Coplan: CAD Program for Calculating Numerous Coplanar Line Types with Consideration of Frequency Dependency

Exact simulation and optimization of coplanar circuits at microwave and millimeter frequencies is impossible with present commercial circuit analysis programs. The implemented models are generally based on static field-theoretical methods which show large discrepancies at higher frequencies in comparison to exact but time-consuming dynamic field-theoretical methods. Furthermore, the present models cover only few types of symmetrical transmission line structures without any discontinuities. In this paper a new model is presented that can be implemented with general circuit analysis programs or used as a stand-alone tool. It produces proper frequency-dispersive results for a wide range of coplanar structures and a range of discontinuities. The model consists of analytical approximation formulas to describe the results of exact theoretical calculations and/or systematic experimental investigations. Agreement of the new model with results from open literature and in-house field theory as well as from published and in-house measurement is shown to be satisfactory.