Translator Disclaimer
29 April 2016 Detection of small metal particles by a quasi-optical system at sub-millimeter wavelength
Author Affiliations +
Inspection of alien metal particles in electronic materials such as glass fibers and resins is a critical issue to control the quality and guarantee the safety of products. In this paper, we present a new detection technique using sub-millimeter wave for films as electric materials in product lines. The advantage of using sub-millimeter wave frequency is that it is easy to distinguish conductive particles from a nonconductive material such as plastic films. Scattering of a submillimeter wave by a metal particle is used as the detection principle. By simulation, it is observed that the scattering pattern varies intricately as the diameter varies from 10 to 700 μm at 300 GHz. The demonstration system is composed of a Keysight performance network analyzer (N5247A PNA-X) with 150–330 GHz VDI extension modules, transmitting and receiving antennas, and focusing dielectric lens. An output signal is radiated via an antenna and focused onto a metal particle on a film. The wave scattered by the metal particle is detected by an identical antenna through a lens. The signal scattered from a metal particle is evaluated from the insertion loss between antennas (S21). The result shows that a particle of diameter 300 μm is detectable at 150–330 GHz through S21 in the experimental system that we prepared. Peaks calculated in simulation were detected in experimental data as well as in the curves of the particle diameter versus S21. It was shown that using this peak frequency could improve S21 level without higher frequency.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yasuyuki Kitahara, C. W. Domier, Makoto Ikeda, Anh-Vu Pham, and Neville C. Luhmann Jr. "Detection of small metal particles by a quasi-optical system at sub-millimeter wavelength", Proc. SPIE 9856, Terahertz Physics, Devices, and Systems X: Advanced Applications in Industry and Defense, 98560H (29 April 2016);


Back to Top