TLM modeling of planar microwave circuits

The Transmission Line Matrix (TLM) method [1] is applied to the analysis of planar circuits for monolithic microwave integrated circuits (MMICs). The high-density packaging of these circuits demands full-wave analysis. Recently, efforts have been made to improve the accuracy and efficiency of the TLM schemes based on symmetrical condensed nodes [2]. The modeling of planar circuits containing thin metallic boundaries and three-dimensional discontinuities require TLM meshes with large numbers of nodes. In order to cover the simulation in reasonable computing time additional models have to be incorporated into a general purpose TLM field solver. We investigate several coplanar structures emphasizing the advantages of TLM method.