宽带雷达目标模拟系统关键技术研究

发布时间：2018-05-08 02:21

本文选题：射频仿真 + 低杂散系统　；参考：《南京航空航天大学》2017年硕士论文

【摘要】：宽带雷达目标模拟系统可以高逼真地模拟复杂目标电磁环境及目标回波信号,从而实现对雷达系统的综合性能测试及技术指标验证。宽带雷达目标模拟系统的应用可以有效缩短雷达系统的研制周期,降低研发成本。本文主要针对低杂散、宽带的雷达目标模拟系统涉及到的关键技术进行研究、实验和分析。首先,实现了1GHz带宽低杂散宽带数字射频存储系统(DRFM)的硬件设计。针对DRFM系统的核心器件宽带ADC和宽带DAC模块进行了理论建模,在此基础上重点对影响系统杂散性能的量化误差、非线性误差以及SINC函数衰落等因素进行了分析及仿真验证。对宽带射频接收单元进行了分析,重点研究了混频器的本振谐波、非线性失真对杂散性能的影响。此外,还分析了高速电路的信号完整性及电源完整性问题对系统性能的影响。其次,根据宽带雷达目标模拟系统的的动态范围要求,设计了数字自动增益控制系统(AGC),给出了以对数检波器、ADC、FPGA和数字控制可变增益放大器为核心的设计方案,完成了硬件电路及控制算法的设计与实现,并进行了实验验证。实验结果表明,数字AGC系统动态范围达到50dB,控制精度达到0.5dBm,能满足系统的动态范围要求。最后,基于上述研究,给出了宽带数字射频存储系统的测试方法,并进行了实验测试与分析。在对ADC、DAC以及整体系统测试的基础上得到了各自的带内无杂散动态范围,并分析了杂散的来源。对DAC的混合模式输出性能进行了测试,并通过产生线性调频信号得到了系统的带内幅频特性曲线。测试结果表明,在0.1~1.1GHz频带内系统的无杂散动态范围优于-50dBc,达到了预期效果。
[Abstract]:The wideband radar target simulation system can simulate the complex target electromagnetic environment and the target echo signal highly and truly, so as to realize the comprehensive performance test and the technical index verification of the radar system. The application of the wideband radar target simulation system can effectively shorten the development cycle of the radar system and reduce the R & D cost. This paper mainly aims at the low miscellaneous. The key technologies involved in the wideband radar target simulation system are studied, experimentation and analysis. First, the hardware design of the 1GHz bandwidth and low stray wideband digital radio frequency storage system (DRFM) is realized. Based on the theoretical modeling of the core component of the DRFM system, the broadband ADC and the broadband DAC module, the emphasis is on the influence of the system stray. The quantitative error of the performance, the nonlinear error and the fading of the SINC function are analyzed and simulated. The wideband radio frequency receiving unit is analyzed. The harmonic of the mixer and the influence of the nonlinear distortion on the stray performance are emphatically studied. In addition, the signal integrity and the power integrity problem of the high speed circuit are also analyzed. Secondly, according to the dynamic range requirements of the wideband radar target simulation system, the digital automatic gain control system (AGC) is designed. The design scheme of the variable gain amplifier with logarithmic geophone, ADC, FPGA and digital control is given. The design and implementation of the hardware circuit and control algorithm are completed, and the design and implementation of the hardware circuit and the control algorithm are completed. The experimental results show that the dynamic range of the digital AGC system reaches 50dB, the control precision reaches 0.5dBm and can meet the dynamic range requirements of the system. Finally, based on the above research, the testing method of the broadband digital radio frequency storage system is given, and the experimental test and analysis are carried out. On the basis of the ADC, DAC and the overall system test, the system has been tested and analyzed. The output performance of the hybrid mode of DAC is tested and the amplitude frequency characteristic curve of the system is obtained by producing the linear frequency modulation signal. The test results show that the non stray dynamic range of the system in the 0.1~1.1GHz band is better than that of -50dBc, and the desired effect is achieved. Fruit.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN955

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