Indonesian Journal of Electrical Engineering and Computer Science Vol. 6, No. 1, April 2017, pp. 180 ~ 184 DOI: 10.11591/ijeecs.v6.i1.pp180-184  180 Received November 2, 2016; Revised January 25, 2017; Accepted February 15, 2017 X-Band Operations Metamaterial Absorber with Extended Circular Ring Topology for Size Reduction M. M. Gajibo 1 *, M. K. A. Rahim 2 , N. A. Murad 3 , O. Ayop 4 , B. D. Bala 5 , H. A. Majid 6 1,2,3,4 Advance RF and Microwave Research Group, Department of Communication Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia 5 Department of Electrical Engineering, Faculty of Engineering, Kano University Science of Technology, Wudil, Kano State, Nigeria 6 Department of Electrical Engineering Technology, Faculty of Engineering Technology, Universiti Tun Hussein Onn Malaysia, Parit Raja, 86400, Batu Pahat, Johor, Malaysia *Corresponding author, e-mail: mmgajibo@yahoo.com Abstract A metamaterial electromagnetic wave absorber consisting of a big circular ring patch with four smaller suppression circular rings is presented in this report. The metamaterial electromagnetic wave absorber introduces the concept of size reduction by suppressing the resonance frequency. An FR4 substrate was used and the incidental wave angles were varied from 0 0 to 60 0 . Simulations results shows peak absorption of 100% was achieved at 10.7 GHz by the absorber for both TE and TM polarization incident waves. Minimum absorption for both TE and TM mode of 90.6% was achieved under TE mode. The metamaterial absorber was being tested with and Ultra-wide band antenna and the results were reported. Keywords: Metamaterial, Absorbers, Ultra-wide band, SSR Copyright © 2017 Institute of Advanced Engineering and Science. All rights reserved. 1. Introduction Electromagnetic waves (EMW) absorbers are structures that neither reflect nor transmit (EMW) but instead they minimize reflection by maximizing energy loss within the structure’s substrate. The theories and concept behind exotic properties of metamaterials (MTM) have long been established [1]. As proposed, MTM being unique structures which where purposely engineered exhibit properties not existing in nature have in recent years drawn numerous attention. Scholars and researchers in the fields of EM (electromagnetic) are at their max trying to exploit all the benefits MTM can offer. The engineering of these elements which involves the manipulating or tempering with the structural configuration of these substances yields unusual properties, which could be desirable for certain applications such as low profile ground plane, cloaking, EM filters, sensing, focus antenna beam, reflectors, phase shifting [2] etc. Furthermore, MTM is divided into subareas which includes artificial magnetic conductor, AMC, electromagnetic bandgap (EBG), frequency selective surface (FSS), left-handed metamaterial (LH-MTM) 2. Proposed Design The proposed MTM absorber structure was designed using FR4 substrate with a dielectric constant of 4.6 with loss tangent of 0.019. One side of the structure consists of one big circle (ring A) and four smaller ones (rings B-E), whereas the other side consist of full ground plane as shown in Figure 1. Secondly, a simple ultra-wideband microstrip patch antenna for x-band operations shown in Figure 2 was designed to test the performance of the proposed MTM absorber. Similarly, the antenna was built on an FR4 substrate of same characteristics as that of the MTM absorber. Absorbance, A(ω) was calculated using A(ω)=1-R(ω)-T(ω) where reflectance, R(ω) is |S11| ^ 2 and transmittance, T(ω) is |S21| ^ 2 [4]. Microwave Studio of Computer Simulation Technology CST® 2015 was used for simulation. brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Universiti Teknologi Malaysia Institutional Repository