Modeling of integrated microstrip lines on silicon substrates up to 140 GHz

This work presents a successive modeling approach for microstrip lines on silicon substrates targeted for integrated millimeter wave circuits. The characteristic impedance and the complex propagation coefficient are extracted from 3D electromagnetic simulations for strip widths in the range of W=2.4−50 um up to 140 GHz. The derivation of the frequency dependence and strip width dependence of these quantities is carried out using curve fitting algorithms. The integration of the determined functions in circuit simulation environments is demonstrated by means of standard physical transmission line models. From measurements of several microstrip test structures the intrinsic microstrip line characteristics are extracted up to 110 GHz by applying de-embedding techniques. The de-embedded measurement results obtained are in a very good agreement with the results of the proposed model and 3D electromagnetic simulations.