Field Solution for a Thin-Film Superconducting Strip Transmission Line

By using Londons' equations, the two-fluid model, and the classical skin effect for the normal component of the current, a sinusoidal wave solution is found for a superconducting transmission line. This solution gives a slow mode of propagation which is dependent on the ratios of the dielectric and superconducting film thicknesses to the penetration depth. At low temperatures and frequencies where the losses are low, the velocity is dispersionless even though there is a component of electric field in the direction of propagation. The solutions for velocity and attenuation vary continuously as one passes through the critical temperature into the normal state. The solutions are interpreted in terms of lumped circuit characteristics.