摘要
线性调频雷达物位计的调频特性直接影响着系统的距离分辨力和信噪比,通过提取零差拍信号的频谱特征,构造衡量调频线性度的评价函数,利用免疫思维进化算法对调频电压曲线分段端点进行寻优,获得非线性的调频电压曲线,来校正压控振荡器的非线性,优化系统的调频特性。实验结果表明,该方法具有良好的效果,在不增加任何硬件设备的基础上,可显著提高系统的调频线性度和信噪比。
Distance resolution and system SNR are directly affected by FM characteristic of the Linear Frequency Modulation Continuous Wave（ LFMCW ） radar level gauge.In this paper, an evaluation function for frequency modulation linearity is constructed by using the spectrum characteristic of beat frequency signals.Later,Immune Mind Evolutionary Algorithm（ IMEA ） is introduced to optimize the end coordinates of the subsections to get nonlinear curve of frequency modulation voltage so as to compensate for the nonlinearity of VCO.Experiments show that the proposed method has good performance with no additional requirement for hardware and time cost,and the linearity and Signal Noise Ratio（SNR） of the system has been improved prominently.
出处
《计算机工程与应用》
CSCD
北大核心
2008年第7期223-226,共4页
Computer Engineering and Applications
基金
国家自然科学基金(the National Natural Science Foundation of China under Grant No.60374029)
山西省青年科学基金项目(the ShanxiProvince Youth Science Foundations under Grant No.2006021016
No.2007021018)
关键词
免疫思维进化算法
LFMCW雷达
压控振荡器
频谱分析
调频非线性
Immune Mind Evolution Algorithm （IMEA）
Linear Frequency Modulation Continuous Wave （LFMCW） radar
Voltage Controlled Oscillator（VCO ）
spectrum analysis
Frequency Modulation（ FM ） nonlinearity
