In this paper, a dual band rectangular microstrip patch antenna with microstrip line is presented. The proposed antenna is designed on FR4 substrate with thickness 1.5 mm and relative permittivity 4.3. The antenna is designed to operate at 2.4/5.8 GHz bands for Wi-Fi/WiMax applications. The obtained return loss is -32.77dB at 2.4 GHz with 7.4% bandwidth and -25.955 dB at 5.8 GHz with 8.17% bandwidth. The practical and simulation result are computed. It is noted that there is a good agreement between the simulation and measured result (using vector network analyzer (VNA).
2. TELKOMNIKA ISSN: 1693-6930
Design of Dual Band Microstrip Antenna for Wi-Fi… (Raad H. Thaher)
2865
A planar Multiband Antenna for GPS, ISM and WiMAX Applications was propsed in [10].
The antenna’s entire area is 59.5x47 mm2 and is printed on an FR-4 substrate and fed by a
50 Ohm microstrip line. Inset Feed Toppled H-Shaped Microstrip Patch Antenna for
PCS/WiMAX Application was proposed in [11]. H-shaped microstrip patch antenna with
grounded plane is investigated for triple band operation. Theproposed antenna of dimension
40×40 is designed on FR4 substrate with dielectric constant εr=4.4 and height h=1.60 mm.
In this paper, a rectangular dual-band microstrip antenna for WiFi/WiMax applications in
2.4/5.8 GHz bands is presented. The antenna consists of a rectangular patch that contains five
rectangular and a rectangular slot in ground plane. The slot in the ground enhances the gain
and bandwidth while the slots in the patch improves the return loss. The proposed antenna is
simulated using CST microwave studio 2016 and the obtained radiation characteristics of the
antenna are presented.
2. Antenna Design
The geometry of the proposed antenna is illustrated in Figure 1, it consists of a
rectangular patch whose width and length are 18.2 mm and 22 mm respectively. The dielectric
material selected for the design is FR-4 which has a dielectric constant 4.3 and a thickness
h=1.5 mm. The antenna is fed by a 50Ω microstrip line with a width 3.7 mm for impedance
matching. Five rectangular slots are etched on the patch which helps achieve dual band
radiation at the desired frequencies. The patch and ground plane are made of copper with
thickness 0.035 mm. A rectangular slot is introduced in ground which has dimension of
40×40 mm. Tables and Figures are presented center, as shown below and cited in the
manuscript.
(a) (b)
Figure 1. Geometry of the proposed antenna: (a) front view (b) back view
Table 1. Design Parameters of the Proposed Antenna
Value (mm)Antenna Parameters
40 ×40Length and width of ground (𝐿 𝑔 × 𝑊𝑔)
40×40Length and width of substrate ( 𝐿 𝑠 × 𝑊𝑠 )
18.2Patch width (W)
22Patch length(L)
3.7Feeder width(𝑊𝑓)
9Feeder length(𝐿 𝑓)
The following equations are used to calculate the dimensions of microstrip antenna [1].
The width of patch is found by:
𝑤 =
𝐶
2𝑓0√
𝜀 𝑟+1
2
(1)
where C is the velocity of light , 𝑓0 is the resonant frequency and 𝜀 𝑟 is the dielectric constant of
substrate. The following equations gives effective dielectric constant of substrate and length
extension ∆𝐿:
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TELKOMNIKA Vol. 16, No. 6, December 2018: 2864-2870
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𝜀 𝑒 =
𝜀 𝑟+1
2
+
𝜀 𝑟−1
2
(1+12
ℎ
𝑤
)−
1
2 (2)
where h is high of substrate.
∆𝐿 =
ℎ
√ 𝜀 𝑟
(3)
The length of the patch is found from:
L =
ℎ
2 𝑓0√ 𝜀 𝑟
− ∆𝐿 (4)
the length and width of the ground are given by the following equations:
𝐿 𝑔 = 𝐿 + 6ℎ (5)
𝑤𝑔 = 𝑤 + 6ℎ (6)
feeder length 𝐿𝑓 and feeder width 𝑤𝑓 for the microstrip feed line are obtained by the following
equations:
𝐿𝑓 =
6ℎ
2
(7)
𝑧0 =
87
√𝜀 𝑟+1.41
ln
5.98ℎ
0.8𝑤 𝑓
(8)
3. Parametric Study
A parametric study is done for obtaining the best parameters for the antenna. The effect
of changing the width, length of patch and width of transmition feed to the return loss are
studied as shown in Figure 2, Figure 3 and Figure 4.
As seen from Figure 2, Figure 3 and Figure 4, changing width of patch effects on the
5.8 GHz frequency mostly. As the value of W increases, the 5.8 GHz frequency is shifted to the
left. W=18.2 mm is chosen for having the best compromise between return loss and bandwidth.
On the other hand, changing patch length affects the 2.4 GHz frequency more. As the value of L
increases, the 2.4 GHz shifted to left and 5.8 GHz shifted to right. L=22 mm is chosen to obtain
radiation at 2.4 GHz and 5.8 GHz. As for the effect of feeder width, its value affects the
impedance matching of microstrip feed to the impedance. 𝑊𝑓=3.7 mm is chosen as the best
value where a good impedance marching is obtained at the two frequencies.
Figure 2. Effect of changing patch width to the reflection coefficient
4. TELKOMNIKA ISSN: 1693-6930
Design of Dual Band Microstrip Antenna for Wi-Fi… (Raad H. Thaher)
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Figure 3. Effect of changing patch length to the reflection coefficient
Figure 4. Effect of changing feeder width to the reflection coefficient
4. Results and Discussion
The return loss vs. frequency of the proposed antenna is shown in Figure 5. The return
loss is found at 2.4 GHz and 5.8 GHz 32.77 dB and -25.955 dB respectively. The band width
obtained at these frequencies are 7.4% in the range (2.3 GHz-2.492 GHz) and 8.17% in the
range (5.586 GHz-6.06 GHz).
Figure 5. Return loss vs frequency of proposed antenna
Figure 6 shows the graph of VSWR at center frequencies for the proposed antenna less
than 2. VSWR (voltage standing wave ratio) or standing wave ratio as a function of reflection
coefficient, which explains power reflected from antenna.
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Figure 6. VSWR vs frequency of proposed antenna
VSWR =
Γ+1
Γ−1
(9)
VSWR is always real and positive value for practical applications. Small value of VSWR
means that the antenna is matched with the transmission line. Antenna is ideal at VSWR value
equal to be 1. When antenna and feed are not matched, some electric energy cannot transfer to
the antenna (i.e. reflection occurs). The polar plots for the directivity characteristic for the two
frequencies are shown in Figure 7. The Gain of the proposed antenna for the two frequencies is
shown in Figure 8. The 3D-radiation pattern for the proposed antenna for the two frequencies is
shown in Figure 9. Figure 10 shows the current distribution for the proposed antenna at the
designed frequencies.
(a) (b)
Figure 7. Polar plots for the directivity characteristic of the proposed antenna: (a) at 2.4GHz
(b) at 5.8GHz
Figure 8. Gain of the proposed antenna: (a) at 2.4GHz and (b) at 5.8GHz
6. TELKOMNIKA ISSN: 1693-6930
Design of Dual Band Microstrip Antenna for Wi-Fi… (Raad H. Thaher)
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(a) (b)
Figure 9. 3D-radiation pattern for the proposed antenna: (a) at 2.4GHz and (b) at 5.8GHz
(a) (b)
Figure 10. Current distribution for the proposed antenna: (a) at 2.4GHz and (b) at 5.8GHz
Figure 11 shows the simulation and the measured results. It is noted that there is a
slight different between the measured and simulation result. This different is attributed to the
manufacturing errors which consist of variation of 𝜀 𝑟 with the frequency, fringing effect and due
to discontinuity. Fabricated antenna of front view and back view as shown in Figure 12.
Figure 11. Measured and simulated reflection coefficient versus frequency
Table 2 shows a comparison among the proposed antenna and antenna in refrence in
term of antenna size, resonant frequency and porpose of antenna. As we seen from this table
that the proposed antenna is smaller in size and sutable for dual band.
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TELKOMNIKA Vol. 16, No. 6, December 2018: 2864-2870
2870
(a) (b)
Figure 12. Fabricated antenna (a) front view (b) back view
Table 2. A comparison Among the Proposed Antenna and Antenna in Reference
Antenna Antenna size (𝑚𝑚2
) Resonant frequency GHz Antenna porpose
Proposed antenna 40 × 40 2.4/5.8 Dual band
[3] 60 × 60 3.5 /5 Dual band
[4] 49 × 53 3.5/5.2 Dual band
[9] 44 × 44 1.8/2.1/3.5 Tri-band
[10] 59.5x47 1.56/2.45/3.53 Tri-band
5. Conclusions
In this paper, a dual band rectangular microstrip antenna at 2.4 GHz/5.8 GHz bands for
Wi-Fi/WiMax applications is presented. The antenna consists of a rectangular patch with five
slot in and a rectangular slot in ground. The result shows acceptable return loss, bandwidth and
gain making it suitable for Wi-Fi/WiMax. The proposed antenna has two bands
(2.314-2.492) GHz and (5.586-6.06) GHz in which the reflection coefficient is less than
-10 dB.The proposed antenna was fabricated and simulated result (using CST) and measured
result (using VNA) are obtained and compared.
References
[1] MA Ali. Design of Fractal Minkowski Diversity Antenna for LTE and Wi-Fi Application. Master degree
thesis. Tun Hussein Onn University. Malaysia. 2015.
[2] S Maci, GB Gentili. Dual-frequency patch antennas. IEEE Antennas and Propagation Magazin. 1997;
39(6).
[3] S Alam, SK Khan, L Saha, MH Pavel, T Rahman. Dual Band Two Elements Inverted-L Antenna for
3.5 & 5 GHz Mobile WiMAX/Wi-Fi Applications. International Journal of Computer Science &
Engineering Survey. 2011; 2(2).
[4] AA Yassin, RA Saeed, RA Mokhtar. Dual-Band Microstrip Patch Antenna Design Using C-Slot for
WiFi and WiMAX Applications. IEEE 5th International Conference on Computer & Communication
Engineering. Malaysia. 2014.
[5] P Bhagat, P Jain. Triple Band Microstrip Patch Antenna with Dual U Slot for WLAN/WIMAX
Applications. SSRG International Journal of Electronics and Communication Engineering. 2014; 1(7).
[6] GV Kumari, PV Chowdary, K Madhulatha, MD Kumar, KA Sagar. A 9 Slots dual band Microstrip
Patch Antenna for Wireless Applications. International Journal of Advanced Research in Computer
and Communication Engineering. 2015; 4(3).
[7] YP Lakshmi, MU Rao, BS Babu. A Dual band Human Shaped Microstrip Patch Antenna for 2.4 GHz
and 5.4 GHz Applications. International Journal of Innovative Research of Research in Electrical,
Electronics, Instrumentation and Control Engineering. 2015; 3(3).
[8] E Sidhu, A Kumar, A Singh. Horse-Shoe Shaped Stacked Microstrip Patch Antenna for WLAN,
WiMAX and IMT Applications. An International Journal of Engineering Sciences. 2016; 17.
[9] MT Guneser, Cihatseker. Tri-Band Compact Microstrip Antenna with Multi slots for
GSM/UMTS/WiMAX Applications. Proceedings of 65th ISERD International Conference, Saudi
Arabia. 2017.
[10] Zahraoui, A Errkik, MC Abounaima, A Tajmouati, LE Abdellaoui, M Latrach. A New Planar Multiband
Antenna for GPS, ISM and WiMAX Applications. International Journal of Electrical and Computer
Engineering (IJECE). 2017; 7(4).
[11] M Aneesh, MG Siddiqui, JA Ansari, A Singh, Kamakshi. 'Inset Feed Toppled H-Shaped Microstrip
Patch Antenna for PCS/WiMAX Application. Indonesian Journal of Electrical Engineering and
Computer Science. 2016; 1(2).
![TELKOMNIKA, Vol.16, No.6, December 2018, pp.2864~2870
ISSN: 1693-6930, accredited First Grade by Kemenristekdikti, Decree No: 21/E/KPT/2018
DOI: 10.12928/TELKOMNIKA.v16i6.10016 2864
Received May 26, 2018; Revised September 17, 2018; Accepted October 8, 2018
Design of Dual Band Microstrip Antenna for Wi-Fi and
WiMax Applications
Raad H. Thaher1
, Zainab S. Jamil*2
Department of Electrical Engineering, Almustansiryiah University, Iraq
*Corresponding author, e-mail:raadthaher55@gmail.com1
, zainab.sj12@gmail.com2
Abstract
In this paper, a dual band rectangular microstrip patch antenna with microstrip line is presented.
The proposed antenna is designed on FR4 substrate with thickness 1.5 mm and relative permittivity 4.3.
The antenna is designed to operate at 2.4/5.8 GHz bands for Wi-Fi/WiMax applications. The obtained
return loss is -32.77dB at 2.4 GHz with 7.4% bandwidth and -25.955 dB at 5.8 GHz with 8.17% bandwidth.
The practical and simulation result are computed. It is noted that there is a good agreement between the
simulation and measured result (using vector network analyzer (VNA).
Keywords: dual band, microstrip antenna, Wi-Fi, WiMax
Copyright © 2018 Universitas Ahmad Dahlan. All rights reserved.
1. Introduction
Microstrip antennas are considered as one of the most used and preferred antennas
compared with regular microwave antennas, and that is due to the fact that these sorts of
antennas are low volume, light weight and thin profile arrangements, which can be made
conformal. The cost of fabrication is likewise low. As a result of these features, they can be
made in extensive amounts. For the polarization sorts, it can bolster both circular and linear
polarization relying upon the radiation design. Microstrip antennas additionally are equipped for
double and even triple frequency operations which is very desirable [1].
Nowadays, wireless communication systems such as WLAN/Wi-Fi or WiMax require
compact and low cost antennas; therefore, microstrip antennas are widely used in these
systems. In spite of their advantages, microstrip antennas have a main limitation in its narrow
bandwidth. A valid solution to widen the bandwidth is dual band operation antennas [2].
There are many dual band antennas proposed for WiFi/WiMax applications. A dual
band inverted-L antenna at 3.5 GHz and 5 GHz was presented in [3]. This antenna has a
simple structure and a single feed aimed for mobile WiMAX and Wi-Fi operation. The overall
dimensions of the antenna was 20×30 mm2 fed by a coaxial connector and ground plane of
60×60 mm2.
Similarly a dual band microstrip antenna patch antenna for WiMAX and Wi-Fi at a
resonant frequencies of 3.5 GHz and 5.2 GHz was proposed in [4]. Epoxy FR-4 substrate
having a dielectric constant of 4.3 with overall size of 49 ×53 1.67 mm3. A microstrip patch
antenna with dual U slot for WLAN/WIMAX applications was proposed in [5]. FR4 substrate
having 4.4 dielectric constant with 1.6 mm thickness and patch dimension of 40×47 mm2.
Likewise, A 9 Slots dual band microstrip patch antenna for wireless applications was
proposed in [6]. The antenna was fed with coaxial feed and used FR4 material as substrate with
4.4 dielectric constant and dimensions of 80x120x3.4 mm. A human shaped microstrip patch
antenna for Wi-Fi and WiMAX applications was proposed in [7]. The designed antenna used air
as substrate with 3.2 mm thickness and 1.0006 permittivity with size of 120×100×3.2 mm3.
Also, a horse-shoe shaped stacked microstrip patch antenna for WLAN, WiMAX and
IMT applications was proposed in [8]. The antenna had a horse-shoe shaped patch placed on
the upper surface of the rigid substrate with an overall dimensions of 40×50 mm2. A a tri-band
microstrip patch antenna aimed at GSM, UMTS and WiMAX applications was presented in [9].
FR-4 substrate was used for the proposed antenna that have 4.4 dielectric constant and
0.02 loss tangent with 1.6 mm thickness and overall size of 44×44×1.6 mm3.](https://image.slidesharecdn.com/4510016-200901085813/85/Design-of-Dual-Band-Microstrip-Antenna-for-Wi-Fi-and-WiMax-Applications-1-320.jpg)
![TELKOMNIKA ISSN: 1693-6930
Design of Dual Band Microstrip Antenna for Wi-Fi… (Raad H. Thaher)
2865
A planar Multiband Antenna for GPS, ISM and WiMAX Applications was propsed in [10].
The antenna’s entire area is 59.5x47 mm2 and is printed on an FR-4 substrate and fed by a
50 Ohm microstrip line. Inset Feed Toppled H-Shaped Microstrip Patch Antenna for
PCS/WiMAX Application was proposed in [11]. H-shaped microstrip patch antenna with
grounded plane is investigated for triple band operation. Theproposed antenna of dimension
40×40 is designed on FR4 substrate with dielectric constant εr=4.4 and height h=1.60 mm.
In this paper, a rectangular dual-band microstrip antenna for WiFi/WiMax applications in
2.4/5.8 GHz bands is presented. The antenna consists of a rectangular patch that contains five
rectangular and a rectangular slot in ground plane. The slot in the ground enhances the gain
and bandwidth while the slots in the patch improves the return loss. The proposed antenna is
simulated using CST microwave studio 2016 and the obtained radiation characteristics of the
antenna are presented.
2. Antenna Design
The geometry of the proposed antenna is illustrated in Figure 1, it consists of a
rectangular patch whose width and length are 18.2 mm and 22 mm respectively. The dielectric
material selected for the design is FR-4 which has a dielectric constant 4.3 and a thickness
h=1.5 mm. The antenna is fed by a 50Ω microstrip line with a width 3.7 mm for impedance
matching. Five rectangular slots are etched on the patch which helps achieve dual band
radiation at the desired frequencies. The patch and ground plane are made of copper with
thickness 0.035 mm. A rectangular slot is introduced in ground which has dimension of
40×40 mm. Tables and Figures are presented center, as shown below and cited in the
manuscript.
(a) (b)
Figure 1. Geometry of the proposed antenna: (a) front view (b) back view
Table 1. Design Parameters of the Proposed Antenna
Value (mm)Antenna Parameters
40 ×40Length and width of ground (𝐿 𝑔 × 𝑊𝑔)
40×40Length and width of substrate ( 𝐿 𝑠 × 𝑊𝑠 )
18.2Patch width (W)
22Patch length(L)
3.7Feeder width(𝑊𝑓)
9Feeder length(𝐿 𝑓)
The following equations are used to calculate the dimensions of microstrip antenna [1].
The width of patch is found by:
𝑤 =
𝐶
2𝑓0√
𝜀 𝑟+1
2
(1)
where C is the velocity of light , 𝑓0 is the resonant frequency and 𝜀 𝑟 is the dielectric constant of
substrate. The following equations gives effective dielectric constant of substrate and length
extension ∆𝐿:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)