射频电源放大器研究

发布时间：2018-03-09 23:02

本文选题：射频放大器　切入点：射频电源　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：射频放大器应用于很多领域,射频电源就是其中之一。本文主要研究射频电源中的射频放大器。该放大器是核心模块,其性能直接决定了整个系统的性能。设计要求不同于其它领域的放大器,实现大功率、高效率、高线性度、低谐波和低杂波一直是设计难点。本文紧密围绕射频电源中射频放大器的实际应用,针对效率增强、杂波和谐波抑制及滤波器优化技术展开研究。提出了一种新的放大器设计方案。该方案将滤波器从第二级放大器之后移到第一级和第二级之前。改变传统的先放大后滤除谐波与杂波的模式,改为先滤波后放大射频信号,显著提高了放大器系统的效率。设计了一种谐振滤波器。该滤波器利用LC串联电路和LC并联电路的阻抗特性,实现频率选择和带通滤波作用。前者对谐振频率信号阻抗小,对偏离谐振频率的信号阻抗大;后者的阻抗特性相反。通过二者的串联与并联组合,射频信号无损通过,杂波信号被吸收。设计了一种三传输线变压器。该变压器连接在功放器输入端和输出端,起抑制谐波与杂波、及变换阻抗的作用。重新设计了推挽式放大器作为功放器,修改了偏置和直流调理电路,在功放管的栅极和漏极接入紧密耦合的互感变压器。互感变压器有助于实现射频信号高增益无损放大。利用Smith圆图工具设计了匹配电路。通过ADS软件对13.56MHz放大器做了仿真分析。设计和制作了27.12MHz放大器电路,测试性能参数,整体性能满足指标要求。
[Abstract]:RF amplifier is used in many fields, RF power supply is one of them. This paper mainly studies RF amplifier in RF power supply. This amplifier is the core module. Its performance directly determines the performance of the whole system. The design requirements are different from other fields of amplifier, to achieve high power, high efficiency, high linearity, Low harmonics and low clutter are always the difficulties in design. This paper focuses on the practical application of RF amplifiers in RF power supply, aiming at enhancing the efficiency. Research on clutter and harmonic suppression and filter optimization is carried out. A new amplifier design scheme is proposed, which moves the filter from the second stage amplifier to the first stage and before the second stage, and changes the traditional preamplifier. The mode of filtering out harmonics and clutter, A resonant filter is designed, which utilizes the impedance characteristics of LC series circuit and LC parallel circuit. Frequency selection and bandpass filtering are realized. The former has small impedance to resonant frequency signal and large impedance to signal deviating from resonant frequency, while the latter has the opposite impedance characteristic. A three-transmission line transformer is designed, which is connected to the input and output terminals of the power amplifier to suppress harmonics, clutter and transformation impedance. The push-pull amplifier is redesigned as the power amplifier. Modified bias and DC conditioning circuits, The tightly coupled mutual-inductance transformer is connected to the gate and drain of the power amplifier tube. The mutual inductance transformer is helpful to realize the high gain nondestructive amplification of RF signal. The matching circuit is designed by using the Smith circle diagram tool. The 13.56MHz amplifier is designed by ADS software. The circuit of 27.12MHz amplifier is designed and fabricated. Test performance parameters, the overall performance to meet the requirements.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN722

【参考文献】