IJEEE, Vol. 1, Issue 3 (June, 2014)
e-ISSN: 1694-2310 | p-ISSN: 1694-2426
REVIEW OF FRACTAL TECHNIQUES FOR DESIGNING MICROSTRIP PATCH ANTENNA FOR X BAND 1
Amanpreet Kaur, 2Dr. Hardeep Singh Saini
1
Dept.of ECE, Indo Global College of Engineering, Mohali, Punjab, India Associate Dean Academic, Indo Global College of Engineering, Mohali, Punjab, India
2
1
amanpreet_90@ymail.com
ABSTRACT: With advancement in communication technology over the past decade, there is an increasing demand for miniaturization, cost effective, multiband and wideband antennas. Fractal antenna designs can support in meeting these requirements. Various techniques and geometries have been introduced for size reduction of microstrip patch antennas. This paper on fractal techniques for designing microstrip antenna exhibits details of fractal geometries developed to get multiband behavior of patch resonator antenna. In this paper the review on various techniques of compactness by fractal geometry on microstrip patch antenna for X band used for satellite communication and radar application are presented.
2
hardeep_saini17@yahoo.co.in
Koch curves and few generalizations of some of these are explored. II. FRACTAL GEOMETRY There are many fractal geometry that have been found to developing new design for antennas [1]. Fig. 1 shows some of these unique geometries. Most of these geometries are infinitely sub-divisible, with each division a copy of the parent. This special nature of these geometries has led to several interesting features uncommon With Euclidean geometry.
Key words: Fractals, Antenna design techniques, Fractal Microstrip Patch Antenna, X band. I. INTRODUCTION In modern wireless communication system and increasing other wireless applications, wider bandwidth, is required, traditionally each antenna operates at a single frequency band, where a different antenna is needed for different application. Therefore large space is required for different antennas. In order to overcome this problem, multiband antenna can be used where a single antenna can operate at many frequency bands. So multiband behavior can be achieved by fractalizing the antenna. Fractal concepts have been increasingly applied to the design of various antennas in recent years because of their Self-similar characteristic and space-filling capability. Fractals were first defined by Benoit Mandelbort in 1975[1], [2]. There are various fractal geometries which have been investigated. These geometries have been used to characterize unique occurrences in pattern of nature that were difficult to define with Euclidean geometries like length of coastlines, the clouds density, and the tree’s branches. Many techniques have been reported to reduce the size of various antennas and to improve the frequency bandwidth [3]. And fractal geometries also provide the ability of multi-band properties [4]. It describes the class of complex geometries that are created through successive iteration of applying a geometric generator to a simple self similar basis. In this study, fractal geometries such as Sierpinski gasket, Hilbert curves, www.ijeee-apm.com
Fig. 1: Various Types of Fractals Used As Antenna
III. REVIEW A large number of Fractal Antenna design approaches have been proposed for wireless applications. The overgrowing body of the literature suggests the design of patch antenna using fractal techniques for X band. The purpose of the survey is donated to a remarkable growth of antenna design techniques in wireless communications A. OCTAGON SHAPED MICROSTRIP FRACTAL ANTENNA The presented antenna is design with new fractal geometry which is circle in octagon shaped [6]. This microstrip patch antenna has been designed for the X band applications. The antenna is capable of covering the 8GHz- 12GHz frequency band. It is observed that the third iteration of the fractal antenna exhibits good wideband characteristics, which can be used in wireless International Journal of Electrical & Electronics Engineering 13
application such as, terrestrial broadband, armature radio and satellite communication. The dimensions of the ground plane are 60x60 mm. The antenna is placed on fr4 substrate with Ԑr = 4.4 and thickness 0.25mm. CPW feed of length 11.2mm and width 2mm is given to the patch [5]. Antenna is designed using High Frequency Structured Simulator (HFSS) software. The patch is a perfect – E conductor. The third iteration is found to have improved antenna parameters compared to the first and second. It is observed that the return loss characteristics reduce as the number of iteration increase. In 8GHz – 12GHz, a wide bandwidth of 3.2112GHz is obtained in the range of 8.53GHz – 11.7470GHz for the third iteration. It is observed that wideband characteristics have improved, as number of iteration increase, due to the current along its edges. The geometry of antenna is described in fig. 2.
iteration one sierpinski gasket geometry has length and width of 4mm and 6mm respectively is cut from the geometry. In the second iteration two sierpinski gasket geometry is cut from the geometry as shown in figure 5. The shape of the second iteration is 1/2 of the first iteration. It is observed that as the fractal iteration increases, the antenna is now resonant at more frequencies. In this design two bands are occurs at 8.5 GHz and 9.5 GHz. In the second iteration, we got the minimum resonant frequency with return loss -21.19 dB at 8.5 GHz, whose bandwidth is 8.82 %. This antenna providing a gain of 5.77dB at 8.5 Ghz. The bandwidth effect changes with the change in resonant frequencies and VSWR is within the accepted level. The geometry of antenna is described in fig. 3.
Fig. 3: Fan shape fractal antenna Fig. 2: Octagon Shaped Fractal Microstrip Antenna
B. FAN SHAPE FRACTAL ANTENNA A novel fan shaped fractal antenna based on sierpinski gasket fractal geometry. The design and simulation of Fan shape fractal antenna has done using IE3D electromagnetic simulation software[7]. This fan shape fractal antenna gives better performance in return loss, efficiency and directivity. This fractal antenna can be used for X band applications and also used in Wi-Fi. This antenna was designed using FR4 EPOXY substrate with height is h = 2.5 and Ԑr = 4.4. This behavior is obtained using coaxial probe fed method. In all iteration feeding point is same and radius of feeding point is 0.25mm. In this work, a fan base is taken and another shape of sierpinski gasket is cut from it. Same procedure is repeated and the result of simulation studies is presented up to second iteration. In the base shape a fan shape of radius 13mm is taken. For the first International Journal of Electrical & Electronics Engineering 14
A. COPLANER RECTANGULAR PATCH ANTENNA An inset fed Coplanar Patch Antenna [8] designed for X band satellite communication. This antenna provides high radiation efficiency and wider bandwidth therefore it could be applicable in many X band satellite systems. It provides 98% radiation efficiency. A coplanar patch antenna has ground and patch on the same side of the substrate. Antenna is designed using High Frequency Structured Simulator (HFSS v13) software. The coplanar patch antenna structure design has following specification [8] length and width is calculated as L=4.3mm, W=10.5mm. The coplanar patch antenna is placed on Rogers/RT duroid 5880 substrate. Substrate height h=0.508mm, permittivity of the substrate εr = 2.2, dielectric loss tangent = 0.0009 and operating frequency is 10 GHz. The strip gap (s) is taken as 0.2mm and width (W) of the coplanar waveguide feed is 1.252mm. Coplanar patch antenna model has a resonance frequency at 10.0557GHz and has a return www.ijeee-apm.com
loss of -32.2009dB. Coplanar patch antenna has an impedance bandwidth of 17.75% (i.e. 1.785GHz) and coplanar patch antenna has 2.79dB directivity value. Due to its high radiation efficiency and wide bandwidth it can be applicable in satellite transponders and in military RADAR and satellite communication systems. The geometry of antenna is described in fig. 4.
Fig.4: Model of Coplanar Patch Antenna in HFSS software
IV. CONCLUSION This review work provided an insight in determining the performance of microstrip patch antenna using various fractal techniques. From this we conclude that
there are many Fractal techniques that used to design a microstrip patch antenna for X band application such as satellite communication, armature radio and radar application. This paper also exposed a Literature Review Table of different techniques. REFRENCES [1] Benoit B. Mandelbrot, The Fractal Nature of Geometry, New York, W. H. Freeman and company, 1977. [2] Ved Vyas Dwivedi, Ph. D. Thesis, ‘ Design and Development of Dual/Tri band miniaturized and compact antenna using metamaterial’,2010. [3] P.E. Mayes, Frequency-independent antenna and broadband derivatives thereof, Proc IEEE 80, 1992, 1103–1123. [4] Lars Josefsson and Patrik Persson. "Conformal Array Antenna Theory and Design," The IEEE Press Series on Electromagnetic Wave Theory. 2006. [5] An Overview of Fractal Antenna Engineering Research by Douglas H. Werner and Suman Gangul, IEEE Antennas and Propagation Magazine, Vol. 45, NO. I, February 2003. [6] B. Hephzibah Lincy A. Srinivasan B.Rajalakshmi, “X – Band Fractal Microstrip Antenna for Wireless Application”, International Journal of Computer Applications (0975 – 8887) Volume 68– No.3, April 2013 [7] Yogesh Bhomia , Devesh Kumar Singh Rathore, “Design and Simulation of Fan Shape Fractal Antenna for X-Band Application”, International Journal of Electronics and Computer Science Engineering. [8] Arvind Singh Jadon, Jalaj Sharma, Ajay Prajapat, Avanish Bhadauria, “Coplanar Rectangular Patch Antenna for X Band Applications Using Inset Fed Technique”, International Conference on Communication Systems (ICCS-2013) Special Issue (November 2013), pp.95-10.
Table 1: Literature Review Table
S.N o. 1. 2.
3.
Antenna Design
Frequency Band
Return loss
Gain
APPLICATION FOR X band
Octagon Shaped Fractal Microstrip Antenna Fan Shape Fractal Antenna
8.53GHz 11.7470GHz 8.5 GHz and 9.5 GHz
-24 dB
7dB 5.77d B
Coplanar Rectangular Patch Antenna
10.0557GHz
-26.79 dB at 9.5 GHz -21.19 dB at 8.5 GHz -32.2009dB
Terrestrial broadband, armature radio and satellite communication. Wi-Fi
www.ijeee-apm.com
2.79d B
satellite transponders and in military RADAR and satellite communication systems
International Journal of Electrical & Electronics Engineering 15