Document Type : Original Research Paper


1 Department of Electrical and Computer Engineering Isfahan University of Technology, Isfahan 84156-83111, Iran

2 Dept. of Electrical & computer Eng. Isfahan University of Technology


A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based the equivalent circuit model, is applied to design a single-layer circuit analogue absorber using double-circular-loop array. Simple guidelines for designing the CA absorber are then formulated. It is demonstrated that the fractional bandwidth of 125.7% is realized for at least 10 dB reflectivity reduction with angular stability to 40˚ for both TM and TE modes. The total thickness of the absorber design is 0.093λL at the lowest operating frequency.

Graphical Abstract

Design of a Single-Layer Circuit Analog Absorber Using Double-Circular-Loop Array via the Equivalent Circuit Model


[1]      E. F. Knott, J. F. Shaeffer, and M. T. Tuley, Radar Cross Section, 2nd ed. Raleigh, NC, USA: SciTech, 2004.

[2]      B. A. Munk, Frequency Selective Surfaces Theory and Design, New York, John Wiley & Sons Inc., 2000.

[3]      K. N. Rozanov, “Ultimate thickness to bandwidth ratio of radar absorbers,” IEEE Trans. Antennas Propagat., vol. 48, no. 8, pp. 1230–1234, Aug. 2000.

[4]      A. Kazemzadeh, “Nonmagnetic ultra wideband absorber with optimal thickness,” IEEE Trans. Antennas Propagat., vol 59, no 1, pp 135–140, 2011.

[5]      F. Costa, A. Monorchio, and G. Manara, “Analysis and design of ultra-thin electromagnetic absorbers comprising resistively loaded high impedance surface,” IEEE Trans. Antennas Propagat., vol. 58, no. 5, pp. 1551-58, May 2010.

[6]         H. Choo, H. Ling, and C. S. Liang, “On a class of planar absorbers with periodic square resistive patches,” IEEE Trans. Antennas Propagat., vol. 56, no 5, pp. 2127–2130, 2008.

[7]      Y. Shang, Z. Shen, and S. Xiao, “On the design of single-layer circuit analog absorber using double-square-loop array,” IEEE Trans. Antennas Propagat., vol. 61, no. 12, 2013.

[8]      M. Li, S. Xiao, Y. Bai, and B. Wang, “An ultrathin and broadband radar absorber using resistive FSS”, IEEE Antennas Wireless Propag. Lett. vol. 11, pp. 748–751, Dec. 2012.

[9]      N. LiuX. ShengC. ZhangJ. FanD. Guo, “A design method for synthesizing wideband band-stop FSS via its equivalent circuit model”, IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 2721-2725, 2017.

[10]      C. C. Chen, “Transmission through a conductive screen perforated periodically with apertures,” IEEE Trans. Microw, pp. 627–632, 1970.

[11]      R. Mittra, C.H. Chan, and T. C wick, “'Techniques for Analysing Frequency Selective Surfaces a Review,” Proc. IEEE, vol 76, pp 1593-1615, 1988.

[12]   R. J. Langley and E. A. Parker, “Equivalent circuit model for arrays of square loops,” Electron. Lett., vol. 18, no. 7, pp. 294–296, Apr. 1982.

[13]   R. J. Langley and A. J. Drinkwater, “improved empirical model for the Jerusalem cross,” IEE Proc. H, Microwaves, Opt. & Antennas, pp 1-6, 1982.

[14]   S. Narayan, B. Sangeetha, T.V. Sruthi, V. Shambulingappa, R. Unnikrishnan Nair, “Design of low observable antenna using active hybrid-element FSS structure for stealth applications”, International Journal of Electronics and Communications (AEÜ) 80, 137-143, 2017.

[15]   R.J. Langley and E. A. Parker, “Double-square frequency-selective surfaces and their equivalent circuit,” Electron. Lett., vol. 19, no. 17, pp. 675–676, Aug. 1983.

[16]   N. Marcuvitz., Waveguide Handbook, McGraw-Hill, New York, 1951.

[17]   I. Anderson, On the theory of self-resonant grids, Bell Syst. Tech. J., 54, pp. 1725-1731, 1975.

[18]   A. Ramezani Varkani, Z.H. Firouzeh, and A. Zeidaabdi-Nezhad, "An Equivalent Circuit Model for Array of Circular Loop FSS Structures at Oblique Angles of Incidence," IET Microwaves, Antennas & Propagation., DOI:  10.1049/iet-map.2017.1004


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