Design of a new metamaterial structure to enhancement the

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Design of a new metamaterial structure to enhancement the

  1. 1. International Journal of Electronics and Communication Engineering & Technology (IJECET), INTERNATIONAL JOURNAL OF ELECTRONICS AND ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME COMMUNICATION ENGINEERING & TECHNOLOGY (IJECET) ISSN 0976 – 6464(Print) ISSN 0976 – 6472(Online) Special Issue (November, 2013), pp. 60-65 © IAEME: www.iaeme.com/ijecet.asp Journal Impact Factor (2013): 5.8896 (Calculated by GISI) www.jifactor.com IJECET ©IAEME Design of a New Metamaterial Structure to Enhancement the Performance of Rectangular Microstrip Patch Antenna Baljeet Singh Sinwar1, Dr. Mithilesh Kumar2 Electronics Eng. Department, UCE, Rajasthan Technical University, Kota-302010 1singh.baljeet27@yahoo.co.in, 2mith_kr@yahoo.com. ABSTRACT: In this paper, a hexagonal shaped structure has been chosen to contruct metamaterial substrate. This hexagonal shaped structure enhances the performance of a rectangular microstrip patch antenna. This metamaterial structure is proposed at a height of 3.2mm from the ground plane. For verifying that the proposed metamaterial structure possesses Negtive values of Permeability and Permittivity within the operating frequency ranges, Nicolson-Ross-Weir method (NRW) has been employed. The patch along with the proposed metamaterial structure is designed using CST-MWS software and compares the results. KEYWORDS: Nicolson-Ross-Weir method (NRW), Rectangular Microstrip patch antenna (RMPA), Return Loss I. INTRODUCTION Microstrip Patch Antennas generally have three components namely ground, substrate, patch. These are low profile, lightweight, low cost antennas. These antennas have some drawback like narrow-bandwidth, low gain etc. Several researches have been done to overcome these drawbacks. In this field of research, Victor Veselago (1968) Engheta and Ziolkowski (2006) introduced the theoretical concept of metamaterials. According to the theory of Vesalago, these materials are generally artificial materials used to provide properties which are not found in readily available materials in nature [1]-[2]. And they have Negtive Refractive Index (NRI), hence they are also called as the Negative Refractive Index materials or Left handed materials LHM (as they follow left hand rule) [3]-[5]. In this work “Hexagonal shaped structure” as a metamaterial structure has been introduced for enhancement the patch antenna parameters. With these improvements this hexagonal structure also possesses double negative properties within the operating frequency ranges. II. ANTENNA DESIGN AND METHODOLOGY The Rectangular microstrip patch antenna parameters are calculated from the formulas given below. International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 60
  2. 2. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME Desired Parametric Analysis: Calculation of Width (W), W= = μ (1) Where, c = free space velocity of light; εr = Dielectric constant of substrate. Effective dielectric constant is calculated as, ε = + (2) h The actual length of the Patch (L), L = Leff - 2ΔL (3) Where, Leff = (4) Calculation of Length Extension, ∆ h = 0.412 ( . ) ( . . h ) h (5) . The RMPA (in Fig. 1) is designed using the calculated parameters shown below in Table 1. Dimensions Dielectric Constant (εr) Loss Tangent (tan δ) Thickness (h) Operating Frequency Length (L) Width (W) Cut Width Cut Depth Path Length Width Of Feed 4.3 0.02 1.6 2.478,2.919 23.69 30.71 4.28 10.0 25.357 2.8 Table 1: RMPA Specifications Unit mm GHz mm mm mm mm mm mm Dimensional view of a rectangular microstrip patch antenna is shown in figure1. Dimensional view of a metamaterial structure is shown in above figure 2. In this structure the dimension of centered rectangular structure is 4×3mm. International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 61
  3. 3. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME To calculate the S-parameters, the proposed structure of metamaterial is placed between the two waveguide ports [6], [7] at the left and right hand side of X axis. In Fig. 3, Y-plane is defined as Perfect Electric Boundary (PEB) and Z-plane is defined as the Perfect Magnetic Boundary (PMB) to create internal environment of waveguide. Subsequently, the wave was excited from the negative X-axis (Port 1) towards the positive X-axis (Port 2). Through this arrangement, the S parameters were obtained in complex form, which are then exported to Microsoft Excel program for verifying the double-negative metamaterial properties of the proposed metamaterial structure by using the NRW approach. Formulas for calculating the value of permittivity & permeability using NRW approach [8][10]: r  2 .c . 1  v 1  w . d .i .(1  v 2 ) (6) 15.357 30.71 2.8 4.28 10 23.69 Fig.1: Rectangular patch antenna 17 11 5 Fig. 2: Proposed meta structure Fig. 3: Proposed metamaterial cover placed between the two Waveguide Ports International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 62
  4. 4. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME  r  r  Where, V1 = S11 + S21 2.s11.c.i w.d (7) V2 = S21 – S11 Where, ω = Frequency in Radian, d = Thickness of the Substrate ,c = Speed of Light,V1 = Voltage Maxima & V2 = Voltage Minima. III. SIMULATION AND RESULTS The values of permittivity (ε) and permeability (µ) are calculated by using (6) and (7) in the simulated frequency range. Graph in figures 4(a) and 4(b) shows that the proposed metamaterial cover possesses negative values of permittivity & permeability at the resonating frequency. Fig. 4: (a) Permeability versus Frequency Graph (b) Permittivity versus Frequency Graph The obtained values of permeability within frequency ranges are given in Table 2 and obtained values of permeability within frequency ranges are given in Table 3. Frq[GHz] Permeability[μr] Re[μr] 2.50 -37.0156377595638-19.348541095219i -37.01564 2.50 -36.5356387155859-19.2237456316763i -36.53564 2.50 -36.0616612486426-19.1020068912619i -36.06166 2.51 -35.5934749420146-18.9832430952429i -35.59347 2.51 -35.1310955048797-18.8673992385962i -35.13110 Table 2: Obtained values of permeability from Excel program Freq[GHz] Permittivity[εr] Re[εr] 2.50 -42.5173256091449-10.4139931114566i -42.51733 2.50 -42.0114436385906-10.3240307338169i -42.01144 2.50 -41.512661109927-10.237130826588i -41.51266 2.51 -41.0207460913582-10.1531922835657i -41.02075 2.51 -40.5357113292545-10.0721436654276i -40.53571 Table 3: Obtained values of permeability from Excel program International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 63
  5. 5. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME Above tables obtained from MS-Excel program. To obtain these values first of all we extract the S-parameters from the proposed metamaterial structure and then use NRW technique. This technique provides easy as well as effective formulation and calculation. Fig.5: Rectangular patch antenna with metamaterial structure Fig.6: S11 of a RMPA with and without metamaterial structure (a) (b) Fig. 7: Radiation pattern of RMPA (a) with proposed metamaterial structure (b) without metamaterial structure The comparison among different parameters of a rectangular microstrip patch antenna with and without metamaterial are shown in Table 4. And it shows that metamaterial improves the performance of a rectangular microstrip patch antenna. Without meta With meta Main Lobe Direction 1.8 dBi 12.2 dBi Rad. Effi. .3455 .7957 Tot. effi. .5674 .008328 Directivity 2.134 dBi 12.94 dBi Side lobe level -14.3 db -13.2 db Angular width[3 dB] 92.7 deg. 94.9 deg. Table 4: Comparison between with or without meta sturcture International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 64
  6. 6. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Special Issue (November, 2013), © IAEME The radiation pattern and table 4 show that the directivity with and without metamaterial is 12.94dbi and 2.134dBi, respectively. These results are showing that there is improvement in directivity of RMPA by incorporating proposed metamaterial structure. IV. CONCLUSION On the basis of simulation results it is observed that the directivity has been improved significantly by incorporating the proposed metamaterial structure at 3.2 mm height from ground plane of the antenna. Along with these improvements this structure improves the main lobe direction and also satisfies Double Negative property within the simulated frequency range. REFERENCES [1]. J.B. Pendry, Negative refraction males a prefect lens, Phys Rev Lett, 85 (2000), pp.3966– 3969. [2]. Bimal Garg, Rahul Tiwari, Ashish Kumar and Tilak Chitransh, “Design of factored ‘X’ shaped metamaterial structure for enhancement of patch antenna gain”, International Conference on Communication Systems and Network Technologies 2011. [3]. D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz. “Composite medium with simultaneously negative permeability and permittivity,” Phys. Rev. Lett., vol. 84, no. 18, pp. 4184–4187, May 2000. [4]. R. A. Shelby, D. R. Smith, and S. Schultz. “Experimental verification of a negative index of refraction,” Science, vol. 292, pp. 77–79, April 2001. [5]. R. W. Ziolkowski and E. Heyman. “Wave propagation in media having negative permittivity and permeability” Phys. Rev. E, vol. 64, pp. 056625:1–15, 2001. [6]. Silvio Hrabar, Juraj Bartolic, “Backward Wave Propagation in Waveguide Filled with Negative Permeability Meta Material”, Antennas and Propagation Society International Symposium, vol. 1 (2003), pp. 110 – 113. [7]. Silvio Hrabar, Gordan Jankovic, Berislav Zivkovic, Zvonimir Sipus, “Numerical and Experimental Investigation of Field Distribution in Waveguide Filled with Anisotropic Single Negative Metamaterial”, Applied electromagnetics and communications (ICEcom), (2005), pp. 1- 4. [8]. Ahmad A. Sulaiman, Ahmad S. Nasaruddin, “Bandwidth Enhancement in patch antenna by metamaterial substrate”, European Journal of scientific research, 2010. [9]. Huda A. Mazid, Mohammad Kamal A. Rahim, Thelasa Masri, “Left-handed metamaterial design for microstrip antenna application”, IEEE International RF and Microwave conference, 2008. BIOGRAPHY Baljeet Singh Sinwar was born in Hanumangarh, Rajasthan, India in 1990. He received the B.Tech degree in Electronics and Telecommunication Engineering from Sri balaji College of Engg and Tech. (Jaipur), India in 2010. He is pursuing his M. Tech in Digital Communication at University College of Engg., Rajasthan Technical University (RTU), Kota, India. His current research interests focus on Antenna and Microwave Engineering. International Conference on Communication Systems (ICCS-2013) B K Birla Institute of Engineering & Technology (BKBIET), Pilani, India October 18-20, 2013 Page 65

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