【作者】 凡守涛；

【导师】 尹应增；

【作者基本信息】 西安电子科技大学 ， 电磁场与微波技术， 2013， 博士

【摘要】 单脉冲气象雷达系统作为高空气象探测的主要设备，一直以来都在我国高空气象探测中发挥着重要的作用。然而，随着科技的发展，基于模拟信号处理方式的单脉冲气象雷达系统的探测精度已无法满足当前高空气象探测的要求，尤其是军事活动对精确高空气象信息的要求。近年来，高速数字电路技术和数字信号处理技术的飞速发展，为雷达数字中频接收提供了良好的基础，数字接收技术已成为雷达发展的必然趋势。本文紧密结合相关科研课题，对单脉冲气象雷达系统进行了深入研究，重点围绕地面雷达的三通道射频接收分系统、信号处理分系统以及用于探空仪的新型印刷天线开展了相关的研究工作。作者的主要研究成果可概括为以下几方面：1.对三通道射频接收分系统进行了深入的研究。首先对射频接收分系统的指标进行了分析与讨论，基于指标要求确定了完整的分系统方案。之后通过仿真软件对设计的方案进行了仿真分析，进一步验证了方案的可行性，并根据仿真结果对设计的方案进行了优化。最后对三通道射频接收分系统进行了实物加工与测试。实测结果表明本文所设计的射频接收分系统具有噪声系数低、动态范围大以及通道隔离性能良好等优点，能够很好地满足单脉冲气象雷达系统的指标要求。2.对射频接收分系统的通道隔离和通道一致性问题进行了研究。将三路射频接收通道进行分离式设计并分别放置在三个独立的金属腔体中，结合对本振信号进行隔离放大的方法，极大地提高了射频接收通道的隔离度。在对三路射频接收通道采用相同硬件设计的基础上，通过加入标校信号源，配合信号处理分系统完成通道间的幅相误差校正，消除了接收链路幅相误差对单脉冲测角的影响。测试结果表明，本文设计的方法能够很好地解决通道隔离和通道一致性问题。3.对信号处理分系统进行了研究。首先，基于信号处理分系统的功能需求，采用FPGA与DSP相结合的方式对信号处理分系统的硬件电路进行了系统的设计。然后，采用数字信号处理方法对分系统的功能进行了详细的分析与实现。雷达系统的实测结果表明采用数字信号处理技术有效地提高了系统的探测精度。4.结合单脉冲气象雷达系统中探空仪天线的应用背景和高空气象探测系统多频/宽带化的发展趋势，对用于探空仪的双频/宽带印刷天线进行了研究。首先，以基本印刷单极子天线为基础，分别利用加载缝隙和寄生单元的方式实现了两款具有双频和宽带特性的印刷单极子天线。然后，以探空仪对天线定向辐射的特殊需求为背景，设计了一款新型印刷环天线。通过在印刷辐射环内外两侧分别引入寄生谐振单元，构建了两个新的谐振频率，有效地展宽了天线的阻抗带宽。更多还原

【Abstract】 As the main equipment of high-altitude meteorological detection, the monopulsemeteorological radar system, for a long time, has played an important role in the field ofChina’s high-altitude meteorological detection. However, with the development ofscience and technology, the detection accuracy of the monopulse meteorological radarsystem based on analog signal processing cannot meet the requirements of currenthigh-altitude meteorological detection, especially in various military activities whichdemand accurate high-altitude meteorological information. In recent years, the rapiddevelopments of high speed digital circuit and digital signal processing technologyprovided a firm foundation for the digital IF receiver in radar system. Digital IF receiverhas become an inevitable trend of the development of modern radar systems. With theconsideration of related research projects and an in-depth study of the monopulsemeteorological radar system, this research is mainly concerned with the study ofthree-channel RF receiver subsystem and signal processing subsystem in ground radarsystem and the analysis and design of new types of printed antennas for radiosonde. Themajor contributions of this dissertation can be outlined as follows:1. A detailed analysis and design of three-channel RF receiver subsystem ispresented. The requirements of RF receiver subsystem are first analyzed and discussedbased on which an integrated design is finalized. To verify its feasibility, the design issimulated and optimized by the computer simulation. Finally, the prototype of thethree-channel RF receiver subsystem is fabricated and tested. The test results show thatthe design of RF receiver subsystem in this dissertation has the advantages of low noisefigure, high dynamic range, and high isolation, which can properly meet the indicatorrequirements of the high-accuracy monopulse radar system.2. A study of channel isolation and channel consistency in RF receiver subsystemis given. The three receiver channels are designed separately and placed in threeindependent metal cavities. Combined with the method of isolating local oscillatorsignals, the isolation between the RF receive channels is greatly improved. On the basisof the same hardware designs for the three-channel RF receiver channels, the amplitudeand phase errors between channels are corrected by adding a calibration signal sourcecoordinated with the signal processing subsystem and the influence of receiving link’samplitude as well as phase errors on monopulse angle measurement is eliminated. The test results show that the method presented in this dissertation is a good solution toimprove the channel isolation and channel consistency.3. The signal processing subsystem is analyzed and designed in detail. Firstly,based on the functional requirements of the subsystem, hardware circuits are designedsystematically by combining FPGA with DSP. Digital signal processing algorithms arethen adopted to analyze detailedly and implement each function of the subsystem. Thetest results of the radar system indicate that the system detection accuracy is effectivelyenhanced by the proposed digital signal processing technology.4. In the context of the application background of radiosonde antennas inmonopulse meteorological radar system and the development trends of multi-band andwideband in radar systems, dual-band and wideband printed antennas applied forradiosonde are discussed. Firstly, two types of printed monopoles with properties ofdual-band and wideband are designed by loading slot and parasitic units on thefoundation of a conventional printed monopole. Secondly, a novel printed loop antennais proposed based on the radiosonde’s special requirements for directed radiation. Byadding parasitic resonant units separately to the inner and outer sides of the printedradiating loop, two additional resonant frequencies are yielded and the impedancebandwidth of the antenna is broadened effectively.更多还原