Ultra Wideband MIMO Notched Antenna for WLAN and Mobile Applications

Transcription

1 Volume 118 No , ISSN: (printed version); ISSN: (on-line version) url: ijpam.eu Ultra Wideband MIMO Notched Antenna for WLAN and Mobile Applications J Prasanth Kumar Research Scholar, ECE Department Gitam Institute of Technology, GITAM University Vishakapatnam, India prasanthkumarjsir@gmail.com Dr. G. Karunakar Associate Professor, ECE Department Gitam Institute of Technology, GITAM University Vishakapatnam, India profkarunakar@gmail.com Abstract A printed antenna with Two element multiple input multiple output antenna with defected ground structure is proposed in this article. The proposed antenna covers ultrawideband range( ghz) having single rejection at the band at WiMAX band. It shows good characteristics at reflection as well as isolation characteristics and gain of almost 3.7db on an average the proposed antenna works at WLAN application with a radiation efficiency of 94 percent and front to back ratio of 64. The recent trends in communications leads to a scope in 5G communications also. Antenna has been analyzed through HFSS software and parameters such as reflection coefficient, e-field and radiation patterns and current distributions have been discussed. The results states that the antenna is best suitable for the handheld applications and portable mobile applications in the day to day life at ultra-wideband technology. Keywords ultra wideband range, notch band,defected ground structure,multiple input and multiple output I. INTRODUCTION The main challenges todays wireless networks focused for the best use of smart mobile devices increases the interest in the use of multiple input and multiple output technologies. To improve the performance and to use the available spectrum of bands the MIMO technique is best suitable [1]. The MIMO systems can increase the systems data rate in both uplink and downlink with limited power and with considerable bandwidth [2]. A PIFA based MIMO system design is seen in [3] which operates at long term evolution band. A planar multiband monopole antenna has been designed and analyzed in [4] which the antenna works at five bands by using meandering lines. In [5] a printed monopole antenna with the implanting defected ground structure. A 4G MIMO antenna has been designed with defected ground structure on the other side of the substrate.to make the design simple and ease for fabrication Mohammed et.al [6] made a compact structure of size 20*20 which is used for the hand-held devices and mobile terminals. A planar diversity antenna with less mutual coupling has been proposed by Mohan in [7]. MIMO antenna plays a vital role in both 4G as well as 5G applications basically the MIMO diversity techniques plays a much attention due to their various advantages over the communication systems as stated [8-9]. A dual band compact bowtie antenna is by zheg in [10]. he compared designed antenna with existing antenna arrays and later with 12 ports in which 6 are horizontal ports and 6 are vertical ports which are formed a symmetric of angle 60 degrees which is used for MIMO-WLAN applications. Loop antennas with high gain has been seen in [11] for a triple band application. The MIMO diversity technique have been used for the proposed antenna and notched at the frequency which are unwanted A dual element MIMO antenna designed and analyzed through HFSS software and FR-4 is taken as the dielectric material which is having the loss tangent of The designed antenna has been working in almost ultra-wideband range having notch band at GHz i.e., at the WiMAX band. MIMO diversity technique and polarization of the proposed antenna has been observed in this article. The analyzed antenna has low profile and easy to fabricate and compact in dimension and exhibits ultra-wide band range. This type of antennas is needed in the day to day life. The parameters such as gain radiation efficiency and radiation patterns of the antenna is also analyzed. The proposed antenna is used for the mobile applications and WLAN 929

2 II. ANTENNA DESIGN A. Antenna Design approach The multiple input and multiple output antenna of length 26mm and width 40mm.FR-4 epoxy dielectric material is selected as the substrate material which is having dielectric constant of 4.4 and thickness of 1.6mm. the microstrip line feed which is having 50ohms characteristics impedance is applied through a SMA connector. A rectangular patch enlarged with a triangle on this top has been designed by using the HFSS software. A partial ground which is covered backside to the antenna in which radiation stubs are attached. And a stub is also used to connect between the two defected grounds as shown in Fig 1. the proposed antenna dimensions and results analysis have been discussed sequentially and table of dimensions regarding the proposed antenna has been demonstrated. Fig 2. S parameters curve of proposed antenna The above figure Cleary stats that other than at a frequency band remaining ultra-wide band coverage is coverage with the proposed antenna. The rejection band in the proposed antenna is from 3GHz to 4. 2GHz.The reflection coefficient and isolation characteristics of the proposed antenna has been analyzed. The following band covers almost all applications and best suitable for the mobile applications and WLAN and also it can be used for the 5G communication. Fig 1: Layout and Dimensions of the proposed antenna W 40mm A 1mm L 26mm B 4mm WF 1.8mm C 1mm LF 9mm S1 4mm LG 8mm S2 1mm WG 31mm ST1 3mm H 1.6mm ST2 3mm Table 1: Dimensions of the proposed antenna The above table represents the dimensions of the proposed antenna. III. RESULTS AND DISCUSSION The proposed antenna analyzed using HFSS software which is leading antenna software. The overall design aims the improvement of bandwidth and ultrawideband coverage. The proposed antenna is used for the daily uses in the hand-held devices Fig 3. VSWR of proposed antenna Fig 3 shows the VSWR plot of the proposed antenna at two different ports has been observed in the fig 3.the ultra-wide band coverage bands except at the WiMAX applications the band almost exhibits good voltage standing wave ratio. (a) 930

3 (b) Fig 4. E-field of an antenna at 5GHz Fig.4 shows the e-field pattern of the proposed antenna at 5GHz.The proposed antenna shows clear polarization diversity when two ports are excited (a) The current distributions of the proposed antenna have been clearly observed on Fig 5. Both conditions have been observed in the fig5. At fig 5(a) we can see the excited port 1 and at fig 5(b) we can see the excited port 2, both graphs states that the current distribution is intense at the feed source point and are normal at the other source points Fig 6. Gain of proposed antenna Fig 6. And Fig 7 Shows the gain and radiation pattern and co and cross polarization of the proposed antenna. A constant gain of about 3.7db with a peak gain of 5.5db. Fig 8 shows the gain vs frequency curve of the proposed antenna.it clearly shows at resonant frequency the peak gain is noticed while at the notch band the gain is two low as almost zero. The radiation patterns explain the orientation of the antenna. In all figures the red colored lines indicated the orientation along the e-plane and other color as the h-plane.by seeing at Fig 7(a) we can clearly sat that a dipole of patterns has been seen in the orientations in the working band and by seeing at fig 7 (b) a slight change in the orientation of the h-plane changes has been noticed under The notch band fig 7(c) and (d) shows the co- polarization and cross polarization of the proposed antenna at working band and at notch band.at working bands the co and cross polarizations are oriented towards the dipole type of radiation where as at notch bands some (b) Fig 5: current distribution of proposed antenna at 5GHz (a)at 5GHz (b) at 3.5GHz 931

4 (C) at 5GHZ (d) at 3.5GHz Fig 7. Radiation patterns and co and cross polarization of proposed antenna at working band (a) and (c)5ghz and at notch band (b)5ghz (d) 3.5GHz Fig 8: Gain vs frequency of proposed antenna Fig 9. parametric study by changing width of the feedline Fig 10. Parametric study by changing the radiating stub(ds) In fig 9 and fig 10 shows the parametric study of the proposed antenna by changing the width of the feed and the radiating stub. Clearly the analysis of the wideband characteristics is maintained at the same base dimensions. By varying the width of the feed the characteristics show enhance by lowing the size and with varying the radiating stub the best outcome is based on base dimension that is at 5mm,. CONCLUSION The MIMO technology is spreading its significance day to day. The proposed antenna model is used for the mobile applications and for the WLAN applications. Proposed model has good radiation characteristics and MIMO diversity. The antenna works in the range of ultra-wideband range(3-10.6ghz) and is most suitable in the new smart phones and at WLAN and in the vehicle antennas. REFERENCES [1] [1] Lu, Junwei, David Ireland, and Robert Schlub. "Dielectric embedded ESPAR (DE-ESPAR) antenna array for wireless communications." IEEE transactions on antennas and propagation 53.8 (2005): [2] [2] Sharawi, Mohammad S. Printed MIMO antenna engineering. Artech House, [3] [3] Yang, Lingsheng, and Tao Li. "Box-folded four-element MIMO antenna system for LTE handsets." Electronics Letters 51.6 (2015): [4] [4] Yao, Yuan, Xing Wang, and Junsheng Yu. "Multiband planar monopole antenna for LTE MIMO systems." International Journal of Antennas and Propagation 2012 (2012). [5] [5] Shoaib, Sultan, et al. "Design and performance study of a dualelement multiband printed monopole antenna array for MIMO terminals." IEEE Antennas and Wireless Propagation Letters 13 (2014): [6] [6] Sharawi, Mohammad S., Muhammad Ikram, and Atif Shamim. "A Two Concentric Slot Loop Based Connected Array MIMO Antenna System for 4G/5G Terminals." IEEE Transactions on Antennas and Propagation (2017). [7] [7] Srivastava G. and Mohan A Compact dual polarized UWB diversity antenna. Microw. Opt. Technol. Lett. 57: [8] [8] Mohammad, Sajad, Hamid Reza Hassani, and Ali Foudazi. "A dual band WLAN/UWB printed wide slot antenna for mimo/diversity applications." Microwave and Optical Technology Letters 55.3 (2013): [9] [9] Sampath, Hemanth, et al. "A fourth-generation MIMO-OFDM broadband wireless system: design, performance, and field trial results." IEEE Communications Magazine 40.9 (2002):

5 [10] [10] Zheng, Wen Chao, et al. "Dual-band dual-polarized compact bowtie antenna array for anti-interference MIMO WLAN." IEEE Transactions on Antennas and Propagation 62.1 (2014): [11] [11] Su, Saou-Wen. "High-gain dual-loop antennas for MIMO access points in the 2.4/5.2/5.8 GHz bands." IEEE Transactions on Antennas and Propagation 58.7 (2010):

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