时钟抖动对中频线性调频采样及脉冲压缩影响的研究  

Research for the Effect on Intermediate Frequency Sampling and Pulse Compression Due to Clock Jitter

作　　者：陈佳民[1,2] 童智勇[1] 杨汝良[1] 

机构地区：[1]中国科学院电子学研究所,北京100190 [2]中国科学院研究生院,北京100039

出　　处：《电子与信息学报》2010年第7期1686-1691,共6页Journal of Electronics & Information Technology

摘　　要：时钟抖动是模数转换过程中影响信号信噪比的最主要因素之一。该文从时域连续信号角度出发,按照高斯随机过程模型,分析了时钟抖动对基带和中频线性调频信号信噪比的影响并给出了近似公式。结合量化噪声的影响,可定量计算影响信噪比各因素之间的关系。仿真结果表明适用于模数转换后所得离散数字信号信噪比计算。合成孔径雷达经过脉冲压缩得到图像,为了抑制旁瓣需要使用窗函数加权,分析了时钟抖动在加窗前后对脉冲压缩时峰值旁瓣比和积分旁瓣比的影响。最后讨论了一些减小时钟抖动的具体措施。Clock jitter is one of the most importation factors that affects the Signal-to-Noise Rate（SNR）.Based on Gaussian random process model and continuous-time system in time domain,this paper analyzes the effect on baseband and intermediate frequency sampling due to clock jitter.Taking into account the quantization noise,an approximate formula of the relationship between SNR and other factors is obtained in time domain.The simulation results show that the formula also be applicable to calculate the SNR in discrete-time system.The paper also discusses the influence of clock jitter on the pulse compression of the Synthetic Aperture Radar（SAR） signal.The window function is used to weight the signal in order to suppress the side lobe in pulse compression process.Finally,several methods to reduce the clock jitter are introduced.

关 键 词：合成孔径雷达 时钟抖动 线性调频信号 中频采样 信噪比 脉冲压缩 

分 类 号：TN958[电子电信—信号与信息处理]