A Compact CSRR Loaded Monopole Antenna with Defected Ground Structure for Mobile WLAN and WiMAX Applications N.A. Jan 1( ✉ ) , A.M. Saleh 1 , M. Lashab 2 , F.M. Abdussalam 1 , L. Djouablia 2 , and R.A. Abd-Alhameed 1 1 Faculty of Engineering and Informatics, University of Bradford, Bradford, UK kakarnayeem@yahoo.com, {A.M.S.Saleh,R.A.A.Abd}@bradford.ac.uk 2 Skikda University, Skikda, Algeria Abstract. A physically compact dual band antenna design is presented for use in mobile WLAN and mid-band WiMAX applications. The antenna design is based on a monopole, with a combination of metamaterial inspired features, based on a defected ground structure (GDS) and a complementary split-ring resonator (CSRR). A single CSRR unit cell is placed over a pentagonal monopole antenna, producing a narrow stop-band frequency in the range from 2.40 GHz to 2.49 GHz. The second operating frequency ranges from 3.44 GHz to 6.25 GHz, the broad- banding being due to the influence of the defected ground structure. The antenna design was optimized using HFSS, paying close attention to size constraints, and ease of integration with the radio front end. Simulation results for return loss, gain and radiation pattern are analyzed and presented. Keywords: Defected ground structure (DGS) · High frequency structure simulator (HFSS) · Complementary split ring resonator (CSRR) · Metamaterial- inspired antenna · Double negative (DNG) behavior 1 Introduction The antenna design proposed in this paper is intended to address the need for dual-band antennas for use in overlapping WLAN (2.4 GHz, 5.2 GHz, 5.8 GHz) and mid-band WiMAX (3.5 GHz) applications, which do not intefere with one another [1]. Various techniques have been investigated to achieve a suitable miniaturization of the radiating elements. Of interest are etched L-shaped. U-shaped and G-shaped metalization patches [4, 5, 6]; loading planar surfaces with complementary split ring resonator (CSRR) meta‐ material [7]; and placing insertions such as shortening pins or resonators in the neigh‐ bourhood of the radiating element [8]. The complementary split ring resonator (CSRR) is the dual of the split ring resonator (SRR) [3]. In [9] CSRR along with EBG is used for miniaturization but the antenna is resonatiing in 2.6 GHZ and 3.23 GHz with limited bandwidth and gain results. The antenna design presented in this paper is said to be metamaterial inspired in the sense that only a unit cell of the CSRR metamaterial is needed to realize the design. As compared to [9], the antenna © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2017 I. Otung et al. (Eds.): WiSATS 2016, LNICST 186, pp. 3–10, 2017. DOI: 10.1007/978-3-319-53850-1_1