TECHNICAL FEATURE
DESIGN OF A DUAL-BAND
PLANAR DIPOLE ANTENNA
FOR WLAN APPLICATIONS
In this article, a dipole antenna is designed to operate in the 2.4 and 5.2 GHz
WLAN bands. A novel T-shape slit is embedded in the dipole antenna to achieve
dual-band operation for WLAN applications, and to avoid increasing the area
of the antenna. The antenna has the dimensions of 7 × 43. 96 × 0.8 mm and good
radiation characteristics. The fabricated antenna has a dual-band bandwidth
covering 2.23 to 2.62 GHz and 4.84 to 5. 38 GHz. The effects of the antenna
parameters (S1, S2 and L3) on the operating band are studied by using various
lengths of the T-shape slit.
L1
W1 WSUB
W2
L2
L4
S1
L3 L2
There has recently been much research on broadband and multi-band antennas for various wireless communication systems. The IEEE has issued regulations for the
wireless local area network (WLAN, 802.11a/b)
since 1999. The development of WLAN has already reached maturity and has become fairly
universal. The development of antennas used
on mobile communication devices is extremely
important. The advantages of the printed dipole antenna1,2 include low profile, light weight
and low cost. Furthermore, it is very suitable
for installation in notebook computers. A dipole antenna
was reported2
where an embedded U-shaped slot in
the two rectangular arms
produced two
additional dipole arms.
These two dipole arms enable the di-
H
X
Z
Y
W3
S2
LSUB
G
pole antenna to generate a lower and a higher
frequency resonance. Similarly, a different
shaped slot, embedded in the dipole antenna,
can produce two additional dipole arms.
3, 4 Two
designs5, 6 of monopole antennas consist of two
strips with the same width and different length.
These strips can generate different operating
frequency bands.
In this article, a rectangular dipole antenna
is demonstrated, where two embedded T-shape slits generate a new resonant mode to
achieve dual-band operation from 2.23 to 2.62
and 4.84 to 5. 38 GHz for WLAN applications.
The proposed antenna is fed with a 50 V mini
coaxial line. The advantages of the proposed
antenna include small size, low cost, easy fabrication. It is very suitable for installation in
a notebook computer, Personal Digital Assistant (PDA) and other mobile communication
devices. Detail design steps and experimental
results for the designs are studied and investigated in this article.
WEN-SHAN CHEN AND
SHIH-HUNG CHENG
Southern Taiwan University, Taiwan, ROC
