Analog/Digital Co-Design Techniques for Broadband Load-Modulated Power Amplifiers

Load modulation technique has been widely used to improve the efficiency of power amplifiers (PAs) such as in Doherty, Outphasing, Load Modulated Balanced Amplifier (LMBA) and Reverse Modulated Dual Branch (RMDB) PAs. However, the variation of the load modulation effects versus frequency result in undesirable high amount of memory effects that limits the use of such techniques for broadband applications. This presentation proposes an analog/digital co-design approach for load modulated PAs to reduce these undesirable memory effects and extend the RF and instantaneous bandwidths in these high efficiency PAs.