The work presents a simple and novel design approach to extend the bandwidth of existing Dielectric Material Based Microwave Absorber (DMBMA). The design comprises planar square patches of DMBMA placed periodically on a metal-backed FR4 sheet. For demonstration purpose, the DMBMA is synthesized by adding conducting carbon fillers in polyurethane matrix, and its electromagnetic parameters are measured in X-band. A single reflection null is observed in DMBMA owing to λ/4 resonance. In comparison, the bandwidth of 8 GHz (10-18 GHz) is achieved for -10 dB reflection for square patch based DMBMA. The thickness of proposed absorber is 2.75 mm. An additional resonant mode is observed due to capacitive coupling between the square patches. The enhanced bandwidth is attributed to the overlapping of λ/4 resonance and induced coupling mode. A good agreement between the simulated and measured data is observed.
2. Qin, F. and C. Brosseau, "A review and analysis of microwave absorption in polymer composites filled with carbonaceous particles," Journal of Applied Physics, Vol. 111, 061301, 2012.
3. Fante, R. L. and M. T. McCormack, "Reflection properties of the salisbury screen," IEEE Transactions on Antennas and Propagation, Vol. 36, No. 10, 1988.
4. Saville, P., Review of Radar Absorbing Materials, Defence Research & Development Atlantic Dartmouth, Canada, 2005.
5. Rozanov, K. N., "Ultimate thickness to bandwidth ratio of radar absorbers," IEEE Transactions on Antennas and Propagation, Vol. 48, No. 8, 1230-4, 2000.
6. Landy, N. I., S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, "Perfect metamaterial absorber," Phys. Rev. Lett., Vol. 100, 207402, 2008.
7. Kundu, D., A. Mohan, and A. Chakraborty, "Comment on `Wide-angle broadband microwave metamaterial absorber with octave bandwidth'," IET Microwaves, Antennas Propag., Vol. 11, No. 3, 442-443, 2017.
8. Panwar, R., S. Puthucheri, V. Agarwala, and D. Singh, "Fractal frequency-selective surface embedded thin broadband microwave absorber coatings using heterogeneous composites," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, No. 8, 2438-2448, 2015.
9. Noor, A. and Z. Hu, "Wideband multilayer Sierpinski carpet array radar absorber," Electronics Letters, Vol. 52, No. 19, 1617-1618, 2016.
10. Brosseau, C., P. Quéffélec, and P. Talbot, "Microwave characterization of filled polymer," Journal of Applied Physics, Vol. 89, 2001.
11. Tuncer, E., Y. V. Serdyuk, and S. M. Gubanski, "Dielectric mixtures: Electrical properties and modeling," IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 9, No. 5, 809-828, 2002.
12. Cheng, E. M., M. F. Malek, M. Ahmed, K. Y. You, K. Y. Lee, and H. Nornikman, "The use of dielectric mixture equations to analyze the dielectric properties of a mixture of rubber tire dust and rice husks in a microwave absorber," Progress In Electromagnetics Research, Vol. 129, 559-578, 2012.
13. Koledintseva, M. Y., R. E. DuBroff, and R. W. Schwartz, "A Maxwell Garnett model for dielectric mixtures containing conducting particles at optical frequencies," Progress In Electromagnetics Research, Vol. 63, 223-242, 2006.
14. Wang, B., J. Wei, Y. Yang, T. Wang, and F. Li, "Investigation on peak frequency of the microwave absorption for carbonyl iron/epoxy resin composite," Journal of Magnetism and Magnetic Materials, Vol. 323, No. 8, 1101-1103, 2011.
15. Luukkonen, O., F. Costa, C. R. Simovski, A. Monorchio, and S. A. Tretyakov, "A thin electromagnetic absorber for wide incidence angles and both polarizations," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 10, 3119-3125, 2009.
16. Costa, F., A. Monorchio, and G. Manara, "Analysis and design of ultra thin electromagnetic absorbers comprising resistively loaded high impedance surfaces," IEEE Transactions on Antennas and Propagation, Vol. 58, No. 5, 1551-1558, 2010.
17. Cheng, Y. and H. Yang, "Design, simulation, and measurement of metamaterial absorber," Journal of Applied Physics, Vol. 108, 034906, 2010.
18. Li, M., H. L. Yang, X. W. Hou, Y. Tian, and D. Y. Hou, "Perfect metamaterial absorber with dual bands," Progress In Electromagnetics Research, Vol. 108, 37-49, 2010.
19. Costa, F., S. Genovesi, A. Monorchio, and G. Manara, "A circuit-based model for the interpretation of perfect metamaterial absorbers," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 3, 1201-1209, 2013.
20. Chambers, B., "Optimum design of a Salisbury screen radar absorber," Electronics Letters, Vol. 30, No. 16, 1353-1354, 1994.
21. Suryanarayan, C., "Mechanical alloying and milling," Progress in Materials Science, Vol. 46, No. 1, 1-184, 2001.
22. Zhu, B., Z.Wang, C. Huang, Y. Feng, J. Zhao, and T. Jiang, "Polarization insensitive metamaterial absorber with wide incident angle," Progress In Electromagnetics Research, Vol. 101, 231-239, 2010.
23. Lu, L., S. Qu, H. Ma, F. Yu, S. Xia, Z. Xu, and P. Bai, "A polarization-independent wide-angle dual directional absorption metamaterial absorber," Progress In Electromagnetics Research M, Vol. 27, 91-201, 2012.
24. Bhattacharyya, S., "A broadband microwave metamaterial absorber with octave bandwidth," Mapan, 299-307, 2016.
25. Brumley, S. A., Evaluation of Microwave Anechoic Chamber Absorbing Materials, Arizona State University, May 1988.