DocumentCode :
3141174
Title :
A non-collinear descent algorithm for controlling the first loop in a feedforward power amplifier
Author :
Braithwaite, R. Neil
Author_Institution :
Powerwave Technol., Santa Ana
fYear :
2008
fDate :
22-24 Jan. 2008
Firstpage :
431
Lastpage :
434
Abstract :
An algorithm for controlling the first loop of a feedforward amplifier is discussed. The ratio of the error and input powers is used to measure the residual of the carrier cancellation and the loop alignment is adjusted to minimize this residual. Three successive non-collinear measurements are used to choose the descent direction, which is close to the gradient direction of the cancellation contours without being collinear with the two most recent measurements. Quantization of the descent direction simplifies the implementation. The step size of the descent is decoupled from the gradient magnitude to ease implementation and improve stability.
Keywords :
circuit stability; feedforward amplifiers; gradient methods; power amplifiers; carrier cancellation; feedforward power amplifier; first loop control; gradient direction; noncollinear descent algorithm; stability; Delay estimation; Distortion measurement; Error correction; Nonlinear distortion; Power amplifiers; RF signals; Radio frequency; Radiofrequency amplifiers; Stability; Virtual manufacturing; Power amplifiers; feedforward amplifiers; feedforward systems; power amplifier linearization;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Radio and Wireless Symposium, 2008 IEEE
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4244-1462-8
Electronic_ISBN :
978-1-4244-1463-5
Type :
conf
DOI :
10.1109/RWS.2008.4463521
Filename :
4463521
Link To Document :
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