Flux modulated static current-voltage characteristics are the basis of DC SQUID being the flux-to-voltage convertor utilized in high-performance magnetic field measurement systems. Those static behaviors are the results of the internal quantum interference between two Josephson junctions. However, the interferometric working principle and the interference phenomena are difficult to be intuitively visualized, either through simulation with conventional models, or through the in-situ measurement inside DC SQUID. Therefore, we redraw the equivalent circuit of DC SQUID in form of the microwave interferometer, and transform it into a concise dynamic system model to study the interferometric mechanism. The double-slit like interference phenomena inside the DC SQUID are visualized through simulations of the AC oscillation current and voltage along the SQUID washer. The concept that DC SQUID is a microwave integrated circuit working as the microwave interferometer rather than a static nonlinear transducer is demonstrated and emphasized. Those concepts help users and designers improve their understandings of quantum interference mechanism of DC SQUID for both circuit design and the practical application system development.

磁通调制的静态电流-电压特性是DC SQUID的基础，DC SQUID是在高性能磁场测量系统中使用的磁通-电压转换器。这些静态行为是两个约瑟夫森结之间的内部量子干涉的结果。但是，无论是通过常规模型的仿真还是通过DC SQUID内部的现场测量，都很难直观地看到干涉工作原理和干扰现象。因此，我们以微波干涉仪的形式重绘了DC SQUID的等效电路，并将其转换为简洁的动态系统模型，以研究干涉测量机理。通过模拟沿着SQUID垫圈的交流振荡电流和电压，可以看到DC SQUID内部的双缝状干扰现象。演示并强调了DC SQUID是用作微波干涉仪而不是静态非线性传感器的微波集成电路的概念。这些概念可帮助用户和设计人员提高对DC SQUID量子干扰机制的了解，以进行电路设计和实际应用系统开发。