Title :
Predistortion Power Amplifier for Base-Station using a Feedforward Loop Linearizer
Author :
Kim, Ildu ; Cha, Jeonghyeon ; Hong, Sungchul ; Woo, Young Yun ; Kim, Jangheon ; Kim, Bumman
Author_Institution :
Dept. of Electr. Eng., Pohang Univ. of Sci. & Technol., Gyeongbuk
Abstract :
A new LPA system using predistorter is described. A feedforward loop is employed in front of the main amplifier to generate the predistortion signal. For verification, the error generation amplifier and the main amplifier are implemented by the same Doherty amplifiers using 90W PEP MRF5S21090 LD-MOSFETs at 2.35 GHz, and the Doherty amplifiers are four way power combined for the main amplifier. It has been monitored at 47.8 dBm, backed-off about 10.8 dB from the 720W PEP. The two-tone and forward-link WCDMA 4FA signals have been used for testing. For the WCDMA signal, the efficiency of the amplifier is about 12.7 %, higher than the general feedforward type LPA by about 2 %. The adjacent channel leakage ratios at 5 MHz and 10 MHz offsets have been improved about 7.1 dB and 5.4 dB, respectively, by the predistorter
Keywords :
code division multiple access; feedforward amplifiers; leakage currents; microwave power amplifiers; 10 MHz; 2.35 GHz; 5 MHz; 720 W; 90 W; Doherty amplifiers; LD-MOSFET; LPA system; WCDMA; base station; error generation amplifier; feedforward loop linearizer; power amplifier; predistortion signal; Delay lines; Feedforward systems; High power amplifiers; Linearity; Multiaccess communication; Power amplifiers; Power generation; Predistortion; Signal generators; Testing;
Conference_Titel :
Microwave Conference, 2006. 36th European
Conference_Location :
Manchester
Print_ISBN :
2-9600551-6-0
DOI :
10.1109/EUMC.2006.281220
