An RF-input chireix outphasing power amplifier

This work presents for the first time an RF-input power amplifier (PA) based on Chireix outphasing, a technique employing two nonlinear but efficient PAs in a power-combining architecture that provides output power control. The RF-input approach eliminates the digitally-intensive signal component separator found in conventional outphasing architectures. We show that a passive network can be used to generate the phase- and amplitude-modulated signals used to drive nonlinear branch PAs in the outphasing system. The technique is demonstrated at 2.14 GHz in a 40-W PA and characterized with both CW and modulated signals.