Title :
High efficiency feedforward power amplifier using a nonlinear error amplifier and offset alignment control
Author :
Braithwaite, R. Neil ; Khanifar, Ahmad
Author_Institution :
Powerwave Technol., Santa Ana, CA, USA
Abstract :
A high efficiency feedforward power amplifier (FFPA) is proposed that uses the Doherty configuration for the both the main amplifier (MA) and error amplifier (EA). Using a nonlinear EA is a deviation from the traditional FFPA. A loop control algorithm is proposed that offsets the alignment setting from the standard value to best utilize the power handling capability and linearity of the MA and EA. A system efficiency of 25% is achieved for a rated output power of 52.7 dBm, while exceeding the WCDMA specifications. Reducing the peak-to-average power ratio (PAPR) of the input signal to 8 dB and using offset control improves the ACLR performance to -62 dBc.
Keywords :
feedforward amplifiers; nonlinear network synthesis; power amplifiers; ACLR performance; Doherty configuration; FFPA; PAPR; WCDMA specifications; efficiency 25 percent; error amplifier; feedforward power amplifier; loop control algorithm; main amplifier; nonlinear EA; offset alignment control; peak-to-average power ratio; power handling capability; Cost function; Feedforward neural networks; Floors; Multiaccess communication; Peak to average power ratio; Power amplifiers; Spread spectrum communication; Linearization; power amplifiers;
Conference_Titel :
Microwave Symposium Digest (IMS), 2013 IEEE MTT-S International
Conference_Location :
Seattle, WA
Print_ISBN :
978-1-4673-6177-4
DOI :
10.1109/MWSYM.2013.6697336
