Input–output characteristics of a 999-stage double-flux-quantum amplifier designed for 1000-fold voltage multiplication
Input–output characteristics of a 999-stage double-flux-quantum amplifier designed for 1000-fold voltage multiplication
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1000倍倍压设计的999级双通量量子放大器的输入输出特性
DOI：
10.7567/jjap.53.053101
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发表时间：
2014
影响因子：
1.5
通讯作者：
M. Maezawa
中科院分区：
文献类型：
--
作者：
Y. Mizugaki;Yusuke Sato;H. Shimada;M. Maezawa
我们评估的输入输出特性的1000倍电压倍增器设计的单通量量子（SFQ）的数字模拟转换器。电压倍增是基于双通量量子放大器（DFQA），最初由Herr在2005年提出。采用Nb/AlOx/Nb集成技术设计并制作了999级DFQA。在实验中，我们使用了两种方法来馈送输入SFQ脉冲序列。一种是过偏置方法，即，输入SFQ脉冲串在过偏置输入结点处产生。对于高达27 µV的输入电压，其对应的约瑟夫森频率为13 GHz，已确认1000倍电压倍增，误差小于±1%。在另一种方法中，DC/SFQ转换器用于馈送输入SFQ脉冲序列。在输入频率为600 MHz时，获得了1000倍的电压倍增，误差为-0.03%，对应的约瑟夫森电压为1.2 µV。在实验中，测量电压的误差可能限制倍增因子的评估精度。
We evaluate the input–output characteristics of a 1000-fold voltage multiplier designed for single-flux-quantum (SFQ) digital-to-analog converters. The voltage multiplication is based on the double-flux-quantum amplifier (DFQA) that was originally proposed by Herr in 2005. We have designed and fabricated a 999-stage DFQA using a Nb/AlOx/Nb integration technology. In experiments, we have used two methods of feeding the input SFQ pulse train. The one is an overbiasing method, i.e., the input SFQ pulse train is generated at an overbiased input junction. A 1000-fold voltage multiplication with errors less than ±1% has been confirmed for input voltages of up to 27 µV, of which the corresponding Josephson frequency is 13 GHz. In the other method, a dc/SFQ converter is used for feeding the input SFQ pulse train. A 1000-fold voltage multiplication with an error of −0.03% has been obtained for an input frequency of 600 MHz, of which the corresponding Josephson voltage is 1.2 µV. In experiments, errors in measured voltages are likely to limit the accuracy in evaluation of the multiplication factor.