RF and microwave Power amplifier architectures

During the initial design phases, it can be complicated to choose a technology and architecture for the development of a microwave amplifier. These initial choices can have significant consequences on the product in terms of cost and solution development time. This article proposes a method for guiding developers in their amplifier design choices, based on a given specification. The determining parameters of the specification strongly depend on the application under consideration (radiocommunications, RADAR, countermeasures, homing...), the platform on which the amplifier will be installed (satellite, aircraft, ship or land vehicle) and the performance (power, frequency band, linearity) targeted. Applications, platforms and performance all play a part in the selection of power amplifier architectures. The performance to be achieved (power, consumption, frequency band, modulation, etc.) will also determine the technology (solid state or microwave tube) to be considered. This article presents the performance factors that will be decisive in the choice of architecture, including but not limited to power. For radio communications applications, linearity is essential. For space applications, electrical efficiency and reliability must be taken into account. The various amplifier architectures are then presented in detail. Finally, using an example of an amplifier specification for a countermeasures application, three different design choices are studied and compared.

At the end of the article, readers will find a glossary and a table of acronyms.