DC-18GHz超宽带低噪声放大器的研究

发布时间：2018-05-20 19:14

本文选题：低噪声放大器 + 超宽带　；参考：《南京理工大学》2017年硕士论文

【摘要】：低噪声放大器位于射频接收机前端,是微波系统的核心部件,其性能好坏直接影响到接收机灵敏度,以及整个系统的噪声系数。同时超宽带技术发展迅猛,性能优良的超宽带低噪声放大器具有很高的研究价值。本论文的主要内容是设计并实现了一款DC-18GHz超宽带低噪声放大器。文章首先对超宽带低噪声放大器的研究背景及发展现状进行了调研,然后对低噪声放大器的相关理论与设计方法进行了详细的介绍与分析。通过比较分析几种常用的宽带放大电路设计方法,最终选择负反馈法作为本文实现超宽带低噪声放大器的设计方法。针对设计指标,选择无封装HEMT管芯,采用三级放大器级联的电路结构,单电源供电,微带与分立元件相结合实现匹配网络。第一级放大电路采用并联电阻负反馈结构以改善放大器稳定性、拓展带宽,同时懫用场效应管并联结构优化宽带噪声性能;第二级、第三级放大电路主要作用是提高增益,改善增益平坦度;输出匹配采用有耗匹配网络,提高系统稳定性,改善输出反射系数。本文使用ADS仿真软件分别对放大器进行了直流仿真、S参数仿真以及版图-原理图联合仿真。低噪声放大器电路拓扑结构设计完成后,采用直接调谐法对电路进行优化设计,得到了比较满意的仿真结果。放大器采用微组装工艺将薄膜电路、管芯等元器件直接烧结在腔体表面,元件之间使用金丝键合技术实现互联。实际测试结果显示该低噪声放大器在DC-18GHz带宽内噪声系数小于2.5dB,增益大于22dB,整机功耗仅为210mW。结果表明,该放大器具有良好的超宽带特性。
[Abstract]:Low noise amplifier (LNA) is the core component of microwave system which is located in the front end of RF receiver. Its performance directly affects the sensitivity of receiver and the noise coefficient of the whole system. At the same time, ultra-wideband (UWB) low noise amplifiers with excellent performance have high research value. The main content of this thesis is to design and implement a DC-18GHz ultra-wideband low-noise amplifier. In this paper, the research background and development status of UWB LNA are investigated, and then the related theory and design method of LNA are introduced and analyzed in detail. By comparing and analyzing several common design methods of wideband amplifier, the negative feedback method is chosen as the design method of UWB LNA in this paper. According to the design index, the unencapsulated HEMT core is selected, the three-stage amplifier cascade circuit structure is adopted, the single power supply, the combination of microstrip and discrete element to realize the matching network. The first stage amplifier adopts the parallel resistor negative feedback structure to improve the stability of the amplifier and expand the bandwidth. At the same time, the field effect tube parallel structure is used to optimize the wideband noise performance, the second stage, the third stage amplifier circuit is mainly used to improve the gain, The gain flatness is improved, and the lossy matching network is used in the output matching to improve the stability of the system and the output reflection coefficient. In this paper, the ADS simulation software is used to simulate the DC simulation parameters and the layout-schematic simulation of the amplifier. After the circuit topology design of low noise amplifier is finished, the circuit is optimized by direct tuning method, and satisfactory simulation results are obtained. The elements such as thin film circuit and tube core are sintered directly on the surface of the cavity by microassembly technology. The elements are interlinked by gold wire bonding technology. The actual test results show that the noise coefficient of the low noise amplifier is less than 2.5 dB in the DC-18GHz bandwidth, the gain is more than 22 dB, and the power consumption is only 210 MW. The results show that the amplifier has good UWB characteristics.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN722.3

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