Reconfigurable Chireix Outphasing Power Amplifier Over Multiple Frequency Bands

This brief presents a new design scheme to expand the operating frequency range of outphasing power amplifier (PA) which is useful for software-defined radio applications. The proposed design scheme offers reconfigurability to multiple operating bands by using reconfigurable Chireix combiner along with wideband PA. For efficiency enhancement at output power back-off at multiple operating frequencies, Chireix combiner should provide correct reactance compensation at each operating frequency. This is achieved by utilizing tunable compensating network, which can be reconfigured to multiple operating frequencies. The proposed methodology is experimentally verified in radio frequency/digital hybrid DSP/field programmable gate array-based platform. The measurement results show efficiency enhancement upto 6-7-dB output power back-off over +/- 25-MHz bandwidth around 1.65, 2.1, and 2.35 GHz.