【作者】 刘锋；

【导师】 来五星；

【作者基本信息】 华中科技大学 ， 机械工程， 2017， 硕士

【摘要】 随着我国经济的飞速发展,各类大跨度桥梁应运而生。由于桥梁体积和跨度的不断增大,传统的变形监测方法已不能满足变形监测要求。近些年来,微波干涉测量技术因其独有的高精度、实时性和非接触式测量等优势,逐渐成为大跨度桥梁变形监测的重要方法之一。微波干涉测量技术利用干涉测量原理,向空间顺序发射步进频率连续波,对包含目标距离信息的回波信号进行逆傅立叶变换,从而得到目标的一维距离像。本文根据雷达系统理论和差分干涉测量技术的基本原理,设计了步进频率连续波雷达的收发电路并验证了系统的可行性。具体的研究内容包括:1)对桥梁变形监测雷达进行了系统设计。根据微波干涉测量技术的原理,计算了雷达系统的基本参数,确定了收发系统的基本结构。2)雷达发射机设计。对基于数字直接频率合成+锁相环的混合频率合成方案进行了相应的电路设计,采用数控衰减器和功率放大器组合的形式对信号源产生的信号进行功率补偿。3)雷达接收机及天线设计。对雷达接收机的关键参数进行了介绍,并设计了零中频结构的接收电路,主要包括低噪声放大电路、低通滤波和正交解调电路;分析了不同天线的优缺点,设计了适用于本系统的高增益喇叭天线。最后,按照“个体-局部-模块-系统”的基本思想对本硬件电路系统进行了调试。更多还原

【Abstract】 With the rapid development of China’s economy,all kinds of large-span bridges came into being.The traditional deformation monitoring method can not meet the requirements of deformation monitoring because of the increasing volume and span of the bridge.In recent years,microwave interference measurement technology has become one of the important means of deformation monitoring of large span bridge because of its unique advantages of high precision,real-time and non-contact measurement.The microwave interferometry technique uses the principle of interferometry to transmit the stepping frequency continuous wave(SFCW)to the spatial,and carries out the inverse Fourier transform on the echo signal containing the target distance information to obtain the one-dimensional distance image of the target.Based on the theory of radar system and the basic principle of differential interferometry,this paper designs a structure of SFCW radar and verifies the feasibility of the system.The specific research includes:1)The system design of bridge deformation monitoring radar.According to the principle of microwave interferometry,the basic parameters of the radar system are calculated and the basic structure of the transceiver system is determined.2)Radar transmission circuit design,designs the circuit based on the DDS + PLL frequency synthesis program,uses the combination of digital attenuator and power amplifier to compensate the signal generated by the signal source.3)Radar receiver circuit and antenna design,introduces the key parameters of the radar receiver,designs the receiving circuit based on zero-IF structure,including low noise amplification circuit,low-pass filter and quadrature demodulation circuit.analysis the advantages and disadvantages of different antennas,designs the high-gain horn antenna for the system.Finally,debugs the hardware circuit system according to the basic idea of "individual-local-module-system".更多还原