可编程约瑟夫森电压基准（programmable Josephson voltage standard，PJVS）已被初步应用于谐波信号的测量与分析，在克服过渡过程和吉布斯效应对测量结果的影响后，仍存在无法避免的非同步采样问题，这会在测量结果中引入较大误差，且影响信号的分析频谱。针对上述问题，提出了基于准同步采样的二次加权傅里叶变换方法，所提方法将准同步采样改进后与加权傅里叶变换结合，通过对原始信号进行两次不同的加权和分步修正，实现了对谐波信号的准确测量。经实验验证，使用该方法对谐波电压测量分析，测量标准偏差可达10-7量级。
英文摘要:
The programmable Josephson voltage standard (PJVS) has been preliminarily applied to the measurement and analysis of harmonic signals. After overcoming the impact of transition process and Gibbs effect on measurement results, there is still an unavoidable non-synchronous sampling problem. This will introduce large errors in the measurement results and affect the analysis spectrum of the signal. In order to solve above problems, a quadratic weighted Fourier transform method based on quasi-synchronous sampling is proposed. This method combines the improved quasi-synchronous sampling with weighted Fourier transform, and realizes the accurate measurement of harmonic signal through two different weighted and step correction of the original signal. The experimental results show that the standard deviation of harmonic voltage measurement can reach 10-7 magnitude.