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。
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.
出处
《国外电子测量技术》
2008年第7期8-10,共3页
Foreign Electronic Measurement Technology
关键词
窗函数
噪声测量
FFT分析
谱密度
windowing function
noise measurement
FFT analysis
spectral density
