This article proposes a periodic-threshold superconductive comparator named amalgamated quasi-one-junction SQUID comparator (AQOS) for sensitivity enhancement. The comparator employs a pair of compound Josephson-junction SQUID with magnetically-controlled effective critical current in quantization to relieve the constraints on the period current without disrupting the non-hysteresis operation state. As a result, the AQOS comparator can achieve three times more comparing operations than the quasi-one-junction SQUID (QOS) comparators, corresponding to a 9 dB sensitivity improvement. The AQOS comparator also adopts the complementary structure and feedback-free topology for linearity and robustness. It can reach a 30 GS/s sampling rate, 0.5 mA period current, −25 dBm sensitivity, more than ±10 % bias current margin, deviation of quantization current peak-to-peak magnitude that is about 10 % of the mean, and the 4.4 dB average DC duty bias margin in simulation from 1 GHz to 30 GHz with a process of 6 kA/cm² Josephson critical current density. A 2-bit AQOS comparator has been fabricated with the SIMIT Nb03 process for the qualification test. It has passed functional tests at low frequency, and its performance metrics, including period current, sensitivity, and bias current margin, have also been proven.

本文提出了一种称为合并准单结 SQUID 比较器（AQOS）的周期阈值超导比较器，用于增强灵敏度。比较器采用一对具有磁控量化有效临界电流的复合约瑟夫逊结SQUID，在不破坏无磁滞工作状态的情况下缓解周期电流的限制。因此，AQOS 比较器可以实现比准单结 SQUID (QOS) 比较器多三倍的比较操作，相当于 9 dB 的灵敏度提高。AQOS比较器还采用互补结构和无反馈拓扑，以实现线性度和鲁棒性。它可以达到30 GS/s的采样率、0.5 mA的周期电流、−25 dBm的灵敏度、超过±10%的偏置电流余量、量化电流峰峰值幅度的偏差约为平均值的10%，以及在 6 kA/cm ²约瑟夫森临界电流密度过程中，从 1 GHz 到 30 GHz 的模拟中平均直流占空比偏置裕度为 4.4 dB 。采用 SIMIT Nb03 工艺制造了 2 位 AQOS 比较器，用于资格测试。它已通过低频功能测试，其性能指标，包括周期电流、灵敏度和偏置电流裕度也已得到验证。