Sub-mmWave Transmission Lines on Silicon-Based Technologies

In modern complementary metal-oxide semiconductor (CMOS) process, the quality of the transmission line is very crucial to the integrated circuit (IC) design. However, with the continuous scaling of the advanced CMOS node, the compact back-end-of-line (BEOL) drastically influence the performance of all passive circuits, which cannot be completely overcome due to the physical limit. After a comprehensive comparison with the various transmission lines from the state-of the-art, three optimum transmission lines (stripline, microstrip, and coplanar waveguides) based on GlobalFoundries (GF)22FDX
^®
are designed and measured. Then, these proposed transmission lines are benchmarked with silicon-filled waveguide to evaluate the potential of the later when moving to the sub-mmWave domain. It shows that the low loss (0.25, 0.46, and 0.6 dB/mm reduction at, respectively, W-band, D-band, and H-band compared with planar TLs) of silicon-filled waveguide opens a new window for the IC designers, especially above 300 GHz.