Energy-efficient broadband Doherty power amplifier for carrier aggregation

This talk will review the recent progress in energy-efficient broadband Doherty power amplifier (PA) and low complexity digital predistortion (DPD) techniques for carrier aggregation. For carrier aggregation application, especially for more than 3 carriers, it is not easy to implement multiband Doherty architecture or achieve required bandwidth. In this situation, broadband Doherty PA with concurrent operation capability is highly desirable. To alleviate the bandwidth burden on conventional Doherty PA, Continuous mode impedance matching method is proposed for Doherty PA for bandwidth enhancement, which utilizes the cross-matching technique to realize the physical output matching network. Owing to the compressive sensing method, the behavioral model can be extracted by using the aliased feedback signal, the broadband PA nonlinearity can be well corrected by the estimated output, and the feedback sampling rate can be reduced drastically.