The topic of this thesis is designing an UMTS-band power amplifier module, and exploring the possibilities of efficiency improvement using the Doherty configuration. The task is based on the re-design of a product from BHE Bonn Hungary Electronics Ltd., since the required parts have become obsolete. The Doherty configuration is a technique using vacuum tubes invented over 70 years ago, which makes the modern implementation using solid-state devices challenging. The efficiency improvement is reached by connecting multiple active devices in parallel, and modulating the impedance seen by each device.
The thesis opens with an overview of the required theory, then follows with the design of the amplifier. Finally the completed design is tested in a simulated environment. During the design process great care had to be taken to conform the constraints imposed by the previous amplifier, which limited the choice of parts and the PCB design itself both in size and layout. The design and simulation were all done in AWR Microwave Office, while the PCB design was done using Altium Designer.