A Systematic Investigation of Coplanar Lines and Discontinuities

A systematic investigation of coplanar lines is presented with respect to, on the one hand, different computation methods, and on the other hand, different effects like passivation layer, metallisation thickness, and skin effect. For the computation of the transmission line parameters of coplanar lines on MMICs, as a result, methods including the metallisation thickness have to be chosen. For low frequencies, skin effect plays an important role, for higher frequencies (> 80 GHz), only the losses due to the skin effect have to be taken into account. Furthermore, some discontinuities - shunt and series capacitances and T-junctions - are investigated, too, resulting in partly new approaches for equivalent circuits suitable for CAD systems.