Vol. 75

Latest Volume
All Volumes
All Issues

Quasi-Millimeter Wave Technique Used for Image of Wood

By Dan Zhang, Chujing Zong, and Atsushi Mase
Progress In Electromagnetics Research Letters, Vol. 75, 19-24, 2018


A quasi-millimeter electromagnetic wave with the frequency of 22-30 GHz is applied to detect knots and holes in wood samples. It has better spatial resolution while keeping good transmission properties compared to microwave region used in the previous experiments. The images of knots and holes in wood are clearly obtained by analyzing the phase and amplitude of the transmitted wave. And the phase measurement results are all better than amplitude results according to phase values changing much more than amplitude.


Dan Zhang, Chujing Zong, and Atsushi Mase, "Quasi-Millimeter Wave Technique Used for Image of Wood," Progress In Electromagnetics Research Letters, Vol. 75, 19-24, 2018.


    1. Hansson, L., N. Lundgren, A. L. Antti, and O. Hagman, "Microwave penetration in wood using imaging sensor," Meas., Vol. 38, 15, 2005.

    2. Johansson, J., O. Hagman, and B. A. Fjellner, "Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber," Wood Sci., Vol. 49, 312, 2003.

    4. Schajar, G. S. and F. B. Orhan, "Microwave non-destructive testing of wood and similar orthotropic materials ," Subsurf Sens. Technol. Appl., Vol. 6, 293, 2005.

    5. Fujii, Y., Y. Fujiwara, Y. Yanase, T. Mori, T. Yoshimura, M. Nakajima, H. Tsusumi, M. Mori, and H. Kurisaki, "Development of radar apparatus for scanning of wooden-wall to evaluate inner structure and bio-degradation non-destructively," Adv. Mater. Res., Vol. 778, 289, 2013.

    6. Baradit, E., R. Aedo, and J. Correa, "Knot detection in wood using microwaves," Wood Sci.Technol., Vol. 40, 118, 2006.

    7. Goldsmith, P. F., C. T. Hsieh, G. R. Huguenin, J. Kapitzky, and E. L. Moore, "Focal plane imaging systems for millimeter-wavelengths," IEEE Trans. Microw. Theory. Tech., Vol. 41, 1644, 1993.

    8. Tanaka, S., Y. Fujiwara, Y. Fujii, S. Okumura, H. Togo, N. Kukutsuand, and S. Mochizuki, "Effect of annual rings on transmission of 100 GHz millimeter waves through wood," J. Wood Sci., Vol. 59, 375, 2013.

    9. Tanaka, S., Y. Fujiwara, Y. Fujii, S. Okumura, H. Togo, N. Kukutsu, and T. Nagatsuma, "Effect of grain direction on transmittance of 100-GHz millimeter wave for hinoki (Chamaecyparis obtusa)," J. Wood Sci., Vol. 57, 189, 2011.

    10. Oyama, Y., L. Zhen, T. Tanabe, and M. Kagaya, "Sub-terahertz imaging of defects in building blocks," NDT&E Int., Vol. 42, 28, 2009.

    11. Wilcox, W. W., "Review of literature on the effects of early stages of decay on wood strength," Wood Fiber, Vol. 9, 252, 1978.