Analyzing Radiated Susceptibility of Superconducting Microstrip Transmission Line Under Plane Wave Excitation

Several studies have been conducted on an externally-excited microstrip transmission line; however, no study, to the best knowledge of the researchers, has examined the superconducting microstrip transmission lines (SMTL), which are the main part of the superconducting circuits. This article aims to investigate the radiated susceptibility of SMTL under plane wave excitation. The analysis is based on modeling the superconducting film as a current sheet with specified impedance. It is revealed that the equivalent sheet impedance depends on the current distribution within the film; hence, London's second equation is employed to obtain an integral equation to acquire the current distribution and, subsequently, the equivalent sheet impedance. Then, the susceptibility of the SMTL is calculated after applying the boundary condition at the equivalent impedance surface. The procedure is performed using spectral-domain approach and verified by COMSOL software. Finally, the susceptibility of the SMTL is examined at different temperatures and for different film thicknesses. The results show that the lower temperature makes the SMTL more susceptible to an external electromagnetic field. Moreover, the same behavior is observed for increased film thickness.