Design of a Compact Ring Slotted Line Feed Microstrip Patch Antenna

Transcription

1 Design of a Compact Ring Slotted Line Feed Microstrip Patch Antenna Mayank Dwivedi 1, Ms.Pallavi Nayyer 2 1 M.Tech student, IITT College of engineering, Nawanshar (Punjab), India 2 Asstt. professor, IITT College of engineering, Nawanshar (Punjab), India ABSTRACT In this paper of Rectangular Microstrip line feed patch Antenna is designed for various wireless Applications. The Antenna is fed by coaxial probe feeding technique. The proposed patch antenna is Designed and Simulated on IE3D simulation software. Using the configuration of ring slotted microstrip line feed patch Antenna, The Return Loss Bandwidth achieved is 55.68% at operating frequency range of to GHz with a Return loss db at resonant frequency GHz. The Antenna parameters such as VSWR, Smith chart, Antenna and Radiation Efficiencies, 3 D Radiation pattern has been analyzed by IE3D simulation based on mom. Keywords: Broadband Antenna, Line feed, Radiation pattern, Radiation efficiency, VSWR & IE3D. 1. INTRODUCTION Generally a Conventional microstrip antenna has a radiating patch of any planar geometry (e.g. square, rectangular, Circular, Ellipse and ring) on one side of a dielectric material substrate printed on a grounded microwave substrate, and have the attractive features of low profile, light weight, low volume, ease of fabrication, and low profile planar configuration which can be easily made conformal to host surface [1-2]. However Microstrip Antenna has a drawback of narrow bandwidth and low gain. The Bandwidth can be increased byvarious technique like cutting slots, stacking, microstrip line and inset feeding, ground slotting and recently by shortpinning between conducting patch and ground plane. Now a days Compact microstrip antenna are getting much more attention due to the increase in demands ofsmall size antennas used in personal and commercial purposes communicational accessories. In order todesign a compact microstrip antenna at a fixed operating frequency higher dielectric constant of substratemust be used [3]. The achievement of high gain of an antenna is the most desirable aspect. To enhance the gain of an antenna one may arrange the different patch element in an array configuration and receives the maximum radiation characteristics. In this design of Ring slotted line feed Microstrip antenna a conducting patch is formed on a dielectric sheet of glass epoxy having dielectric constant of 4.2 and ground plane is formed on the back side of the sheet. In this Antenna design the Return loss bandwidth achieved 55.68% and maximum radiation and Antenna efficiencies are obtained 97% and 94% at 1.36 GHz and 1.54 GHz. 2. DESIGN OF RECTANGULAR PATCH To design a rectangularmicrostrip patch antenna following parameters such as dielectric constant of substrate ( r), the resonant frequency (f r ) and height of the substrate (h) should be considered for calculating the length and the width of the rectangular microstrip patch. 1: Width (W) Calculation: The width of the mictrostrip patch antenna can be calculated by the given equation as follows; 2: Calculation of effective dielectric constant (Ereff); The following equation gives the effective dielectric constant is given by 3: Calculation of length extension (Δl) ; The following equation gives the length extension in terms of (W/h) ratio and effective dielectric constant. Volume 1, Issue 4, December 2012 Page 57

2 4: Calculation of actual length of patch (L); The following equation gives thelengthof patch as, 5: calculation of the length and width of ground plane: Ideally the ground plane is assumed of infinite size in length and width but it is practically impossible to make a such infinite size ground plane, so to calculate the length and width of a ground plane following equations are given as, 6: Determination of feed point location (X f,y f ): The center of the patch is taken as the origin and feed point location is given by the coordinates (X f,y f ) from the origin. The feed point must be located at that point on the patch, where the input impedance is 50 ohms for the resonant frequency. Hence a trial and error method is used to locate the feed point. The resonant frequency is taken at the return loss which is the most negative point of S 11 parameter. Table 1: Proposed antenna design parameters Parameters Design frequency Height of substrate Ground length(l g ) Ground width (W g ) L W L 1 W 1 L 2 W 2 Values 3 GHz 1.6 mm 40 mm 60 mm 13 mm 31 mm 10.8 mm 4 mm 2 mm 2 mm Figure 1Geometry of proposed antenna Volume 1, Issue 4, December 2012 Page 58

3 3. IE3D RESULTS AND DISCUSSION Various graphs result from the analysis of the patch by giving the feed point location x = mm and y = 24.1 mm are shown in figures. Fig 2 shows the graph of return loss verses frequency. The total bandwidth is calculated 55.68% at operating range to GHz. Fig 3 shows the antenna and radiation efficiency. The maximum radiation efficiency is occurred 97% at 1.36 GHz and maximum antenna efficiency is obtained 94% at 1.54 GHz. Fig 4 shows the Smith chart verses frequency plot shows the input impedance which should be ideally 50Ω used for impedance matching. Fig 5 shows the graph of VSWR. The minimum value of VSWR is about 1.18 at GHz. The value of VSWR should be less than 2 for desirable communication. Fig 6 & 7 shows the 3D radiation pattern and 3D view of proposed antenna. Figure 2 Return loss graph of proposed antenna Figure 3 Radiation and antenna efficiency graphs of proposed antenna. Volume 1, Issue 4, December 2012 Page 59

4 Figure 4 Smith chart of proposed antenna Figure 5 VSWR plot of proposed antenna Figure 6 3D Radiation pattern of proposed antenna Figure 7 3D view of proposed antenna 4. CONCLUSIONS In this design of compact ring slotted broadband line feed microstrip patch antenna has been designedforhigh-speed wireless communication systems compatible in the range of b for wireless applications. The return loss bandwidth is measured 55.68%below 10 db covering a range of to GHz frequency band. The maximum radiation and antenna efficiencies are obtained 97% and 94%. The antenna is thin andcompact with the use of low dielectric constant substrate material. The proposed geometry is designed using glass epoxy as a dielectric between the ground plane and patch. These features are very useful for portability of wireless communication equipment s used worldwide. Volume 1, Issue 4, December 2012 Page 60

5 REFERENCES [1]K. L. Wong, Design of Nonplanar Microstrip Antennas and Transmission Lines, Wiley,New York, [2] A. Balanis, Antenna Theory analysis and design, Microstrip Antenna, Chapter 14, pp [3] Zakir Ali, Vinod Kumar Singh, Ashutosh Kumar, AyubShahanaz, E shaped Microstrip Antenna on RogersSubstrate for WLAN applications Proc. IEEE, pp ,oct [4]A. M. Hadian, H.R. Hassani, Wideband RectangularMicrostrip Patch Antenna with U-Slot, IEEE, Electronics letters,vol. 33, No. 25, April [5] Amit A. Deshmukh and K. P. Ray, Compact Broadband Slotted Rectangular Microstrip Antenna, IEEE antennas and wireless propagation letters, vol. 8, No. 3, March 2009, PP [6] B.K. Ang& B.K. Chung A wideband E shapedmicrostrip patch antenna for 5-6 GHz Wireless communications PIER,75, pp , [7] Shivnarayan and Babau R. Vishvakarma, Microstrip Patch Antenna with Inclined Slot for Dual-Band Operation, Electronic letters, Vol. 33, No. 22, February 2006, PP [8] C.Y. Chiu, C.H. Chan and K.M. Luke, Study of slotted microstrip patch antennas with folded patch fee, Microwave Antennas propagation., vol. 152, No. 5, October [9] C.Y. Chiu, C.H. Chan and K.M. Luke, Study of slotted microstrip patch antennas with folded patch feed, Microwave Antennas propagation., vol. 152, No. 5, october [10]Z. L. Dafalla, W. T. Y. Kuan, A. M. Abdel Rahman, and S. C.Shudakar, Design of a Rectangular Microstrip Patch Antenna at 1 GHz, Rf And Microwave Conference, October ,Subang, Selangor, Malaysia. [11] Gh. Z. Rafi and L. Shafai, V-slotted rectangular microstrip antenna witha stacked patch,ieeeproc-microw. AntennasPropag. Vol. 146, No.1.January 2001, PP [12] Mohammad A.A.,Subhi H., Ahmad A. K. and Juma S.M, Bandwidthenhancement of stacked rectangular microstrip patch antenna,ieee Trans.Antennas Propagation, vol. 49, No. 1, 2001 pp [13] Aaron Shackelford46, Kai-Fong Lee, Deb Chatterjee, On Reducing the Patch Size of U-Slot and L-Probe Wideband Patch Antennas, IEEE Electronics Letters, Vol. 34, 1998, pp Volume 1, Issue 4, December 2012 Page 61