Title :
A novel envelope-termination load-pull method for ACPR optimization of RF/microwave power amplifiers
Author :
Sevic, J.F. ; Burger, K.L. ; Steer, M.B.
Author_Institution :
Spectrian Corp., Sunnyvale, CA, USA
Abstract :
A novel load-pull method for envelope-termination characterization is presented. The method enables the source and load envelope terminations to be easily evaluated to further optimize the linearity/efficiency tradeoff of RF/microwave power transistors used in digital wireless communication systems with time-varying envelopes. Results are presented for a 53 mm low-voltage LDMOS transistor at 850 MHz. It is shown that the optimal envelope termination may in general be complex, in contrast to the commonly held belief that the envelope-termination must be approximately zero. A simplified Volterra series analysis is used to qualitatively explain how the envelope termination impacts linearity.
Keywords :
UHF power amplifiers; Volterra series; circuit testing; microwave power amplifiers; optimisation; 850 MHz; ACPR optimization; RF power amplifiers; Volterra series analysis; adjacent channel power ratio; characterization method; digital wireless communication systems; envelope-termination load-pull method; linearity/efficiency tradeoff optimisation; load envelope terminations; low-voltage LDMOS transistor; microwave power amplifiers; source envelope terminations; time-varying envelopes; Impedance; Linearity; Microwave amplifiers; Microwave theory and techniques; Microwave transistors; Optimization methods; Power amplifiers; Radio frequency; Radiofrequency amplifiers; Wireless communication;
Conference_Titel :
Microwave Symposium Digest, 1998 IEEE MTT-S International
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
0-7803-4471-5
DOI :
10.1109/MWSYM.1998.705093
