High efficiency feed-forward RF power amplifier with predistoration enchancement

Claim 1

An RF power amplifier arrangement comprising: an RF input port to which an RF input signal is applied; an RF output port from which an RF output signal is derived; first and second RF signal processing paths coupled between said input and output ports and containing first and second RF power amplifiers; said first RF signal processing path including a first RF signal vector modulator, that is controllably operative to adjust one or more parameters of a first RF input signal component applied to said first RF power amplifier; said second RF signal processing path including a predistortion unit containing a second RF signal vector modulator and a predistorter, that is controllably operative to predistort a second RF input signal component applied to said second RF power amplifier in a manner that compensates for the presence of distortion energy applied to said second RF power amplifier that is not applied to said first RF power amplifier, and an intermodulation distortion (IMD) extraction circuit coupled to said RF input port and to an output of said first RF power amplifier, and being operative to generate said second RF input signal component as a combination of said RF input signal and an IMD component present in an amplified RF output signal from said first RF power amplifier; and an output signal combiner coupled to outputs of said first and second RF power amplifiers and said output port, and being operative to produce said RF output signal as a composite RF output signal, in which RF carrier components produced by said first and second RF power amplifiers constructively sum and IMD components produced thereby destructively combine.