Title :
An independently controllable AM/AM and AM/PM predistortion linearizer for cdma2000 multicarrier applications
Author :
Park, Chan-Wang ; Beauregard, François ; Carangelo, Gary ; Ghannouchi, Fadhel M.
Author_Institution :
AmpliX Wireless & Satcom, Montreal, Que., Canada
Abstract :
An independently controllable AM/AM and AM/PM predistortion linearizer that consists of two bias feed resistances linearizers is proposed. Each linearizer has a biased parallel diode connected to the each port of a 90° hybrid. This linearizer allows independent adjustment of the AM/AM and AM/PM curves by using two adjustable voltages to compensate the power amplifier non-linearities. The instantaneous characterization of the power amplifier is performed, so that the non-linearity correction may be determined. The predistortion linearizer can improve the ACPR by 6 dB with cdma2000 multicarrier signals. By applying this predistortion amplifier to the main amplifier in a feed forward amplifier system, ACPR performance of the entire feed forward amplifier for a cdma2000 multicarrier environment will be improved
Keywords :
Schottky diodes; amplitude modulation; code division multiple access; feedforward; multiuser channels; phase modulation; power amplifiers; radiofrequency amplifiers; 1.96 GHz; 60 MHz; 90° hybrid; ACPR; Schottky diodes; bandwidth; bias feed resistance linearizers; biased parallel diode; cdma2000 multicarrier signals; center frequency; independently controllable AM/AM predistortion linearizer; independently controllable AM/PM predistortion linearizer; power amplifier nonlinearity compensation; quadrature hybrid; Attenuators; Bandwidth; Character generation; Circuits; Feeds; Phase shifters; Power amplifiers; Predistortion; Schottky diodes; Voltage;
Conference_Titel :
Radio and Wireless Conference, 2001. RAWCON 2001. IEEE
Conference_Location :
Waltham, MA
Print_ISBN :
0-7803-7189-5
DOI :
10.1109/RAWCON.2001.947507
