知识与财富的链接
利用快速傅里叶变换（FFT）测试模数转换器（ADC）的信噪比（SNR）必然存在非相干采样,导致测量结果会受频谱泄漏的影响。针对此问题,提出了一种利用Blackman-Harris窗三谱线插值测试高速ADC SNR的方法。基于MATLAB构建了验证平台,采用美国模拟器件公司（ADI）的AD9627等高速ADC产品的行为级动态模型进行了仿真验证。结果表明,在非相干程度最大的情况下,基于Blackman-Harris窗三谱线插值测试得到的SNR误差低于0.23dB,达到了ADI公司提供的测试标准,证明该法能很好地抑制频谱泄漏的影响,提高SNR测试精度。
In the practical measurement of signal to noise ratio（SNR）of analog-to-digital converters（ADCs）by using fast Fourier transformation（FFT）method,the non-coherent sampling is inevitable,leading to spectral leakage which in turn affects the calculation accuracy and final measurement results.In this paper,a new method based on the Blackman-Harris windowed triple-spectrum-line interpolation is presented for the measurement of ADC’s SNR by FFT.The simulation platform is built based on MATLAB and the behavioral dynamic models of the high-speed ADC products of Analog Devices Inc.（ADI）are simulated.The simulation results show that,even in the case of the maximum non-coherent degree,the SNR error is less than 0.23 dB and reaches the testing standards provided by ADI,confirming that the proposed method is effective for suppressing the spectral leakage effects and improving the SNR test accuracy.
