Microstrip Patch Antenna using Fractal Geometry for Wireless Applications

Microstrip Patch Antenna using Fractal Geometry for Wireless Applications

Shiyaniya Mayuri N. Haripara Shilpa M. Parmar Divya P. Electronics and communication dept. Electronics and communication dept. Electronics and communication dept. C.U.Shah college of engg. and tech. C.U.Shah college of engg. and tech. C.U.Shah college of engg. and tech. Wadhwan, Surendranagar, Gujarat. Wadhwan, Surendranagar, Gujarat. Wadhwan, Surendranagar, Gujarat.

Abstract- In this paper we compare fractal antenna with simple microstrip antenna having same dimension. We can note that using fractal antenna we can obtain multi frequency. Using fractal antenna the weight of the antenna is decreasing because of fractal but it is somewhat difficult to design. The result shows that return loss and VSWR are increased with increase in fractal iteration, but the gain decreases.

KeywordsFractal, Antenna, Microstrip.

1. INTRODUCTION

   Micro strip is the second generation antennas. It is a metallic patch, printed on thin grounded dielectric substrate using a process similar to lithography in which patterns are printed on the substrate while fabricating printed circuit boards or integrated circuit. The main advantages are its low weight and low cost. Narrow bandwidth and low efficiency are its main disadvantages.

   describing partly random chaotic phenomena such as a crystal growth and galaxy formation.

   B. Geometry of antenna

   Parameters Values

   Resonant frequency fr 2.4 GHz Height of dielectric substrate h 1.59mm Dielectric constant r 4.4(FR4)

   Length of substrate Ls 47 mm

   Width of substrate Ws 56.45mm

   Length of patch Lp 28mm

   Width of patch Wp 38mm

   Thickness of ground Ts 0.05mm

   Fig-1 simple microstrip antenna

2. FRACTAL ANTENNA

A. Introduction of a fractal

Fractal antennas are still in their early stages of development.

1. Simulation

   Fig-2 Fractal antenna

   In 1988, the first fractal antenna later on patent and published was built by Dr Nathan Cohen. As we know antenna size and operating wavelength are related such that, when the size of an antenna is made much smaller than the operating wavelength or less than one fourth of the operating wavelength (/4), it becomes highly inefficient.

   A curve or geometrical figure, each part of whish has the same statistical character as a whole. They are used in which similar pattern recur at a progressively smaller scale, and in

   HFSS is a commercial finite element method solver for electromagnetic structures from Ansys. The acronym originally stood for High Frequency Structural Simulator. It is one of several commercial tools used for antenna design, and the design of complex RF electronic circuit elements including filters, transmission lines, and packaging. It was originally developed by Professor Zoltan Cendes and his students at Carnegie Mellon University. Prof. Cendes and his brother Nicholas Cendes founded Ansoft and sold HFSS

   stand-alone under a 1989 marketing relationship with Hewlett-Packard, and bundled into Ansoft products. After

   various business relationships over the period 1996-2006, H- P (which became Agilent EEsof EDA division) and Ansoft

   L=Leff-2

   • And Leff is given as:

     L = 1

     went their separate ways: Agilent with the critically acclaimed FEM Element and Ansoft with their HFSS products, respectively. Ansoft was later acquired by Ansys.

   • So, length L is given as:

     eff

     2 µ0 0

2. Microstrip line feed

   As illustrated in Figure, a microstrip patch can be connected

   = 1

   2 µ0 0

   2

   directly to a microstrip transmission line. At the edge of a patch, impedance is generally much higher than 50 ohms (e.g., 200 ohms). To avoid impedance mismatch, sections of quarter-wavelength long impedance transformers can be used to transform a large input impedance to a 50-ohm line. With this feed approach, an array of patch elements and their microstrip power division lines can all be designed and chemically etched on the same substrate with relatively lower fabrication cost per element. However, the leakage radiation

   • Length is a critical parameter because of the inherent narrow bandwidth of the resonant element, and hence equation should be used to obtain an accurate value of the line length L.

   • Here, 2L is the apparent increase in the slot length due to the current flowing around the end of each slot.

F. Result of microstrip antenna

of the transmission lines, in some cases, may be large enough to raise the sidelobe or cross-polarization levels of the array radiation.

Name X Y

m01.00 2.3980 -17.5463

-2.00

-4.00

XY Plot 1

HFSSDesign1 ANSOFT

Curve Info dB(St(patch_T1,patch_T1))

Setup1 : Sw eep

dB(St(patch_T1,patch_T1))

-6.00

-8.00

1. Equations

   • The practical width of the microstrip patch conductor that will produce an effective resonator is given by

     = 1 2

     -10.00

     -12.00

     -14.00

     -16.00

     -18.00

     m1

     2.00 2.20 2.40 2.60 2.80 3.00

     Freq [GHz]

     Fig-3 S-parameter

     Name 3m01.00 2

     X .4000 1.3

     Y 182

     X

     Y Pl

     ot 2

     HFSS Cu VS

     Desig rve Info WRt(pat

     n1 ANSO ch_T1)

     25.00 20.00 15.00 10.00 5.00

     S

     etup1 : S

     w eep

     FT

     2 µ00 ( + 1)

     VSWRt(patch_T1)

   • However, for widths smaller than those selected according to equation, the radiator efficiency is lower while for larger widths, the efficiency is greater.

   • However, excessive width is not desirable because

     the influence of higher order modes becomes significant which may cause field distortion. The

     m1

     0.00

     2.00 2.20 2.40 2.60 2.80 3.00

     Freq [GHz]

     Fig-4 VSWR

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='0deg'

     rETotal Setup1: LastAdaptive Freq='2.4GHz' Phi='10deg'

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='20deg'

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='30deg'

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='40deg'

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='50deg'

     rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='60deg'

     Curve Info

     ideal width for practical use can be determined from equation, although the value may not correspond to the optimal one.

   • Once W is known, the effective dielectric constant,

     -90

     -60

     -30

     Radiation Pattern 1

     0

     30

     0.80

     0.60

     60

     0.40

     0.20

     90

     HFSSDesign1 ANSOFT

     is calculated using equation

     -120

     120

     +1 ( 1) 1+12h

     = + W

     -150

     -180

     150

     2 2

     Fig-5 Radiation pattern

   • Substitute this value of into equation for the equivalent length of the transmission line extension.

     0.412 + 0.3 + 0.264

     0.258 + 0.8

     =

   • The length, L of the microstrip resonator slot is then given by

Fig-6 Gain

1. Result of Fractal antenna

   Name X Y

   m01.00 2.1380 -20.6122

   m2 5.9360 -40.9506

   m-35.00 6.6470 -28.7793

   m4 7.1380 -16.9521

   XY Plot 1

   HFSSDesign1 ANSOFT

   Curve Info

   dB(St(feedline_T1,feedline_T1)) Setup1 : Sw eep

   ACKNOWLEDGMENT

   First I would like to thank Mr.A.I.Darvadiya sir, Mr. B.H.nagpara sir, Mr. H.H.Mathukiya sir, Mr. Darshit Trivedi, and the entire department of Electronic and Communication

   m5 9.3290 -15.0585

   dB(St(feedline_T1,feedline_T1))

   -10.00

   -15.00

   m1

   -20.00

   -25.00

   -30.00

   -35.00

   -40.00

   -45.00

   m5 Engineering at Shri C.U.Shah College of Engineering and technology, Wadhwan which prepared me for this project.

   m4

   m3

   m2

   I wish to personally thank Dr. K. H. Wandra sir, Prof. D. N. Khandhar for giving me the opportunity to work on this very demanding and very rewarding project and for his devotion to

   1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

   Freq [GHz]

   Fig-7 S-parameter

   this project. I wish to also personally Mr. A.I.Darvadiya sir

   support and great advice and for being there during crunch

   Y 2143

   0181

   X

   .1410

   .9360

   Name

   8m01.00 2

   m2 5

   XY Plot 2

   1.

   1.

   HFSSDesign1 ANSOFT

   Sw ee

   Setup

   2386

   3183

   4278

   Curve Info VSWRt(feedline_T1)

   time.

   6.5790

   7.1530

   9.3300

   m3 1.

   70.00

   m4 1.

   m5 1.

   60.00

   VSWRt(feedline_T1)

   50.00

   40.00

   30.00

   20.00

   10.00

   0.00

   1 : p

   m1 m2 m3 m4 m5

   Our sincerest appreciation must be extended. We also want to thank faculties of the College. They have been very kind and helpful to us. We want to thank all teaching and nonteaching staff to support us. I also thankful my friends who directly or indirectly support me for choosing this project for final year degree engineering. We would like to express our sincere

   1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

   Freq [GHz]

   Fig-8 VSWR

   gratitude to our Guides for their help during the course of the

   -30

   Radiation Pattern 1

   0

   30

   0.14

   HFSSDesign1 ANSOFT

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='0deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='10deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='20deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='30deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='40deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='50deg'

   rETotal Setup1 : LastAdaptive Freq='2.4GHz' Phi='60deg'

   Curve Info

   project right from selection of the project, their constant encouragement, expert academic and practical guidance.

   -90

   -60

   -120

   0.11

   0.07

   0.04

   -150 150

   -180

   60

   90

   120

   CONCLUSION

   Microstrip antenna using Fractal geometry is Multiband antenna by using fractal antenna more than one Frequency can be obtained. So, we can use Fractal antenna for many Applications instead of using different antenna for various

   Fig-9 Radiation Pattern

   Fig -10 Gain

   Sr. No.	Parameters	Sierpinski Carpet Fractal Geometry
   		Simple MSA	Fractal Antenna
   1	Resonant Frequency	2.38	2.14 5.9 6.5 7.1 9.3
   2	Return loss(dB)	-21.58	-20.61 -40.95 -28.77 -16.95 -15.038
   3	VSWR	1.1	1.21 1.01 1.2 1.3 1.4

2. Comparision of fractal antenna with microstrip antenna

applications. Also the weight of fractal antenna is light and size is compact. Using Fractal antenna we can improve VSWR and impedance. Also the return loss is improved due to use of fractal geometry.

REFERENCES

1. A. Azari & J. Rowhani Ultra wideband fractal microstrip antenna design progress in electromagnetic research c, vol. 2.

2. Amandeep Kaur & Yadwinder Kumar Design and Simulation of Sierpinski Pre fractal Antenna Using HFSS vol.1 IJRITCC.

3. Rahul Batra, P. L. Zade & Dipika Sagne Design and Implementation of Sierpinski Carpet Fractal Antenna for Wireless Communication

   Volume 1 IJSRET

4. Neetu, Savina Banasl & R K Bansal Design and Analysis of Fractal Antennas based on Koch and Sierpinski Fractal Geometries vol.2 IJAREEIE.

5. Constantine A. Balanis, Antenna theory, Analysis and design.

6. Antenna and wave propagation, technical publication, third edition, by

U.A. Bakhsi.