L波段固态脉冲功率放大器的研制

发布时间：2018-03-23 13:44

本文选题：L波段　切入点：脉冲功率放大器　出处：《电子科技大学》2015年硕士论文

【摘要】：脉冲功率放大器广泛应用于雷达和无线通信发射机中,是发射机的核心部件,其性能的好坏直接决定整个通信系统的性能。相对于真空器件,固态器件具有结构紧凑、可靠性好、工作电压低等优点。因而固态脉冲功率放大器的研究成为热点。本文将要完成L波段固态脉冲功率放大器的设计。经过分析和比较,选择了功放加脉冲调制电路的架构。整个放大器由预驱动级、驱动级和功放级三级构成。本文首先介绍了功放的分类,根据不同类型功放的特点,选择预驱动级和驱动级工作于A类,功放级工作于AB类。然后使用ADS软件,采用小信号S参数法仿真了各级放大器的稳定性因子,确保放大器稳定地工作,设计了预驱动级和驱动级的输入输出匹配电路和直流偏置电路;以负载牵引的方法仿真设计了功放的输入输出匹配电路,使放大器的输出功率和增益达到设计要求。通过ADS软件对功放的版图进行了Momentum电磁仿真,使仿真结果与实际情况更接近。文中对比介绍了开关调制、栅极调制、漏极调制等不同调制方式的特点,最终选择了漏极调制方式。使用具有快速上升沿和下降沿的功率MOSFET驱动晶体管的漏极实现脉冲调制。本文为功率放大级设计了温度补偿电路,可以将温度对功放静态工作点的影响降到最低。最后使用Protel99软件设计了电源和调制电路的PCB版图,使用AutoCAD软件设计了射频放大链路的电路版图和金属屏蔽结构件。完成了功放和调制电路的设计仿真,需要对电路进行测试。本文介绍了调试过程中需要注意的问题,并为不同的电路模块和脉冲功放整机设计了不同的调试方案。主要使用矢量网络分析仪、信号源、功率计、衰减器等测试仪器对电路进行了调试,最后测得驱动放大器在工作频带内的增益为31dB,功率放大级的增益为20dB,脉冲输出功率达到250W,工作频带内增益平坦度小于1dB。脉冲上升沿为35ns,下降沿46ns,脉冲顶降小于0.81dB,达到了设计指标。最后对全文进行了总结,得出了相关结论,指出了文中存在的不足,并提出了相应的改进方向。
[Abstract]:Pulse power amplifier is widely used in radar and wireless communication transmitter. It is the core component of transmitter. Its performance directly determines the performance of the whole communication system. Therefore, the research of solid-state pulse power amplifier has become a hot topic. This paper will complete the design of L-band solid-state pulse power amplifier. The structure of amplifier plus pulse modulation circuit is selected. The amplifier consists of three stages: predrive stage, drive stage and power amplifier stage. This paper first introduces the classification of power amplifier, according to the characteristics of different types of power amplifier. The predrive stage and drive stage are selected to work in Class A and the power amplifier stage works in Class AB. Then the stability factor of the amplifier is simulated by using the small signal S parameter method with ADS software to ensure the stable operation of the amplifier. The input and output matching circuit and DC bias circuit of the predrive stage and the drive stage are designed, and the input and output matching circuit of the power amplifier is simulated by the method of load traction. The output power and gain of the amplifier meet the design requirements. The Momentum electromagnetic simulation of the power amplifier layout is carried out by ADS software, which makes the simulation results closer to the actual situation. The switching modulation and gate modulation are compared and introduced in this paper. The characteristics of different modulation modes, such as drain modulation, are finally selected. The pulse modulation is realized by using a power MOSFET driving transistor with fast rise edge and drop edge. A temperature compensation circuit is designed for the power amplifier stage. The influence of temperature on the static working point of power amplifier can be minimized. Finally, the PCB layout of power supply and modulation circuit is designed by using Protel99 software. The circuit layout and metal shielding structure of RF amplifier link are designed by using AutoCAD software. The design and simulation of power amplifier and modulation circuit are completed, and the circuit needs to be tested. Different debugging schemes are designed for different circuit modules and pulse power amplifier. The circuit is debugged by using vector network analyzer, signal source, power meter, attenuator, etc. Finally, the gain of the driving amplifier in the working band is 31 dB, the gain of the power amplifier is 20 dB, the output power of the pulse is 250 W, the gain flatness in the working band is less than 1 dB, the rising edge of the pulse is 35 ns, the descending edge is 46 ns, and the top drop of the pulse is less than 0.81dB. Finally, the paper summarizes the whole paper. The conclusion is drawn, the deficiency of the paper is pointed out, and the corresponding improvement direction is put forward.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722.75

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