Antenna Design using SMTL for WiMAX/WLAN Anil Kumar Gupta, Niraj Kumar School of Electronics Engineering VIT University Chennai Campus

Introduction In wireless communication, dual band antenna is a vital issue these days. This paper presents the simulation analysis of Wi-MAX and WLAN using Meta-material transmission lines. They have brought to define bandwidth enhancement using a metamaterial transmission line with cpw-feed. These techniques are used to reduce the physical size but to increase the bandwidth and efficiency of antenna. The effect of metamaterial transmission line on various antenna parameters like radiation efficiency, gain and bandwidth are discussed.

Literature survey At the beginning of the work several types of dual band antennas have been studied in order to achieve wider bandwidth [4]. Dual band antennas have been widely implemented in wireless communication applications and few disadvantages have limitations to their performance characteristics [2]. A wideband and compact resonant transmission-line metamaterial (TL-MTM) antenna is proposed based on the principle of double resonance. A wideband characteristic is enabled when the corresponding two resonant frequencies suitably merge together into one single passband [6].

Problem Definition Problem of generation a surface wave. bandwidth limitation, low gain and then decrease in radiation pattern. Degradation in bandwidth due to increase in antenna size. Thus, increase in antenna size, increases the radar cross-section. Antenna Efficiency reduces due to surface wave.

Design Methodology Loading of dielectric material in a substrate of an antenna- The physical size of an antenna will depend upon permittivity and shape of dielectric. Thus, loading of high dielectric will reduce the bandwidth of antenna by enhancing the quality factor. It is due to high concentration of electric field within the high dielectric region. Using simplified metamaterial transmission line in dual band antenna- In dual band antenna design, the bandwidth can be a widened by increasing the height or thickness of the substrate up to certain limit. A metamaterial transmission line geometry is introduced that can increase impedance bandwidth of antenna and provides flexibility in dimensions of feed line.

Results and discussion Fig(2) Return loss of dual band antenna using dielectric substrate resonated at 2.4 to 3.5GHz (∊r = 4.3)

Comparison Between Different Frequency NUMBER OF FREQUENCIES (IN GHZ) BANDWIDTH (IN MHZ) IMPEDANCE BANDWIDTH(%) 2.4 150 6.25 3.5 290 8.10

Inferences from results Antenna over Simplified metamaterial transmission line gives better impedance bandwidth than the conventional antenna. Bandwidth is also increased from 150MHz to 290MHz.

Future scope Dual frequency band was shown in simulated graph, so this antenna can be used for wide band transmission applications with enhancement in its parameters by optimizing the design parameters.

References [1] X. L. Sun, S. W. Cheung, and T. I. Yuk, “Compact Dual-band monopole antenna for 2.4/3.5GHz WiMAX Applications” Progress in Electromagnetics Research Symposium Proceedings, Taipei, March 25-28, 2013. [2] D.Upadhyay, R.P. Dwivedi, “Antenna Miniaturization Techniques for Wireless Applications”Eleventh International Conference on Wireless and Optical Communications Networks (IEEE), 2014. [3] C.A. Balanis, “Antenna Theory ” john wiley & SonsInc,3rd edition 2005. [4] S. Venkatrami Reddy, Aditya Singh, Yadu Nath. K and M. Jaleel Akhtar,” Design of a Practical Dual-band Planar Monopole Antenna for WLAN and WiMAXApplications”, IEEE National Conference on Communications, 15-17 Feb. 2013. [5] Cheng Zhou, Guangming Wang, Jiangang Liang, Yawei Wang, and Binfeng Zong, “Broadband Antenna Employing Simplified MTLs for WLAN/WiMAX Applications”IEEE Antennas and wireless propagation letters, vol.13, 2014. [6] J. Zhu and G. V. Eleftheriades, “A compact transmission-line metamaterial antenna with extended bandwidth”, IEEE Antenna Wireless Propagation Lett. vol.8, pp.295-298, 2009. [7] C. Caloz and T. Itoh, “Electromagnetic Metamaterials,: Transmission Line Theory and Microwave Applications:The Engineering Approach Hobokon,NJ,USA:Wiley, 2006. [8] Wen-Shan Chen, Yu-Chen Chang, Hong-Twu Chen, Fa-Shian Chang, and Hsin-Cheng Su, ” Novel Design of Printed Monopole Antenna for WLAN/WiMAX Application”, IEEE Antennas and Propagation Society International Symposium, pp 1529- 1532, 9-15 June 2007. [9] David M. Pozar , “Microwave engineering”4th edition john,john wiley & Sons inc.2012,pp.135-152. [10] Surabhi Dwivedi, Vivekanand Mishra, Yogesh P.Kosta, “Metamaterial inspired patch antenna miniaturization technique For satellite”1st International Conference on emerging technology,trends communication and networking, vol.121, 103-120, 2012.

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