RF power transistors have important applications in RF communication systems such as 2G and 3G, and WiFi/WiMax, as a component of power amplifiers. LDMOS (laterally-diffused metal oxide semiconductor) high power transistors are virtually ubiquitous in base stations and long transmitters in RF wireless communications, meaning that their growing development and implementation with changing communication standards, is an important area of research. This book describes how modern RF power transitor technology is developed and used, with particular focus on LDMOS and III-V devices. This book is suitable for pratictioners, graduate students, and academic researchers in the fields of RF and microwave engineering. This is part of The Cambridge RF and Microwave Engineering Series.