Title :
Extremely low-distortion multi-carrier amplifier-self-adjusting feed-forward (SAFF) amplifier
Author :
Narahashi, Shoichi ; Nojima, Toshio
Author_Institution :
NTT Radio Commun. Syst. Labs., Kanagawa, Japan
Abstract :
A newly developed nonlinear distortion compensation circuit is presented for high-frequency power amplifiers (PAs), the self-adjusting feedforward (SAFF). A self-adjusting function utilizing a microprocessor and pilot signals provides both precise and stable distortion compensation performance. One of the most important SAFF applications is to construct a multicarrier transmitting amplifier for mobile communications. A computer analysis is performed to predict the required minimum output power backoff for an ideal multicarrier transmitter and the distortion improvement necessary for SAFF to attain the minimum output power backoff operation. Moreover, experimental results of multicarrier amplification using a 100-W 1.5-GHz-band GaAs-FET SAFF-PA show that the required distortion improvement of over 30 dB can be stably obtained
Keywords :
computer aided analysis; electronic engineering computing; mobile radio systems; power amplifiers; radiofrequency amplifiers; telecommunications computing; 1.5 GHz; 100 W; GaAs; II-V semiconductor; UHF; computer analysis; high-frequency power amplifiers; microprocessor; minimum output power backoff; mobile communications; multicarrier amplification; multicarrier transmitter; multicarrier transmitting amplifier; nonlinear distortion compensation circuit; pilot signals; self adjusting feedforward amplifier; Application software; Circuits; High power amplifiers; Microprocessors; Mobile communication; Nonlinear distortion; Performance analysis; Power amplifiers; Power generation; Transmitters;
Conference_Titel :
Communications, 1991. ICC '91, Conference Record. IEEE International Conference on
Conference_Location :
Denver, CO
Print_ISBN :
0-7803-0006-8
DOI :
10.1109/ICC.1991.162253
