Distribution of current, surface impedance, and damping in superconductor coupled microstriplines

The nonuniform current distribution in the transverse cross section of the coupled conductors of a microstripline made with superconductor films leads to a substantial dependence of the losses in the line on the relative position of the coupled strips. Analytical expressions are obtained in the static approximation for the current distribution in the coupled conductors for even and odd modes, and the current distribution in the ground plane is found. The influence of the relative position of the conductors on the impedance per unit length and on the damping of electromagnetic waves in a structure with coupled superconductor lines are investigated for excitation of even and odd modes.