Strategies are explored to reduce the electromagnetic simulation time of electrically large superconducting transmission line structures while retaining model accuracy. The complex surface reactance of an infinite thin-film superconducting sheet is evaluated with the BCS (Bardeen–Cooper—Schrieffer) theory and is used as an input to model the phase velocity and characteristic impedance of finite width transmission line structures. Commercially available electromagnetic simulation software packages are employed for the calculations, and the results are compared with limiting analytic forms from the literature. The influences of line width, metallization thickness, and substrate height on microstrip transmission line propagation are considered in detail, and a scaling approach is presented to compensate for the leading-order effect in numerical simulations. These findings are particularly important near the energy gap of the superconductor due to the influence of the kinetic inductance on the transmission line dispersion.

中文翻译：

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超导微带传输线结构的建模策略

探索了在保持模型精度的同时减少大型超导传输线结构的电磁仿真时间的策略。使用 BCS（Bardeen-Cooper-Schrieffer）理论评估无限薄膜超导片的复表面电抗，并将其用作模拟有限宽度传输线结构的相速度和特征阻抗的输入。计算采用市售电磁仿真软件包，并将结果与​​文献中的极限分析形式进行比较。详细考虑了线宽、金属化厚度和衬底高度对微带传输线传播的影响，并且提出了一种缩放方法来补偿数值模拟中的领先阶效应。由于动感电感对传输线色散的影响，这些发现在超导体能隙附近尤为重要。