Analysis of microwave characteristics of a variable spacing planar high-temperature superconducting waveguide in DC magnetic field

A theoretical analysis of the microwave propagation characteristics of a variable spacing planar high-temperature superconducting waveguide in DC magnetic field is presented. It is based on the linear response vortex dynamics, in which the two-fluid model is generalized to include the effects of the moving vortices. Firstly a sinusoidal field solution for this structure is derived, and then the propagation properties such as the attenuation constant, phase velocity and quality factor are investigated by exploiting the material parameters of the superconductors together with dielectric substrates. The effects of the variable spacing and vortices are also illustrated and discussed.