Agilent 35670内部窗函数对噪声波形分析的影响

黄勇军 徐卓华 易文胜
杭州应用声学研究所,杭州310012
摘　要:频谱分析设备多具有FFT分析和谱密度分析功能,噪声测量中发现使用不同窗函数进行FFT分析时,通过频带电压级换算出来的噪声谱密度与直接测量结果有差异。利用35670动态信号分析仪,对不同窗函数情况下的FFT频带电压级和噪声谱密度级测量结果进行比较,实验表明：35670谱密度级测量结果能真实反映输入信号的能量分布,FFT频带电压级的测量结果则需要进行修正。[著者文摘]

Effect on noise analysis due to windowing function of Agilent 35670Huang Yongjun, Xu Zhuohua, Yi Wensheng Hangzhou Applied Acoustics Research Institute, HangZhou 310012Abstract:Usually, spectral analysis equipments have the functions of FFT analysis and spectral density analysis. When different window functions are applied to FFT analysis in noise measurement, differences are shown that the direct measurement results of the noise spectral density are not same with the one derived from band voltage level. With the 35670- dynamic signal analyzer, the FFT band voltage level is compared with the measurement results of noise spectral density level for different window functions. The experiment shows that the spectral density level results of 35670-analyzer are more accurate to express the energy distribution of input signals and modifications are required when the measurement re- sults of FFT band voltage level are used.[著者文摘]

Key words:windowing function; noise measurement;FFT analysis; spectral density