Design and Analysis of Fractal Triangle Microstrip Patch Antenna with Strip Line Feed for Dual-Band Frequency

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014)

641

Design and Analysis of Fractal Triangle Microstrip Patch

Antenna with Strip Line Feed for Dual-Band Frequency

Priyanka Agrawal

1

, Sudhir Kumar Sharma

2

1M.Tech Scholar, Jaipur National University, Jaipur, Rajasthan, India

2 Head, Dept. of E & C Engineering, Jaipur National University, Jaipur, Rajasthan, India

Abstract— A decrease in physical size and multiband ability are essential requirements for antenna incoming wireless devices.The antenna based on Sierpinski fractal antenna theory. Design & simulation of fractal triangle microstrip patch antenna done by using IE3D software of Zeland. In this paper, a special technique is proposed to design a new patch antenna, shapes is equilateral triangular fed by a 50-Ω microstrip line. Then the planned antenna was fabricated on FR4 Epoxy/glass substrate with dielectric constant 4.4. Fractal antenna properties were observed from the measurement of bandwidth, beamwidth, standing wave ratio (VSWR < 2), return loss (S11), directivity and also radiation pattern are measured in this project. The antenna exhibit dual frequencies that are work on S band & C band applications.

Keywords— Microstrip antenna, beamwidth, dielectric,

Strip line, IE3D.

I. INTRODUCTION

Modern telecommunication system requires antennas with wider bandwidth and smaller dimensions than conventionally possible [1]. With the advance of wireless communication systems and increasing of its applications, multiband antenna with different shapes and design become a great demand and desirable for many of uses as personal

communication systems, diminutive satellite

communication terminals and other applications involved wireless communication [2]. This situation arising different shapes and types of antenna were designed to search finding for the different variations in antenna characteristic [2]. There various types of fractal antennas include [3]:

• the von Koch curve

• the Sierpinski (gasket and carpet)

• the fractal tree .

The proposed antenna structure comes under Sierpinski Gasket as its structure is repeated again and again [4]. The fractal geometries are featuring two expected common properties which are self-similarity and space filling properties [4] [5]. Both of these properties turn out to be a reason why fractals come out as an attractive way in designing antenna.

Self-similarity properties interpreted as antenna which holds the duplication of itself at several scales and able to operate in similar way at several wavelength [6]. This property allowing the wider band and reveal the multiband frequencies produced. The other one is space filling properties interpreted as reduction in antenna size which allow the antenna is fabricated smaller than elementary shape and attains the small surrounding space [1][6].

The design of patch antenna based on Sierpinski fractals [7]. The construction of the proposed fractal shape is carried out by applying a finite number of times an iterative process performed on a simple starting topology [8]. Figure 1 shows the iteration process of fractal triangle patch antenna.

(a) 1st Iteration (b) 2ndIteration (c) 3rdIteration

Fig.1. Basic concept of Iteration

II. DESIGN AND SPECIFICATION

The software part of our project revolved around determination of the radiation pattern and return loss curve (s11 V/S frequency) of patch antenna. There are two essential parameter for design of patch antenna which are:

1) Dielectric constant of the substrate (εr): A substrate with a high dielectric constant reduces the dimensions of the antenna.

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014)

642

We designed fractal patch antenna. Such fractal antennas have multiple bands or are genuinely wideband. They may replace a suite of antenna systems, disposing of tuning and matching circuitry, and fit in unique or constrained form factors. Fractals are complex geometric designs that repeat themselves, or their statistical proper ties on many scales, and are thus “self identically.” Fractals, through their self- identically property, are natural systems where this complexity provides the sought-after antenna properties. The proposed antenna is based on the below Fig. 2:

Fig.2. Proposed Geometry

The antenna is planar fractal triangular patch antenna with three iteration fed by micro strip line width of micro strip is 3 mm for match impedance with 50 ohms of transmission line, FR4 substrate with dielectric constant (εr) 4.4, loss tangent (tanδ) 0.025 and 1.59 mm of thickness (h) with infinite ground structure. The transmission line model is applicable to infinite ground planes only. However, for practical concern, it is necessary to have a finite ground plane. It has been shown that same results for finite and infinite ground plane can be obtained if the size of the ground plane is greater than the patch dimensions by approximately six times the substrate thickness all around the periphery. The Dimension for the antenna is given in following Table 1:

Table 1

Dimension Of Fractal Geometry

A Microstrip Line type feed is to be used in this design. Length and Width of Microstrip Line is taken 15 mm and 3 mm respectively. Figure 3: shows the three dimensional image of triangle fractal patch antenna design by IE3D software.

Fig.3. 3D Image of Fractal Antenna Design During Simulation on IE3D Software

III. SIMULATION &RESULTS

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014)

643

A. Return loss

S11 gives us the reflection coefficient of antennas. Reflection coefficient is proportional to the ratio of reflected to the input power of the antenna. Antennas usually radiate efficiently for particular range of frequencies. At these frequencies the give out power should be almost equal to input power, i.e., reflected power must very small.

Fig.4. Return Loss Curve

From the above curve we can see that this antenna will operate at frequency 2.72 GHz and in frequency band [5.23 GHz– 5.70GHz] so it is clear that antenna will work in C band and L band. Bandwidth for frequency band is 8.60%.

B. VSWR Curve

VSWR is defined as the ratio of the maximum voltage in the standing wave. The higher the impedance mismatch, the higher the amplitude of standing wave. A perfect impedance match would cause no voltage standing wave, so the proportion of the highest voltage to the lowest would be 1 (1:1).

From the curve it is clear that VSWR varies between 1 and 2 for both frequency 2.72 GHz and frequency band [5.23GHz - 5.70GHz] so it shows impedance matching between microstrip line and Transmission Line.

Fig.5. VSWR Curve

C. Impedance Curve

The input impedance curve of the antenna obtained after simulation is shown in figure.6.

Fig.6. Input Impedance Curve

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014)

644

This result suggests that antenna is designed precisely and antenna is in good matching with the feed line. Under present case most of the fed power to antenna will radiate.

D. Radiation Pattern

The elevation pattern shows unidirectional property of antenna because it radiates all the power for all the frequencies in one direction only.

Fig.7. Radiation Pattern Gain Display

E. Directivity

Fig.8. Total Field Directivity

From the above curve it is clear that at 2.72 GHz directivity is 3.17dB and in Frequency band [5.23 GHz – 5.70 GHz] it varies from -1.21dB – to 2.61dB.

The simulated results for various parameters as return loss, radiation pattern, gain etc., have been getting from this software. Table 2 shows the various parameters used in the designing of dual band fractal triangle patch antenna.

Table 2 Simulation Results

IV. CONCLUSION

Upon the conclusion of our project we made the following assessment of our work: The overall working of antennas was understood. The major parameters (such as Return Loss curves, Radiation Patterns, Directivity and VSWR) that affect design and applications were studied and their implications understood. The constructed Fractal Micro strip Patch antennas operated at the desired frequency and frequency band. Fractal micro strip patch antenna was simulated (using IE3D) and the desired level of optimization was obtained.

Acknowledgment

I would like to thank, Dr Sudhir Kumar Sharma Professor, Jaipur National University, jaipur for providing the testing facility and valuable suggestions for this work.

REFERENCES

[1] N. Abdullah, M.A. Arshad, E. Mohd, S. A. Hamzah “Design of Minskowsi Fractal Antenna for Dual Band Application” IEEE May 13-15, 2008 Kuala Lumpur, Malaysia

[2] Best, S.R. (2005). “The Koch Fractal Monopole Antenna: The Significant of Fractal Geometry in Determining Antenna Performance.” Technical Report. Manchester, NH: Cushcraft Corporation.

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 7, July 2014)

645

[4] Tsachtsiris, G.F., Soras, C.F., Karaboikis, M.P. and Makios V.T. (2004). “Analysis of a Modified Sierpinski Gasket Monopole Antenna Printed on Dual Band Wireless Devices.” IEEE Transactions on Antenna Propagation, Volume 52, No.10. 2571 – 2579.

[5] Carlos Puente-Baliarda, Jordi Romeu, Rafael Pous and Angle Cardama, (1998). “On the Behaviour of the Sierpinski Multiband Fractal Antenna”, IEEE Transaction on Antennas and Propagation Letters, Vol. 46, No. 4.

[6] Lam, S.C. (1997). “A Steerable Planar Antenna System for WLAN” University of Queensland: B. Eng. Thesis.

[7] Matteo J.A. and Hesselink L. (2005). “Fractal Extension of Near-Field Aperture Shapes for Enhanced Transmission and Resolution.” OPTICS EXPRESS, Volume 13, No. 2, 636 – 647.

Figure

Fig.2. Proposed Geometry
Fig.2. Proposed Geometry p.2
Table 1 Dimension Of Fractal Geometry

Table 1

Dimension Of Fractal Geometry p.2
Fig.3. 3D Image of Fractal Antenna Design During Simulation on IE3D Software
Fig.3. 3D Image of Fractal Antenna Design During Simulation on IE3D Software p.2
Fig.8. Total Field Directivity
Fig.8. Total Field Directivity p.4
Table 2  Simulation Results

Table 2

Simulation Results p.4
Fig.7. Radiation Pattern Gain Display
Fig.7. Radiation Pattern Gain Display p.4

References

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