Title :
A base control Doherty power amplifier for improved efficiency in GSM handsets
Author :
Ferwalt, Darren W. ; Weisshaar, Andreas
Author_Institution :
TriQuint Semicond., USA
Abstract :
A Doherty power amplifier that uses DC base voltage to control output power is presented. A single base control amplifier is first analyzed, then two such amplifiers are combined to create a Doherty amplifier for constant envelope modulation schemes, such as GSM. A new GSM power probability density function (PDF) is presented, and the average PA current is calculated using this data. Average current for the base control Doherty amplifier is compared to that of an ideal class B amplifier and to a Doherty amplifier composed of two class B amplifiers. A prototype design is then implemented at 30 MHz with GaAs HBTs, and measured results are reported.
Keywords :
HF amplifiers; III-V semiconductors; cellular radio; gallium arsenide; heterojunction bipolar transistors; mobile handsets; power amplifiers; prototypes; 30 MHz; GSM handset; GaAs; GaAs HBT; PDF; control Doherty power amplifier; high frequency amplifier; modulation; probability density function; prototype design; Computer science; GSM; Power amplifiers; Power generation; Probability density function; Radio frequency; Radiofrequency amplifiers; Semiconductor optical amplifiers; Telephone sets; Voltage control;
Conference_Titel :
Microwave Symposium Digest, 2004 IEEE MTT-S International
Print_ISBN :
0-7803-8331-1
DOI :
10.1109/MWSYM.2004.1339115
