Many different transistor technologies exist, each with its place and purpose. To date, there is no transistor technology specifically designed for DPST use. It is a valuable exercise then to evaluate the suitability of the transistor technologies that are available for use in a DPST RF power amplifier design. Doing just this is the purpose of this chapter.
Chapters in Part I relate the properties of various DPST architectures to features in examples of transistor characteristic curves. The extension of these to actual transistor characteristic curves is particularly important, because if the selected transistor technology does not have the needed features in its characteristic curves, then the DPST project is immediately doomed. It will never work properly simply because the transistors chosen will not support the necessary performance features. To avoid this catastrophe, it is necessary to understand what each available technology can support with respect to the necessary performance features.
This extensive chapter is very important because it draws together for the first time all of the DPST relevant characteristics of each commercially available RF transistor technology in one place. Each technology is comprehensively represented by the same 12 measurement sets to allow comparison of their relative behavior. More importantly, the applicability of each transistor technology – or not – to the needs of DPS transmitter designs are evaluated.
With this comprehensive data now available, there are two primary objectives:
• selection of the most appropriate transistor technology can be made in an informed manner to enhance success of any particular DPS transmitter design project, and
• transistor manufacturers can review the present states of the art shown here to further improve the applicability of their technologies within the growing importance of DPS transmitters.
This chapter begins with establishing a transistor characteristic wish-list from the DPS transmitter designer's point of view: in an ideal world what the transistor technologies would be like to make the DPS transmitter design projects easy to complete and put into stable production.