摘要
直接数字线性调频(linear frequency modulation,LFM)源中相位截断会引入线性度误差,影响线性调频信号在雷达系统中的性能。首次运用离散数学理论分析了相位截断所引起的线性度误差,得到了相位截断不引入线性度误差的充要条件,推导了一般情况下线性度和调频斜率误差的数学表达式。采用蒙特卡罗方法得到了调频斜率误差在4种可能取值上的分布规律及其数字特征。通过仿真实例,定量评估了相位截断对线性度的影响,根据所得结论为实际应用提供了设计建议。仿真结果验证了理论推导的正确性。
The phase truncation in direct digital linear frequency modulation（LFM） synthesizer can cause the linearity error,which will degrade the performance of LFM signals in radar systems.The linearity error caused by the phase truncation is analyzed specifically for the first time by using the discrete mathematics theory.The necessary and sufficient condition of no linearity errors in the presence of phase truncation is obtained.The exact expressions of linearity and the FM slope error are derived under normal circumstance,and the distribution of the FM slope error on four candidate values is obtained by exploring Monte Carlo method.The effect of phase truncation on linearity is also numerically evaluated through simulation examples.Some practical design suggestions are proposed according to the conclusions obtained.Simulation results demonstrate the correctness of the theoretical derivation.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2011年第2期259-263,共5页
Systems Engineering and Electronics
基金
国家重点基础研究发展计划(973计划)基金(2007CB310605)
国家部委科技重大专项基金(2009ZX03007-003-02)资助课题
关键词
直接数字合成
相位截断
线性调频
线性度
direct digital synthesis
phase truncation
linear frequency modulation（LFM）
linearity
