 Open Access
 Total Downloads : 1178
 Authors : Deepender Dabas, Abhishek
 Paper ID : IJERTV2IS90634
 Volume & Issue : Volume 02, Issue 09 (September 2013)
 Published (First Online): 21092013
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Design of Circular Micro strip Patch Antenna with different Slots for WLAN & Bluetooth Application
Design of Circular Micro strip Patch Antenna with different Slots for WLAN & Bluetooth Application Deepender Dabas 1, Abhishek 2
Assistant Proffesor,Dept.of ECE,Panipat Institute of Engineering&Technology,Panipat,India1
PG Scholar ,Dept.of ECE,Panipat Institute of Engineering & Technology ,Panipat India2
Abstract
In this paper, the design and analysis of circular microstrip patch antenna with different slot for the W L A N & B l u e t o o t h Application is presented.The shape of proposed antenna is circular.The operating frequency of antenna is 1.52.5 GHz, The antenna design consists of a single layer of substrate with thickness 1.6 mm with dielectric constant of 2.4.The simulation results of proposed circular microstrip patch antenna for different slots are done by the help of IE3D Zealand Software. For the analysis of antenna we used the Cavity Model. This antenna is fed by a coaxial probe feeding. The effects of different parameters like return loss, r a d i a t i o n p a t t e r n a r e studied.
KeywordsCircular Microstrip patch antenna antenna, ( C M P A ) Return loss, Radiation Pattern, Antenna efficiency, Radiation efficiency

Introduction
In recent years, the current trend in commercial and government communication systems has been to develop low cost, minimal weight, low profile antennas that are capable of maintaining high performance over a large spectrum of frequencies. This technological trend has focused much effort into the design of micro strip (patch) Antennas.The approach of the microstrip antenna enjoys all the advantages of printed circuit technology. The other drawbacks of basic microstrip structures include low power handling capability, loss, half plane radiation and limitation on the
maximum gain. For many practical designs, the advantages of microstrip antennas far compensate their disadvantages [2]. However, research is still ongoing today to conquer some of these disadvantages. This paper, introduces designing and an analysis of Circular micro strip patch antenna with different s lots for WLAN & Bluetooth applications. The circular m icro strip patch antenna as shown in Figure 1.

Antenna Design and Structure
A.Circular Microstrip Patch Antenna The proposed configuration of the antenna is shown in Figure 1. The antenna design consists substrate of a single layer of thickness 1.6 mm. The dielectric constant of the substrate is 2.4 and antenna is fabricated on RT Duroid material. as shown in Figure 1.
Figure 1.Microstrip Antenna with Circular Patch
There are different slots in designing the circular microstrip antenna,these slots are square rectangula r,cross ,U,H etc.The effect of changing The slot length and width are studied on parameters like gain,return loss, radiation efficiency,antenna efficiency etc.A coaxial probe feed is used at different points by changing the feed locations and their effect are seen on above parameters.

Design Equation
Because of fringing effect electrically the patch of antenna looks larger than its physical dimensions.The enlargement of L is given by eq 2.1shown below
Where the effective (relative) permittivity is given by eq
2.2 shown below
This is related to the ratio of h/W. The larger the h/W, smaller the effective permittivity the effective length of the patch is given by
nm
nm
f cKnm

Design Procedure
If the substrate parameter(r and h) and the operating frequency(fr) are known than we can easily calculate the dimensions of patch antenna using above simp lified equation following design equation to design
the antenna
Step 1: Using equation (2.4) to find out the resonant frequency of circular patch
Step2:Calculate the effective permittivity using the equation (2.2)
Step 3:Compute the extension of the length using the equation (2.1)
Step 4: Determine the length L by solving the equation for L giving the solution
Resonant Frequency(Fr)
1.53 GHz
Dielectric Constant (r)
2.4
Radius of circular patch (r)
25 mm
Substrate Thickness(h)
1.6 mm
Loss Tangent
0.02
Resonant Frequency(Fr)
1.53 GHz
Dielectric Constant (r)
2.4
Radius of circular patch (r)
25 mm
Substrate Thickness(h)
1.6 mm
Loss Tangent
0.02
Table 1. Dimensions of the Prescribed Antenna
.


Method of Analysis
There are many methods of analysis for microstrip antennas. The microstrip antenna generally has a two dimensional radiating patch on a thin dielectric substrate and therefore may be categorized as a two dimensional planar component for analysis purposes. The analysis methods for microstrip antennas can be broadly divided into two groups. In the first group the methods are based on equivalent magnetic current distribution around the patch edges (similar to slot antennas).
2ae r
Where the derivative of the Bessel function of Order n & c is velocity of light
There are three popular analytical techniques [3],

The Transmission Line Model

The Cavity Model

The Multiport Network Model
In the second group, the methods are based on the electric current distribution on the patch conductor and the ground plane (similar to dipole antennas used in conjunction with Full wave Simulation/Numerical analysis methods). Some of the numerical methods for analyzing microstrip antennas are listed as follows:

The Method of Moments

The FiniteElement METHOD

The Spectral Domain Technique

The FiniteDifference Time Domain Method
In this work we used the Cavity Model Method.


Results & Discussions
For the proposed circular microstrip antenna design
,IE3D software is used.The proposed antenna is designed with the circular patch radius of 25 mm with different slots e.g. square,rectangle,h,u,cross etc..The slot length and width is varied for obtaining the better return loss,gain and radiation and antenna efficiency and obtaining the resonant frequency
for the desired wireless applications of WLAN and Bluetooth applications .The feed locations are also varied at different locations points to obtain the better results.Some of better results obtained for the proposed circular microstrip patch antenna are discussed with their s parameters return loss vs frequency graph and 3D radiation pattern.

Circular Microstrip Antenna Designed without Slot
Figure 2 shows Circular Patch with Radius=25mm &Feed Location at position =(7,0)
Figure 2. Cmpa Designed without Slot
Figure 3 shows Return Loss (S11) for above antenna designed & Return loss of 20 dB is obtained at a frequency range of 2.24 GHz. as shown below
Figure 3. Return Loss vs Frequency
We obtained the following antenna parameters

Radiation Efficiency=87.67%

Antenna Efficiency=82.70 %

Gain of +6.51 dBi
Figure 4. 3D Radiaion Pattern


Cmpa Designed with Square Slot
Figure 5 shows Circular Patch with square slot with slot length and width l,w =(7,7) at Feed Location ( 7,0) & at Slot position (7,7)
Figure 5.Cmpa Designed with Square Slot
Figure 6 shows Return Loss (S11) for square slotted antenna & the Return loss of 14.2 dB is obtained at a frequency range of 2.17 GHz as shown below:
Figure 6.Return Loss vs Frequency
We obtained the following antenna parameters in square slotted antenna

Radiation Efficiency=88.47%

Antenna Efficiency=84.98 %

Gain of 6.59 dBi
Figure 7 shows 3D radiation pattern
Figure 7. 3D Radiation Pattern


Cmpa Designed with Rectangular Slot
Figure 8 shows Circular Patch with rectangular slot with Feed Location (7,0) & Slot position at (10,10) with slot length and width l,w (7,5)
Figure 8.Cmpa Designed with Rectangular Slot
Figure 9 shows Return Loss (S11) for rectangular slotted antenna & theReturn loss of 14 dB is obtained at a frequency range of 2.17 GHz as shown below:
Figure 9. Return Loss vs Frequency
We obtained the following antenna parameters in rectangular slotted antenna

Radiation Efficiency=88.32%

Antenna Efficiency=83.88 %

Gain of+ 6.53 dBi
Figure 10.3D Radiation Pattern


Cmpa Designed with H Slot
Figure 11 shows Circular Patch with H slot with slot length and width l,w (7,2) at Feed Location (22,0)
Figure 11. Cmpa Designed with H Slot
Figure 12 shows Return Loss (S11) for above antenna designed &
Return loss of 31 dB is obtained at a frequency range of 1.7 GHz as shown below:
Figure 12. Return Loss vs Frequency
We obtained the following antenna parameters in H slotted antenna

Gain of 10.84 dBi

Radiation Efficiency=6.23%

Antenna Efficiency= 5.4%
Figure 13 shows 3D radiation pattern for H slotted antenna
Figure 13. 3D Radiation Pattern


Cmpa Designed with Cross Slot
Figure 14 shows Circular Patch with cross slot with slot length and width l, w (10,3) at Feed Location ( 7,0) & Slot Position(7,7)
Figure 14. Cmpa Designed with Cross Slot
Figure 15 shows Return Loss (S11) for cross slotted antenna
Return loss of 9 dB is obtained at a frequency range of 2.13 GHz as shown below:
Figure 15. Return Loss vs Frequency
We obtained the following antenna parameters in cross slotted antenna

Gain of +5.93 dBi

Radiation efficiency=78.31%

Antenna efficiency=72.98 %
Figure 16 shows 3D radiation pattern for cross slotted antenna
Figure 16. 3D Radiation Pattern
4.6 Cmpa Designed with U Slot
Figure 17 shows Circular Patch with U slot with slot length and Width l,w (7,2) at Feed Location (0,22)
Shape of Slots
Reso nant frequ ency (fo) GHz
Retu rn Loss (dB)
Gain( dBi)
Antenna Efficien cy ()%
Radiat ion Effici ency ()%
Feed Positi on(x,y
)
Withou t Slot
2.24
20
+6.51
82.70
87.67
(7,0)
Square
2.17
14.2
+6.59
84.98
88.47
(7,0)
Rectan gle
2.17
14
+6.53
83.88
88.32
(7,0)
H
1.7
31
– 10.84
5.4
6.23
(22,0)
Cross
2.13
9
+5.93
72.98
78.31
(7,0)
U
1.7
24
– 10.69
52.57
35.68
(0,22)
Shape of Slots
Reso nant frequ ency (fo) GHz
Retu rn Loss (dB)
Gain( dBi)
Antenna Efficien cy ()%
Radiat ion Effici ency ()%
Feed Positi on(x,y
)
Withou t Slot
2.24
20
+6.51
82.70
87.67
(7,0)
Square
2.17
14.2
+6.59
84.98
88.47
(7,0)
Rectan gle
2.17
14
+6.53
83.88
88.32
(7,0)
H
1.7
31
– 10.84
5.4
6.23
(22,0)
Cross
2.13
9
+5.93
72.98
78.31
(7,0)
U
1.7
24
– 10.69
52.57
35.68
(0,22)
Figure 17. Cmpa Designed with U Slot
Figure 18 shows Return Loss (S11) for above antenna designed & Return loss of 24 dB is obtained at a frequency range of 1.7 GHz as shown below:
Figure 18. Return Loss vs Frequency
We obtained the following antenna parameters in U slotted antenna
Gain= 10.69 dBi , Antenna Efficiency=52.57% Radiation Efficiency=35.68 %
Figure 19.3D Radiation Pattern
Table 2. Result Comparison



Conclusion and Future Prospectus
This paper presents the designing and analysis of the Circular Microstrip patch antenna is done using IE3D software and analysis is done by using Cavity Model method. In this paper, the prescribed antenna design is simulated over the value of the return loss and gain,antenna and radiaton efficiency From the simulation results, we can say that the s q u a r e s l o t c i r c u l a r microstrip antenna gives the better results at operating frequency 2 . 17 GHz. Without changing the permittivity and height of the substrate, the effect of various parameters of Cmpa are studied. In simulation and measurement the return loss has a negative which states that the losses are minimum during the transmission. Circular Micro strip patch antenna were successfully incorporated with H, U, +, Rectangle & square slots The effect of varying the slot width and slot length were studied under great details with the help of experimental results. The proposed patch yield desirable results throughout the operating frequency range. Above all, the Cmpa
designed with square slot gave the better results with gain of + 6.59 dBi &antenna efficiency 84.98 % and radiation efficiency 88.47 % at resonance frequency of 2.17 GHz and we obtained the minimum return loss of 31 dB of CMPA designed for H slot.Thus the
proposed antenna can be used for WLAN & Bluetooth application with the resonant frequency between 1.53 GHz. In future others different type of feed techniques a n d d i f f e r e n t m e t h o ds o f a na l ys i s m od e l s can be used to calculate the overall performance of the antenna without missing the optimized parameters in the action. The gain, antenna e f f ic i ency, rad iatio n efficiency can further enhanced by incorporated the different type of slots cutting in conventional circular microstrip patch antenna and using different substrate we can further achieved the better antenna parameters. and designed Cmpa can be used in high frequency range of wireless communication e.g. WIMAX ,X Band ,KU Band etc.
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