the amplitude of a second signal that is also coupled to the input of the amplifier, comprising: combining the first and second signals and providing the combined signal to the input of the amplifier, wherein the second signal is an alternating current signal; adjusting an amplitude level of the second signal so as to control the gain of the amplifier in respect to amplifying the first signal, by overdriving the amplifier; and wherein the alternating current signal is varied in amplitude and or pulse-width to provide various degrees of harmonic and or intermodulation distortion for the alternating current signal at the output of the amplifier, while substantially providing a varied amplitude of the first signal at the output of the amplifier, with substantially lower distortion of the first signal when compared to the distortion of the alternating current signal.