Coplanar transmission lines on silicon substrates for the mm-wave applications

Abstract

This work investigates the design of two different coplanar transmission lines and their application at millimeter wave frequencies up to 100 GHz. The coplanar structure has been selected to improve the grounding and also to remove the effect of the fillers on the transmission line. The two transmission lines differ by their bottom metal layer pattern. In the first transmission line the bottom metal is solid ground while in the second transmission line the bottom metal layer is used as a shield. The transmission lines are optimized for different parameters like insertion loss, inductance per unit length and size. Also to justify the electromagnetic simulated models of the transmission lines, different transmission lines have been realized and measured. The characteristics of the transmission lines are extracted from the measurement results. Comparison of the model and the measured results shows a good agreement up to 100 GHz. Finally, two 60 GHz amplifiers in 90 nm CMOS technology were designed based on these transmission lines.