Transient emission from microstrip interconnects: theoretical formulation and CAD modeling

A hybrid technique suitable for the space-time analysis of the transient spurious emission from microstrip interconnects is presented. The proposed technique requires the preliminary evaluation of the surface current excited on the microstrip interconnecting lines by means of a transmission line model accounting for dispersive effects. The radiated field is then computed in the frequency domain by applying the saddle-point asymptotic technique to the integral expression of the electric field involving the dyadic Green's function. The transient signals excited along the interconnects, and the corresponding radiated field, are finally determined by using the IFFT. Radiation mechanisms are investigated, and the influence of the structure's electrical and geometrical parameters is discussed.