Determining Carbon Fiber Composite Loading with Flip-Chip Measurements to 110 GHz
Nina P. Basta, Aaron M. Hagerstrom, Jasper A. Drisko, James C. Booth, Edward J. Garboczi, Christian J. Long, Nathan D. Orloff
Electrical properties of materials are a necessary part of any circuit design. With emerging applications at millimeter- wave frequencies, there is a need to characterize new materials before they come to market. At frequencies below about 67 GHz, it is common to perform both on- wafer calibrations and on-wafer materials characterization with multiple transmission lines fabricated on a material under test. In contrast, at frequencies above 67 GHz, it is common to employ a multiple-offset-reflect calibration technique. Here, we explore the possibility of employing multiple-offset-reflect devices for on-wafer materials characterization at frequencies up to 110 GHz. To compare our results, we performed companion analyses with multiline thru- reflect-line, extracting the permittivity of fused silica and SU-8, a common photo-curable polymer. For fused silica, we obtained a permittivity of 𝟑. 𝟖𝟎 ± 𝟎. 𝟎𝟏 across the full frequency regime. For SU-8, we obtained a permittivity of 𝟑. 𝟑𝟎 ± 𝟎. 𝟎𝟏 at 28 GHz, which agreed with the literature.
IEEE Transactions on Microwave Theory and Techniques