Full-wave characterisation of superconducting microstrip lines

A new theoretical model is presented to characterise a superconducting micr ostrip line on a lossy substrate, and the effects of strip thickness and lo sses on circuit performance studied. Although the high-T-c superconductor i s considered anisotropic; the effect of this anisotropy may be neglected in the characterisation of the microstrip transmission line. New integral equ ations for the electric field components are formulated in the spectral dom ain using the exact dyadic Green's function of Mao ct nl,, applied to the s uperconducting microstrip structures. A suitable procedure is developed for a CAD tool to analyse the lines of lossy substrates. Results for attenuati on constant and effective permittivity as a function of frequency and norma lised temperature are obtained.