DESIGN AND SIMULATION OF A 4X1 MICRO STRIP PATCH ARRAY FOR SYNTHETIC VISION RADAR APPLICATION J.Jayapriya 1 and Dr. B.Elizabeth Caroline,Ph.D.,. 2 1 Student, Dept of ECE, IFET College of Engineering, Villupuram 2 Associate Professor, Dept of ECE, IFET College of Engineering, Villupuram Jayapriya2244.pj@gmail.com, Becaroline05@yahoo.com ABSTRACT: Synthetic Vision Radars are under progress which will provide computer-generated visual scenes during flying and landing of aircraft. This Radar operates at 33.7 35.2 and 92 100 GHz. It helps the pilot to see the surrounding situation even at the low visibility condition. This paper is designed and simulated by using patch array with the inset feeding technique. The proposed antenna is designed using RT/ Duroid5880 substrate with permittivity of 2.2. The inverted U slot is used in each patch of the 4x1patch array. The design is analysed to increase gain, directivity and better radiation pattern. The measured frequencies of single band 4x1 linear patch array are observed at 34GHz for a novel system. The HFSS software is used for designing the patch array antenna and the result is analysed. I. INTRODUCTION: The basic equipment in the wireless communication is antenna [1, 2]. An antenna transmits and receives electromagnetic waves. Most antennas are resonant devices, which operate efficiently over a narrow frequency band. By the early 1980s, basic micro strip antenna elements and arrays were well established in term of design and modeling. There are certain properties for the wideband air launched micro strip patch array antenna used in high speed 3-dimensional synthetic Vision Radar [6]. We altered the 2 1 linear array to 4 1 linear patch array and analyzed increased gain, directivity and better radiation patterns and consists of four rectangular patches in a linear array configuration. The purpose of this work is to develop a high gain and high directivity antenna that is working on 34GHz frequency that is deployable in aircrafts. Inverted U slot in the patch of each element is made to enhance the characteristics of the antenna. II. 4x1 PATCH ANTENNA DESIGN: Antenna elements consist of a rectangular patch, substrates, a slotted ground plate, and a feeding circuit [3]. The 2x1 microstrip antenna is first formed by arranging the two patch at the distance of 0.1 λo. By combining two 2x1 patch array, the 4x1 is formed. 1
All the patch in the array should have same dimensions. The proposed antenna has been designed at the operating frequency(f) = 34 GHz, using dielectric substrate RT/duroid5880 of relative permittivity εr =2.2 and thickness h=0.25mm. The micros trip patch elements are arranged with equal spacing of 1.0λo. The proposed antenna is inset fed at b2 (X=9.70, Y=0mm). Depending on the variation of frequency, the dimensions will also varies. The same values of height, length, width and inverted U slot is used in 4x1 patch array as well as in 2x1 patch array with the dielectric substrate (h) and the same dielectric material at the design frequency [2]. So we used same dimensions of single patch antenna are, At first we design the simple rectangular patch antenna with U slot and inset feed technique. A 2x1 patch array antenna with RT/duroid5880 substrate has been designed and simulated at 28.5 GHz frequency as shown in fig 1. The 50 Ω quarter wave length transmission line is used generally feed point is taken Z1 = Z2= 50Ω resistance. An inverted U slot is also designed in the patch of each element to enhance the characteristics of the antenna. Now this 2x1 patch array is implemented in 4 1 patch array antenna at the frequency 34GHz as shown in fig 2. It is stimulated using HFSS microwave studio software. The design of 4x1 microstrip patch array antenna using HFSS software is given in the figure.2 Actual width(w)= 6.5mm Actual length(l)= 3.89mm Effective Dielectric Constant(εeff)=2.2 L1 =10.16mm L2 = 3.62mm b1=1.63mm b2=9.60mm Fig.1 2x1 micro strip patch array at 28.5GHz Fig.2 4x1micro strip patch array at 34GHz III. ANALYSIS AND RESULT: The 4 1 patch array antenna is stimulated using on HFSS microwave software. By 2
simulation, we get the results of single band at frequency f=34ghz. We get return loss, increased gain, directivity and better radiation patterns. It is consists of four rectangular patch array. The radiation gain of the single and four element array is shown Fig.4, and Fig.5 respectively. A. Return loss: Fig. 4 Gain of the Single patch The return loss of the 2x1 patch array at 5.5GHz is high when compared to the return loss of 4x1 micro strip patch array. The return loss of proposed antenna is -40.02dB. The return loss is very less when compared to the existing antenna. It is given in the following fig.3 Fig. 5 Gain of 4x1 microstrip patch array C. Radiation pattern: Fig.3 return loss for 4x1 patch array B. Gain: The gain of the 2 1 array patch model 3D gain is obtained as 6.30dB and for 4 1 patch array antenna the gain is obtained as 7.6305 db. The 3dimensional radiation pattern of single patch is given in fig.4 and four elements is shown fig.5. The radiation pattern shows radiated power variation as the function of direction away from the antenna. This power variation is observed in the far field as the function of theta and phi. The 2dimensional radiation pattern of four elements is shown fig.6 and fig.7 plotted in decibels (db) H-field and E-field respectively. - As the function of Theta: 3
VI. Conclusion: Fig. 6 Radiation pattern as function of Theta - As the function of Phi: In this paper, a rectangular micro strip patch antenna with inverted U slot for single band applications is simulated for ka-band applications using Inset feeding technique. The gain of the simulated array was found to be 7.6305dB. The proposed antenna array shows better gain performance and radiation characteristics at 34GHz frequency. This 4x1 patch antenna array is efficient, light weight and low cost. Hence it has wide range of application in the field of radars and other satellite application. VII. REFERENCE: 1. RH Holden, JA Preiss, G Ledonne Microstrip patch antenna - Wiley/IEEE Press, 1995 Fig. 7 Radiation Pattern as function of Phi Table I: Comparison of 2x1 patch array and 4x1 patch array PARAMETERS 2X1PATCH ARRAY 4X1 PATCH ARRAY Gain 6.9672dB 7.6305dB Directivity 8.3687dB 9.1397dB Return loss -31.7140dB -40.02dB Bandwidth 337MHz 359MHz 2. Deschamps, G.A., \Microstrip microwave antennas," Proceedings of Third USAF Symposium on Antennas, 2001. 3. ZI Dafalla, WTY Kuan, AMA Rahman Design of Microstrip Patch array at 1GHz frequency - Journal of Microwave and Optoelectronics, Vol., N. O 3,December 2004. 4
4. James, J. R. and P. S. Hall, Handbook of Microstrip Antennas, Peter Peregronic Ltd., London,1989. 5. MT Islam, MN Shakib, N Misran- Multi slotted microstrip patch antenna for Wireless Communication - IEEE Trans. Antennas Propag., vol. 48, no. 8, pp. 1149 1152, Aug. 2009. 6. C.A. Balanis, "Antenna Theory Analysis and Design", 3rd edition, 2005. 7. C. Woode, Improved bandwidth of microstrip antennas, Proc. Inst. Elect. Eng., vol. 127, no. 3, pt. H, pp. 231 234, Jun. 2010. 8. Huque, T. I., Hossain, K., Islam, S., & Chowdhury- Design and Performance Analysis of Microstrip Array Antennas With Optimum Parameters For high frequency Applications International Journal of Advanced Computer Science and Applications, 2(4), 81-87, 2011. 9. JV Gohil, D Bhatia - Engineering (NUiCONE), 2012 Nirma - Design of 2x1 circularly polarized patch microstrip patch antenna array at 5.8GHz frequency ISM Band Application - IEEE proceedings of International Conference on Computational Intelligence and Computing Research 2014 5