International Journal of Electronics and Communication Engineering & Technology (IJECET),   International Journal of Elect...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 097...
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Complementary symmetric corner truncated compact square microstrip antenna for wide band operation

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Complementary symmetric corner truncated compact square microstrip antenna for wide band operation

  1. 1. International Journal of Electronics and Communication Engineering & Technology (IJECET), International Journal of Electronics and CommunicationEngineering & Technology 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME ISSN 0976 – 6464(Print), ISSN (IJECET) IJECETISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online)Volume 1, Number 1, Sep - Oct (2010), pp. 99-106 ©IAEME© IAEME, http://www.iaeme.com/ijecet.html COMPLEMENTARY-SYMMETRIC CORNER TRUNCATED COMPACT SQUARE MICROSTRIP ANTENNA FOR WIDE BAND OPERATION Kishan Singh Department of PG Studies and Research in Applied Electronics Gulbarga University Gulbarga, E-Mail: kishanskrish@gmail.com Shivasharanappa N Mulgi Department of PG Studies and Research in Applied Electronics Gulbarga University Gulbarga, E-Mail: s.mulgi@rediffmail.com ABSTRACT A novel design of complementary-symmetry V-slot corner truncated square microstrip antenna is designed for dual band operation with a gain of 8.51 dB. When arm of V-slot is extended, the antenna resonates for triple band of frequencies. Further, by adding one more arm to extended V-slot in the form of W. The triple bands are merged into a single band and antenna gives maximum 85.37% of bandwidth and maximum gain of 10.38 dB without affecting the nature of broad side radiation characteristics. Truncating the corners of square patch makes the antenna compact in its size as that of conventional square microstrip patch antenna. Details of the antenna design are presented and experimental results are discussed. The proposed antennas may find the application for the microwave communication systems operating from 6 to 18 GHz of frequencies. Keywords: complementary-symmetry, wide band, gain, truncating, compact. 1. INTRODUCTION In the recent communication era, the microstrip antennas have become one of the most dynamic fields of antenna theory. The advantages of microstrip antennas include small size, lightweight, low cost, easy to fabricate and low profile [1-3]. However, its bandwidth is limited to a few percentages, which is one of the major drawbacks. In fact, one of the popular techniques used for the enhancement of bandwidth is truncating the 99
  2. 2. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEcorners of radiating patch [4-5]. This technique also reduces the size of the patch andmakes the antenna compact. The compact antennas are more useful for the portablemicrowave communication equipment such as global positioning satellite (GPS)receivers. Further, the compact, dual or triple band microstrip antennas are moreattractive in recent microwave communication systems. When system requires operatingat two or more distinct band of frequencies, dual or triple band frequency patch antennasmay avoid the use of separate antennas for each operating band. Particularly theseantennas are attractive for many military and commercial applications where it isdesirable to have a single antenna that can be dynamically reconfigured to transmit and/orreceive on multiple frequency bands. The dual and triple band microwave antennas arerealized by many methods [6-9]. But in this paper a simple concept has been used indesigning complementary-symmetry V-slot corner truncated square microstrip antenna toachieve dual and triple band operation. Further by controlling the arm of V-slot, the triplebands are merged into a single band and antenna gives highest bandwidth and gain.2. DESIGNING OF ANTENNA GEOMETRY The artwork of proposed antennas is designed by using the equations available forthe design of square microstrip antenna [10, 1] and is sketched using computer softwareAuto CAD–2006 to achieve better accuracy. The antennas are fabricated usingphotolithography process on low cost glass epoxy substrate material of thickness h = 3.2mm and dielectric constant εr = 4.2. Figure 1 Geometry of VCCSMA 100
  3. 3. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 1 shows the geometry of V-slot complementary-symmetry cornertruncated square microstrip antenna (VCCSMA). The VCCSMA is derived from squaremicrostrip antenna, which is designed for the resonant frequency of 9.4 GHz. The lengthand width of the complementary-symmetry square patch are L and W respectively. Thecorners of square patch is truncated by Ls= Ws= 2 mm. The VCCSMA structure iscomplementary- symmetry along its center axis. The complementary V-slots are havingan angle of 240 between the arms. The V-slots are placed at one end of the non-radiatingedges along the length of VCCSMA. The dimensions of V-slot are taken in terms of λo,where λo is the free space wavelength in cm corresponding to the designed frequency of9.4GHz. The length and width of V-slot or complementary V-slot are taken as VL and Vwrespectively. The antenna is fed by using microstripline feeding. This feeding has beenselected because it is simple in design and can be simultaneously fabricated along withthe antenna element. The feed arrangement consist of quarter wave matching transformerof length Lt and width Wt which is connected between microstripline feed of length Lfand width Wf. At the tip of microstripline feed a 50Ω co-axial SMA connector is used forfeeding the microwave power. Figure 2 Geometry of ECCSMA Figure 3 Geometry of WCCSMA Figure 2 shows the geometry of extended V-slot complementary-symmetry cornertruncated square microstrip antenna (ECCSMA). In this figure one more arm is added toV-slot of VCCSMA. The feed arrangement of this antenna remains same as that of Figure1. Further an arm of V-slot of ECCSMA is extended. The extended slot appears in theform of W. This antenna is named as W-slot complementary-symmetry corner truncatedsquare microstrip antenna (WCCSMA) as shown in Figure 3. The feed arrangement ofthis antenna remains same as that of Figure 1. Table 1 shows the list of designedparameters of the proposed antennas. 101
  4. 4. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Table 1 Design Parameters of Proposed Antennas Antenna Dimension in Parameters mm h 3.2 L 7.6 W 7.6 Wt 1.0 Lt 4.1 Wf 6.3 Lf 4.0 WS 2.0 LS 2.0 VL 2.0 VW 0.253. EXPERIMENTAL RESULTS Figure 4 Variation of return loss versus frequency of VCCSMA The bandwidth over return loss less than −10 dB for the proposed antennas ismeasured on Vector Network Analyzer (Rohde & Schwarz, Germany make ZVK model1127.8651). The variation of return loss versus frequency of VCCSMA is as shown inFigure 4. From this figure it is seen that, the VCCSMA resonates for two bands offrequencies BW1 and BW2. The magnitude of each operating band is found to be 11.16%and 36.01% respectively which is determined by the equation,  (f − f )  Bandwidth =  2 1  ×100 % (1)  fc  102
  5. 5. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 5 Variation of return loss versus frequency of ECCSMAWhere, f1 and f2 are the lower and upper cut-off frequencies of the band respectivelywhen its return loss becomes −10 dB and fc is the center frequency between f1 and f2. Theobtained dual bands are due to the fundamental resonance of the patch and combinedeffect of complementary V-slots as they resonate near to the patch resonance [11]. Whenarm of V-slot is extended i.e. ECCSMA, the antenna resonates for triple band offrequencies BW3, BW4 and BW5 with a magnitude of 11.30%, 42.51% and 8.70%respectively. The variation of return loss versus frequency of this antenna is as shown inFigure 5. From this figure it is clear that the bandwidth BW3 remains closely same as thatof BW1 as shown in Figure 4, but BW4 increases to 42.51% which is 18.02% more whencompared to BW2 as shown in Figure 5. The appearance of BW5 is due to extension of V-slot, which resonates independently in ECCSMA [12]. Figure 6 Variation of return loss versus frequency of WCCSMA The variation of return loss versus frequency of WCCSMA is as shown in Figure6. From this figure it is seen that the antenna resonates for single band of frequency BW6 103
  6. 6. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEand gives maximum 85.37% of bandwidth. The merging of all three bands BW3, BW4 andBW5 as shown in Figure 5 into BW6 in WCCSMA is due to combined resonance effect ofradiating element and slots that resonates very close to the patch resonance [12]. The slotcan be either resonant or non-resonant if it is resonant the current along the edges of theslot introduces an additional resonance, which adds to the fundamental resonance ofradiating element, causing merging of nearby bands and hence enhancement in thebandwidth [11, 13] which is evident from Figure 6. The gain of the proposed antennas is measured by absolute gain method. Thepower transmitted ‘Pt’ by pyramidal horn antenna and power received ‘Pr’ by antennaunder test (AUT) are measured independently. With the help of these experimental data,the gain (G) dB of AUT is calculated by using, P   λ  (G) dB=10 log  r  - (G t ) dB - 20log  0  dB (2)  Pt   4πR Where, Gt is the gain of the pyramidal horn antenna and R is the distance between thetransmitting antenna and the AUT. Using equation (2), the maximum gain of theproposed antennas measured in their operating bands BW1, BW4 and BW6 are found to be8.51 dB, 9.25 dB and 10.38 dB respectively. Hence it is clear that WCCSMA giveshighest gain when compared to VCCSMA and ECCSMA. Figure 7 Radiation Pattern of VCCSMA measured at 8.53 GHz Figure 7-9 shows the typical co-polar and cross-polar radiation pattern ofVCCSMA, ECCSMA and WCCSMA respectively measured at their operating bands.From these figures it is clear that, the patterns are broadsided and linearly polarized.Hence it is seen that the WCCSMA show the nature of radiation pattern same as that ofVCCSMA and ECCSMA in spite of enhancement in the impedance bandwidth and gain. 104
  7. 7. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 8 Radiation Pattern of ECCSMA measured at 13.07 GHz Figure 9 Radiation Pattern of WCCSMA measured at 12 GHz4. CONCLUSION From the detailed experimental study, it is concluded that, the dual band operationobtained from VCCSMA can be converted into triple bands by extending the arm of V-slot. Further, extending V-slot in the form of W-slot i.e. WCCSMA, the triple bandoperation is converted into single band and antenna gives maximum 85.37 % ofbandwidth and 10.38 dB of gain without changing the nature of radiation characteristics.The proposed antennas are simple in their design and fabrication and they use low costglass substrate material. These antennas may find the application in the microwavecommunication systems operating from 6 to 18 GHz of frequencies.ACKNOWLEDGEMENTS The authors would like to thank the authorities of Dept. of Sci. & Tech. (DST),Govt. of India, New Delhi, for sanctioning the Network Analyzer under the FIST projectto the Department of Applied Electronics, Gulbarga University, Gulbarga.REFRENCES1 Balanis C. A. (1982), Antenna theory analysis and design, John Wiley & Sons, New York.2 Kin-Lu Wong, Compact and Broad band microstrip Antennas, A Wiley-Inter Science Publication John Wiley & Sons. Inc. 105
  8. 8. International Journal of Electronics and Communication Engineering & Technology (IJECET),ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME3 Garg Ramesh, Bhatia Prakesh, Bahl Inder and Boon Apisakittir (2001), Microstrip Antennas Design Hand Book, Artech House Inc.4 Jeong Gye-Tack, Kim Woo-Soo and Kwak Kyung-Sup (2006), “Design of corner truncated square-spiral microstrip patch antenna in the 5Ghz band,” Microwave Opto Technol Letts, Vol. 48, pp. 529-532.5 Chen Wen-Shyang, Kunwu-Chun and Wong Kin-Lu (2001), “Novel compact circularly polarized square microstrip antenna,” IEEE Trans. Antenna Propag, Vol.49, pp.340-342.6 Selvarani M. and Gunasekaran N. (2010), “Dual band L-Probe Fed Rectangular Microstrip Antenna with Parasitic Element,” Journal of Mobile Communication, Vol. 4, No. 3, pp. 60-63.7 S. Chakrabarti. (2009), “Dual frequency planar microstrip antenna,” Applied Electronics Conference, pp. 1-4.8 Alkanhal. M. A. S. (2009), “Composite compact Triple-band microstrip antennas,” Progress in Electromagnetic Research, Vol. 93, pp. 221-236.9 Row Jeen-Sheen (2003), “Triple-band microstrip patch antenna”, Microwave Opto Technol Letts, Vol. 38, pp. 120-123.10 J D Kraus John (2006), Antennas for all applications, Tata McGraw-hill Publishing Company Limited, New Delhi.11 Rafi Gh. Z. and L Shafai. (2004), “Wideband V-slotted diamond–shaped microstrip patch antenna,” Electron. Lett., Vol. 40, pp-1166-1167.12 Kumar G. and Ray K. P. (2003), Broad band microstrip antennas, Artech House, Boston, London, pp. 152-157.13 Chakraborty Samik., Gupta Bhaskar, and Poddar D. R. (2005) “Development of closed form formulae for aperture coupled microstrip antenna,” Journal of Science and Industrial Research, Vol. 40, pp. 482-486. 106

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