Title :
Study of the Output Load Mismatch Effects on the Load Modulation of Doherty Power Amplifiers
Author :
Hammi, Oualid ; Sirois, ôJérme ; Boumaiza, Slim ; Ghannouchi, Fadhel M.
Author_Institution :
Schulich Sch. of Eng., Calgary Univ., Alta.
Abstract :
In this paper, an analysis of the output load mismatch effects on the operation of Doherty power amplifiers is presented. A load-pull based LDMOS transistor model is used to investigate the effects of the load mismatch on the load modulation seen by the carrier and peaking amplifiers of a Doherty scheme. Then, the power added efficiency and the gain of the Doherty amplifier are evaluated for various load mismatch conditions. It is shown that the performance of the Doherty amplifier is more sensitive to the phase of the load reflection coefficient rather than its magnitude. Moreover, there is a phase of the load reflection coefficient for which the amplifier performance are much less sensitive to the load mismatch
Keywords :
modulation; power amplifiers; transistors; Doherty power amplifiers; load modulation; load reflection coefficient; load-pull based LDMOS transistor model; output load mismatch effects; Computer architecture; Impedance; Linearity; Peak to average power ratio; Power amplifiers; Power engineering and energy; Radio transmitters; Radiofrequency amplifiers; Reflection; Semiconductor optical amplifiers; Doherty amplifier; efficiency; linearity; load mismatch; power amplifiers;
Conference_Titel :
Radio and Wireless Symposium, 2007 IEEE
Conference_Location :
Long Beach, CA
Print_ISBN :
1-4244-0445-2
Electronic_ISBN :
1-4244-0445-2
DOI :
10.1109/RWS.2007.351850
