微波线性功率放大器的研究

【作者】 张翔；

【导师】 唐小宏；

【作者基本信息】 电子科技大学 ， 无线电物理， 2005， 硕士

【摘要】 随着无线通信的迅猛发展,通信频率资源变得越来越紧张,功率放大器是射频系统的关键部件,也是产生非线性的主要部件,因此对功率放大器的线性化是一项即具有重要实际意义又具有挑战性的课题。本文详细分析了微波功率放大器的非线性特性,介绍了反馈、前馈、预失真等各种线性化技术的基本原理。根据拟采用方案对前馈功率放大系统的时域和频域进行了详细分析,从系统的角度得出了交调和无用失真完全抵消时各部分的关系,为设计前馈放大器提供了实用、有效的方法。根据分析结论,针对中国自主开发的TD-SCDMA 标准,设计实现了2.35GHz 的功分器、功率合成器、耦合器以及矢量调制器和功率放大器,最终实现了结构简单、体积小巧的前馈功放系统,完成了对放大器的线性化,三阶交调系数优于-50dBc 比线性化之前三阶交调系数改善了40dB。为进一步提高前馈功率放大系统的线性化水平提供了理论基础,具有工程参考价值。更多还原

【Abstract】 With the development of wireless communication, the frequency resourcesbecome more and more nervous. The power amplifier is the necessary component inradio frequency system and also a main part of nonlinear products, so it has theimportant actual meaning and the topic of the challenge to linearize the poweramplifier.In this paper we study the nonlinear characteristic of microwave power amplifiersystem. Introduce the basic principle of feedback, feedforward and pre-distortiontechnical to linearize. According to project I analyze a feedforward power amplifiersystem on the time and frequency field, we can conclude the relationship of all partsin this system when intermodulation distortions and other interference have beenremoved. Those provide a practical and valid method for designing a feedforwardpower amplifier. Utilizing these and for TD-SCDMA we research and develop thedivider, coupler, bridge and power amplifier at 2.35GHz. Finally I accomplished asimple and minimal structured feedforward power amplifier. Its measured third-orderintermodulation distortion (IMD) is -50dBc, which is 40dB greater than there is nolinearization technique. It proves the foundation of the theories and a reference priceof the project for getting a greater IMD.更多还原