volume | PIER Journals

Abstract

Biomass used for energy, whether it is extracted from forest residues or agricultural waste, contributes in many areas, such as power production, the construction industry, and also as a major source of different organic and inorganic compounds in the petrochemical industry. In recent years, research has identified a very remarkable use of agricultural waste, especially rice husks, as a microwave absorber in a pyramidal shape. However, absorbers built in this shape are fragile and require a very high degree of care, especially near the access panels, doors, and high traffic areas of the anechoic facility. This paper presents the results of a detailed experimental investigation of a more-robust, new design that is based on the concept of impedance or dielectric grading of rice-husk material. The absorber was fabricated using multiple layers of rice-husk material with increasing dielectric loss along the incident wave propagation axis. This type of fabrication technique provides more robust design of the microwave, rice-husk absorber with less thickness, as compared to the geometricallytapered, pyramid, or wedge absorbers. Free-space transmission and radar cross section (RCS) methods have been used, to study the electromagnetic compatibility (EMC) performance over the frequency range of 4-8 GHz. After the receiving equipment was calibrated by the thrureflect-line (TRL) calibration technique, the experiments were performed inside the anechoic chamber. The performance of the absorber was evaluated by incorporating the effects of circular-hole perforation, cross-polarized seams, and different metallic back plates. The proposed absorber demonstrated good performance (< -10 dB) for normal and 60° off the normal incident angles over the frequency range of 4-8 GHz. Reflectivity performance also was found to be comparable to one of the commercially-available absorbers.

1. Kartini, , K., H. B. Mahmud, and M. S. Hamidah, "Absorption and permeability performance of Selangor rice husk ash blended grade 30 concrete," Journal of Engineering Science and Technology,, Vol. 5, No. 1, , 1-16, 2010.

2. Jain, A. K., S. K. Sharma, and D. Singh, , "Reaction kinetics of paddy husk thermal decomposition," IECEC-96,, Vol. 4, 2274-2279, 1996, .
doi:0-7803-3547-3-7/16

3. Nornikman, H., F. Malek, P. J. Soh, A. A. H. Azremi, F. H. Wee, and A. Hasnain, "Set up and results of pyramidal microwave absorbers using rice husks," Progress In Electromagnetics Research, Vol. 111, 141-161, 2011.
doi:10.2528/PIER10101203

4. Chung, , B. K., H. T. Chuah, and , "Modeling of RF absorber for application in the design of anechoic chamber," Progress In Electromagnetics Research,, Vol. 43, 273-285, 2003.
doi:10.2528/PIER03052601

5. Schmitt, , R., , Electromagnetics Explained: A Handbook for Wireless/RF, EMC, and High-speed Electronics, , Elsevier Science, 2002.

6. Morgan, , D., , "A Handbook for EMC Testing and Measurement," Peter Peregrinus,, 1994.

7. Sasagawa, T., O. Hashimoto, S. Watanabe, T. Saito, and H. Kurihara, "Examination on temperature distribution of a pyramidal EM-wave absorber under high power injection," Proceedings of Asia-Pacific Microwave Conference,, 2007..

8. Ali, , I. A., L. J. Auchterlonie, and , "Temperature distribution in uniform and layered microwave absorbers in waveguide," IEE Proc., Vol. 130, No. 3, , 1983.

9. Ott, , H. W., , Electromagnetic Compatibility Engineering, John Wiley & Sons, Inc., Hoboken, , 2009.
doi:10.1002/9780470508510

10. Pozer, , D. M., Microwave Engineering, , 3rd Ed., John Wiley & Sons, 2005.

11. Tong, , X. C., " Advanced Materials and Design for Electromagnetic Interference Shielding, ," CRC Press, Taylor & Francis Group,, 2009.

12. Kumar, , S. B., U. Raveendranath, P. Mohanan, K. T. Mathew, M. Hajian, and L. P. Ligthart, "A simple free-space method for measuring the complex permittivity of single and compound dielectric materials," Microwave and Optical Technology Letters,, Vol. 26, No. 2, Jul. 2000.
doi:10.1002/1098-2760(20000720)26:2<117::AID-MOP14>3.0.CO;2-I

13. Helme, , B. G., "Measurements of the microwave properties of materials," IEEE Colloquium on Industrial Uses of Microwaves, Vol. 1, No. 7, 1990.

14. Williams, , N., V. K. Varadan, D. Ghodgaonkar, and V. V. Varadan, Measurement of transmission and reflection of conductive lossy polymers at mi, IEEE Transaction on Electromagnetic Compatibility, Vol. 32, No. 3, 236-240, Aug. 1990..
doi:10.1109/15.57119

15. Barker-Jarvis, , J., et al., "Dielectric characterization of low-loss materials-A comparison of techniques," IEEE Trans. Dielectric. Electr. Insul., Vol. 5, No. 4, 571-577, Aug. 1998.
doi:10.1109/94.708274

16. Trabelsi, , S., S. O. Nelson, and , "Calibration methods fo nondestructive microwave sensing of moisture content and bulk density of granular materials," Transactions of the ASAE,, Vol. 47, No. 6, 1999-2008, 2004.

17. Trabelsi, , S., S. O. Nelson, and , "Nondestructive sensing of bulk density and moisture content in shelled peanuts from microwave permittivity measurements," Food Control, , Vol. 17, , 304-311, 2006.
doi:10.1016/j.foodcont.2004.11.004

18. Trabelsi, , S., A. W. Kraszewski, and S. O. Nelson, "Phase-shift ambiguity in microwave dielectric properties measurements," IEEE Transactions on Instrumentation and Measurement, Vol. 49, No. 1, , Feb. 2000..
doi:10.1109/19.836309

19. Williams, , T., , EMC for Product Designers, , 3rd Ed., United Kingdom, 2001.

20. Jose, , K. A., V. V. Varadan, and V. K. Varadan, "Free-space vs. one horn interferometer techniques for radar absorber measurements," Microwave Journal, 1998.

21. Rolfes, I. and B. Schiek, "Calibration methods for microwave free space measurements," Advances in Radio Science 2, 19-25, 2004.

22. "Agilent network analysis applying the 8510 trl calibration for non-coaxial measurements," Product Note 8510-8A..

23. Chung, , B. K., H. T. Chuah, and , "Design and construction of a multipurpose wideband anechoic chamber," IEEE Antennas and Propagation Magazine, Vol. 45, No. 6, Dec. 2003.
doi:10.1109/MAP.2003.1282178

24. Malek, , F., E. M. Cheng, O. Nadiah, H. Nornikman, M. Ahmed, M. Z. A. A. Aziz, A. R. Othman, P. J. Soh, A. A. H. Azremi, and A. Hasnain, "Rubber tire dust-rice husk pyramidal microwave absorber," Progress In Electromagnetics Research,, Vol. 117, 449-477, 2011.

25. Nornikman, H., B. H. Ahmad, M. Z. A. A. Aziz, F. Malek, H. Imran, and A. R. Othman, "Study and simulation of an edge couple split ring resonator (EC-SRR) on truncated pyramidal microwave absorber," Progress In Electromagnetics Research , Vol. 127, 319-334, 2012.
doi:10.2528/PIER12030601

26. Ren, , L. S., Y. C. Jiao, J.-J. Zhao, and F. Li, "RCS reduction for a fss-backed reflectar-ray using a ring element," Progress In Electromagnetics Research Letters, Vol. 26, 115-123, 2011.
doi:10.2528/PIERL11071201

27. Lee, , H. M., H. S. Lee, and , "A dual band metamaterial absorber based with resonant-magnetic structures," Progress In Electromagnetics Research Letters, Vol. 33, 1-12, 2012.

28. Elsheakh, , D. N., H. A. Elsadek, E. A. Abdallah, M. F. Iskander, and H. Elhenawy, "Ultra wide bandwidth umbrella-shaped microstrip monopole antenna using spiral artificial magnetic conductor (SAMC)," IEEE Antennas and Wireless Propagation Letters,, Vol. 8, 1255-1258, , 2009.
doi:10.1109/LAWP.2009.2036571

29. Yiqiang, , W., F. Tao, and , "The study on a patch antenna with PBG structure," Third International Symposium on Intelligent Information Technology Application, Vol. 3, 565-567, 2009.
doi:10.1109/IITA.2009.424

30. Hemming, L. H., Electromagnetic Anechoic Chambers a Fun-damental Design and Specification Guide, IEEE Press, Wiley-Interscience, 2002.

31. Hemming, , L. H., , Architectural Electromagnetic Shielding Hand-book,, IEEE Press, , 1992..

32. IEEE 299--1997, "IEEE standard method of measuring the e®ectiveness of electromagnetic shielding enclosures,", 1997.

33. NSA 94-106, National Security Agency Specification for RF Shielded Enclosures: General Specifications, , Oct. 24 1994.

34. Koledintseva, M. Y., A. G. Razmadze, A. Y. Gafarov, V. V. Khilkevich, J. L. Drewniak, and T. Tsutaoka, "Attenuation in extended structures coated with thin magneto-dielectric absorber layer," Progress In Electromagnetics Research, Vol. 118, 441-459, 2011.
doi:10.2528/PIER11053012

35. Hiatt, , R. E., et al., "A study of VHF absorbers and anechoic rooms," Report 5391-I-f, University of Michigan, , Feb. 1963.

36. Zhou, , L., W. Wen, C. T. Chan, and P. Sheng, , "Reflectivity of planar metallic fractal patterns," Applied Physics Letters, Vol. 82, Feb. 17 2003.
doi:10.1063/1.1581366

37. "C-Ram LF and LF-W flexible foam sheet broadband microwave absorber," Technical Bulletin 320-1, Document Control No. N-07-000-01353-3., 2008.
doi:www.cumingmw.com

Dr. Muhammad Nadeem Iqbal

Dr. Mohd Fareq Bin Abd Malek

Mrs. Suzanna Harun Ronald

Dr. Muhammad Shafiq Bin Mezan

Dr. Khairudi Mohd Juni

Dr. Rogayah Chat