AN ULTRAWIDEBAND ANTENNA FOR WIRELESS APPLICATIONS

International Conference on Engineering Trends and Science & Humanities (ICETSH-2015) AN ULTRAWIDEBAND ANTENNA FOR WIRELESS APPLICATIONS 2 1 1 E. S...
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International Conference on Engineering Trends and Science & Humanities (ICETSH-2015)

AN ULTRAWIDEBAND ANTENNA FOR WIRELESS APPLICATIONS 2

1

1 E. Sricithra, PG Student M. Vinoth, PG Student S. Jana,Associate Professor Electronics and Communication Engg., Electronics and Communication Engg., Electronics and Communication Engg., Mookambigai College of Engineering, Mookambigai College of Engineering, Mookambigai College of Engineering, Pudukkottai, TamilNadu, India. Pudukkottai, TamilNadu, India. Pudukkottai, TamilNadu, India.

Abstract— Microstrip antennas are also known as printed antennas and they have a variety of applications in radar systems, microwave communication links, satellite communication systems, wireless and mobile communication systems, medical equipment, etc. In this paper, a model of inverted T- slot rectangular patch antenna is designed and simulated to evaluate the performance. The proposed antenna is designed to cover the common wireless applications. The output results are taken and analyzed for their radiation pattern and transmission losses. The reference/characteristic impedance taken is 50 Ω and the operating frequency domain is 1.7GHz to 7.68 GHz. The microstrip patch antenna is encapsulated in the FR-4 low cost substrate whose dielectric constant is 4.4. Keywords— Inverted T-slot, Microstrip patch, defected ground structure (DGS).

communication systems, which operate at 1.7 GHz to 7.68GHZ band. The inverted T-slot antenna covers all the wireless applications such as GSM/Radio, WLAN, Wi-Fi, Extended C-band, INSAT/Super Extended C-band and Military standard (MIL-STD) 202. II. DESIGN CALCULATIONS The width and length of the patch antenna are calculated by using transmission line design equations. The width of the microstrip patch antenna is given as in equation (1): √ where

I. INTRODUCTION

(1)

r = dielectric constant of the substrate

An antenna acts as a transitional structure between free space and guiding device [9]. There are various types of antennas available such as wire antennas, aperture antennas, reflector antennas, array antennas, lens antennas and microstrip patch antennas. Of these the microstrip patch antenna is easy to fabricate and has the following characteristics: low profile, light weight, simple and inexpensive. It consists of a metallic or a radiating patch on one side of a dielectric substrate and a ground plane on the other side [7]. The different shapes of patches are square, rectangular, circular etc. The proposed antenna is used to obtain multi-band operation with enhanced gain.

f 0 = frequency of operation, c = Velocity of light (3 * 108 m/s)

The proposed antenna is designed with an inverted T- slot on a radiating patch. The defected ground structure otherwise known as mid-hole technique [6], is used to enhance the gain of the antenna. The multi-band antenna is designed to cover various applications in a single antenna with a simple structure to face the new challenges in wireless communications [12]. The inverted T-slot antenna is implemented with a single FR-4 substrate. The proposed antenna is designed and simulated using High Frequency Structure Simulator (HFSS) tool. The HFSS is based on finite element method. It is an industrial standard for simulating 3D full wave electromagnetic fields and provides good standard accuracy [13]. The design equations are based on the transmission line model and it is the easiest of all [4]. The proposed antenna is simple in structure.

W    ( reff  0.3)(  0.264)  h  L  0.412h  W    ( reff  0.258)(  0.8)  h  

This paper describes the design and simulation of microstrip patch antenna for the current wireless

ISSN: 2348 – 8549

The effective dielectric constant is given as in equation (2): [ where

]

(2)

h=height of substrate.

The effective length is given as in equation (3): (3) The length extension is given as in equation (4):

(4)

The actual length is obtained by equation (5): L = Leff - 2ΔL

(5)

For the design, the ground plane dimensions are given as: Lg = 6h + L

(6)

Wg = 6h + W

(7)

Strip line feeding:

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International Conference on Engineering Trends and Science & Humanities (ICETSH-2015) A strip line fed type-feeding technique is used in this design. The feeding point must be located at that point on the patch where the input impedance is 50 ohms for the resonant frequency. III. ANTENNA GEOMETRY The conventional rectangular microstrip patch antenna is designed on FR-4 Epoxy substrate material, having following specifications Substrate: FR-4 Epoxy, Height: 1.6 mm. Here the rectangular patch has length and width 36.4 mm and 46.8 mm respectively. Four narrow slits are taken out from the patch to improve the performance of the antenna as multi-band functionality. The frequency of operation is taken as 1.95GHz.

S.No.

IV. RESULTS AND DISCUSSION The patch antenna is simulated using Ansoft HFSS. Fig. 2 and Fig. 3 shows Return Loss and VSWR plot of the design. 4.1 SIMULATED RESULTS: A. Return loss It is a measure of the reflected energy from a transmitted signal, which is commonly expressed in decibels (dB). Larger the value, lesser is the energy reflected. The results obtained are shown in Fig. 2.

TABLE I Design Specification Parameters

Fig.2 Return Loss of the antenna with frequency

Values

Unit

1

Ground Patch dimension (L*W)

46.2 * 56.4

mm2

2

Patch dimensions (L * W)

36.4 * 46.8

mm2

3

Relative Permittivity (εr)

4.4

No

4

Dielectric loss tangent (tanδ)

0.00018

No

5

Resonant Frequency (fo)

1.95

GHz

6

Slots (L* W)

16 * 6, 14 * 6

mm2

7

Square hole in ground (L * W)

4*4

mm2

8

Feed (L* W)

8*3

mm2

Fig.1 Simulated antenna structure using HFSS

B. VSWR VSWR stands for voltage standing wave ratio. It is a function of the reflection coefficient, which describes the power reflected from the antenna. For small VSWR, the antenna is better matched to the transmission line and more power is delivered to the antenna. Fig.3 shows VSWR plot of proposed design. Fig.3 VSWR of the antenna

Ansoft NameCorporation X 1.7000

1.6955

m2

4.1500

1.5231

m3

5.7950

1.5437

3.50 m4

6.5650

1.1428

m5

6.6700

1.1571

m6

6.9500

1.6717

7.6850

1.2358

3.00

The structure of the designed patch antenna is shown in Fig. 1 and Fig. 2 in 3D model. An inverted T-slot is formed on the patch element. The feed is applied in a horizontal polarization. It is assigned with an air box boundary and virtual radiation to create far field radiation pattern and assigned with an excitation of the lump port.

VSWR(LumpPort1)

m7

XY Plot 3

Y

4.00 m1

HFSSDesign1 Curve Info VSWR(LumpPort1) Setup1 : Sw eep1

2.50

2.00 m1

m6 m3

m2

1.50

m7

m5 m4

1.00

0.50

0.00 1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

Freq [GHz]

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International Conference on Engineering Trends and Science & Humanities (ICETSH-2015) From the above results, we can say that the designed antenna is having seven bands of operations. Return loss parameter obtained at all these frequencies has value less than -10dB. The value of VSWR at all these resonating frequency bands is also between 1 and 2. Hence, we can say that designed antenna, which is resonating at seven different resonating frequencies, is a multi-band antenna. Fig. 4 shows 3D polar plot of the proposed design. Total directivity of the proposed antenna is 3.984 dB.

D. Radiation Pattern: The term radiation pattern refers to the directional (angular) dependence of the strength of the radio waves from the antenna or other source. The radiation pattern for the proposed patch antenna is shown in Fig.7. The Fig. 8 & Fig. 9 shows the near and far field pattern of the antenna.

Fig.4 Directivity plot of the proposed antenna

Fig.7 Radiation Pattern of the proposed antenna

C. Gain

Radiation Pattern 53

Ansoft Corporation

HFSSDesign1 Curve Info

0

Total gain of the proposed antenna is 3.314 dB. Fig. 5 shows 3D polar plot of the proposed design. Fig. 6 shows the gain of individual application bands generated by the proposed antenna.

-30

dB(NearEPhi) Setup1 : LastAdaptive

30 27.20

dB(NearEPhi)_1 Setup1 : LastAdaptive

24.40 -60

60 21.60

18.80

-90

90

-120

120

-150

150 -180

Fig.8 Far field radiation pattern of the proposed antenna

Radiation Pattern 43

Ansoft Corporation

Fig.5 Gain plot of the proposed antenna

HFSSDesign1 Curve Info

0 -30

dB(rEPhi) Setup1 : LastAdaptive

30 -2.00

dB(rEPhi)_1 Setup1 : LastAdaptive

-9.00 -60

60

dB(rEPhi)_2 Setup1 : LastAdaptive

-16.00

-23.00

-90

90

-120

120

-150

150 -180

Fig.9 Near field radiation pattern of the proposed antenna Fig.6 Peak Gain plot of the proposed antenna

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International Conference on Engineering Trends and Science & Humanities (ICETSH-2015) The Table II shows the overall results of the proposed antenna.

4.2 MEASURED RESULTS: The proposed prototype was fabricated and tested for the achieved results through simulation using Network Analyzer. The fabricated antenna is shown in Fig.10. Fig. 10 (a) shows the top view and Fig. 10 (b) shows the bottom view of the proposed structure. The tested result is plotted in Fig.11, which are compared along with the simulation results. From the comparison plot, the simulated and fabricated results were same and the antenna achieved a hepta band and perfect resonance at the desired frequency range of 1.7GHz to 7.68 GHz. From Fig.11 gives evident that of simulated and measured results in the proposed hepta band antenna.

TABLE II Results of Proposed antenna Sl.No.

Operating Band (GHz)

Return Loss (dB)

VSWR

Gain (dB)

1

1.7

-11.76

1.69

3.89

2

4.15

-13.66

1.52

5.67

3

5.78

-13.4

1.54

7.44

4

6.56

-23.52

1.14

8.32

5

6.67

-22.75

1.15

7.79

6

6.96

-11.99

1.64

9.27

7

7.68

-19.91

1.23

9.27

V.CONCLUSION

(a)

The inverted T-slot antenna has been designed using flame retardant (FR-4) substrate with a dielectric constant value of 4.4. The proposed structure is simulated using HFSS simulator. From the results obtained in Fig. 2, it is evident that the proposed antenna can be used for real time wireless applications for attenuating the frequency, ranging from 1.7GHz to 7.68 GHz. This antenna achieves a good return loss and gain of about 3.31dB. The simulated results and measured results were compared, it gives the good performance and better gain of the proposed antenna.

Top View

REFERENCES

(b)

[1]

Amit Kumar & Sanjay Singh, ―Designing and Analysis of T-Shape Microstrip Antenna for the 4G Systems‖, Global Journal of Computer Science and Technology Network, Web & Security, Volume 13, Issue 8, Version 1.0, Year 2013, pp 15-18.

[2]

Annapurna Das and Sisir K Das,‖Microwave engineering‖, 2 edition,tata McGraw Hill company Limited,2010.

[3]

Anuja Jadhav, Nikhil Borawake, Pradnya Shinde, Vishal Bharate, ―Novel T-Shaped Planar Dual Band Antenna with Slotted Ground for ISM/WLAN Operations‖, International Journal of Soft Computing and Engineering (IJSCE), ISSN: 2231-2307, Volume3, Issue-2, May 2013, pp 11-13.

[4]

Arun K. Saurabh, Dinesh K. Srivastava,‖Design and Analysis of 4Shape Slotted Broadband Rectangular Microstrip Patch [MSP] Antenna‖, International Journal of Review in Electronics & Communication Engineering (IJRECE), Volume 1, Issue 5, December 2013, pp 131-134.

[5]

Arun K. Saurabh, Sunil Kumar, D. K. Srivastava,‖ Design and Bandwidth Enhancement of Rectangular Microstrip Patch Antenna using Double H-Slot Technique for Broadband Applications‖, International Journal of Advanced Research in Computer and Communication Engineering,Vol. 2, Issue 12, December 2013,pp 4570-4574.

[6]

Arun Singh Kirar, Dr. P. K. Singhal, ―Design & Analysis Of An Inverted-T Shaped Antenna With DGS For Wireless Communication‖, International Journal of Advanced Research in Computer Engineering & Technology (IJARCET) Volume 2, Issue 7, ISSN: 2278 – 1323, July 2013, pp 2302-2306.

[7]

Constantine A.Balanis,‖Antenna Theory design‖,Wiley India edition, 3 rd Edition 2005.

Bottom View

Fig.10 Proposed antenna structure

Fig.11 Comparison results of proposed antenna structure

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analysis

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nd

and

International Conference on Engineering Trends and Science & Humanities (ICETSH-2015) [8]

Deepak, Dhaynendra Parashar Dr.Vinod K.Singh , Rajeev S. Pathak,‖ A study on inverted T shaped micro strip antenna at different frequencies‖, International Journal Of Engineering And Computer Science, ISSN:2319-7242, Volume 2, Issue 11 Nov.2013, Pp 3180-3183.

[9]

John d Kraus,‖antennas‖, 2nd edition,Tata McGraw Hill Company Limited,1997.

[10] Gada Mahmood Faisal, Kaydar Majeed Quboa, Dia Mohamad Ali,‖ Quad-Band Dual-Layer Microstrip Antenna Design for Mobile Handset‖, American Journal of Electrical and Electronic Engineering, 2014, Vol. 2, No. 2,pp 51-56. [11] Khushboo Naruka, Prof.(Dr.) Sudhir Kumar Sharma, Devendra Soni,‖ Design and Analysis of Double layer Microstrip patch antenna‖, International Journal of Modern Communication Technologies & Research (IJMCTR), ISSN: 2321-0850, Volume2, Issue-1, January 2014, pp 12-14. [12] Mohammad Monirujjaman Khan, Musa Magani, Atiqur Rahman and Clive Parini,‖ A Dual Band Planar Inverted F Antenna for Body-Centric Wireless Communications‖, School of Electronic Engineering and Computer Science, Queen Mary University of London Mile End Road, London E1 4NS,2012. [13] Parminder Singh, Anjali Chandel, Divya Naina ,‖Bandwidth Enhancement of Probe Fed Microstrip Patch Antenna‖, International Journal of Electronics Communication and Computer Technology (IJECCT), Volume 3, Issue 1 (January 2013),pp 368371. [14] Prabhaker Singh, G.S. Tripathi , Amit Kumar Gupta,‖ Design of small size extended T-shaped patch Microstrip antenna‖, VSRD International Journal of Electrical, Electronics & Communication Engineering, Vol. 3, No. 1, January 2013 / 25, e-ISSN : 22313346, p-ISSN : 2319-2232,pp 25-27. [15] Ratnesh Kumari, Mithilesh Kumar ,‖Inverted T-Slot Compact Microstrip Antennas for Multiband Operations‖, International Journal of Scientific & Engineering Research, Volume 4, Issue 10, October-2013, ISSN 2229-5518,pp 267-275. [16] Swaraj Panusa, Mithlesh Kumar,‖ Quad-Band U-Slot Microstrip Patch Antenna‖, International Journal of Scientific Research Engineering & Technology (IJSRET), ISSN 2278 – 0882, Volume 3, Issue 1, April 2014, pp 145-148. [17] P.Vetriselvi, Sathiyamoorthy Murugan., Dr.V.Rajamani ,‖Design Of Wideband U Slot Microstrip Antenna‖, International Journal of Innovative Res arch in Science, Engineering and Technology Volume 3, Special Issue 3, March 2014,pp 1382-1386. [18] Zhongbao Wang, Shaojun Fang, Shiqiang Fu,‖Wideband DualLayer Patch Antenna Fed by a Modified L-Strip‖, Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. 9, No. 2, December 2010,pp 89-98.

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