2366 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 16, 2017
A Compact Wideband Dual-Polarized Slot Antenna
With Five Resonances
Biao Peng, Shufang Li, Senior Member, IEEE, Jianfeng Zhu, Li Deng, and Yue Gao, Senior Member, IEEE
Abstract—This letter presents the design and analysis of a
compact dual-polarized slot antenna using a triple-mode stepped
slot-line resonator and a dual-mode cross-shaped monopole. The
orthogonal polarization is achieved by feeding the two ports
symmetrically at the opposite positions of the slot. All the five
resonance frequencies can be flexibly adjusted by tuning different
dimension parameters, so by increasing the frequency difference
between the five resonance modes, a very wide common operating
band (1.63–2.93 GHz) is obtained and also with a high port
isolation (<−32 dB). Finally, by loading two grounded lumped
capacitors on the cusp sections of the monopole, its second
resonance frequency can be independently reconfigured.
Index Terms—Compact, dual polarization, high isolation, mul-
timode, wideband slot antenna.
I. INTRODUCTION
P
OLARIZATION diversity is an effective operation in
modern multiple-input–multiple-output telecommunica-
tion systems, so the design of dual-polarized antenna is impor-
tant in both academics and industry. Compared to the space and
radiation pattern diversity antennas, dual-polarized antennas can
probably be designed with higher port isolation using simpler
antenna structures due to the orthogonal performance. As pre-
sented in [1], a dual-polarized base station antenna was designed
with port isolation lower than −36 dB without utilizing decou-
pling elements. In the next-generation mobile communication
systems, smart devices with wider range of telecommunica-
tion frequencies will be required to cover multicommunication
channels, so dual-polarized antennas with compact size, high
port isolation, and also wide operating band will definitely be
in high demand.
Compared to three-dimensional structures, planar antennas
are much more compact and easier to fabricate. As shown in
[2] and [3], planar dual-polarized antennas were designed with
compact size and also high isolation. However, these structures
need complex feeding networks to implement the orthogonal
performance, and the antenna fractional bandwidths (FBWs) are
Manuscript received May 7, 2017; accepted June 9, 2017. Date of publication
June 22, 2017; date of current version August 14, 2017. This work was supported
by the National Natural Science Foundation of China under Grant 61427801
and Grant 61601040. (Corresponding author: Shufang Li.)
B. Peng, S. Li, J. Zhu, and L. Deng are with the Beijing Key Laboratory of
Network System Architecture and Convergence, Beijing University of Posts and
Telecommunications, Beijing 100876, China (e-mail: pengbiao688@163.com;
lisf@bupt.edu.cn; zhujianfeng@bupt.edu.cn; dengl@bupt.edu.cn).
Y. Gao is with the School of Electronic Engineering and Computer Sci-
ence, Queen Mary University of London, London E1 4NS, U.K. (e-mail:
yue.gao@ieee.org).
Color versions of one or more of the figures in this letter are available online
at http://ieeexplore.ieee.org.
Digital Object Identifier 10.1109/LAWP.2017.2718553
Fig. 1. Layout of the proposed dual-polarized slot antenna.
TABLE I
D
IMENSION PARAMETERS OF THE PROPOSED ANTENNA
Param. mm Param. mm Param. mm Param. mm
W 74.00 W
P 1
1.32 W
P 2
2.50 W
P 3
1.00
W
0
52.00 W
1
32.00 W
2
6.70 W
3
2.60
W
4
9.60 L
P 1
15.30 L
P 2
26.20 L
P 3
11.00
L 106.00 L
0
44.00 L
1
6.00 L
2
10.50
L
3
17.70 L
4
1.50 S
1
16.00 S
2
1.20
d
0
1.00 d
1
11.32 d
2
9.70 d
3
9.80
relatively narrow, i.e., not more than 7%. In contrast, since sym-
metrical slot can support two orthogonal degenerate modes [4],
slot antennas show competitive advantages in achieving orthog-
onal performance and wide operating band at the same time. In
[5], a smart ultrawideband dual-polarized slot antenna was real-
ized with high port isolation using a very simple feeding struc-
ture. Nevertheless, when operating frequencies become lower,
the design of dual-polarized slot antennas with wide bandwidth
(BW) is still challenging, and there are rarely works managed
to obtain FBWs more than 50%. In [6] and [7], dual-polarized
slot antennas with FBWs of 27.9% and 45.8% were proposed.
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