Agilent 35670內(nèi)部窗函數(shù)對(duì)噪聲波形分析的影響

黃勇軍 徐卓華 易文勝
杭州應(yīng)用聲學(xué)研究所,杭州310012
摘　要:頻譜分析設(shè)備多具有FFT分析和譜密度分析功能,噪聲測(cè)量中發(fā)現(xiàn)使用不同窗函數(shù)進(jìn)行FFT分析時(shí),通過(guò)頻帶電壓級(jí)換算出來(lái)的噪聲譜密度與直接測(cè)量結(jié)果有差異。利用35670動(dòng)態(tài)信號(hào)分析儀,對(duì)不同窗函數(shù)情況下的FFT頻帶電壓級(jí)和噪聲譜密度級(jí)測(cè)量結(jié)果進(jìn)行比較,實(shí)驗(yàn)表明：35670譜密度級(jí)測(cè)量結(jié)果能真實(shí)反映輸入信號(hào)的能量分布,FFT頻帶電壓級(jí)的測(cè)量結(jié)果則需要進(jìn)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