Thiết kế anten vi dải phân cực tròn cho ứng dụng WLAN dải tần 2,4 GHz pot

T Phn A: Khoa hc T  ng: 26 (2013): 97-104

97

THIT K ANTEN VI DNG DNG WLAN
DI TN 2,4 GHZ
c Li
1
c Danh
2
1
H thun ti hph H 
2
B n t Vii hc C
Thông tin chung:
 08/01/2013
19/06/2013

Title:
Design of a Circularly Polarized
Microstrip Antenna for 2.4 GHz
WLAN Applications
Từ khóa:

WLAN
Keywords:
Microstrip antennas, circular
polarization, WLAN
ABSTRACT
This paper presents a circularly polarized microstrip antenna used
for 2.4 GHz WLAN applications. The designed antenna consists of a

circular patch fabricated on FR-4 substrate with a V-shaped slot
carved on its surface and a circular metal plate (reflector). The
antenna substrate is stacked above the reflector by a small distance.
The antenna size and positions of the two feeding ports using
coaxial cables are optimized to have a circularly polarized antenna
with resonant frequency at 2.44 GHz, 8.43-dBi peak gain, and the
isolation between the two ports below -20 dB. The simulation results
show good agreement with the measurement. The proposed antenna
can be used for 2.4 GHz wireless access points (APs) with 2x2
multiple-input multiple-output (MIMO) antenna systems.

 

-
           -4



-


         
2x2.

1 
   th    
chu ph thuc rt nhi
th    c bit, loi anten vi
di (microstrip antennas) v  m nh
g to th lc

s dng ph bi th
 n hi i. Anten vi d  i anten
  xu   i G. A. Deschamps
    c


-Elnaga, E. A. F. Abdallah,
and H. El-Hennawy thit k   c
ng cho b c th RFID (radio 
T Phn A: Khoa hc T  ng: 26 (2013): 97-104

98
frequency identification) di tn s 2,4 GHz
[3], Dau-Chyrh Chang, Bing-Hao Zeng, and
Ji-Chyun Liu vi thit k anten mng hiu sut
cao [4]. Anten vi d u dng c
 l
th c thit k  ng ng dng c
th [5].
in t 
 mt gi u
qu   gim  ng ca hi ng
phn x      c
bing hi s dng di
chuyn vi tr      
nhi   i thi    
c     trong thi gian qua,
chng h



       
Nc
thit k m li cao,
tin bng trc vng
dng cho h thng WLAN di tn 2,4 GHz.
Vi khe kh m bc x bng
vt liu mch in FR- 
a anten (S
12
, S
21
c ci thin khong
6 dB so vi loc ch
m bc x FR-c
thit k   c s d  t anten
t b
i h thng MIMO 2x2. Kt
qu  
x S
11
, S
22
, S
12
, S
21
i kt qu
 c thc t  li c   c
kim chng thc t 
 dng AP vi anten  li 4 dBi.

2 
    
     


         

  
u cho vic thit k anten ch c
ng. T        
 tng anten s
dng phn mm Ansys HFSS [11].
     u ca anten

Tn s cng
c
a
f
re
r

2
8412.1

(1)
  u dng ca t  c
c:
0.5
2
1 ln 1.7726

2
e
r
ha
aa
ah





  






(2)
Tn s cng ca anten
GHzf
r
44.2
.
Mch in FR-4 vi: Hng s 
6.4
r

 m mch in
mmh 6.1

.
1.8412
2
e
rr
ac
f


(3)
0.5
2
1 ln 1.7726
2
F
a
hF
Fh
r

















(4)
Vi:
9
8.791 10
rr
F
f



(5)
Mt phn x ng

2
.
Kho  a mt phn x  m

10

.
V t port
4
0

r

.
Vi

c:
57
rr
c
mm
f



(6)
 ci thi       
ca anten, mt khe kh c to
n tm mch in FR-
c ca khe kh nh
b
T Phn A: Khoa hc T  ng: 26 (2013): 97-104

99
   u ch   c
c   n m  ng HFSS
nh
c t       
t  n x bng kim lo   
r
1
= 55 mm, bn mc x FR-
     m kim loi mt

kho  
2

) h
2
= 6 mm, tm mch in
FR-  ng s  
6.4
1


  
h
1
= 1.6 mm. Mn tm mch in FR-4
khc m i
c r
2
= 3 mm, b = 10 mm,
c = 13 mm, d = 4 mm. Cc
th hin  
Bng k thut tiu bng
trc vi 2 
t khong r
0

c cc t
 c s phi hp tr 
ng ti tn s
  li, suy hao

phn x        c
t ra.



















3 
c thit k n
m  c
c b
R&S ZBV8. T kt qu c
c th hi   t anten
n s cng ti 2,44 GHz,
 l    s
phn x S

11

22
 
 
12
 S
21

Bn m
o
o

r
o
r
o
a

r
2
d
d
c
c
b
b
r
1
Tm phn x


T Phn A: Khoa hc T  ng: 26 (2013): 97-104

100
ph i kt qu  
  s ng t


0

200 MHz.
 kim nghim thc t v  li,
anten c g t access point WLAN
di tn 2,4 GHz, chu
2x2 (vi 2 anten bc x   li 4
dBi). Kt qu  a
 c  
mnh cng
l 
u c
ng l72
   n mm Netstumbler [12]
      c s dng
     t qu  ng 
 ngh, vi khe
khc ch m bc x FR- 
ly S
12
(S
21

) trong di tn s 2,4 ~ 2,5 GHz
c ci thin khong 6 dB so vi lo

Kt qu  S
11
, S
22

hp vi s lic thc t. Kt qu c
thc nghi u
c c
vng hp s dng cng
 l    kt lun anten
c thit k       
 
u.

 th bc xa anten

 th bc xa anten
T Phn A: Khoa hc T  ng: 26 (2013): 97-104

101

 s phn x S11

 s phn x S
22

 

1 2 3 4 5 6 7 8
-35
-30
-25
-20
-15
-10
-5
0
5
Frequency [GHz]
S11 dB
S
11


simulated
Measured
1 2 3 4 5 6 7 8
-40
-35
-30
-25
-20
-15
-10
-5
0
5
Frequency [GHz]

S22 dB
S
22


simulated
Measured
1 2 3 4 5 6 7 8
-35
-30
-25
-20
-15
-10
-5
0
Frequency [GHz]
S12 dB
S
12


simulated
Measured
T Phn A: Khoa hc T  ng: 26 (2013): 97-104

102

(a)

(b)
 s ng VSWR  




T Phn A: Khoa hc T  ng: 26 (2013): 97-104

103





t qu
12
(S
21
) v
4 
M    c thit k
cho ng dng WLAN di tn 2,4 GHz. Kt
qu v  li, tn s cng, h s phn
x  c bng
 ng s dng phn mm Ansys HFSS
p vi kt qu c thc tu
 ng t  c thit k   
c ra v  l 
     c s d  t
       

WLAN 2,4 GHz vi h thng anten MIMO
2x2.
LI CM T
        ph
       
t  i h     
 tr trong vic 
ca anten.
2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3
-35
-30
-25
-20
-15
-10
-5
0
5
Frequency [GHz]
S12 dB
S
11


Co khe chu V
Khong co khe chu V
T Phn A: Khoa hc T  ng: 26 (2013): 97-104

104
O

1. 
 Proceedings of Third USAF
Symposium on Antennas, 1953.
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Communications, Chap. 5, Wiley, New York,
2003.
3. T. G. Abo-Elnaga, E. A. F. Abdallah, and H.
El-Hennawy, UWB Circular Polarization
RFID Reader Antenna for 2.4 GHz Band,
PIERS Proceedings, Xi'an, China, March 22 
26, 2010.
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Chyun Liu, High Performance Antenna Array
with Patch Antenna Elements, PIERS
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Microstrip Antennas, Peter Peregronic Ltd.,
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6. V. G. Kasabegoudar and K. J. Vinoy, a
broadband suspended microstrip antenna for
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resonator antennas using a single probe feed,
Progress In Electromagnetics Research C, Vol.
3, 81  94, 2008.
8. Wan
single layer wideband U-Slot microstrip patch

IEEE Antennas Wireless
Propag. Lett., Vol. 7, 9  12, 2008.
9. -gain
multilayered antenna for wireless
Microw. Opt. Technol. Lett.,
Vol. 5, No. 7, 1923  1929, 2008.
10. -fed stack
patches," IEEE Trans. Antennas Propag., Vol.
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11. Ansys HFSS software. URL:

12. Netstumbler software. URL: