Title :
An overview of efficiency enhancements with application to linear handset power amplifiers
Author_Institution :
Semicond. Products Sector, Motorola Inc., Tempe, AZ, USA
Abstract :
A consequence of high spectral efficiency provided by second and third generation cellular systems is the requirement for linear power amplifiers in the transmitter unit of the mobile handset. The battery nature of the mobile phone emphasizes high amplifier efficiency for extending talk time and battery life. This represents an inherent trade-off between amplifier efficiency and linearity. Recent efforts have focused on considering alternative approaches with the goal of improving the efficiency/linearity performance trade-off compared to traditional single-ended Class A/B topologies. Some alternative approaches are examined here.
Keywords :
HEMT integrated circuits; UHF integrated circuits; UHF power amplifiers; cellular radio; code division multiple access; telephone sets; GaAs PHEMT based amplifier; IS-95 CDMA systems; W-CDMA systems; amplifier efficiency; amplifier linearity; battery life; efficiency/linearity performance trade-off; envelope following amplifier; envelope tracking; high spectral efficiency; linear power amplifiers; mobile handset transmitter unit; overview; second generation cellular systems; talk time; third generation cellular systems; two-stage GaAs HEMT IC; High power amplifiers; Linearity; Power amplifiers; Power generation; RF signals; Radio frequency; Radiofrequency amplifiers; Semiconductor optical amplifiers; Telephone sets; Voltage;
Conference_Titel :
Radio Frequency Integrated Circuits (RFIC) Symposium, 2002 IEEE
Conference_Location :
Seattle, WA, USA
Print_ISBN :
0-7803-7246-8
DOI :
10.1109/RFIC.2002.1011507
