矢网测试装置设计及关键电路实现

发布时间：2017-12-31 00:41

本文关键词：矢网测试装置设计及关键电路实现　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：进入二十一世纪以来,信息化、数字化、网络化、智能化成为人类世界的显著标签,空间充斥着微波射频信号,这使得信息产业得到迅猛发展,作为信息、数据系统、终端的基础,微波射频器件、组件正处于爆炸式发展阶段。测试是科技发展基础,矢量网络分析仪作为微波射频元器件最重要的测试评价工具,需要应对各种新需求,满足不同情况下对仪器功能性、经济性、实用性的要求。课题研究目标为设计一款能够满足通信系统、信息化终端等产业中微波射频电路组件科研生产测试需求,能够实现基本网络参数测试功能,具备极高性价比、可规模化应用推广的创新架构经济型网络分析仪。本课题主要工作包括以下几个方面:①充分利用半导体产业技术进步成果,采用以先进半导体工艺为基础设计实现的多信道、高性能软件无线电收发集成电路AD9361作为接收机核心,设计系统整体实现方案。将传统的三接收机、四接收机通道简化为两通道,不仅降低了仪器成本,同时也避免了通道间相互干扰。②设计了新型的、采用电容补偿的、多节级联微带线定向耦合器。传统单节微带线定向耦合器难以达到宽频率、高方向性的目标,利用电容补偿、多节级联的方式可以大大优化定向耦合器的性能,弥补频率范围和方向性方面的不足。③设计了反向信号隔离模块。利用放大器对信号正向放大、反向隔离的特点,使用两级低噪声放大器外加固定衰减器的方式,不仅可以降低大反射信号对参考通道的干扰,同时可以补偿激励信号在到达待测件前由功分器、定向耦合器等器件产生的损耗。④由于AD9361无法覆盖300KHz~70MHz低频率范围,在其前端又加入了一级上变频电路,将低频频率升频到可处理的90MHz。⑤课题还在AD9361芯片前外加前置放大器和可控衰减器,提高接收机灵敏度和动态范围。论文从系统整体功能指标出发,详细分析结构中每个单元的指标需求,整个系统的设计过程中,预先充分考虑了各种可能出现的问题,对单元模块分别进行设计和仿真优化。实践中对课题成果进行测试,与标准矢量网络分析仪的测试结果进行对比分析,成功实现了预计目标。
[Abstract]:Since 21th century, information, digitization, networking, intelligence has become a remarkable label in the human world, the space is full of microwave radio frequency signal, which makes the information industry develop rapidly as information. Data system, terminal foundation, microwave RF devices and components are in the explosive development stage. Testing is the basis of the development of science and technology. Vector network analyzer is the most important testing and evaluation tool for microwave RF components. We need to meet all kinds of new requirements and meet the functional, economic and practical requirements of the instrument under different circumstances. The objective of this study is to design a communication system that can meet the requirements of the communication system. In the information terminal and other industries, microwave RF circuit components scientific research and production testing requirements, can achieve the basic network parameters testing function, with very high performance and price ratio. The main work of this paper includes the following aspects: make full use of the technological progress of semiconductor industry in the following aspects: 1. Based on the advanced semiconductor technology, a multi-channel, high-performance software radio transceiver integrated circuit (AD9361) is used as the core of the receiver to design the overall implementation scheme of the system. The four-receiver channel is simplified to two channels, which not only reduces the cost of the instrument, but also avoids the interference between channels. 2. A new type of channel is designed with capacitive compensation. Traditional single-section microstrip line directional coupler is difficult to achieve the goal of wide frequency and high directivity. The performance of directional coupler can be greatly optimized by using capacitive compensation and multi-section cascade method. The reverse signal isolation module is designed to make up for the deficiency of frequency range and directivity. The characteristics of the amplifier are used to amplify the signal in the forward direction and in the reverse direction. Using a two-stage low-noise amplifier with a fixed attenuator can not only reduce the interference of the large reflection signal to the reference channel, but also compensate the excitation signal by the power divider before reaching the test piece. The loss of directional coupler and other devices. 4. Because the AD9361 can not cover the low frequency range of 300kHz / s 70MHz, a first stage up-conversion circuit is added to the front end of the device. A preamplifier and a controllable attenuator are added in front of the AD9361 chip to raise the frequency of the low frequency to 90MHz. 5. Improve the sensitivity and dynamic range of the receiver. From the system overall functional indicators, detailed analysis of each unit in the structure of the index requirements, the entire system design process. Considering all kinds of possible problems in advance, the unit modules are designed and optimized by simulation. In practice, the results of the project are tested and compared with the test results of the standard vector network analyzer. The target was successfully achieved.
【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】：TM935

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