Venter, J.J.P. (Johannes)Franc, Anne-LaureStander, TinusFerrari, Philippe2021-07-222022-05Venter, J. J. P., Franc, A.-L., Stander, T. and Ferrari, P. (2022) “Transmission lines characteristic impedance versus Q-factor in CMOS technology,” International Journal of Microwave and Wireless Technologies. Cambridge University Press, 14(4), pp. 432–437. doi: 10.1017/S175907872100060X.1759-0787 (print)1759-0795 (online)10.1017/S175907872100060Xhttp://hdl.handle.net/2263/80957This paper presents a systematic comparison of the relationship between transmission line characteristic impedance and Q-factor of CPW, slow-wave CPW, microstrip, and slow-wave microstrip in the same CMOS back-end-of-line process. It is found that the characteristic impedance for optimal Q-factor depends on the ground-to-ground spacing of the slow-wave transmission line. Although the media are shown to be similar from a mode of propagation point of view, the 60-GHz optimal Q-factor for slow-wave transmission lines is achieved when the characteristic impedance is ≈23 Ω for slow-wave CPWs and ≈43 Ω for slow-wave microstrip lines, with Q-factor increasing for wider ground plane gaps. Moreover, it is shown that slow-wave CPW is found to have a 12% higher optimal Q-factor than slow-wave microstrip for a similar chip area. The data presented here may be used in selecting Z0 values for S-MS and S-CPW passives in CMOS that maximize transmission line Q-factors.en© The Author(s), 2021. Published by Cambridge University Press in association with the European Microwave Association.Coplanar waveguideMicrostripMillimeter wave integrated circuitsSlow-wave transmission linesPostprint Article