Analysis of anisotropic conductors on anisotropic substrates

A full-wave finite-difference time-domain technique is used to study the anisotropy associated with anisotropic conductors on anisotropic substrates. The scheme is applied to analyze high temperature superconductor (HTS) YBCO film deposited on anisotropic sapphire substrate. The effect of the anisotropy on the performance of the coplanar waveguide and the microstrip line is evaluated. The losses and the dispersion characteristics, as well as the current distributions inside the HTS, are calculated. It is shown that the 90/spl deg/ r-cut sapphire substrate structure has lower loss and lower effective dielectric constant than the 0/spl deg/ r-cut substrate.<>