Patent attributes
An amplifier circuit 11 comprises an amplifier 12, an indicator of desired power 15, a power control circuit 14 and a power measuring circuit 13. The amplifier 12 amplifies an input signal to produce an output signal, and has an input for controlling a supply current I and an input for receiving a supply voltage V and supply current I, for driving the amplifier. The power control circuit calculates and applies values of both a supply voltage V and a supply current I, according to any one of a plurality of desired power levels, in order to operate the amplifier with maximum efficiency over a wide range of power levels. The power control circuit may further comprise a power control loop whereby adjustment of the output power can also be effected according to a measurement of output power and a desired level of output power.
