Comparative analysis of GaAs/LDMOS/GaN high power transistors in a digital predistortion amplifier system

Silicon LDMOS transistors have long been employed as the technology of choice for high power amplifiers in cellular infrastructure equipment. With each successive generation, improvements have been achieved in the areas of power, efficiency, linearity and reliability. As device performance approaches ideal, the focus for improvements has shifted to circuit based techniques and alternate device technologies such as GaAs, and lately GaN. Employing these technologies successfully in high power amplifier designs affords unique opportunities and challenges. In addition, as distortion correction techniques migrate towards the digital domain, new algorithms must address the unique properties of each technology. In this paper a comparative analysis of GaAs, LDMOS, and GaN devices are performed in a digitally predistorted amplifier system.