Abstract: Methods and apparatuses are provided for achieving efficient power usage by a power amplifier. For example, there is provided an apparatus comprising: a processor unit providing one or more processor outputs, one of the processor outputs comprising a control voltage; and a variable gain amplifier operatively coupled to the processor and the power amplifier, wherein the variable gain amplifier comprises a piecewise linear circuit that receives the control voltage from the processor unit and provides a supply voltage to the power amplifier. In one embodiment, the processor unit is operatively coupled to a receiver that receives a feedback signal via radio link from a remote base station. The piecewise linear circuitry adjusts the supply voltage to the power amplifier at an exponential rate according to power requirements of the power amplifier.

Abstract: A power system comprising a front end regulator coupled to an input supply voltage (Vin) and providing a regulated input supply voltage (Vbp). The front end regulator compares the input supply voltage (Vin) and the regulated input supply voltage (Vbp) and maintains a substantially constant voltage difference between the input supply voltage (Vin) and the regulated input supply voltage (Vbp) to thereby reduce ripple of the input supply voltage (Vin). A DC-DC switching mode power converter is operatively coupled to the front end regulator and receives the regulated input supply voltage (Vbp). The DC-DC switching mode power converter thereby provides a regulated output voltage (Vout).