A novel wideband and reconfigurable high average efficiency power amplifier

This work presents theory and measurements of a new power amplifier based on the Doherty topology. It is theoretically shown that, by using a new set of design parameters with a Doherty power amplifier topology, the proposed amplifier can provide high efficiency, both at full output power and at power back-off, over a much improved bandwidth compared to the conventional Doherty power amplifier configuration. It is also shown that the proposed amplifier allows for simple reconfiguration of the efficiency in power back-off. A demonstrator circuit using individually controlled main and peak amplifier input signals is designed to validate the theoretical findings. Measurements show state-of-the art efficiency bandwidth at both full output power and at power back-off, as well as reconfigurable efficiency, thus validating the theory and demonstrating the potential of the proposed PA for use in future wireless transmitter applications.

[1]  L.C.N. de Vreede,et al.  A High-Efficiency 100-W GaN Three-Way Doherty Amplifier for Base-Station Applications , 2008, IEEE Transactions on Microwave Theory and Techniques.

[2]  A. Z. Markos,et al.  Frequency Response Analysis and Bandwidth Extension of the Doherty Amplifier , 2011, IEEE Transactions on Microwave Theory and Techniques.

[3]  D. E. Dawson,et al.  Closed-Form Solutions for the Design of Optimum Matching Networks , 2009, IEEE transactions on microwave theory and techniques.

[4]  R Darraji,et al.  A Dual-Input Digitally Driven Doherty Amplifier Architecture for Performance Enhancement of Doherty Transmitters , 2011, IEEE Transactions on Microwave Theory and Techniques.

[5]  L.C.N. de Vreede,et al.  A wide-band 20W LMOS Doherty power amplifier , 2010, 2010 IEEE MTT-S International Microwave Symposium.

[6]  Jangheon Kim,et al.  Analysis of a Fully Matched Saturated Doherty Amplifier With Excellent Efficiency , 2008, IEEE Transactions on Microwave Theory and Techniques.