基于数字预失真的高效率线性化功率放大器射频电路设计-通信与信息系统专业论文.docx

万方数据 万方数据 摘 要 摘 要 无线通信行业已经进入了 3G 时代，一些国家的运营商甚至已经开始 4G 的商 用化。高速发展的无线通信标准对通信设备提出了更加苛刻的要求。功率放大器 作为无线通信基站发射链路的重要部件，其性能直接影响着无线通信的质量。 高效率与线性化是功率放大器的发展方向，在众多功率放大器效率增强技术 当中，Doherty 放大器技术以其性能优良、结构简单、成本低廉等优点，近年来受 到越来越多的重视。当 Doherty 技术与数字预失真技术结合之后，成为了一种十分 适合现代通信标准的高效率线性化技术。 本文的内容是一款 WCDMA 频段的基于数字预失真技术的高效率线性化功率 放大器的射频电路设计，此外还包括与之搭配的驱动放大器、发射机链路等模块 的电路设计。 文章首先介绍了高效率线性化功率放大器领域的研究进展和现状。 其次介绍并分析了功率放大器的分类及主要性能技术指标，介绍了当前几种 典型的效率增强技术和线性化技术。 然后对本设计的技术指标进行分析，选定器件，完成了发射链路各模块设计、 驱动放大器仿真设计以及 Doherty 放大器的 ADS 仿真设计，并完成各个模块的印 刷电路板设计。 最后对制作出的驱动放大器和 Doherty 放大器进行基本指标的测试。 通过以上的成果，充分验证了本设计在节能型 WCDMA 基站中的工程可行性， 为进一步的研究与生产提供了可选择的方案，具有重要的工程实践意义和经济价 值。 关键词：Doherty，功率放大器，高效率，ADS I Abstract Abstract The 3rd generation communication systems are already in widely use throughout the world and in some countries the 4th generation communication systems are also put into commercial use. Modern communication standards have more strict demands in wireless devices. As an important part of the transmission chain, power amplifiers are playing an ever so important role in system design. Achieving high efficiency and good linearity are the two main goals in designing a power amplifier. Among the various efficiency enhancement techniques, the Doherty amplifier has gained more and more notices these days for its low cost and simple structure. It becomes a more powerful structure when combining with Digital Pre-distorion, which is highly suitable for modern communication systems. This dissertation is about the design of a DPD based high-efficiency linear power amplifier used for WCDMA base stations or repeaters, as well as the related design of the transmission chain and drving amplifier. Firstly, the newly development of the PA design is introduced. Then the power amplifier theories are specified in several chapters. After then, the analysis of the design requirements is presented, the choices of devices and the simulation are completed and the PCBs of these modules are finished. At last, I tested the sample machine