Title :
A new adaptive feedforward amplifier using imperfect signal cancellation
Author :
Kim, Bumman ; Woo, Young Yuii ; Yang, Youngoo ; Yi, Jaehyok ; Nam, Joongjin ; Cha, Jeonghyeon
Author_Institution :
Dept. of Electron. & Electr. Eng., Pohang Univ. of Sci. & Technol., Kyungbuk, South Korea
Abstract :
This paper describes a new adaptive feedforward amplifier for WCDMA system using an imperfect signal cancellation. Due to the complicated signal statistics, the distortion generated by the error amplifier is significantly reduced by the imperfect signal cancellation. Therefore, the performances of feedforward amplifier are improved with this new adaptation technique., especially for the modulated signals with a high peak-to-average ratio. For verification, a 2.14 GHz feedforward amplifier with 80 W output power has been implemented and tested with digital control circuits. The results, compared to the perfect signal cancellation, show more than 7 dB improvement of ACLR at 80 W output power. The efficiency is also improved from 7.5 % to 9 % at the same ACLR´s.
Keywords :
UHF power amplifiers; adaptive signal processing; code division multiple access; feedforward; 2.14 GHz; 7.5 to 9 percent; 80 W; ACLR; RF linear power amplifier; WCDMA system; adaptive feedforward amplifier; digital control circuit; imperfect signal cancellation; wireless system; Costs; Digital control; Distortion; Error correction; High power microwave generation; Multiaccess communication; Peak to average power ratio; Power amplifiers; Power generation; Signal generators;
Conference_Titel :
Microwave and Millimeter Wave Technology, 2002. Proceedings. ICMMT 2002. 2002 3rd International Conference on
Print_ISBN :
0-7803-7486-X
DOI :
10.1109/ICMMT.2002.1187854
