TY - JOUR
T1 - Transmission lines characteristic impedance versus Q-factor in CMOS technology
AU - Venter, Johannes J.P.
AU - Franc, Anne Laure
AU - Stander, Tinus
AU - Ferrari, Philippe
N1 - Publisher Copyright:
© The Author(s), 2021. Published by Cambridge University Press in association with the European Microwave Association.
PY - 2022/5/20
Y1 - 2022/5/20
N2 - This 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.
AB - This 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.
KW - Coplanar waveguide
KW - microstrip
KW - millimeter wave integrated circuits
KW - slow-wave transmission lines
UR - http://www.scopus.com/inward/record.url?scp=85104632837&partnerID=8YFLogxK
U2 - 10.1017/S175907872100060X
DO - 10.1017/S175907872100060X
M3 - Article
AN - SCOPUS:85104632837
SN - 1759-0787
VL - 14
SP - 432
EP - 437
JO - International Journal of Microwave and Wireless Technologies
JF - International Journal of Microwave and Wireless Technologies
IS - 4
ER -