Patent ID: 8290086

Claim:
A method for an outphasing transmitter to produce an output signal generated, at least in part, from a digital input signal, the method for the outphasing transmitter comprising: producing a first constant modulation (CM) signal, a second constant modulation (CM) signal, a third constant modulation (CM) signal and a fourth constant modulation (CM) signal from the digital input signal; converting each of the first CM signal, the second CM signal, the third CM signal and the fourth CM signal from a digital state to an analog state with a respective digital-to-analog converter; filtering each of the first CM signal, the second CM signal, the third CM signal and the fourth CM signal with a respective pulse shaping filter and outputting a respective in-phase signal and a respective quadrature signal; modulating the first in-phase signal and the first quadrature signal with a first quadrature modulator (QM) to produce a first modulated signal, modulating the second in-phase signal and the second quadrature signal with a second quadrature modulator (QM) to produce a second modulated signal, modulating the third in-phase signal and the third quadrature signal with a third quadrature modulator (QM) to produce a third modulated signal, and modulating the fourth in-phase signal and the fourth quadrature signal with a fourth quadrature modulator (QM) to produce a fourth modulated signal; amplifying each of the first modulated signal, the second modulated signal, the third modulated signal, and the fourth modulated signal with a respective power amplifier; combining the first modulated signal and the second modulated signal with a first power combiner to produce a first combined signal, and combining the third modulated signal and the fourth modulated signal with a second power combiner to produce a second combined signal; and combining the first combined signal and the second combined signal with a third power combiner to produce the output signal.