Rectangular MicrostripPatch Antenna for 2.45 GHz Wireless Applications

IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 08, 2015 | ISSN (online): 2321-0613

Rectangular Microstrip Patch Antenna for 2.45 GHz Wireless Applications Miss Anjali Majale1 Mrs.S.R.Mahadik2 1 P.G. Student 2Associate Professor 1,2 Department of Electronics & Telecommunication Engineering 1,2 Dr. J. J. Magdum College of Engineering Jaysingpur, Shivaji University, Kolhapur India Abstract—This paper presents a microstrip patch antenna with diagonally symmetrical slots for RFID applications.

The unequal length center slots with four rectangular slots on its diagonal axes are embedded onto the square patch radiator. These slots are introduced to achieve compact size.

The coaxial feed is used to excite the proposed antenna. The antenna is fabricated using FR4 Dielectric Substrate (relative permittivity =4.4, loss tangent=0.001) and coaxial feed. These designed antennas are fabricated and used in real time applications. Microstrip Patch Antenna using IE3D software and study the effect of antenna dimensions Length (L),and substrate parameters, relative Dielectric constant, substrate thickness (t) on the Radiation parameters of Bandwidth and Beam-width.

Key words: FR4 Dielectric Substrate, Microstrip Patch Antenna, Return Loss, RFID Reader Antenna, VSWR, IE3D

are also widely used [1]. The inner conductor of the coaxialline (sometimes referred to as a probe) is connected to the radiating patch, while the outer conductor is connected to the ground-plane, as shown in Figure 2 Hence among different feeding techniques; co-axial fed technique is used for the design of rectangular microstrip patch antenna at 2.45GHz

I. INTRODUCTION In the field of wireless communications, antenna plays very important role. Microstrip antenna is key building in wireless communication. Out of many antennas in communication system, microstrip antenna is very popular and well known for its advantages such as low fabrication cost, low profile, low volume and it has capability of dual and triple frequency operations. Because of these features this antenna attracts many researchers to investigate performance of antenna in various ways. Different types of microstrip antennas have been proposed for many applications with different shapes such as rectangular, circular disc, elliptical etc [7]. In this paper, we used rectangular structure.

The demand in commercial and military wireless systems is due to capabilities of proposed Antenna such as low weight, low profile, low cost, easily combined with design and technology, and relatively simple fabrication.

Fig. 2: The Co-axial Probe Feed Technique II. DESIGN SPECIFICATION In this the procedure for designing a square microstrip patch antenna in IE3D software is explained. And the results obtained from the simulations are demonstrated. The Rectangular microstrip patch antenna parameters are calculated from the following formulas [1]. Hence, the essential parameters for the design are: f r = 2.45 GHz   

 r =4.4

h = 1.6 mm

A. Calculation of the Width (W): The width of the Micro-strip patch antenna is given by equation as: 1

W=

2 fr  0 0

2 = 0 2 r  1 2 fr r  1

B. Calculation of Effective Dielectric Constant (εreff): The following equation gives the effective dielectric constant as: Fig. 1: Microstrip patch antenna In order to simplify analysis and performance prediction, the patch is generally rectangular, circular, triangular, elliptical or some other common shape. The rectangular microstrip patch antenna is the widely used of all the types of microstrip antennas that are present .The substrate material, dimension of antenna, feeding technique will determines the performance of microstrip antenna. The simplest method of feeding the patch is by a coplanar microstrip line, also photo etched on the substrate. Coaxial feeds

eff 

r  1 r  1 2

2

1 h  1  12  w 

C. Calculation of the Effective length (Leff): The following equation gives the effective length as: 0 c Ll  L  2L   2 l 2 f 0 l L 

h

l

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Rectangular Microstrip Patch Antenna for 2.45 GHz Wireless Applications (IJSRD/Vol. 3/Issue 08/2015/147)

D. Calculation of the Length Extension (ΔL): The following equation gives the length extension as: w  0.264 h    eff  0.258  w  0.8 h

L =0.412h  eff  0.3

E. Calculation of actual length of patch (L): The actual length is obtained by the following equation: 1 L  2L 2 fr eff  0 0 F. Calculation of the ground plane dimensions (Lg and Wg): Lg = 6h + L =6(1.6) +28.83=38.43 Wg = 6h + W =6(1.6)+37.26=46.86 G. Feed Location Design: The position of the coaxial cable can be obtained byusing (Dr. Max Ammnan):

X

f

L

 2

reff

Where Xf is the desire input impedance to match the coaxial cable and εreff is the effective dielectric constant. =W

Y

f

2

III. ANALYSIS AND PARAMETERS FOR ANTENNA DIMENSIONS

The rectangular Microstrip patch Antenna designed at 2.45GHz frequency, dielectric constant =4.4 and height from the ground plane h= 1.6 mm. The parameter of rectangular microstrip patch antenna are L=30mm, W=30 mm. The simple rectangular Microstrip patch Antenna is designed at 2.45 GHz.

Fig. 3: Top View of the rectangular patch A coaxial probe type feed is to be used in this design. As shown in Figure 3, the center of the patch is taken as the origin and the feed point location is given by the co-ordinates (Xf, Yf) from the origin. The feed point must be located at that point on the patch, where the input impedance is 50 ohms for the resonant frequency. Hence, a trial and error method is used to locate the feed point. For different locations of the feed point, the return loss (RL) is compared and that feed point is selected where the R.L is most negative. There exists a point along the length of the patch where the RL is minimum. Hence in this design, Yf was kept constant at zero and only Xf was be varied to locate the optimum feed point.

Parameter Dimension Unit

Dielectric constant(  r ) 4.4 Frequency( f r ) 2.45 GHz Height(h) 1.6 mm Practical Width(W) mm Velocity of Light(v) 3*10^8 ms^-1 0.001 Loss Tangent(  ) Practical Length(L) mm Table 1: Microstrip patch antenna specification IV. SIMULATED RESULTS The simulated results obtained by considering an equivalent circuit of rectangular microstrip patch antenna for calculating various parameters. The designed parameters are utilized on Zealand’s IE3D evaluation software version 9.2.

A. Return Loss: The proposed rectangular micro-strip patch antenna (RMSA) with dimensions given above in table 1 was simulated as shown in figure 2 using FR4 substrate with dielectric constant 4.4 and the substrate height is 1.6 mm, and loss tangent is 0.001 is considered [7]. The value of return loss is -23db in this proposed antenna. A negative value of return loss shows that this antenna had not many losses while transmitting the signal.

B. VSWR: The value of voltage standing wave ratio(VSWR) should be ranges from 1 to2.The return loss of the antenna obtained is -23 dB at the center frequency of 2.45 GHz as shown in Fig. 2.

Fig. 4: RL Curve VSWR parameter of a patch antenna indicates how well is the antenna matched with the feed. VSWR result obtained from the simulation is 1.3 at 2.45GHz which implies proper matching at the intended frequency.

Fig. 5: VSWR plot

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Rectangular Microstrip Patch Antenna for 2.45 GHz Wireless Applications (IJSRD/Vol. 3/Issue 08/2015/147)

[6] Dr. Max Ammnan, “Design of Rectangular Microstrip Patch Antennas for the 2.4 GHz Band” Dublin Institute of Technology [7] Pozar D.M., and Schaubert D.H (1995) Microstrip Antennas, the Analysis and Design of Microstrip Antennas and Arrays, IEEE Press, NewYork, USA

Fig. 6: Smith Chart plot

Fig. 7: 3D Radiation pattern V. CONCLUSION A microstrip patch antenna with diagonally symmetrical slot for RFID applications is presented for 2.45GHz frequency.

The results for the proposed antenna above shows that the coaxial probe fed rectangular microstrip patch antenna can be used for applications in cordless handset and for cellular applications. The resonance frequency of the simulated patch is 2.43GHz. The simulated results show that the rectangular microstrip patch antenna will be compact and low cost solution for cell phone applications in GSM band.

REFERENCES [1] Constantine. A. Balanis, Antenna Theory, Analysis and Design, John Wiley & Sons, New York, 2005 [2] Raied A. R. Ibrahim, Mustapha C.E. Yagoub, Riadh W.Y.Habash,“Microstrip Patch Antenna for RFID Applications”School of Information Technology and Engineering,University of Ottawa, Ottawa, Ontario.

Canada [3] Harvesh Singh Panwar, Firoz Khan, Puneet Khanna “Design & Analysis of Square Microstrip Patch Antenna” (IJRTE) ISSN: 2277-3878, Volume-2, Issue3, July 2013 [4] Er Nitin Agarwal, Dr.D.C.Dhubkarya, Er Rinkesh Mittal “Designing & Testing of Rectangular Micro strip antenna operating at 2.0 GHz using IE3D” Global Journal of Researches in Engineering Volume 11 Issue 1 Version 1.0, February 2011 [5] Yogesh choukiker optimization of dual band microstrip patch antenna using PSO by Department of electronic and communication engineering National Institute of Technology Rourkela India in 2009.

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