Effect of enhanced current crowding in a CPW with a thin ferroelectric film

Enhanced current crowding is predicted at the edges of the conducting strips in thin ferroelectric film coplanar waveguides (CPWs). A minimum current crowding depth is expected, which depends on the CPW geometry and dielectric constant of the ferroelectric film. In practical CPW devices the enhanced current crowding can increase the conductor losses by up to four times. The current crowding depth may be smaller than the skin depth or London penetration depth (for high temperature superconducting CPW).