Effects of ground-to-ground connections on coplanar waveguide calibration standards for terahertz on-wafer measurements
Paper in proceeding, 2025
On-wafer measurements at terahertz frequencies remain challenging; discontinuities or asymmetries in coplanar waveguide (CPW) transmission lines can excite higher-order modes, leading to inaccurate calibration. In this work, we study the effects of two types of odd-mode suppression structures for CPW lines and compare them with a conventional design. The waveguides were fabricated on a semi-insulating InP substrate, and measurements were performed between 325 GHz to 1100 GHz. We show that by connecting the ground planes using air bridges, the accuracy of the calibration is improved. The probable reason is the suppression of the odd mode; however, secondary effects, such as crosstalk, require further investigation.
Author
Patrik Blomberg
Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory
WiTECH
Jerome Cheron
National Institute of Standards and Technology (NIST)
Helena Rodilla
Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory
WiTECH
Jan Stake
Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory
WiTECH
International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz
21622027 (ISSN) 21622035 (eISSN)
Vol. 2025
International conference on Infrared, Millimeter and Terahertz waves.
Helsingfors, Finland,
Helsingfors, Finland,
THz kommunikation - NU
Swedish Foundation for Strategic Research (SSF) (CHI19-0027), 2021-01-01 -- 2025-12-31.
Areas of Advance
Information and Communication Technology
Infrastructure
Kollberg Laboratory
Myfab (incl. Nanofabrication Laboratory)
Subject Categories (SSIF 2025)
Other Electrical Engineering, Electronic Engineering, Information Engineering
DOI
10.1109/IRMMW-THz61557.2025.11320108