本文首先简要综述了 连续波调频无线电引信的定距原理，该引信是发射调频等幅连续波信号的近感系统，其发射信号的频率按调制信号规律而变化，利用回波信号与发射信号的频率之差来确定近感系统与目标之间的距离。针对连续波调频无线电引信，在理论上分析了回波信号与发送信号的差频信号特征 ， 发现用差频信号频率进行定距的常用方法存在距离模糊 ， 定距精度不高 。进一步分析差频信号发现差频信号包络幅度随着距离而变化，针对这一特性选用了谐波比较式调频多普勒信号处理方式。谐波比较式调频多普勒信号处理方式基本思路为将差频信号送入带通滤波器滤出差频信号的二次谐波和四次谐波，再对这两路谐波分别进行混频，得到幅度随距离变化的多普勒信号包络，根据包络幅度与距离之间的对应关系进行定距。根据谐波比较式调频多普勒信号处理方式确定了三角波调频多普勒定距系统方案 ， 并 利用 Matlab/Simulink 建立系统模型 、 进行系统仿真 ， 判定其具有正确性与可行性 。最后利用单片机技术，针对调频多普勒引信信号处理特征，设计单片机数据采集与处理系统，为使得系统小型化，使用同一片单片机产生本振信号和调制信号，最后在印制电路板上调试并实现其功能。8324
关键词 关键词 关键词 关键词 ： 谐波比较；差频分析；单片机；信号采集与处理Title Microcontroller-based continuous wave Doppler
signal test
Abstract Abstract Abstract Abstract
Firstly,this paper briefly reviewed the principle of measuring distance in the
continuous wave FM radio fuse.The fuse is a near-sense system by launching
continuous wave FM signal with equal amplitude.The frequency of the transmitted
signal in the fuse
changes according to the law of modulated signals,determining the distance by the
frequency difference between the transmitted signal and the echo signal.
Against the continuous wave FM radio fuse,analysed the characteristics of the
frequency difference signal.Found that there existed a fuzzy distance in the commonly
used methods whitch measuring distance according to the frequency of the frequency
difference signal.Further analysis showed that the amplitude of the frequency
difference signal's envelope varied with the distance.Against this characteristic,chose d
a harmonic comparison FM doppler signal processing method.
The basic idea of the harmonic comparison FM doppler signal processing method
is sending the frequency difference signal to the band-pass filter and filterring out the
twice and the four times harmonic frequency signal.Then mixing these two road
harmonics signal,getting the envelope of the doppler signal,and measuring the distance.
D etermined a triangle FM wave doppler distancing systerm.Creating a systerm
modle using Matlab/Simulink to determine the correctness and feasibility of the
method.
Finally, using the SCM technology created a data acquisition and processing
system.To make the system small, used the same SCM to generate the local oscillator
signal and the modulated signal,and debugged it on the printed circuit board.
Keywords: Keywords: Keywords: Keywords: C omparison of H armonic, Analysis of the Post-Mix Signal , Signal
Processing, MCU目录
1 引言  1
2 谐波比较式调频多普勒定距原理  3
2.1 三角波调制方式的差频理论分析 . 3
2.1.1 静止目标差频理论分析  3
2.1.2 运动目标差频理论分析  6
2.2 谐波比较式调频多普勒定距系统 . 8
3 谐波比较式调频多普勒引信中心控制单元设计  13
3.1 混频本振和调制信号的产生 . 13
3.1.1 混频本 振 和调制信号初始相位的设置  13 基于单片机的连续波多普勒信号测试:http://www.751com.cn/tongxin/lunwen_6611.html