24GHz混合集成FMCW源研究

发布时间：2018-01-15 01:27

本文关键词：24GHz混合集成FMCW源研究　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,随着算法与芯片器件的不断成熟,以及各国对雷达在民用领域工作频段的逐步开放,雷达越来越多的应用在目标定位识别、飞行导航、船舶汽车防撞等领域。微波毫米波FMCW雷达因其分辨率高、算法简易、全天候工作和体积小等优势尤其受到关注。FMCW频率源作为雷达防撞系统的核心,研究体积小、功耗低与高性能的FMCW频率源具有重要的工程意义和社会价值。论文从介绍FMCW频率源的国内外发展动态开始,分析常用的FMCW频率源合成方案及其优缺点。在此基础上,根据系统要求提出了采用DDS直接激励PLL设计方法的K波段FMCW频率源方案。出于低功耗、小型化的考虑,方案选用功耗小、成本低的DDS芯片,利用晶振的五次谐波作为DDS的参考频率,避免了晶振多次倍频、放大与滤波链路,同时采用了集成VCO的锁相芯片代替传统锁相环。测试结果表明,24GHz线性调频频率源能够输出23.76~24GHzFMCW信号,输出信号功率为12dBm,带内平坦度不大于2dB,相位噪声优于-70dBc/Hz@10KHz,杂散抑制度高于45dBc,满足了系统指标。频率源的直流功耗为2.8W,其尺寸仅为58mm×53mm×19mm,达到了低功耗与小型化的目的。完成频率源之后,在该FMCW频率源的基础上集成了微带阵列天线与下变频芯片组成FMCW收发前端对测距功能进行验证。为了达到对系统功率合理分配与降低成本的目的,方案选择具有谐波混频功能的下变频芯片。天线采用隔离度更好的收发双天线的形式,同时采用可以与腔体共形的平面微带阵列天线来减小系统的体积。微带阵列天线方位角为7度,仰角为28度,副瓣抑制16dB,具有良好的方向性,设计尺寸为103mm×66mm×0.508mm。受限于实验条件,本文对其进行近距(3m、4m、5m、7m、8m、9m)测距实验,实验结果表明本系统可以实现对目标距离测量,且测量精度较好。
[Abstract]:In recent years, with the maturation of algorithms and chip devices, and the gradual opening of the frequency band of radar work in the civil field, radar is more and more used in target location identification, flight navigation. The microwave millimeter wave FMCW radar has high resolution and simple algorithm. The advantages of all-weather operation and small size are paid more attention to. FMCW frequency source as the core of radar collision prevention system, the research volume is small. FMCW frequency source with low power consumption and high performance has important engineering significance and social value. This paper introduces the development of FMCW frequency source at home and abroad. The common FMCW frequency source synthesis scheme and its advantages and disadvantages are analyzed. According to the system requirements, a K-band FMCW frequency source scheme using DDS direct excitation PLL design method is proposed. For the consideration of low power consumption and miniaturization, the DDS chip with low power consumption and low cost is selected. The fifth harmonic of crystal oscillator is used as the reference frequency of DDS to avoid the multiple frequency doubling, amplification and filter link of crystal oscillator, and the phase-locked chip integrated with VCO is used to replace the traditional phase-locked loop. The test results show that. The 24GHz LFM frequency source can output 23.76Hz 24GHz FMCW signal, the output power is 12dBmand the in-band flatness is not more than 2dB. The phase noise is better than -70 dBc / Hz @ 10kHz, and the spurious suppression degree is higher than 45dBc, which satisfies the system specification. The DC power consumption of the frequency source is 2.8 W. Its size is only 58mm 脳 53mm 脳 19mm, which achieves the goal of low power consumption and miniaturization. On the basis of the FMCW frequency source, the microstrip array antenna and down-conversion chip are integrated into the FMCW transceiver front-end to verify the ranging function. In order to achieve a reasonable allocation of power and reduce the cost of the system. The scheme chooses the downconversion chip with harmonic mixing function. The antenna adopts the form of receiving and transmitting dual antennas with better isolation. At the same time, a planar microstrip array antenna with conformal cavity is used to reduce the volume of the system. The azimuth and elevation angles of the microstrip array antenna are 7 degrees and 28 degrees respectively, and the sidelobe suppression is 16 dB, so it has good directivity. The design size is 103mm 脳 66mm 脳 0.508mm. limited by the experimental conditions, this paper has carried out a short-range ranging experiment of 3mm ~ 4m ~ (4m) ~ (5m) ~ (7m) ~ 8m ~ (9 m). The experimental results show that the system can measure the target distance, and the measurement accuracy is good.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957

【参考文献】