宽带电磁参数测量系统的研究
发布时间：2018-09-06 17:52
【摘要】：相对介电常数和损耗角正切是微波介质材料的两个重要性能参数,近几十年来,随着微波技术的发展,微波电路以及天线正在向小型化方向发展,同时对微波介质材料的性能也提出了更高的要求,由此对微波介质材料电磁参数的精准测量也提出了更高的要求。本文针对电磁参数测量仪器存在价格昂贵、测量复杂、测量精度不高等问题,设计了一套宽带电磁参数测量系统。文章首先介绍了比较成熟的电磁参数的测量方法,其次对本文所采用的测量方法与系统各个模块的设计进行了详细的介绍。本文主要工作如下：1、根据测量放置待测介质前后天线输入阻抗的变化反演出介质的电磁参数的方法研发了一个宽带电磁参数测量系统,该系统可实现在1 GHz-3.5 GHz的频率范围内对中、低介电常数介质材料和中、高损耗介质材料的相对介电常数和损耗角正切的测量；2、天线设计：由于系统利用的是近场微扰法而且测量带宽较宽,故需要设计一款宽带定向天线。通过对平面微带天线的研究,并借助天线宽带化技术,设计并制作了一款宽带平面定向天线。该天线尺寸为90 mmx90 mm×1 mm,工作频率范围为1 GHz～4 GHz,极化方式为线极化。实测和仿真结果表面,该天线在测量系统频段内定向性良好,且实测最大增益可达到8dBi,能够满足宽带电磁参数测量系统的要求；3、射频电路的设计：设计了一款由表贴器件组成的宽频带射频电路。并且为了提高测量系统的测量精度,减小电路带来的误差,针对射频电路的特点专门设计了一套校准方法。在测量前首先使用所设计的校准方法对系统进行校准,然后对介质材料进行测量。实验结果表明,所设计的校准方法能够有效提高测量精度。4、基带信号处理：采用STM32单片机采集射频电路下变频后的中频信号,并通过对算法的编程处理,最终实现对介质材料的电磁参数的测量。
[Abstract]:Relative dielectric constant and loss angle tangent are two important performance parameters of microwave dielectric materials. In recent decades, with the development of microwave technology, microwave circuits and antennas are developing towards miniaturization. At the same time, higher requirements for the performance of microwave dielectric materials are put forward, and higher requirements for accurate measurement of electromagnetic parameters of microwave dielectric materials are put forward. Aiming at the problems of high price, complex measurement and low precision of electromagnetic parameter measuring instrument, a wideband electromagnetic parameter measuring system is designed in this paper. This paper first introduces the more mature measurement methods of electromagnetic parameters, and then introduces the measurement methods and the design of each module of the system in detail. The main work of this paper is as follows: 1. A wideband electromagnetic parameter measurement system is developed according to the method of measuring the variation of the input impedance of the antenna before and after placing the medium under test. The system can measure the relative dielectric constant and loss angle tangent of medium, low dielectric constant dielectric material and medium and high loss dielectric material in the frequency range of 1 GHz-3.5 GHz. 2. Antenna design: because the near field perturbation method is used in the system and the measurement bandwidth is wide, it is necessary to design a wideband directional antenna. Based on the research of planar microstrip antenna and wideband antenna technology, a broadband planar directional antenna is designed and fabricated. The antenna size is 90 mmx90 mm 脳 1 mm, operating frequency range is 1 GHz~4 GHz, polarization mode is linear polarization. The measured and simulated results show that the antenna has good orientation in the frequency band and the maximum gain can reach 8dBi. it can meet the requirements of wideband electromagnetic parameter measurement system. 3. Design of RF circuit: a wide band RF circuit is designed. In order to improve the measurement accuracy and reduce the error caused by the circuit, a calibration method is designed for the characteristics of RF circuits. The designed calibration method is used to calibrate the system before measurement, and then the dielectric material is measured. The experimental results show that the proposed calibration method can effectively improve the accuracy of measurement .4. baseband signal processing: STM32 single-chip microcomputer is used to collect if signals after down-conversion of RF circuits, and the algorithm is programmed to deal with them. Finally, the measurement of electromagnetic parameters of dielectric material is realized.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM937
，
本文编号：2227084
[Abstract]:Relative dielectric constant and loss angle tangent are two important performance parameters of microwave dielectric materials. In recent decades, with the development of microwave technology, microwave circuits and antennas are developing towards miniaturization. At the same time, higher requirements for the performance of microwave dielectric materials are put forward, and higher requirements for accurate measurement of electromagnetic parameters of microwave dielectric materials are put forward. Aiming at the problems of high price, complex measurement and low precision of electromagnetic parameter measuring instrument, a wideband electromagnetic parameter measuring system is designed in this paper. This paper first introduces the more mature measurement methods of electromagnetic parameters, and then introduces the measurement methods and the design of each module of the system in detail. The main work of this paper is as follows: 1. A wideband electromagnetic parameter measurement system is developed according to the method of measuring the variation of the input impedance of the antenna before and after placing the medium under test. The system can measure the relative dielectric constant and loss angle tangent of medium, low dielectric constant dielectric material and medium and high loss dielectric material in the frequency range of 1 GHz-3.5 GHz. 2. Antenna design: because the near field perturbation method is used in the system and the measurement bandwidth is wide, it is necessary to design a wideband directional antenna. Based on the research of planar microstrip antenna and wideband antenna technology, a broadband planar directional antenna is designed and fabricated. The antenna size is 90 mmx90 mm 脳 1 mm, operating frequency range is 1 GHz~4 GHz, polarization mode is linear polarization. The measured and simulated results show that the antenna has good orientation in the frequency band and the maximum gain can reach 8dBi. it can meet the requirements of wideband electromagnetic parameter measurement system. 3. Design of RF circuit: a wide band RF circuit is designed. In order to improve the measurement accuracy and reduce the error caused by the circuit, a calibration method is designed for the characteristics of RF circuits. The designed calibration method is used to calibrate the system before measurement, and then the dielectric material is measured. The experimental results show that the proposed calibration method can effectively improve the accuracy of measurement .4. baseband signal processing: STM32 single-chip microcomputer is used to collect if signals after down-conversion of RF circuits, and the algorithm is programmed to deal with them. Finally, the measurement of electromagnetic parameters of dielectric material is realized.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM937
，
本文编号：2227084
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