Ram et al. / Front Inform Technol Electron Eng 2017 18(4):570-577 570 Optimal array factor radiation pattern synthesis for linear antenna array using cat swarm optimization: validation by an electromagnetic simulator * Gopi RAM †1 , Durbadal MANDAL 1 , Sakti Prasad GHOSHAL 2 , Rajib KAR 1 ( 1 Department of Electronics and Communication Engineering, National Institute of Technology, Durgapur 713209, India) ( 2 Department of Electrical Engineering, National Institute of Technology, Durgapur 713209, India) † E-mail: gopi203hardel@gmail.com Received Oct. 30, 2015; Revision accepted Feb. 16, 2016; Crosschecked Mar. 14, 2017 Abstract: In this paper, an optimal design of linear antenna arrays having microstrip patch antenna elements has been carried out. Cat swarm optimization (CSO) has been applied for the optimization of the control parameters of radiation pattern of an antenna array. The optimal radiation patterns of isotropic antenna elements are obtained by optimizing the current excitation weight of each element and the inter-element spacing. The antenna arrays of 12, 16, and 20 elements are taken as examples. The arrays are de- signed by using MATLAB computation and are validated through Computer Simulation Technology-Microwave Studio (CST-MWS). From the simulation results it is evident that CSO is able to yield the optimal design of linear antenna arrays of patch antenna elements. Key words: Patch antenna; Linear antenna array; Cat swarm optimization (CSO); Side lobe level (SLL) http://dx.doi.org/10.1631/FITEE.1500371 CLC number: TN957.2; TP391 1 Introduction The antenna is a far-reaching element here and now with the constantly progressive technology. An- tenna plays an imperative role in short or long dis- tance wireless communication. The contemporary research is going on for the development of antenna with accuracy and efficiency. For long distance communication, the antenna should be highly di- rective with high gain and less interference. However, the radiation characteristics of a single type antenna will be of low directivity, low gain, and low efficiency (Krous, 1950; Simon et al., 1994; Stutzman and Thiele, 1998; Balanis, 2005; Blank and Hutt, 2005). To accommodate these characteristics, the single type antenna will have to have a large size, which is es- sentially impractical and battens high inordinate. To overcome this problem, identical antennas are ar- ranged in an array of identical elements. The geo- metric arrangements of the arrays may be of different configurations according to the areas of applications (Haupt, 1997; Güney and Akdaǧli, 2001; Haupt and Werner, 2006; Hardel et al., 2011; Guo et al., 2015). The different array structures may be of linear (Pan- duro et al., 2009a), circular (Mandal et al., 2009; Panduro et al., 2009b), planar (Balanis, 2005), or conformal (Balanis, 2005) type, or hybridization of these structures. The reduction of side lobe levels (SLLs) is an important issue for the antenna research community. The optimal uniform and nonuniform inter- element spacing and current excitations, respectively, allow an accelerated and flexible design. All these procedures control both the peak and average SLLs (Mouhamadou and Vaudon, 2007; Yallaparagada et al., 2011; Ram et al., 2012; Liu et al., 2015). If the Frontiers of Information Technology & Electronic Engineering www.zju.edu.cn/jzus; engineering.cae.cn; www.springerlink.com ISSN 2095-9184 (print); ISSN 2095-9230 (online) E-mail: jzus@zju.edu.cn * Project supported by SERB, Department of Science and Technology, Government of India (No. SB/EMEQ-319/2013) ORCID: Gopi RAM, http://orcid.org/0000-0002-2243-9925 © Zhejiang University and Springer-Verlag Berlin Heidelberg 2017