A NEW MODIFIED SLOTED SIERPINKSI GASKET FRACTAL MICROSTRIP ANTENNA FOR WLAN AND RFID APPLICATIONS

Abstract

A sierpinkski gasket fractal antenna for WLAN ,RFID ISM band applications proposed ,designed and simulated .The proposed modified sierpinksi slotted fractal patch designed in order to achieve radiation characteristics. The simulated antenna has a total dimensions of 25*25 ,simulated results of an antenna is -18 dB return loss for 2.4 GHz to 2.256 GHz with 56% .This frequency bands cover the IEEE 802.11 (WALAN) and RFID ISM bands ,the simulated return loss ,radiation ,patterns and directivity ,gain of the antenna are presented

Keywords

sierpinski Gasket fractal, WLAN applications, RFID application, ISM band, slotted fractal

INTRODUCTION

Recent years different fractal antennas have been developed for various wireless applications ,such as miniature and multiband .Geometry of design [2] of a sierpinksi gasket fractal design ensures a successful geometry of a broadband applications antenna.sierpinksi mounted on the rectangular patch explained in [1].A single broad band sierpinski fractal antenna fed by 50 Ω microstrip feed line [3]In fractal antenna microstrip feed is most efficient fed method in order to achieve broad band width ,small size ,better impedance matching ,easy to integrate with MIC circuits , low loss and and achieve perfect radiation characteristics [3][5].Many fractal antennas implemented using carpet or sierpinksi fractal [6][7][8][9] in this antennas are increase the band width and also increase the thickness of the antenna [10].

In this paper we introduce the new modified triangular sierpinski gasket fractal antenna method of momentum (MOM) using iterated function system (IFS) geometrical properties [2] with modification. In this proposed modified triangular slotted sierpinksi for single band operations. The proposed antenna covers the RFID ,WLAN ISM band (2.4 -2.456 GHz) band with -18 dB return loss .The design and simulation was performed using method of momentum (MOM) simulation software .This paper also describe design and simulated performance of the proposed antenna .

II. ANTENNA CONFIGURATION

The proposed sierpinski antenna geometry shown in fig.3. A sierpinski fractal patch is printed on the one side of the substrate and ground plane is printed on the other side of substrate with 30mil thickness and the dielectric constant εr =3.38. The microstrip fed is used for the sierpinski fractal patch which fed out edge of the rectangular patch. Microstrip fed line have 50 Ω impedance can be used to excite sierpinski fractal patch shown in fig.2. It has the vertex angle A and Resonant frequency controlled by the each iteration. The proposed sierpinski fractal antenna printed on the Rogers Ro4003 dielectric substrate (εr =3.38 and 30 mil).

This can be calculated by using formula given by

The antenna matched at frequencies calculate approximately for fractal antenna given below

The iterated function can be represent by,

Where,

a,b,c,d ,e and f are real numbers

Thus our scaling factor can calculate approximately by

Fig.3 Proposed Configuration Of The New Modified Triangular Slotted Sierinski Gasket Fractal Antenna. Height of the modified triangular is determined by using the following equations

Length of the seirpinski gasket calculate by given below

Fig illustrates the proposed antenna configuration of a sierpinski fractal antenna for IEEE 802.11 b/g and RFID ISM frequency (2.4-2.456) band.

The geometry design parameters are L=25mm,W=25 mm,h1=6 mm,h2=6 mm , h3=4 mm,h4= 4 mm,The proposed antenna using microstrip fed to excite the proposed antenna ,simulation of the proposed antenna using ADS method of momentum simulation tool.

III. RESULTS

Simulated return loss of the proposed antenna shown in fig.4 for εr=3.38 and h=30 mil L*W is 25 * 25.In this geometry proposed new modified triangular slotted siernksi gasket fractal antenna reduce the thickness of the antenna compare to other siernksi gasket fractal antenna which is 30 mil and increase the bandwidth. The return loss of the proposed antenna is -18dB at 2.42GHz.The simulated resonant frequency resonate around 2.4-2.45GHz. Bandwidth of the proposed antenna is suitable for the WLAN, RFID antenna communications. The resonant frequency of the antenna is shown in fig 1 . Simulated frequency good agreement with the frequency band of WLAN,RFID ISM band which is 2.45GHz and simulated by the ADS MOM technology. Microstrip line feed is excite the triangular slotted antenna, The simulated impedance bandwidth for -18db return loss 56 % at the 2.4GHz, Hence proposed new modified triangular slotted seirnksi gasket fractal antenna can be cover the WLAN and RFID ISM band.

Radiation pattern of the proposed antenna is shown in fig.4 . In this radiation pattern shown x-z planes and y-z plane at 2.45GHz from the fig.4 . The proposed antenna radiated in omnidirectional pattern ,this radiation pattern combines both the Eφ and Eθ components .

Microstrip fed is excite the modified sierpinski gasket antenna this current distribution is shown in fig.5 .The simulated radiation pattern is similar to the standard triangular fractal dipole antenna .The simulated antenna gain 3.14 dBi for resonant frequency 2.4GHz .

IV. CONCULUSION

Thus the proposed new modified sierpinksi gasket slotted fractal for WLAN ,RFID ISM band antenna simulated and simulated with slotted triangular patch ,this proposed antenna used modified slotted triangular patch used to achieve broad bandwidth ,The simulated return loss shown proposed antenna has single operating frequency band (2.4-2.245GHz) which covers the WLAN ,RFID ISM bands .The radiation pattern of the modified sierpinksi gasket fractal antenna is omnidirectional ,Hence proposed antenna suitable for WLAN ,RFID applicatons.

Figures at a glance

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

References

1. [1] Kuem C. Hwang,,”A Modified Sierpinski Fractal Antenna for Multiband Application” IEEE antennas and wireless propagation letters, vol. 6, 2007
2. H. O. Pietgen, H. Jurgerns, and D. Saupe, Chaos and Fractals, New Frontiers in Science. New York: Springer Verlag, 1992.
3. C. Puente, C. Borja, M. Navarro, and J. Romeu, “An iterative model for fractal antennas: Application to the Sierpinski gasket antenna,” IEEE Trans. Antennas Propag., vol. 45, no. 5, pp. 713–719, May 2000.
4. J. Soler, J. Romeu, and C. Puente, “Mod-p Sierpinski fractal multiband antenna,” presented at the AP2000 Millennium Conf. Antennas Propag., Davos, Apr. 9–14, 2000.
5. D. H. Werner and S. Ganguly, “An overview of fractal antenna engineering research,” IEEE Antennas Propag. Mag., vol. 45, no. 1, pp.38–57, Feb. 2003.
6. C. Puente-Baliarda, J. Romeu, R. Pous, and A. Cardama, “On the behavior of the Sierpinski multiband fractal antenna,” IEEE Trans. AntennasPropag., vol. 46, no. 4, pp. 517–524, Apr. 1998.360
7. C. T. P. Song, P. S. Hall, and H. Ghafouri-Shiraz, “Perturbed Sierpinski multiband fractal antenna with improved feeding technique,”IEEE Trans. Antennas Propag., vol. 51, no. 5, pp. 1011–1017, May 2003.
8. P. W. Tang and P. F. Wahid, “Hexagonal fractal multiband antenna,”IEEE Antennas Wireless Propag. Lett., vol. 3, pp. 111–112, 2004.
9. C. T. P. Song, P. S. Hall, and H. Ghafouri-Shiraz, “Multiband multiple ring monopole antennas,” IEEE Trans. Antennas Propag., vol. 51, no.4, pp. 722–729, Apr. 2003.
10. G. J. Walker and J. R. James, “Fractal volume antennas,” Electron.Lett., vol. 34, no. 16, pp. 1536–1537, Aug. 1998.
11. C. T. P. Song, P. S. Hall, H. Ghafouri-Shiraz, and D. Wake, “Fractal stacked monopole with very wide bandwidth,” Electron. Lett., vol. 35,no. 12, pp. 945–946, Jun. 1999.
12. R. Hossa, A. Byndas, and M. E. Bialkowski, “Improvement of compact terminal antenna performance by incorporating open-end slots in ground plane,” IEEE Microw. Wireless Compon. Lett., vol. 14, no. 6,pp. 283–285, Jun. 2004.
13. B. Sanz-Izquierdo, J. Batchelor, and R. Langley, “Multiband printed PIFA antenna with ground plane capacitive resonator,” Electron. Lett.,vol. 40, no. 22, pp. 1391–1392, Oct. 2004.
14. M. F. Abedin and M. Ali, “Modifying the ground plane and its effect onplanar inverted-F antennas (PIFAs) for mobile phone handsets,” IEEE Antennas Wireless Propag. Lett., vol. 2, pp. 226–229, 2003.
15. K. C. Hwang, “A modified Sierpinski fractal antenna for multiband application,”IEEE Antennas Wireless Propag. Lett., vol. 6, pp. 357–Jun. 2007.