volume | PIER Journals

Abstract

Forward scattering effects have been studied and compared when nonhomogeneous medium is illuminated by coherent and quasi-noise sources operating in mm-wave and microwave ranges. Double-layers dielectric structure simulating Fabry-Perot resonator properties was employed to develop a relevant model used for comparing transmittances of both coherent and noise signals. Experiments with nonhomogeneous materials such as coal, wood chips, sand and others have proved the basic modeling predictions and the role of noise bandwidth in averaging process important for material characterizations. It was found out that efficient averaging associated with noise nature of probing signal can be reached for the relative noise bandwidth of 25% and more.

1. Chen, L. F., C. K. Ong, C. P. Neo, V. V. Varadan, and V. K. Varadan, Microwave Electronics --- Measurement and Materials Characterization, John Wiley, 2004.

2. Koh, G., "Experimental study of electromagnetic wave propagation in dense random media," Waves in Random Media, 39-49, 1991. Google Scholar

3. Toropainen, A. P., "New method for measuring properties of nonhomogeneous materials by a two-polarization forward-scattering measurement," IEEE Trans. MTT, Vol. 41, No. 12, 2081-2086, 1993.
doi:10.1109/22.260690 Google Scholar

4. Sihvola, A., "Electromagnetic mixing formulae and applications," IEEE Electromagnetic Waves Series, Vol. 47, 2004. Google Scholar

5. Kandala, C. V. and J. Sundaram, "Nondestructive measurement of moisture content using a parallel-plate capacitance sensor for grain and nuts," IEEE Sensors Journal, Vol. 10, No. 7, 1282-1287, 2010.
doi:10.1109/JSEN.2010.2041446 Google Scholar

6. Trabelsi, S. and S. O. Nelson, "Microwave sensing technique for nondestructive determination of bulk density and moisture content in unshelled and shelled peanuts ," Transactions of the ASABE, Vol. 49, No. 5, 1563-1568, 2006. Google Scholar

7. Li, Z., A. Sharma, A. I. M. Ayala, M. N. Afsar, and K. A. Korolev, "Broadband dielectric measurements on highly scattering materials," IEEE Trans. IM, Vol. 54, No. 5, 1397-1405, 2010. Google Scholar

8. Polivka, J., P. Fiala, and J. Machac, "Microwave noise field behaves like white light," Progress In Electromagnetics Research, Vol. 111, 311-330, 2011.
doi:10.2528/PIER10041304 Google Scholar

9. Kapilevich, B., B. Litvak, T. Ben Yehuda, and O. Shotman, "Comparative characteristics of coherent and incoherent microwave scattering in dense inhomogeneous layers," Russian Physics Journal, Vol. 49, No. 9, 913-916, 2006.
doi:10.1007/s11182-006-0201-y Google Scholar

10. Ghavami, M., L. B. Michael, and R. Konho, Ultra Wideband Signals and Systems in Communication Engineering, John Wiley & Sons, 2004.

11. Cornbleet, S., Microwave and Geometrical Optics, Academic Press, 1994.

12. Pozar, D., "Microwave Engineering," John Wiley & Sons, 2005. Google Scholar

13. Kapilevih, B. and B. Litvak, "THz characterization of high dielectric-constant materials using double-layer sample," Microwave and Optical Technology Letters, Vol. 49, No. 6, 1388-1391, 2007.
doi:10.1002/mop.22442 Google Scholar

14. Kapilevich, B. and J. Polivka, "Noise versus coherency in mm-wave material characterization," The 33rd International Conference on Infrared, Millimeter, and Terahertz Waves,, Paper ID#1139, California Institute of Technology, Pasadena, California, USA, 2008. Google Scholar

15. Polivka, J., "An overview of microwave sensor technology," High Frequency Electronics, Vol. 6, No. 4, 32-42, 2007. Google Scholar

16. Mathcad Professional "Smoothing of X-Y data by Kernel smoothing," Data Analysis Documentation, 2001. Google Scholar

Prof. Boris Kapilevich

Dr. Boris Litvak