20120140501022

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20120140501022

  1. 1. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 187 A NOVEL DESIGN AND DEVELOPMENT OF SUPERIMPOSED SQUARE SLOT TWO ELEMENT RECTANGULAR MICROSTRIP ARRAY ANTENNA FOR WIDE BANDWIDTH AND INTENSIFIED GAIN Dr. Nagraj Kulkarni1 and Dr. S. N. Mulgi2 1 Department of Electronics, Government College, Gulbarga-585 105, Karnataka, India 2 Department of PG Studies and Research in Applied Electronics, Gulbarga University, Gulbarga-585106, Karnataka, India ABSTRACT A novel design of two element rectangular microstrip array antenna incorporating the two superimposed square slots on the radiating patches is presented for wide bandwidth and high gain. The maximum bandwidth of 93.07 % with a peak gain of 9.24 dB is achieved in the present study. The antenna exhibits a virtual size reduction of 27% and shows broadside radiation pattern across its entire operating band. The design concept of the antenna is described. The experimental results are presented and discussed. The proposed antenna may find applications in WiMax of IEEE802.16d (5.7-5.9 GHz), HIPERLAN/2 (5.725 to 5.825 GHz) and radar communication systems. Key Words: Two element, superimposed, square slot, wideband, high gain 1. INTRODUCTION In recent years, microstrip antennas (MSAs) have become the attractive candidate for the antenna designers because of their useful features such as low profile, light weight compatibility with integrated-circuit technology [1] etc. The patch antennas are receiving increasing interest in various newly emerging communication systems such as WLAN, WiMAX, HIPERLAN/2 etc, since they provide many advantages over traditional microwave antennas in terms of achieving dual, triple and multiple bands which are realized by using different techniques such as, cutting slots of different geometries like rectangular, L-shape, E-shape, circular, square [2-7] etc. In many applications, the wide bandwidth and gain are the essential components to use the antenna for specific applications. During the last decade, many efforts have been put forth to realize bandwidth widening techniques of microstrip antennas, which include the use of impedance matching, multiple resonators and a thick INTERNATIONAL JOURNAL OF ADVANCED RESEARCH IN ENGINEERING AND TECHNOLOGY (IJARET) ISSN 0976 - 6480 (Print) ISSN 0976 - 6499 (Online) Volume 5, Issue 1, January (2014), pp. 187-194 © IAEME: www.iaeme.com/ijaret.asp Journal Impact Factor (2013): 5.8376 (Calculated by GISI) www.jifactor.com IJARET © I A E M E
  2. 2. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 188 substrate [8, 9] etc. But, the two element array antenna having a superimposed square slot on the rectangular radiating patch and H shaped slots on the ground plane is used for enhancing the bandwidth and gain. This kind of study is found to be rare in the literature. The slot loading technique provides the freedom to design the required slot irrespective of their size or shape and can be suitably loaded at the desired place on the geometry of the antenna for broadening the bandwidth of the antenna [10]. Also, the array technique, gives the flexibility to design the required feed line between the array elements to energize, which helps in enhancing the gain of the antenna [11]. 2. ANTENNA DESIGN The low-cost glass epoxy substrate material of area ASub × BSub having a thickness of h = 1.6 mm and dielectric constant εr = 4.2 is used to fabricate the proposed antenna. Artwork of the antennas is sketched using computer software Auto-CAD to achieve better accuracy. The antennas are etched using photolithography process. Fig. 1: Geometry of SSTRMSAA Figure 1 shows the geometry of the superimposed square slot loaded two element rectangular microstrip array antenna (SSTRMSAA). The antenna has two rectangular patches that are present at distance of D1 mm possessing the length L and width W that are designed for the resonant frequency of 3.5 GHz, using the basic equations, (1) where, c is the velocity of light in mm, fr is the designed frequency in GHz, εe is the effective dielectric constant and ∆l is the extension length of the fringing field in mm. r e c L = 2 l (mm) 2f ε − ∆
  3. 3. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 189 The ∆l and εe are given by, (2) The square slot of sides X mm is considered as base slot whose dimensions are constant while another variable square slot of sides Y mm is superimposed on the base slot. These square slots are placed at the center of the rectangular patch at a distance of 6.2 mm and 9.3 mm from non radiating side (L) and the radiating side (W) of the patch. The two H shaped slots which are D2 mm apart and each having a width 1 mm are incorporated on the ground plane such that the mid-point of H slot lies exactly below the center of the each radiating patch. The HH and HV are the horizontal and vertical arm lengths of the H shaped slot. The dimensions D1, D2, X, HH and HV are taken in terms of λ0, where λ0 is the free space wavelength in millimeter corresponding to the designed frequency of 3.5 GHz. The parallel feed arrangement is used in the present study, because it has the advantage over series fed arrangement, that is, its wideband performance. The feed arrangement shown in this figure is a contact feed and has the advantage that it can be etched simultaneously along with the antenna elements. The microstripline feed arrangement is designed using the relations available in the literature [12]. A 50 feed line of length L50 and width W50 is connected to 100 line of length L100 and width W100 to form a two way power divider. A quarter wave transformer of length LTr and width WTr is connected between 100 feed line and midpoint of the radiating elements to establish perfect impedance matching. A 50 semi miniature –A connector is used at the tip of the 50 feed line. The various parameters of the proposed antenna are enlisted in Table 1. Table 1: Various parameters of SSTRMSAA Antenna Parameters Dimensions in (mm) Antenna Parameters Dimensions in (mm) W 26.6 WTr 0.15 L 20.4 X 4 L50 21.84 D1=D2 λ0/1.96 W50 3.2 ASub 90 L100 21.88 BSub 50 W100 0.74 HV λ0/9.96 LTr 10.92 HH λ0/8.32 ( ) ( ) e e W ε + 0.3 +0.264 h l = 0.412h W ε 0.258 +0.8 h         ∆   −       1 - 2 r r e ε +1 ε 1 h ε = + 1+12 2 2 W −       r r c 2 W = 2f ε +1
  4. 4. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 190 3. RESULTS AND DISCUSSION The Vector Network Analyzer (Germany make, Rohde and Schwarz, ZVK model 1127.8651) is used to measure experimental return loss of SSTRMSAA. The experimental impedance bandwidth over return loss less than -10 dB is calculated using the formula, 2 1 Bandwidth (%) = C f f f − × 100 % where, f2 and f1 are the upper and lower cut off frequencies of the resonating bands when their return loss reaches -10 dB and fC is a centre frequency of f2 and f1. Fig. 2: Variation of return loss versus frequency of SSTRMSAA when X= 4 mm and Y=2 mm Figure 2 shows the return loss versus frequency of SSTRMSAA when X= 4 mm and Y=2 mm. It is clear from this figure that, the antenna resonates for dual bands with their respective bandwidths are BW1=17.6 % (6.74-5.65 GHz) and BW2= 11.27% (8.43-7.53 GHz). The resonating bands BW1 and BW2 are due to the fundamental resonance of the patches and the currents along the edges of the superimposed square slots. Fig. 3: Variation of return loss versus frequency of SSTRMSAA when X= 4 mm and Y=4 mm.
  5. 5. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 191 Figure 3 shows variation of return loss versus frequency of SSTRMSAA when the side length of the superimposed square slot is increased from 2 mm to 4 mm. It can be noted from this figure that, the antenna resonates again for two bands with their respective bandwidths are BW3=48.52% (6.76-4.12 GHz) and BW4= 60.79% (14.5-7.74 GHz). Further, it is observed from this figure that, the bandwidths BW3 and BW4 are enhanced from 17.6% to 48.52% and 11.27 % to 60.79% respectively when compared to the bands BW1 and BW2 of Fig. 2. This increase in the bandwidth is due to effect of increase in the combined area of the two superimposed square slots. Also, the H shaped slot on the ground plane helps in widening the bandwidth of the antenna. Fig. 4: Variation of return loss versus frequency of SSTRMSAA when X= 4 mm and Y=3 mm Figure 4 shows the return loss versus frequency of SSTRMSAA when the side length of the superimposed square slot is decreased from 4 mm to 3 mm. It is clear from this figure that the antenna resonates for three bands with their respective bandwidths are BW5= 20.7% (2.82-2.29 GHz) BW6= 5% (3.28-3.12 GHz) and BW7= 93.07% (12-4.38 GHz). The combined effect of decrease in the area of the superimposed square slots and the presence of H shaped slot on the ground plane makes two bands BW3 and BW4 shown in Fig. 3 to split into three bands BW5, BW6 and BW7 causing the first band BW5 to resonate at 2.555 GHz, which is less than the designed frequency i.e. 3.5 GHz, this shows the virtual size reduction of about 27%. The second band BW6 resonates at 3.2 GHz which is very close to the designed frequency of antenna shows the fundamental resonance of the antenna. Furthermore, the bandwidth of the third band BW7 is enhanced to a maximum of 93.07% when compared to the BW4 of Fig. 3. Hence it is clear that the variation of location of the superimposed square slot on the patch element is effective in controlling the bandwidth of the antenna. Fig. 5: Radiation pattern of SSTRMSAA measured at 6.195 GHz.
  6. 6. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 192 Fig. 6: Radiation pattern of SSTRMSAA measured at 5.44 GHz Fig.7: Radiation pattern of SSTRMSAA measured at 3.2 GHz The co-polar and cross-polar radiation patterns of SSTRMSAA are measured in their operating bands at 6.195, 5.44 and 3.2 GHz respectively and are as shown in Figures 5 to 7. From these figures, it can be observed that, the patterns are broadside and linearly polarized, the cross polar level is maximum -15 dB down when compared to their co–polar power level indicates the directional nature of the radiation. The gain of SSTRMSAA is calculated using the absolute gain method given by the relation, 0 ( ) 10 log - ( ) - 20log 4 r t t P G dB G dB dB P R λ π =           (3) where, Gt is the gain of the pyramidal horn antenna and R is the distance between the transmitting antenna and the antenna under test (AUT). The power received by AUT, ‘Pr’ and the power transmitted by standard pyramidal horn antenna ‘Pt’ are measured independently. The SSTRMSAA gives a peak gain of about 9.24 dB in its operating band when X = 4 mm and Y = 2 mm. The variation of gain versus frequency of SSTRMSAA is plotted in Fig. 8.
  7. 7. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 193 Fig. 8. Variation of gain versus frequency of SSTRMSAA 4. CONCLUSION From the detailed study, it is found that, the SSTRMSAA can be made to operate between 2.82 to 12.43 GHz by loading two superimposed square slots on the radiating patch and H shaped slots on the ground plane. The bandwidth is enhanced to 93.07 % by varying the combined area of superimposed square slots. The SSTRMSAA also gives a peak gain of 9.24 dB which is quite large when compared to the gain of conventional rectangular microstrip antenna designed for the same resonant frequency. The variation of the dimension of superimposed square slot on the patch does not change the nature of broadside radiation characteristics. The proposed antennas are simple in their geometry and are fabricated using low cost glass epoxy substrate material. These antennas may find applications in WiMax of IEEE802.16d (5.7-5.9 GHz), HIPERLAN/2 (5.725 to 5.825 GHz) and radar communication systems. ACKNOWLEDGEMENTS The authors would like to thank the Dept. of Science & Technology (DST), Govt. of India, New Delhi, for sanctioning Vector Network Analyzer to this Department under FIST project. REFERENCES 1. Kumar, G, and K. P. Ray, Broadband Microstrip Antennas, MA : Artech House, Norwood, 2003. 2. Ge,Y., K.P.Esselle, and T.S.Bird, “ A broadband E-shaped patch antenna with microstrip compatible feed,” Microwave and Optical Technology Letters, Vol .42, No.2, 2004. 3. Kishan Singh, R. B. Konda, N. M. Sameena, and S. N. Mulgi, “Design of square microstrip Antenna for dual wideband Operation”, Microwave and Optical Technology Letters, Vol. 51, No 11, 2578-2582, 2009. 4. Kuo, J.S, and K.L. Wong, “A compact microstrip antenna with meandered slots in the ground plane,” Microwave and Optical Technology Letters, Vol. 29, 95-97, 2001. 5. Ray, K.P., S. Ghosh, and K.Nirmala, “Multi layer multi-resonator circular microstrip antenna for broad band and dual band operations,” Microwave and Optical Technology Letters, Vol. 47, 489-494, 2005.
  8. 8. International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 – 6480(Print), ISSN 0976 6. Behera,. S, and Vinoy, K.J, “Microstrip square ring antenna for dual band operation,” Progress In Electromagnetics Research, PIER 93, 7. Sadat,S., Fardis, M., Geran, F, and Dadashzadeh, G, “A compact microstrip square antenna for UWB applications,” 179, 2007. 8. Roy .J.S., Chattoraj, and N. Swain, “ wireless communications,” 2006. 9. Rafi, Gh. Z, and Shafai, L, “Wideband V antenna,” Electronics Letters, 10. N. M. Sameena, R. B. Konda, and S. N. Mulgi, “Broadband, high symmetry Microstrip array antenna,” No. 10, 2256-2258, 2010. 11. Y.S. Kumar, V.V. Srinivasan, V.K. circularly polarized aperture Radar Symposium India (IRSI 12. Bahl, I. J, and P. Bhartia, Microstrip Antennas, A 13. P. Naveen Kumar, S.K. Naveen Kumar and S.N.Mulgi, “Design and Development of Rectangular Microstrip Antenna for Quad and Triple Band Operation”, Int of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 3, 2013, pp. 132 - 138, ISSN Print: 0976 14. Kishan Singh and Shivasharanappa N Mulgi Compact Square Microstrip Antenna Electronics and Communication Engineering & Technology (IJECET), Volume 2010, pp. 99 - 106, ISSN Print: 0976 15. Suryakanth B and Shivasharanappa N Mulgi, Dual Band Microstrip Antenna Cross Polarization”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume ISSN Online: 0976 –6472. BIO-DATA Dr. Nagraj Kulkarni Electronics from Gulbarga Universit respectively. He is working as a Electronics Government Degree college Gulbarga. of Microwave Electronics. Dr. S.N. Mulgi received from Gulbarga University Gulbar is working as a professor in the Department of University, Gulbarga. Electronics. International Journal of Advanced Research in Engineering and Technology (IJARET), 6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 1, January (2014), © IAEME 194 Behera,. S, and Vinoy, K.J, “Microstrip square ring antenna for dual band operation,” Progress In Electromagnetics Research, PIER 93, 41–56, 2009. , M., Geran, F, and Dadashzadeh, G, “A compact microstrip square antenna for UWB applications,” Progress In Electromagnetic Research PIER Roy .J.S., Chattoraj, and N. Swain, “short circuited microstrip antenna for multi Microwave and Optical Technology Letters, Vol .48, 2372 Rafi, Gh. Z, and Shafai, L, “Wideband V-slotted diamond-shaped microstrip patch Electronics Letters, Vol. 40, No. 19, 1166-1167, 2004. N. M. Sameena, R. B. Konda, and S. N. Mulgi, “Broadband, high-gain Complementary symmetry Microstrip array antenna,” Microwave and Optical Technology Letters Y.S. Kumar, V.V. Srinivasan, V.K. Lakshmeesha, and S. Pal, “High gain, aperture coupled microstrip Antenna”, Proceedings of the osium India (IRSI-07), 228–230, 2007. Bahl, I. J, and P. Bhartia, Microstrip Antennas, Artech house, New Delhi, 1980 P. Naveen Kumar, S.K. Naveen Kumar and S.N.Mulgi, “Design and Development of Rectangular Microstrip Antenna for Quad and Triple Band Operation”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 3, 138, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. Shivasharanappa N Mulgi, “Complementary-Symmetric Corner Truncated Compact Square Microstrip Antenna for Wide Band Operation”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume , ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. Shivasharanappa N Mulgi,, “Design and Development Dual Band Microstrip Antenna with Enhanced Bandwidth, Gain, Frequency Ratio ernational Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 1, Issue 1, 2010, pp. 88 - 98, ISSN Print: 0976 Nagraj Kulkarni received his M.Sc, M.Phil and Ph.D degree in Applied Electronics from Gulbarga University Gulbarga in the year 1995, respectively. He is working as an Assistant professor and Head in the Department of Electronics Government Degree college Gulbarga. He is actively working of Microwave Electronics. received his M.Sc, M.Phil and Ph.D degree in Applied Electronics from Gulbarga University Gulbarga in the year 1986, 1989 and 2004 respectively. He professor in the Department of Applied Electronics Gulbarga University, Gulbarga. He is an active researcher in the field of Microwave International Journal of Advanced Research in Engineering and Technology (IJARET), 6499(Online) Volume 5, Issue 1, January (2014), © IAEME Behera,. S, and Vinoy, K.J, “Microstrip square ring antenna for dual band operation,” , M., Geran, F, and Dadashzadeh, G, “A compact microstrip square-ring slot Research PIER 67, 173- antenna for multi-band Vol .48, 2372-2375, shaped microstrip patch gain Complementary- Microwave and Optical Technology Letters, Vol. 52, Lakshmeesha, and S. Pal, “High gain, low side lobe, the Inter -national rtech house, New Delhi, 1980. P. Naveen Kumar, S.K. Naveen Kumar and S.N.Mulgi, “Design and Development of ernational Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 3, Symmetric Corner Truncated ernational Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 1, Issue 1, nd Development of Low Profile, ith Enhanced Bandwidth, Gain, Frequency Ratio and Low ernational Journal of Electronics and Communication Engineering & , ISSN Print: 0976- 6464, degree in Applied y Gulbarga in the year 1995,1996 and 2014 in the Department of He is actively working in the field his M.Sc, M.Phil and Ph.D degree in Applied Electronics ga in the year 1986, 1989 and 2004 respectively. He Applied Electronics Gulbarga field of Microwave

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