Rectangular Trangular Slot Anteena.pdf

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978-1-4244-9074-5/10/$26.00 ©2010 IEEE

2010 Annual IEEE India Conference (INDICON)

Abstract - A single feed multi frequency compact rectangular

microstrip antenna is presented in this paper. A triangular slot isintroduced at the upper edge of the patch to reduce the resonant

frequency A small piece of triangular patch is grown within the

triangular slot to improve the gain bandwidth performance ofthe antenna. The antenna size has been reduced by 32.9% when

compared to a conventional square patch with a maximum of 160MHz bandwidth and –34 dB return loss Mainly it is developed to

operate in the WiMax frequency range of 3.2-3.8 GHz with 26.67% bandwidth ratio.

Index Terms – Multi frequency, Compact, Gain –Bandwidthperformance, WiMax.

I. I NTRODUCTION

In recent years demand of small antennas on wirelesscommunication has increased the interest of research work oncompact microstrip antenna design among microwaves andwireless engineers [1-5]. The size of the antenna is effectivelyreduced by cutting slot in proper position on the microstrip

patch. The work to be presented in this paper is also acompact microstrip antenna design obtained by cutting atriangular slot on the patch but here in addition to thetriangular slot a small piece of triangular patch is developedwithin the area of triangular slot to increase the return lossand gain-bandwidth performance of the antenna. Generally toachieve a good bandwidth at a particular resonant frequencysubstrate is chosen with lower value of dielectric constant. Toreduce the size of the antenna substrates are chosen withhigher value of dielectric constant [6-7]. Our aim is to reducethe size of the antenna as well as increase the operating

bandwidth. The proposed antenna (substrate with εr =4.4) has again of 5.36 dBi and presents a size reduction of 32.9% whencompared to a conventional square microstrip patch with a

maximum bandwidth of 160 MHz The simulation has beencarried out by IE3D software which uses the MOM method.Due to the Small size, low cost and low weight this antenna isa good candidate for the application of WiMax technology inthe frequency range of 3.2-3.8 GHz with 26.67% bandwidthratio.

II. A NTENNA CONFIGARATION

The configuration of the conventional antenna is shownin Figure 1. The antenna is a 20mm x 20 mm square patch .

The dielectric material selected for this design is an FR4epoxy with εr =4.4 and substrate height =1.6mm

Several parameter of the antenna have been investigated toimprove bandwidth, gain and return loss performance of theantenna. Co-axial probe feed of radius 0.5 mm with a simpleground plane arrangement is used.

Figure 1 : Antenna 1 configuration.

Figure 2 shows the configuration of antenna 2 which isdesigned with a similar substrate. A triangular slot of length

‘p’ and width ‘q’ is created on the rectangular patch.

Triangular Slot Microstrip Patch Antenna forWireless Communication

Ujjal Chakraborty , Samiran Chatterjee , S.K.Chowdhury , P.P.Sarkar# ECE Department, D.B.C.Roy Engineering College, Durgapur, West Bengal, India

*ECE Department, Arryabhatta Institute of Engineering and Management, Durgapur, West Bengal, India## ECE Department, JIS College of Engineering, Phase-III, Block-A5, Kalyani, Nadia, West Bengal, India

*USIC Department, University Of Kalyani, Nadia, West Bengal, India

[email protected]

1 [email protected] [email protected] [email protected]




Figure 2: Antenna 2 configuration

A small triangular patch is added within the area of triangularslot which is placed ‘a’ and ‘b’ distance apart from the side ofthe triangular slot. The location of coaxial probe-feed(radius=0.5 mm) is shown in figure 2 as well.

The parameters investigated are ‘p’, ’q’. ’a’,’ b’ and t.Parametric study have been conducted on the above structure

by changing these parameter and observe the effect on the RLand bandwidth. Best result was achieved for the followingvalues of the parameters: p=4,q=4,a=0.75,b=2.5 and t=6.75.

III. R ESULTS A ND DISCUSSION

Simulated (using IE3D [9]) results of return loss inconventional and slotted antenna structures are shown inFigure 3-4. A significant improvement of frequency reductionis achieved in antenna 2 with respect to the conventionalantenna1 structure.

Figure 3: Return loss of the antenna 1.

Table 1:Mark shown in the figure 3indicate the following properties.

In the conventional antenna return loss of about -24.3 dB isfound at 5.01 GHz and -26.47 dB at 7.84 GHz..Corresponding bandwidth are 30 MHz and 80 MHz

Figure4: Return loss of the antenna 2.

Table 2:Mark shown in the figure 4 indicate the following properties

Due to the presence of slots at the edge of the patch ofantenna 2 multi frequency operation is obtained with largevalues of frequency ratio. For antenna 2 return loss -34 dB isobtained at 3.36 GHz,-26.6 dB at 4.93 GHz and -20 dB at 7.5GHz.. Corresponding 10 dB bandwidth is 160 MHz,30 MHzand 80 MHz respectively as shown in figure 4.

The simulated E plane radiation patterns for antenna 2 areshown in Figure 5-8 The 3 dB Beam width is about 137° for

phi=0o,and more than 90o for phi=90o and the absolute gain is

about 5.37dBi for 3.335 to 3.495 GHz frequency range .




Figure 5: Radiation Pattern of the antenna 2 for 3.336 GHz

Figure 6: Radiation Pattern of the antenna 2 for 3.412GHz

Figure 7: Radiation Pattern of the antenna 2 for 3.496 GHz

Figure 8: Radiation Pattern of t he antenna 2 for 3.36 GHz

Figure 9 shows the directivity versus frequency plot forthe antenna 2.It is observed that upto 4.5 GHz frequencydirectivity of the antenna 2 is greater than 5 dBi.

Figure 9: Directivity versus frequency plot for the antenna 2.

Efficiency of the antenna 2 with the variation of frequency isshown in figure 10.It is found that for the lower band ofoperation efficiency of the antenna 2 is about 72-80 %.

Figure 14: Antenna efficiency versus frequency plot for the antenna 2.




IV. CONCLUSIONS

A single feed single layer triangular slot microstrip antennahas been proposed in this paper. It is shown that the proposedantenna can operate in three frequency band. Triangular slotreduced the size of the antenna by 32.9 % and addition of asmall triangular patch within the area of the triangular slot

increase the bandwidth upto 160 MHz with a return loss of -34dB ,absolute gain about 5.37 dBi and 3 dB beamwidth of 137

o.

Efficiency of antenna has been achieved 80 % for the lower band,60 % for the middle band and 40 % for the higher bandof operation.Alteration of the location of the triangular slot canmore reduce the lower resonant frequency but divide the lower

band into two different band with lower value of bandwidth.An optimization between size reduction and bandwidthenhancement is maintained in this work.

ACKNOWLEDGEMENT

We acknowledge gratefully the financial support for thisWork provided by AICTE (India) in the form of a project

Entitled “DEVELOPMENT OF COMPACT, BROADBANDAND EFFICIENT PATCH ANTENNAS FOR MOBILECOMMUNICATION”.

R EFERENCES

[1] J.-W. Wu, H.-M. Hsiao, J.-H. Lu and S.-H. Chang, “Dual broadband design of rectangular slot antenna for 2.4 and5 GHz wireless communication”, IEE Electron. Lett. Vol.40 No. 23, 11th November 2004.

[2] Rohit K. Raj, Monoj Joseph, C.K. Anandan, K. Vasudevan,P. Mohanan, “ A New Compact Microstrip-Fed Dual-Band

Coplaner Antenna for WLAN Applications”, IEEE Trans.

Antennas Propag., Vol. 54, No. 12, December 2006, pp3755-3762.

[3] Zhijun Zhang , Magdy F. Iskander , Jean-ChristopheLanger, and Jim Mathews, “Dual-Band WLAN DipoleAntenna Using an Internal Matching Circuit”, IEEE Trans. Antennas

and Propag.,VOL. 53, NO. 5, May 2005, pp 1813-1818.

[4] I. Sarkar, P. P. Sarkar, S. K. Chowdhury A new compact

printed antenna for mobile communication. 2009Loughborough Antennas & Propagation Conference 16-17

November 2009, Loughborough, UK

[5] J. -Y. Jan and L. -C. Tseng, “ Small planar monopoleAntenna with a shorted parasitic inverted-L wire for

Wireless communications in the 2.4, 5.2 and 5.8 GHz. bands” , IEEE Trans. Antennas and Propag. , VOL. 52, NO. 7, July 2004, pp -1903-1905.

[6] I. J. Bahl and P. Bhartia, “ Microstrip Antennas”, Artech

House, Dedham, MA, 1980.

[7] E. O. Hammerstad, “ Equations for Microstrip CircuitDesign”, Proc. Fifth European Microwave Conf. Pp 268-272, September 1975.

[8] C. A. Balanis, “Advanced Engineering Electromagnetics”,

John Wiley & Sons., New York, 1989.

[9] Zeland Software Inc. IE3D: MoM-Based EM Simulator.Web: http://www.zeland.com/

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Rectangular Trangular Slot Anteena.pdf