Efficiency improvement of LDMOS transistors for base stations: towards the theoretical limit

The paper presents the evolution in LDMOST technology of the last decade, leading to a present 32 percent efficiency value for a two carrier W-CDMA signal with -37dBc IM3 and discusses future prospects to increase the performance even further. The achieved reduction of parasitic elements currently opens the way for system concepts such as high efficiency classes and Doherty type concepts