Abstract: A polar modulation power amplifier circuit includes a control circuit (101) to determine and provide a load selection signal (127), wherein the load selection signal (127) is determined responsive to a requested power signal (119). A power amplifier (113) is responsive to a power control signal (141), for amplifying an RF signal (139) to produce an amplified signal (145), having an output power level. A variable impedance matching circuit (117) is responsive to the load selection signal (127), to adjust a relationship between the control level and the output power level, to produce a range-adjusted amplified signal (147).

Abstract: According to the apparatus of the present disclosure, dual gate control and dual gain control uses variable voltages on the gates of first stage (302) and a second stage (304) to control the output power. In alternate embodiments, dual drain control is also employed using a variable voltage supply on the drains of the first stage (302) and the second stage (304). In particular, a level shifter circuit (421) is employed to convert a positive voltage gate control signal to negative voltage with respect to ground. Drain current limiting circuits (417, 419) are used to sample drain currents and generate gate voltages to maintain a desired current ratio between stages of a multi-stage amplifier. When dual drain control is also employed, a 1:1 ratio of drain control voltages is employed at low power levels, with a single drain control at higher power levels.