Characterization of a 1 mm (DC to 110 GHz) Calibration Kit for VNA

• Main Authors: Chihyun Cho, Jin-Seob Kang, Joo-Gwang Lee, Hyunji Koo
• Format: Article
• Language: English
• Published: The Korean Institute of Electromagnetic Engineering and Science 2019-10-01
• Series: Journal of Electromagnetic Engineering and Science
• Subjects: calibration; coaxial; covariance; impedance; uncertainty; w-band
• Online Access: http://www.jees.kr/upload/pdf/jees-2019-19-4-272.pdf

This paper presents an evaluation method for a 1 mm coaxial calibration kit that can be used from DC to 110 GHz. The analytical model for the calibration kit was revisited and verified by comparing it with the electromagnetic High-Frequency Structure Simulator (HFSS). We also proposed a method to measure or appropriately estimate the physical parameters of the analytic model. This approach calculates the uncertainty based on the physical parameters, so that the uncertainty can be appropriately propagated to different measured quantities based on the covariance between all frequencies, including the real and imaginary parts. To verify the proposed method, a commercially available 1 mm calibration kit was evaluated, and the impedance of a device under test was measured using the evaluated kit. We compared the measured results with those of the National Institute of Standards and Technology (NIST) and confirmed that they agreed well with each other within the uncertainty. Additionally, the multiple reflections caused by the impedance mismatch between the signal source and the instrument was corrected, and its calibrated uncertainty was obtained in the time domain. Thus, the uncertainty of the impedance measurement in the frequency domain was properly propagated to the time domain.