A radio frequency transmitter, comprising: a first RF power amplifier; a second RF power amplifier; a combiner to combine output signals of the first and second RF power amplifiers; a first digital-to-RF modulator to generate an RF input signal for the first RF power amplifier based on first information indicative of a first amplitude and a first phase; a second digital-to-RF modulator to generate an RF input signal for the second RF powere amplifier based on second information Indicative of a second amplitude and a second phase; a first voltage control unit to provide a variable supply voltage to the first RF power amplifier in response to a first control signal; a second voltage control unit to provide a variable supply voltage to the second RF power amplifier in response to a second control signal; and a controller to: receive date indicative of a vector to be transmitted from the transmitter; select first and second voltage levels for the first and second power amplifiers, respectively, that are capable of providing the vector at the output of the combiner; select first and second input phase angles for the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner; select first and second input amplitude levels to be provided to the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner, wherein at least one of the first input amplitude level and the second input amplitude level are such that the corresponding power amplifier is backed off from a saturation point associated with the voltage level selected for that power amplifier; and generate the first information based on the first input phase angle and the first input amplitude level, generate the second information based on the second input phase angle and the second input amplitude level, generate the first control signal based on the first selected voltage level, and generate the second control signal based on the second selected voltage level, thereby setting an ouput power level of the RF transmitter. a first RF power amplifier; a second RF power amplifier; a combiner to combine output signals of the first and second RF power amplifiers; a first digital-to-RF modulator to generate an RF input signal for the first RF power amplifier based on first information indicative of a first amplitude and a first phase; a second digital-to-RF modulator to generate an RF input signal for the second RF powere amplifier based on second information Indicative of a second amplitude and a second phase; a first voltage control unit to provide a variable supply voltage to the first RF power amplifier in response to a first control signal; a second voltage control unit to provide a variable supply voltage to the second RF power amplifier in response to a second control signal; and a controller to: receive date indicative of a vector to be transmitted from the transmitter; select first and second voltage levels for the first and second power amplifiers, respectively, that are capable of providing the vector at the output of the combiner; select first and second input phase angles for the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner; select first and second input amplitude levels to be provided to the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner, wherein at least one of the first input amplitude level and the second input amplitude level are such that the corresponding power amplifier is backed off from a saturation point associated with the voltage level selected for that power amplifier; and generate the first information based on the first input phase angle and the first input amplitude level, generate the second information based on the second input phase angle and the second input amplitude level, generate the first control signal based on the first selected voltage level, and generate the second control signal based on the second selected voltage level, thereby setting an ouput power level of the RF transmitter. receive date indicative of a vector to be transmitted from the transmitter; select first and second voltage levels for the first and second power amplifiers, respectively, that are capable of providing the vector at the output of the combiner; select first and second input phase angles for the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner; select first and second input amplitude levels to be provided to the first and second power amplifiers, respectively, to achieve the vector at the output of the combiner, wherein at least one of the first input amplitude level and the second input amplitude level are such that the corresponding power amplifier is backed off from a saturation point associated with the voltage level selected for that power amplifier; and generate the first information based on the first input phase angle and the first input amplitude level, generate the second information based on the second input phase angle and the second input amplitude level, generate the first control signal based on the first selected voltage level, and generate the second control signal based on the second selected voltage level, thereby setting an ouput power level of the RF transmitter.