SIMULATION OF AN ELEVATED COPLANAR WAVE-GUIDE USING 2-D FDTD

Nonlinear transmission lines (NLTL's) are commonly used together with sampling circuits for millimeter-wave instruments. Recently, the use o f an elevated coplanar waveguide (CPW) has been proposed to increase t he band,vidth of sampling circuits [1]. A full-wave analysis between 1 0 and 500 GHz of such an elevated CPW using 2-D FDTD will be presented here. The influence of the elevation heights on the capacitance and t he loss behavior of the transmission line will be discussed. The analy sis shows that the distributed capacitance of the elevated CPW is four times lower and the losses are at least divided by two in comparison to a normal CPW at 300 GHz.