Equivalent circuit model of on-wafer interconnects for CMOS RFICs

An equivalent circuit model of on-wafer interconnects was extracted directly from the S-parameter measurements. In the proposed model, the skin effect and the substrate losses have been considered. Furthermore, an additional element was introduced to predict the fringing effect for the first time. A hybrid genetic algorithm was used for the parameter extraction. The constructed two-Π model is computationally efficient and is shown to be sufficiently accurate for RF applications. The accuracy was demonstrated by the on-wafer measurements of interconnects with various physical dimensions, fabricated on the top-metal layer, employing a 0.18 μm RF-CMOS process.