Characteristics of Superconducting Transmission Line with Metal Grating for Microwave Circuits

A rigorous theoretical analysis is presented to describe the microwave behavior of a superconductor-normal periodic transmission line (S-N TL). For infinitely long periodic S-N TL, our method is based on the ABCD matrix representation of microwave unit cells in conjunction with Floquet theorem. By limiting the number of unit cells, the periodic network is sensitive to its boundaries. Boundary conditions at two ends of the structure impose an extra constraint which reveals the concept of resonant frequencies and discrete phase constant. In this case, we apply the same technique to the S-N TL, but instead of Floquet theorem, we use scattering matrix to model the finite structure.