High-Resolution Millimeter-Wave Tomography System for Nondestructive Testing of Low-Permittivity Materials

Och A, Holzl PA, Schuster S, Scheiblhofer S, Zankl D, Pathuri-Bhuvana V, Weigel R (2021)

Publication Type: Journal article

Publication year: 2021

Journal

IEEE Transactions on Microwave Theory and Techniques Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 69

Pages Range: 1105-1113

Article Number: 9241450

Journal Issue: 1

DOI: 10.1109/TMTT.2020.3030662

Abstract

Tomographic microwave imaging is employed as a method of nondestructive testing in a wide range of industrial applications, e.g., for quality control. However, many low-permittivity materials, such as gaseous substances or foam with high air content, do not provide sufficient contrast to the environment to be measured with existing systems. This article introduces a 77-79-GHz high-resolution tomography system that facilitates the characterization of materials with relative permittivity close to one and very small attenuation. Fully integrated frequency-modulated continuous-wave radar transceivers are utilized as sensors to reduce the system cost and complexity significantly. The medium-dependent time-of-flight between different radar sensors is evaluated to reconstruct the permittivity distribution inside an area-under-test. To solve the underdetermined inverse problem, two methods based on the Tikhonov regularization and total variation regularization are implemented. Individual impacts on measurement uncertainty are investigated. Custom-designed horn antennas ensure a sufficient number of signal paths between the sensors. A prototype is built using two synchronized radar modules and a rotary stage to emulate a higher number of sensors. System simulations and measurements are conducted utilizing various low-permittivity foam phantoms. Successful reconstructions of the 2-D permittivity distribution demonstrate the feasibility of this approach.

Authors with CRIS profile

Robert Weigel Lehrstuhl für Technische Elektronik

Involved external institutions

Infineon Technologies Austria AG AT Austria (AT) voestalpine Stahl GmbH AT Austria (AT) Silicon Austria Labs AT Austria (AT)

How to cite

APA:

Och, A., Holzl, P.A., Schuster, S., Scheiblhofer, S., Zankl, D., Pathuri-Bhuvana, V., & Weigel, R. (2021). High-Resolution Millimeter-Wave Tomography System for Nondestructive Testing of Low-Permittivity Materials. IEEE Transactions on Microwave Theory and Techniques, 69(1), 1105-1113. https://dx.doi.org/10.1109/TMTT.2020.3030662

MLA:

Och, Andreas, et al. "High-Resolution Millimeter-Wave Tomography System for Nondestructive Testing of Low-Permittivity Materials." IEEE Transactions on Microwave Theory and Techniques 69.1 (2021): 1105-1113.

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