Design and optimization of microstrip patch antenna with defected ground structure & circular slot o by eSAT Journals

IJRET: International Journal of Research in Engineering and Technology

eISSN: 2319-1163 | pISSN: 2321-7308

DESIGN AND OPTIMIZATION OF MICROSTRIP PATCH ANTENNA WITH DEFECTED GROUND STRUCTURE & CIRCULAR SLOT ON THE PATCH Vandana Chopra1, Maninder Kaur2, K.V.P Singh3, Sumit Kumar Jha4 Doaba Institute of Engineering & Technology, Kharar, Mohali, Punjab, vandana_yng@yahoo.com

Abstract A single feed compact rectangular micro strip patch antenna (MSA) for triple band application is presented in this paper. The proposed antenna has Circular slot on the patch and dumble shaped defected ground structure (DGS). To make the proposed antenna more efficient the optimization of the antenna design parameters have been done using HFSS’s optometric. For the proposed antenna three resonant frequencies have been obtained at 2.33GHz, 7.60GHz and 8.53GHz with Bandwidth of 102Mz,130MHz and 127MHz return loss of -15.80db ,-18.77db and -36.57db respectively. The characteristics of the designed structure are investigated by using FEM based electromagnetic solver, HFSS. An extensive analysis of the return loss, gain and bandwidth of the proposed antenna is presented. The simple configuration and low profile nature of the proposed antenna leads to easy fabrication and make it suitable for the application in wireless communication systems. Mainly it is developed to operate in the WLAN, WiMAX & RADAR application.

Key Words: Bandwidth, Return loss, Patch, DGS, RADAR ----------------------------------------------------------------------***--------------------------------------------------------------------1. INTRODUCTION

2. CONVENTIONAL MSA DESIGN, RESULTs &

Microstrip antennas are very attractive because of their low profile, low weight, conformal to the surface of objects and easy production. A large number of microstrip patches to be used in wireless applications have been developed [1-3]. Design of WLAN antennas also got popularity with the advancement of microstrip antennas [4-5]. Wireless local area network (WLAN) requires three band of frequencies: 2.4GHz (2400-2484MHz), 5.2GHz (5150-5350MHz) and 5.8GHz (5725-5825MHz). WiMax has three allocated frequency bands. The low band (2.5-2.69GHz), the middle band (3.2-3.8 GHz) and the upper band (5.2-5.8GHz).Tele communication via satellite and RADAR use the 4-8GHz band of frequency. The size of antenna is effectively reduced by cutting slot in proper position on the microstrip patch. The use of DGS for size reduction of microstrip antenna, although its application has been reported for harmonic reduction [6], crosspolarization suppression [7] and mutual coupling reduction [8] in antenna arrays etc. This paper presents the application of dumble shaped defected ground structure (DGS) in microstrip antenna for size reduction and to achieve useful multiband. While maintaining the antenna size, the broader operating bandwidth (BW) [9,10] is realized by cutting the slots of either half wave or quarter wave in length, having different shapes like U-slot, V-slot, L-slot, and a pair of rectangular slots inside the patch [11,12]. In this paper T-slot has been presented. The slot introduces a mode near the fundamental mode of the patch and realizes broadband response.

ANALYSIS The design of the antenna is shown in figure 1(a). The antenna has 29mm x 25mm rectangular patch. The dielectric material selected for this design with εr = 4.4 and substrate height =1.57mm. The antenna has been designed using the transmission line model. Where the transmission line model is most accurate To design the conventional rectangular micro strip patch antenna that operates at frequency around 2.45GHz, the dimensions can be found using [3]: Step 1: Determination of the Width (W).The width of the Microstrip patch antenna is given by [3] W = 37.26mm. Step 2: Determination of effective dielectric constant (εreff). The effective dielectric constant is represented by [3]. By substituting εr = 4.4, W = 36.26 mm and h = 1.57 mm, it can be determined that εreff = 4.4. Step 3: Determination of the effective length (Leff) The effective length is given by [3]. By substituting εreff = 4.4, c = 3×10^8 m/s and f0 = 2.45 GHz, it can determine that Leff = 29.126 mm. Step 4: Determination of the length extension (ΔL) [3] The length extension may be represented by substituting εreff = 4.4, W = 36.26 mm and h = 1.57 mm, it can be determined that ΔL = 0.01634 mm. Step 5: Determination of actual length of patch (L): The actual length is obtained by using expression L = Leff -2ΔL

__________________________________________________________________________________________ Volume: 02 Issue: 07 | Jul-2013, Available @ http://www.ijret.org

183

IJRET: International Journal of Research in Engineering and Technology By substituting Leff = 29.126 mm and Î&#x201D;L = 0.01634 mm, the actual length can determined as L = 29.093 mm

eISSN: 2319-1163 | pISSN: 2321-7308

the ground have been made defected with the dumble shaped defected ground structure as shown in figure 2(b).

The actual length of the patch has been found using [3]. Now from the above calculated data antenna has been designed on HFSS 13.0. The design is shown in figure below:

Figure 2(a): Simulated Design of Triple Band MSA (Front View showing Circular slot)

Figure 1(a): Conventional Microstrip Patch Antenna Design XY Plot 1

HFSSDesign1

0.00

-5.00

dB(S(p1,p1))

-10.00

-15.00

-20.00

ANSOFT

Curve Info Name

dB(S(p1,p1)) Setup1 : Sw eep

2.4350 -15.2698

3.8220 -18.8795

4.6470 -12.5699

6.2780 -12.0942

7.1730 -13.7811

9.1610 -23.4725

9.5470 -14.8572

3.7830 -9.9500

3.8600 -10.1159

m10

4.6160 -10.1492

m11

4.6940 -10.0327

m12

6.2410 -9.9187

m13

6.3090 -10.0819

m14

7.1370 -9.9513

m15

7.2140 -10.0013

m16

9.1060 -9.6058

m17

9.2180 -10.0614

m18

9.4840 -9.9289

m19

9.5960 -10.1142

m8m9

m12 m13

m11 m10

m16 m17 m18m19

m14 m15

Figure 2(b): Simulated Design of Triple Band MSA (Back View showing DGS)

m5 m7

Name

Delta(X)

Delta(Y)

Slope(Y)

InvSlope(Y)

d(m8,m9)

0.0770

-0.1659

-2.1549

-0.4641

d(m10,m11)

0.0780

0.1165

1.4938

0.6694

d(m12,m13)

0.0680

-0.1632

-2.4007

-0.4165

d(m14,m15)

0.0770

-0.0500

-0.6492

-1.5405

d(m16,m17)

0.1120

-0.4556

-4.0677

-0.2458

d(m18,m19)

0.1120

-0.1853

-1.6542

-0.6045

-25.00 1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Freq [GHz]

Figure 1(b): S-Parameter plot of the conventional Microstrip Patch Antenna

The fronts view of the antenna shows the Circular slot which is made by etching the patch. The defected ground structure has been made on the ground of the patch antenna which has dumble shape by etching the ground plane. The antenna parameter is given in table below: Table 1: Dimensions of the Microstrip Patch Antenna

In the figure 1(b) the S-parameter plot of the MSA design of figure1(a) is shown and from the plot we can easily calculate the bandwidth as well as returnloss which are at 2.43GHz, 3.82GHz, 4.64GHz, 6.27GHz, 7.17GHz, 9.16GHz and 9.54GHz and bandwidth of 77MHz, 78MHz, 68MHz, 77MHz, 112MHZ and 112 MHz were obtained respectively. Due to the presence of the multiple bands as well as presence of so many numbers of varying amplitudes this antenna will consume too much power and hence will not radiate effectively on the particular selected band.

3. MSA with CIRCULAR slot and DGS- DESIGN, RESULTs & aNALYSIS Now the patch antenna has been improved with the Circular slot on the rectangular patch which is shown in figure2 (a) and

Variable Length of the Patch(lp) Width of the Patch(wp) Thickness of the Patch(t) Width of the Ground(wg) Length of the Ground(lg) Width of the Substrate(ws) Length of the substrate(ls) Height of the Substrate(h) Dimension of the symmetrical rectangular box on the ground Dimension of rectangular box connector on the ground Width of the feed Line(wf) Radious of Circle on Patch

Value 25.054mm 29.036mm 0.035mm 21.056mm 34.874mm 41.456mm 34.874mm 1.57mm 6.5mm,4.5mm 2.5mm.1mm 0.8mm 5mm

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IJRET: International Journal of Research in Engineering and Technology XY Plot 1

HFSSDesign1

0.00

ANSOFT

Curve Info dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-2.50

dB(S(p1,p1))

-5.00

eISSN: 2319-1163 | pISSN: 2321-7308

21mm

28mm

22mm

21mm

29mm

22mm

21mm

23mm

21mm

22mm

23mm

21mm

23mm

21mm

24mm

23mm

21mm

25mm

23mm

21mm

26mm

23mm

21mm

27mm

23mm

21mm

28mm

23mm

-7.50 m3m4

m5 m6

-10.00 Name

-12.50 m1

-15.00

2.3020 -14.5506

8.9230 -16.6466

2.2530 -9.8809

2.3510 -9.9714

8.8190 -9.9814

9.0360 -9.9271

Name

Delta(X)

Delta(Y)

Slope(Y)

InvSlope(Y)

d( m3,m4)

0.0980

-0.0905

-0.9239

-1.0823

d( m5,m6)

0.2170

0.0543

0.2502

3.9975 m2

-17.50 1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Freq [GHz]

Figure 2(c): S-Parameter plot of the MSA with DGS and Circular Slot In the figure 2(c) the S-parameter plot of the MSA design of figure2 is shown and from the plot we can easily calculate the bandwidth and returnloss which are (98MHz,-14.55db), (217MHz, -16.64db) at 2.30GHz and 8.92GHz respectively.

XY Plot 1

HFSSDesign1

0.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-10.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-15.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

dB(S(p1,p1))

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-20.00

4. OPTIMIZATION OF MSA

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-25.00

To get the best possible result the antenna has been optimized in a number of ways. Here optimizations of the patch antenna is Discussed.

ANSOFT

Curve Info

-5.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-30.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-35.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-40.00

-45.00 1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Freq [GHz]

Width Optimization Here the width of the microstrip patch antenna have been optimized, the width of patch (WP), the width of ground (wg) and the width of substrate (ws) have been simultaneously optimized. Table2: Width optimization Variation

21mm

22mm

21mm

23mm

21mm

24mm

21mm

25mm

21mm

26mm

21mm

27mm

21mm

28mm

21mm

29mm

21mm

22mm

21mm

22mm

21mm

23mm

22mm

21mm

24mm

22mm

21mm

25mm

22mm

21mm

26mm

22mm

21mm

27mm

22mm

Figure 3(a): S-Parameter plot of the MSA with DGS and Circular Slot in Width Optimization From this analysis the best width combination has been selected and now Radious of the circular slot on the patch have been optimized.

Radious Optimization Now the Radious of the microstrip patch antenna have been optimized to get the best possible result. Table 3: Radious Optimization

Variation 1 2 3 4 5 6 7 8 9

rad 2mm 3mm 4mm 5mm 6mm 7mm 8mm 9mm 1mm

Now the plots have been taken on all the variations and the obtained accumulated plot is shown in figure below:

__________________________________________________________________________________________ Volume: 02 Issue: 07 | Jul-2013, Available @ http://www.ijret.org

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IJRET: International Journal of Research in Engineering and Technology XY Plot 1

HFSSDesign1

0.00

eISSN: 2319-1163 | pISSN: 2321-7308

ANSOFT

Curve Info dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm' dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm' dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-12.50

dB(S(p1,p1))

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm' dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm' dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-25.00

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm' dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

-37.50 1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Freq [GHz]

Figure 3(a): S-Parameter plot of the MSA with DGS and Circular Slot in Radious Optimization

Figure 4(b): 3D-Polar plot of the Optimized MSA with DGS and Circular Slot on the patch

5. OPTIMIZED MICROSTRIP PATCH ANTENNA Radiation Pattern 1

HFSSDesign1

ANSOFT

RESULTs & ANALYSIS

-30

30 -15.00 -16.00

Now the microstrip patch antenna has been optimized in all the possible ways to get the best possible results and final results are presented in this section.

-60

60 -17.00 -18.00

-90

Table4: Optimized dimensions of the proposed MSA

-120

120

-150

Value 25.054mm 21mm 0.035mm 21 mm 34.874mm 22mm 34.874mm 1.57mm 6.5mm,4.5mm

150 -180

Figure 4(c): Radiation Pattern plot of the Optimized MSA with DGS and Circular Slot on the patch In the figure 4(a) the S-parameter plot of the MSA design of figure4 is shown and from the plot we can easily calculate the bandwidth and returnloss which are (102MHz -15.08db),( 130MHz -18.77db) & ( 127MHz -36.57db) at 2.33GHz,7.60GHz,8.53GHz respectively.

6. COMPARISIONS & CONCLUSIONS

2.5mm.1mm

Table5: Table of Comparisons

0.8mm 1mm

Frequencies ( Returnlos s (db Bandwidth GHz) ) (MHz)

Now figure below shows all the plots that have been taken. Name

XY Plot 1

HFSSDesign1

m10.00 2.3300 -15.0854 m2

7.6080 -18.7761

8.5330 -36.5709

2.2770 -10.0422

2.3790 -10.0065

7.5410 -9.8150

7.6710 -9.9112

8.4700 -10.0414

8.5970 -10.1685

m6m7

m4m5

-25.00

Name

Delta(X)

d(m4,m5)

0.1020

0.0357

0.3496

2.8604

d(m6,m7)

0.1300

-0.0962

-0.7399

-1.3515

-0.12712.00 -1.0006

-0.9994 3.00

-37.50

77MHz, 78MHz, 68MHz, 77MHz, 112MHz, 112 MHz

With Circular Slot on the patch and DGS

2.30GHz, 8.92GHz

-14.55db,16.64db

98MHz, 217MHz

m8m9

d(m8,m9) 1.000.1270

Conventi onal Des Des ign ign

-15.26db, 18.87db, -12.56db,12.09db, -13.78db,23.47db, -14.85db.

dB(S(p1,p1)) Setup1 : Sw eep ls='34.874mm'

dB(S(p1,p1))

-12.50

2.43GHz, 3.82GHz, 4.64GHz, 6.27GHz, 7.17GHz, 9.16GHz, 9.54GHz.

ANSOFT

Curve Info

Delta(Y)

Slope(Y)

InvSlope(Y) m3

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Freq [GHz]

Figure 4(a): S-Parameter plot of the Optimized MSA with DGS and Circular Slot on the patch

-15.08db,Optimized 2.33GHz,7.60G 18.77db, -36.57db. Des ign Hz,.8.53GHz

102MHz, 130MHz, 127MHz

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IJRET: International Journal of Research in Engineering and Technology

Now we have the results of both the conventional MSA as well as the Optimized MSA with DGS & Circular Slot. These results are presented in the table above As we can easily analyze from the above table that the proposed Microstrip Patch Antenna will work in the frequency range of 2-8GHz. which covers the frequency of operation of WLAN, WiMAX, and wireless communication through satellite as well as the frequency of operation of RADARthat’s why it is multipurpose microstrip patch antenna.

[13]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9] [10] [11]

[12]

David Sinchez-Hemindez and Ian D. Robertson, “Analysis and Design of a Dual-Band Circularly Polarized Microstrip Patch Antenna” IEEE Transactions on Antennas and Propagation, issue 43, No2, February, 1995. Ramesh Garg, Prakash Bhatia.et.al ―Microstrip Antenna Design Handbook‖ Artech House antennas a propagation library, London, ISBN-0-89006-513-6, 2001. Constantine A. Balanis- Antenna Theory Analysis and Design, Second Edition, John Wiley & Sons (Asia) Pte Ltd. ISBN 9971-51-233-5,2001 S. Bhunia, M.-K. Pain, S. Biswas, D. Sarkar, P. P. Sarkar, and B. Gupta, “Investigations on Microstrip Patch Antennas with Different slots and Feeding Points” , Microwave and Optical Technology Letters, VOL 50, NO. 11, November 2008 pp 2754-2758. D. N. Elsheakh, H. A. Elsadek, and E. A. Abdallah "Reconfigurable Single and Multi Band Inset Feed Microstrip Patch Antenna for Wireless Communication Devices" Progress In Electromagnetics Research C, Vol. 12, 191{201, 2010}. H. W. Liu, Z. F. Li and X. W. Sun, “A Novel Fractal Defected Ground Structure for Microstrip Line,” Journal of Active and Passive Electronic Devices, Vol. 1, 2006,pp. 311-316. C. S. Kim, J. S. Park, D. Ahn and J. B. Lim, “An Improved 1-D Periodic Defected Ground Structure for Microstrip Line,” IEEE Microwave and Wireless Components Letters, Vol. 10, No. 4, 2004, pp. 180-182. Z. Li and Y. Rahmat-Samii, “PBG, PMC, and PEC Ground Planes: A Case Study of Dipole Antennas,” IEEE Antennas and Propagation Society International Symposium, Vol. 2, 2000, pp. 674-677. I.J. Bahl and P. Bhartia, Microstrip antennas, Artech House, 1980. G. Kumar and K. P. Ray, Broadband Microstrip Antennas, First Edition, USA, Artech House, 2003. T.Huynh , K. F. Lee, “Single-Layer Single Patch Wideband Microstrip Antenna,” Electronics Letters, vol. 31, no. 16, August 1995, pp. 1310-1312. R. Chair, K. F. Lee, C. L. Mak, K. M. Luk and A. A. Kishk,“Miniature Wideband Half U-Slot And Half E Patch Antennas,”IEEE Transactions on Antenna And Propagations, vol. 52, no. 8,August 2005, pp. 2645-2652.

Barun Mazumdar, Ujjal Chakraborty, Aritra bhowmik, S.K.Chowdhury, 2012 “Design of Compact Printed Antenna for WiMAX & WLAN Applications”, Elsevier Ltd., pp 87 – 91.

BIOGRAPHIES Vandana Chopra, she is M.Tech (ECE) student at Doaba Institute of Engineering & technology, Mohali. She has earlier completed her B.Tech in ECE from HEC, Haryana. Her area of interest are Antenna & Wave Propagation, Antenna designing and fabrication, Signal Processing, and optical fibre communication. Email id: vandana_yng@yahoo.com

REFERENCES [1]

eISSN: 2319-1163 | pISSN: 2321-7308

Maninder Kaur She is M.Tech by Qualification and currently working as Assistant Professor cum Coordinator at Doaba Institute of Engineering and Technology. Her area of interest is Image Processing, optical Communication and Wireless Communication. She has published nine Papers in International Journals. She has attended four national conferences and five International Conferences. Email id: maninderecediet@gmail.com Dr. K V P Singh, he is working as Director Principal at Doaba Institute of Engineering and Technology. Dr. Singh is B.Tech, M.Tech, PHD, and PDF Qualified. He has attended many international and National conferences and have Published Paper in national and International Journals. Sumit Kumar Jha, He has received B.Tech degree in ECE from Kurukshetra University, at SDDIET, Panchkula and M.Tech degree from Kurukshetra University, at ACE & AR Ambala. He is currently guiding a number of students in their thesis/dissertation and also has published his research paper in International Journal. His research interests are Wireless and Mobile Communication, Microstrip antennas, Wave propagation, Signal Processing, Wind Energy Conversion Systems. Email id: skjha.indian@gmail.com

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