Murakami, H.; Fukuda, T.; Otera, H.; Kamo, H.; Miyoshi, A. Development of a High-Sensitivity Millimeter-Wave Radar Imaging System for Non-Destructive Testing. Sensors2024, 24, 4781.
Murakami, H.; Fukuda, T.; Otera, H.; Kamo, H.; Miyoshi, A. Development of a High-Sensitivity Millimeter-Wave Radar Imaging System for Non-Destructive Testing. Sensors 2024, 24, 4781.
Murakami, H.; Fukuda, T.; Otera, H.; Kamo, H.; Miyoshi, A. Development of a High-Sensitivity Millimeter-Wave Radar Imaging System for Non-Destructive Testing. Sensors2024, 24, 4781.
Murakami, H.; Fukuda, T.; Otera, H.; Kamo, H.; Miyoshi, A. Development of a High-Sensitivity Millimeter-Wave Radar Imaging System for Non-Destructive Testing. Sensors 2024, 24, 4781.
Abstract
The development of non-destructive testing (NDT) methods for infrastructure facilities and residential buildings that may affect human life is urgent to prevent collapse due to aging or damage in the event of earthquakes and other events. In this study, we developed a single-input and multiple-output (SIMO) synthetic aperture radar (SAR) imaging system using a high-sensitivity millimeter-wave (MM-wave) array antenna module with high directivity and absolute gains of 13.5 dB and 14.5 dB for the transmit and receive antennas, respectively. After various performance evaluations, we successfully demonstrated the usefulness of this system in NDT. Specifically, we observed cracks hidden by fiberglass tape and black acrylic paint during measurements on concrete materials. In addition, we demonstrated the transmission performance of the MM-wave against a thin concrete plate and obtained the attenuation distance Λ_exp=6.0 mm. Furthermore, in the experiment using composite materials consisting of ceramic tiles and a refractory board bonded together, and another experiment using composite plywood which is used in ordinary residential construction materials in Japan, we were able to observe defects in the internal structure that are invisible to the human eye through a perspective view.
Engineering, Safety, Risk, Reliability and Quality
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