前馈放大器中抵消环路的研究  

Study of Cancellation Loop in Feed-forward Amplifier

作　　者：李玉兰[1] 石玉[1] 何泽涛[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,四川成都610054

出　　处：《现代电子技术》2011年第2期151-153,156,共4页Modern Electronics Technique

摘　　要：为了尽可能提高前馈放大器的线性,减少抵消环路抵不匹配及辅助放大器的非线性给系统带来的不良影响。在此通过前馈电路模型讨论分析了经第一抵消环后未完全抵消的基波信号和辅助放大器的非线性对系统造成的影响可以忽略不计的条件。通过该关系式能方便准确的估算出该条件下系统能达到的三阶互调,并通过实验验证。In order to improve the linearity of feed-forward amplifier and reduce adverse effects of the unmatched cancella- tion loops and nonlinear auxiliary amplifier on the systems, based on the feed-forward circuit model, the influences of the re- sidual fundamental wave signal and auxiliary amplifier＇s nonlinearity on the systems are analyzed. The conclusion is that the fundamental wave signal can be negligible. The third-order intermodulation of the system which works under this condition smoothly can be estimated by the formula. It is verified by an experiment.

关 键 词：前馈放大器 抵消环路 三阶互调 LINC 

分 类 号：TN919-34[电子电信—通信与信息系统]