脉冲调制信号相位噪声数值分析

Numerical Analysis for the Phase Noise of Pulse Modulated Signals

利用频谱折叠法对脉冲调制信号的相位噪声进行理论分析,在不同频率相位噪声分量不相关的近似条件下,首次提出点频脉冲和线性调频脉冲调制信号的相位噪声计算公式,详细分析了脉宽、重频、带宽等脉冲调制参数对相位噪声恶化量的影响。基于得到的公式,通过数值算法对点频脉冲和线性调频脉冲的相位噪声进行定量计算,并搭建测试平台进行验证。点频脉冲调制情况下计算与测试误差小于1dB,线性调频脉冲调制情况下小于3dB,证实了所提出脉冲信号相位噪声计算方法的有效性。

The spectrum-folding theory is utilized in this paper to analyze the phase noise degradation of pulse modulated RF signals.Based on the approximation that phase noise of different frequency components is uncorrelated,formulas for calculating the phase noise of single-frequency pulsed and linear frequency modulated RF signals are proposed for the first time.The impact of such pulse modulation parameters as pulse width,pulse repetition frequency,and bandwidth on phase noise degradation after pulse modulation is elaborated.Based on the derived formulas,numerical analysis methods are used for quantitative calculation of the phase noise of single-frequency pulsed and linear frequency modulated RF signals,and an experimental test bench is set up for verification.Calculation errors compared with measurement results are within 1 dB for single-frequency pulse modulation and 3 dB for linear frequency modulation respectively,which proves the validity of the proposed method.