Efficiency improvement in Doherty power amplifier by using Class F approach

In this contribution, the design of an uneven AB-C Doherty power amplifier (DPA) in GaN technology, implementing a Class F configuration for the Main device, is presented. Theoretical support will be given to understand why and how some relevant DPA's design parameters have to be carefully selected when a Class F strategy is adopted. Moreover, a comparison between the output performance obtained from a simple tuned load DPA and the here presented Class F DPA will be given. From the experimental results, the realised Class F DPA achieved, in an output back-off of 6 dB, an average drain efficiency of 50% with a saturated output power of 3.2 W at 2.14 GHz.