Effect of Height on Edge Tapered Rectangular Patch Antenna using Parasitic Stubs and Slots Gurpreet Kaur #1, Er. Sonia Goyal #2 M. tech student, Departmentof electronics and communication engineering, Punjabi University patiala #1 Assistant Professor, Departmentof electronics and communication engineering, Punjabi University patiala #2 Abstract- In this paper an rectangular patch with parasitic stub whose edge have been cut, with two slots near the feedline has been proposed. The antenna is designed using HFSS software. The designed antenna shows wideband characteristics having simulated bandwidth of 96 %.The overall dimension of the antenna are 35 35 1.6 mm 3.This antenna obtained maximum gain of 9.55dB having VSWR is less than 2. Keywords- Microstrip patch antenna, Parasitic stubs, Slot antenna, wideband I. INTRODUCTION The idea of microstrip patch antenna was introduced in 1950 s but it become popular and used in various applications in 1970 s. Microstrip patch antenna are used in various applications where small size, less weight, low cost, high performance and easily fabricated and installed antennas are required such as in military, RADARS and mobile wireless communications.. A microstrip antenna consists of a rectangular patch on a ground plane separated by dielectric substrate [1]. The patch in the antenna is made of a conducting material Cu (Copper) or Au (Gold) and this can be in any shape of rectangular, circular, triangular, elliptical or some other common shape. In basic form, a Microstrip Patch antenna as shown in fig 1 consists of a radiating patch on one side of a dielectric substrate which has a ground plane on the other side. Fig 1. Microstrip Patch Antenna [1] The radiating patch and the feed lines are usually photo etched on the dielectric substrate. Microstrip patch antenna are resonant type of antenna because they resonate at particular frequency hence the bandwidth is small in these antenna. Another disadvantage is low power handling capability and spurious feed radiation [3].The bandwidth of the antenna can be increased by increasing the height of the patch and decreasing the substrate permittivity. Another method to increase the bandwidth is by exciting the antenna by aperturecoupled technique but it is more complex due to the complex feed element design. Because of the fast growing demand in wireless communication, mobile communication, radar applications and any other application coplanar waveguide fed antennas have invited much interest due to light weight, low profile, small size, and ease of fabrication [12]. A microstrip patch antenna is used to process ultra high frequency signals. Microstrip patch antenna is a wideband, narrow beam, occupy less space antenna placed over an insulating material such as FR4, glass, ceramic etc whose dielectric constant lies between 2.2 εr 12 The microstrip antenna mainly consist of Ground, Substrate, patch and feed line. The base of the antenna is known as ground plane. Just above the ground with the same dimension a substrate is placed. In this paper the effect of change of height of substrate has been shown for h=1.57, 1.59, 1.6, 2mm. Partial ground plane is used to decrease the back reflections and to increase the bandwidth two parasitic stubs are added on the two sides of patch and the top corner of the patch as well as the stubs are cut in order to increase the bandwidth. Two slots are also added at the end of the patch to decrease the return loss thus the return loss up to -57 dbi is obtained when the height of the substrate is h=2mm. The VSWR for each case is less than 2. II. ANTENNA DESIGN AND IMPLEMENTATION Wideband microstrip patch antenna has been designed by taking a rectangular patch of 20 12mm 2.Upper corner of the patch as well as the stub corner have ISSN: 2231-5381 http://www.ijettjournal.org Page 368
been cut. Now a T shape slot is applied on the patch as shown in the fig.5 and the effect of change of height of substrate has been studied. All the simulation have been simulated in HFSS software.the designed parameters with corresponding values are shown in the table. found that the height of the substrate is increases their return loss also increases. Subject Dimensions Ground Size 35 9.4mm Patch Size 20 12mm Substrate Used FR4_Epoxy Thickness 1.6mm Stub size 2.6 6mm Slit size 4.6mm Table 1. Design parameter and corresponding values Fig.3 Input reflection coefficient of simple rectangular patch antenna to show the effect of change of height of substrate. Fig. 4 Input reflection coefficient result of edge tapered, stub using on simple patch with h=2,1.6,1.59,1.57mm. (a) Simple patch antenna The antenna has been shown in Fig. 2 shows that the parasitic stub of 2.5 6mm has been united with the patch and the upper corner of the patch has been cut this will reduce the size of the patch as well as to increase the bandwidth. For simple patch effects of height of substrate h=1.57, 1.59,1.6,2 mm has been shown below it has been (b) Edge tapered rectangular patch antenna Fig 2: 2-D view of simple and edge tapered antenna Fig 5. Proposed microstrip patch antenna ISSN: 2231-5381 http://www.ijettjournal.org Page 369
Fig. 6 Input reflection coefficient result of edge tapered, stub using on simple patch with h=2, 1.6, 1.59, 1.57mm. (a) h= 1.57 Gain is defined as the four pi times the ratio of an antenna s radiation intensity in a given direction to the total power accepted by the antenna. The following equation is used to calculate gain in HFSS: Where U is the radiation intensity in watts per steradian in the direction specified. P acc is the accepted power in watts entering in antenna. (b) h= 1.59 (c) h=1.6 Fig. 7 Gain total of proposed antenna for different substrate height of h=1.57,h=1.59,h=1.6,h=2mm ISSN: 2231-5381 http://www.ijettjournal.org Page 370
Fig. 8 shows the radiation pattern that is the value of phi at 0 and 90 degree that is co and cross polarisation has been differ by -40 db when h=1.57mm. IV. CONCLUSION In this paper, an antenna with edge tapered, slots and parasitic stubs has been designed.the corner edge of the stubs and as well as the patch has been cut in order to reduce stray electric fields. The total size of the antenna is 35 35 1.6mm 3.The designed antenna shows an impedance bandwidth of 96% for height h=1.57mm with a maximum peak gain of 9.55dB and maximum radiation efficiency of 99.3% such antenna used in wideband applications. (d) h= 2 Fig. 8 Radiation pattern of proposed antenna for different height of substrate III. RESULTS AND DISCUSSION From the fig. 3 it has been concluded that for height h=2, bandwidth get decreased and the average percentage bandwidth obtained is 33%. Better radiation pattern is obtained for h=2 it is -40 db at frequency 3.37 GHz. As it will be concluded that as the height of substrate increases radiation pattern become better. For h=1.57 maximum value of phi that is the difference between co and cross-polarisation is - 18dB at frequency 5.84. For h=1.59, 1.6 mm maximum value of phi is -26dB. The return loss with variable height of substrate has been shown in fig. 4. It is clear from the figure that for height h=2 better return loss upto-30db has been obtained. As we decrease the height of substrate their return loss also gets reduced but their bandwidth gets increase. The return loss of proposed antenna with slot on patch are shown in the fig. 5. It is clear from the above figure that the return loss at height h=2mm are much better than other results maximum return loss obtained is -57.64dB at 7.37GHz as shown in figure 4. Fig.7 shows the gain of proposed antenna with different substrate height h=1.57,1.59,1.6,2mm. The results of maximum gain obtained by changing the height are shown in fig. 7. The maximum gain obtained is 9.55dB for height h=1.6mm REFRENCES [1] Parvathy P. Chandran, Mr. Sanoj Viswasom, Gain and Bandwidth optimization of Microstrip Patch antenna, 2014 Fourth International Conference on Advances in Computing and Comunications [2] R.K. sharan,s.k. Sharma,A.Gupta,R.K Chaoudhary An Edge Tapered Rectangular Patch Antenna with Parasitic Stubs and Slot for Wideband Applications Wireless Pers Commun Vol 86,2016, pp 1213 1220 [3] K.Sankar,R.Bargavi, and S.Arivumani Samson Single Layer Dual band G-shaped patch antenna International Conference on Communication and Signal Processing, 2014, pp-636-639. [4] R. Ghatak, S. Chatterjee and D.R. Poddar Wideband fractal shaped slot antenna for X-band application Electronics Letters Vol. 48, 2012. [5] A. Yadav, B.Chauhan, A. Jain Microstrip Symmetrical E-Shape Patch Antenna for the Wireless Communication Systems International Journal of Emerging Technology and Advanced Engineering Volume 2, Issue 12, 2012,pp 241-244. [6] Balanis, C. A. (2005). Antenna theory: Analysis and design. Hoboken: Wiley. [7] Amit A. Deshmukh1 and K. P. Rav Multi-Band Configurations of Stub-LoadedSlotted Rectangular Microstrip Antennas IEEE Antennas and Propagation Magazine, Vol. 52, No.1, February 2010 pp 89-103. [8] S. E Jasim, M. A. Jusoh, M. H. Mazwir and S. N. S. Mahmud FINDING THE BEST FEEDING POINT LOCATION OF PATCH ANTENNA USING HFSS ARPN Journal of Engineering and Applied Sciences VOL. 10, NO. 23, DECEMBER 2015 pp17444-17449. [9] R. Zaker, C. Ghobadi, and J. Nourinia Novel Modified UWB Planar Monopole Antenna With Variable Frequency Band-Notch Function IEEE Antennas And Wireless Propagation Letters, Vol. 7, 2008,Pp-112-114. [10] S Behera and K. J. Vinoy Multi-Port Network Approach for the Analysis of Dual Band Fractal Microstrip Antennas IEEE Transactions On Antennas And Propagation, Vol. 60, 2012 Pp-5100-5106 [11] Yikai Chen, Shiwen Yang, and Zaiping Nie Bandwidth Enhancement Method for Low Profile E-Shaped Microstrip Patch Antennas IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 58, NO. 7, JULY 2010 pp2442-2447 [12] ARUN GEORGE R. NAKKEERAN Conductor Backed CPW Fed Antenna for 2.4 GHz WLAN Applications ISSN: 2231-5381 http://www.ijettjournal.org Page 371
International Conference on Green Computing, Communication and Conservation of Energy (ICGCE)2013, pp112-115 [13] S.Chidambara Krishnan, S.A.Arunmozhi Design of CPW Fed Monopole Microstrip Patch Antenna for Wi-Fi Application International Conference on Communication and Signal Processing, April 3-5, 2014, India pp1942-1946. ISSN: 2231-5381 http://www.ijettjournal.org Page 372