基于约瑟夫森量子电压的谐波电压测量方法研究

约瑟夫森量子电压目前大多应用于正弦信号的测量,极少有针对谐波信号的研究。对可编程约瑟夫森电压基准应用于谐波检测的可行性进行了研究,实现谐波电压向量子电压过渡。在使用阶梯波交流量子电压进行谐波电压测量时,由于过渡过程和吉布斯现象的存在,部分数据出现较大波动;若将该部分处于过渡过程的数据纳入傅里叶变换,会导致恢复得到的信号幅值和相位失真。针对这一问题,提出了一种新的谐波电压计算方法:加权傅里叶变换。该方法通过将处于过渡过程的数据权重置零的方式,实现了谐波电压的准确测量。实验结果表明,谐波电压幅值和相位测量结果较理想,幅值测量标准差均小于1 μV,相位测量标准差均小于15 μrad。

Research on Harmonic Voltage Measurement Method Based on Josephson Quantum Voltage

At present,Josephson quantum voltage is mostly used for the measurement of sinusoidal signals,and there is very little research on the harmonic signals.The feasibility of applying programmable Josephson voltage standard to harmonic measurements was investigated,in order to realize the harmonic voltage to the voltage quantum traceability.When using the staircase wave AC quantum voltage for harmonic voltage measurement,some data fluctuated greatly due to the transition process and the Gibbs phenomenon.If the data in the transition process is included in the Fourier transform,the recovered signal amplitude and phase will be distorted.To solve this problem,a new harmonic voltage calculation method,weighted Fourier transform was proposed.The method achieved accurate measurement of harmonic voltage by resetting the data weight in the transition process to zero.The experimental results showed that the amplitude and phase measurement results of harmonic voltage were ideal,the standard deviation of amplitude was less than 1μV,and the standard deviation of phaseis was less than 15μrad.