ANALYSIS OF COPLANAR-WAVE-GUIDE DISCONTINUITIES WITH FINITE-METALLIZATION THICKNESS AND NONRECTANGULAR EDGE PROFILE

In this paper, the hybrid finite-element method (FEM) is proposed to a nalyze the coplanar-waveguide (CPW) discontinuities with finite-metall ization thickness, A variational formula for the electric field in the slot region between upper and lower half-space is derived by applying the variational-reaction theory and solved by the FEM, In the limitin g case of zero metallization thickness, this finite-element analysis i s reduced to a moment-method analysis using Galerkin's approach with r ooftop basis functions, The edge profile effects of a trapezoidal slot cross resulting from the etching or sputtering process can also be ea sily considered by this approach, Some numerical results are presented for short-and open-ended CPW discontinuities for different conductor thicknesses, It has been shown that not only the metallization thickne ss, but also the conductor-edge profile, can produce noticeable effect s on circuit performance and should be taken into account for accurate ly modeling the CPW discontinuities.