Quasi-TEM spectral domain analysis of thick microstrip for microwave and digital integrated circuits

A procedure to compute the effective dielectric constants and characteristic impedances of thick microstrip is formulated utilising the computationally efficient quasi-TEM spectral domain method. The results calculated for the impedance and effective dielectric constant are shown to agree well with those obtained by the integral equation and finite element methods. The decrease in the effective dielectric constant of a microstrip as a function of strip thickness is also shown to agree well with the measured data.