Wide band Slotted Microstrip Antenna for Wireless communications

Transcription

1 International Journal of Electronics and Computer Science Engineering 301 Available Online at ISSN Wide band Slotted Microstrip Antenna for Wireless communications Pawan Kumar 1, Malay Ranjan Tripathy 2, H.P. Sinha 3 1 Department of ECE, JIET JIND 2 Department of ECE, Amity University Noida 3 Department of ECE, MM University, Mulana, Haryana, India er.pawan35@gmail.com Abstract The proposed antenna design approach is based on a single-layer, rectangular patch (Length=80mm and Width=60mm) with inverted U-slot, horizontal and vertical edge slots on the patch with coaxial probe feed. The proposed antenna is modeled using IE3D electromagnetic (EM) simulation packages namely IE3D from Zeland. The proposed antenna shows the return loss below -10dB in the frequency range from 3.5GHz to 8.3GHz.The maximum directive gain is 4.8 dbi at 6.0GHz and minimum VSWR isfound1.6 at 4.0 GHz. The antenna design is suitable for wireless local area network (WLAN) operation in the 5.2/5.5/5.8 GHz band. However, to further support the worldwide interoperability for microwave access (WiMAX) applications and sufficiently large bandwidth to cover the 5.8 GHz WiMAX bands. Key word: Wide band, microstrip antenna, Wi-Fi, WI-MAX. 1. INTRODUCTION In recent years, microstrip antennas have been receiving much attention due to their low profile, light weight and small size [1-3]. In various communications and radar system microstrip antenna is much desired. Several methods for obtaining multi-band or wide-band characteristics have been developed [4-10]. This paper introduces a microstrip antenna with a single layer, the proposed antenna design approach is based on a single-layer, single-rectangular patch with inverted U- slot and slots in horizontal and vertical edges, coaxial probe feed wideband microstrip antenna. The antenna has a simple structure and it is designed to operate in WI-FI, WI-MAX frequency bands. Studies on the impedance and radiation characteristics of the proposed antenna indicate that has an impedance bandwidth from 3.5GHz to 8.3 GHz and VSWR are less than2 in the mentioned wideband. It covers the lower band 3.82 GHz and upper band 5.2/5.5/5.8GHz band for WI-FI, WI-MAX application. II. ANTENNA STRUCTURE The basic structure of this single layer microstrip antenna in Figure 1(a).The length of rectangular patch antenna is L=80mm and width W= 60mm.The substrate dielectric constant (ε r =4.3)and height( h)=1.6mm with the tangent loss 0.02 is used. The single rectangular patch with inverted U-slot and inverted U-slot with edge slots as shown in figure 1(b) and figure 1(c) respectively.dimensions of the proposed antenna as shown in table1. L1 L2 L3 L4=L5 30mm 2mm 5mm 23.5mm W1 W2 W3 W4 15mm 13.5mm 9.42mm 10mm Table1. Dimension of the proposed antenna

2 302 Figure 1(a) Antenna Geometry with no slot Figure 1(b) Antenna Geometry with inverted U- slot. Figure 1(c) Antenna Geometry with inverted U- slot and edge slots Figure 1(d). Antenna Geometry of proposed antenna III. RESULTS AND DISCUSSION The initial design of the proposed antenna is modeled using electromagnetic (EM) simulation packages namely IE3D from Zeland Figure 2. shows the return loss of the proposed antenna.

3 302 Figure.2. Return losses S11, parameter Case 1: in this case there are no slots cut on the patch, no edge cut on the patch. This simple antenna is simulated and the return losses are shown in figure 2. The proposed antenna with the impedance bandwidth of 0.8 GHz. shows the minimum return losses -18.5db at 6 GHz resonant frequency Case 2: in this case there is inverted U slot is cut on the patch at the position X, Y 16.5, 16.5) with 5mm uniform width. The inverted U slot dimensions are length, width(33mm,31.5mm).the antenna is simulated and the return losses are shown in figure 2. The proposed antenna shows the minimum return losses -16.6db at 7 GHz resonant frequency with the impedance bandwidth of 1.8 GHz. Case 3: in this case there is inverted U slot is cut on the patch at the position X, Y(16.5,16.5) with 5mm uniform width. The inverted U slot dimensions are length, width(33mm,31.5mm).the edge slots are cut horizontal and vertically. A edge slot of the dimension L2,W4(2mm,10mm)is cut along the length and a edge slot of the dimension(10mm,9.4mm)is cut along the width of the patch. The proposed antenna is simulated and the return losses are shown in figure 2. The proposed antenna minimum return losses db at 4GHz resonant frequency with the impedance bandwidth of 4.8 GHz. shows the Figure 3 shows the variation of VSWR with the frequency which also shows the satisfactory result at resonant frequency i.e. VSWR with in value, less than 2.0.The value of VSWR of the simulated antenna is found less than 2.0 at the entire band width 3.5 GHz to 8.3 GHz frequency. Figure4. shows the radiation pattern of the antenna Figure 3.Variation of VSWR with the frequency

4 303 Figure 4. Radiation pattern of the proposed antenna Figure 5. Shows the antenna gain in dbi with respect to frequency. The antenna gain of the proposed antenna is 2dBi 4.9 dbi at the frequency range between 3.5GHz to 8.3GHz. The proposed antenna shows the gain is moderate in the frequency range from 3.5GHz to 8.3GHz. Figure.5 Antenna gain of the proposed antenna Figure6. Shows the Directive gain in db with respect to frequency. The proposed antenna shows the directive gain 8dBi to 11 dbi in the frequency range from 3.5 GHz to 8.3GHz. Figure6. Directivity of the proposed antenna. Figure7. Radiation efficiency of the proposed antenna. The proposed antenna shows the radiation efficiency between the frequency range 3.5GHz to 8.3GHz. It varies 20% to 41% within the bandwidth. The radiation efficiency of the proposed antenna is poor.

5 304 Figure7. Radiation efficiency of the proposed antenna. IV CONCLUSION The proposed antenna design approach is based on a single-layer, rectangular patch with inverted U-slot and edge slots on the patch, coaxial probe feed wideband microstrip antenna. The proposed antenna shows the return loss below -10dB in the frequency range from 3.5GHz to8.3ghz.the maximum directive gain and VSWR are seen to be more than 4 dbi and less than 2 within the frequency band. The antenna design is suitable for wireless local area network (WLAN), Wi-Fi and Wi-MAX applications in 5.2/5.5/5.8 GHz band. The edge slots on horizontal and vertical side give the wideband. The proposed Antenna is expected to have great potential usage in modern communication system.to enhance the bandwidth edge slots are studied. REFERENCES [1.] Balanis, C.A., Antenna Theory: Analysis and Design, John Wiley & Sons, Inc., USA, [2.] Wong, K.L., Compact and Broadband Microstrip Antenna, John Wiley & Sons, Inc., New York, NY, [3.] Garg, R.P. Bahartia, and A.Ittipiboon, Microstrip Antenna Design Handbook, Artech House, Bosten, London, [4.] A. A. Deshmukh and G. Kumar, Half U-slot loaded rectangular microstrip antenna, IEEE AP-S Int. Symp. USNC/CNC/URSI National Radio Science Meeting, vol. 2, 2003, pp [5.] HUANG C.Y., LIN C.C., CHEN W.F, Multiple band-stop bow-tie slot antennas for multiband wireless systems, IET Microwave Antennas Propagation 2008, 2, (6), pp [6.] K. F. Lee, S. L. Steven Yang, A. A. Kishk, "Dual and Multi Band U-Slot Patch Antennas, IEEE antenna and Wireless Propagation Letters, 7, 2008, pp [7.] K.F. tong and T.P. Wong, Circularly Polarized U-Slot antenna, IEEE Transactions on Antenna and Propagation,AP- 55, 8, August 2007,pp [8.] Y.X.Guo,A.Shackelford,K.F.Lee AND K.M.Luk, Broadband Qquarter-Patch Antenna With a U-shaped Slot, Microwave and Optical Technology Letters, 28,2001,pp [9.] A. A. Deshmukh and G. Kumar, Compact broadband stacked Microstrip antenna, Microwave and Optical Technology Letters, vol.48, no. 1,pp 93-96, Jan [10.] B.Ooi and M.Leong, "Novel design of broadband stacked patch antenna, IEEE Transactions on Antenna and Propagation, vol. 50.pp , Oct Pawan Kumar is currently working as Assistant Professor in Department of ECE, JIET JIND, Haryana, India and research scholar in Department of ECE, Maharishi Markandeshwar University, Mullana Ambala, Haryana, India 2 Dr.Malay Ranjan Tripathy is working as a Professor in Department of ECE of Amity School of Engineering and Technology Noida (U.P.) 3 Dr.H.P.Sinha is working as a Professor and Associate Director in Department of ECE, Maharishi Markandeshwar University, Mullana -Ambala, Haryana, India