Planar transmission lines with finitely thick conductors and lossy substrates

Various types of lossy planar transmission lines are analyzed by extending the spectral domain approach. Introduction of the finite metallization model and choice of the proper basis functions for the model not only overcomes the computational difficulty, but also reduces drastically the computation labor for the calculation of the conductor loss. Numerical results include the effective dielectric constants, characteristic impedance and total losses for slot lines, coplanar waveguides and strip lines. Numerical computations show that the currents on the side walls of the metal conductors make a considerable contribution to the conductor loss and cannot be neglected and that the quasi-static approximation gives reasonable results for the loss calculation of coplanar waveguides if the metallization thickness effect is taken into consideration properly.<>