Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique for Multi-Band and Broadband Applications

Abstract

Double dipoles on a single-layer substrate are utilized to construct a triple-mode printed quasi-Yagi antenna for the multi-band and broadband antenna applications. A stub-loaded dipole generating two resonant modes (i.e., lower dual-mode dipole) is allocated on the underside of a simple dipole (i.e., upper single-mode dipole) introducing the third resonant mode. Using these three resonant modes, three compact printed quasi-Yagi antennas, i.e., tri-band, dual-band and broadband printed quasi-Yagi antennas, are designed with the same antenna prototype but different parameter values. Seen from the measured results, all of these three antennas have good unidirectional radiations, high radiation efficiencies and low cross-polarization levels at the operating frequencies within the impedance bandwidths.

Full text

Received April 3, 2018, accepted May 14, 2018.
Digital Object Identifier 10.1109/ACCESS.2018.2838328
Printed Quasi-Yagi Antennas Using Double
Dipoles and Stub-Loaded Technique for
Multi-Band and Broadband Applications
KAI DA XU 1,2, (Member, IEEE), DAOTONG LI 3, (Member, IEEE),
YANHUI LIU 1, (Member, IEEE), AND QING HUO LIU 4, (Fellow, IEEE)
1Department of Electronic Science, Xiamen University, Xiamen 361005, China
2State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
3Center of Aerocraft TT&C and Communication, Chongqing University, Chongqing 400044, China
4Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708 USA
Corresponding author: Daotong Li (dli@cqu.edu.cn)
This work was supported in part by the Venture and Innovation Support Program for Chongqing Overseas Returnees under Grant
cx2017095, in part by the Fundamental Research Funds for the Central Universities under Grant 106112017CDJXY500002, in part by the
National Natural Science Foundation of China under Grant 61601390, and in part by the State Key Laboratory of Millimeter Waves Open
Research Program under Grant K201813.
ABSTRACT Double dipoles on a single-layer substrate are utilized to construct a triple-mode printed
quasi-Yagi antenna for the multi-band and broadband antenna applications. A stub-loaded dipole generating
two resonant modes (i.e., lower dual-mode dipole) is allocated on the underside of a simple dipole (i.e.,
upper single-mode dipole) introducing the third resonant mode. Using these three resonant modes, three
compact printed quasi-Yagi antennas, i.e., tri-band, dual-band, and broadband printed quasi-Yagi antennas,
are designed with the same antenna prototype but different parameter values. Seen from the measured results,
all of these three antennas have good unidirectional radiations, high radiation efficiencies, and low cross-
polarization levels at the operating frequencies within the impedance bandwidths.
INDEX TERMS Broadband antenna, dual-band antenna, quasi-Yagi antenna, stub-loaded technique,
tri-band antenna.
I. INTRODUCTION
Since the printed quasi-Yagi antenna on the dielectric sub-
strate was first presented in [1], it has been researched
extensively [2]–[6] due to its advantages of low profile,
light weight and easy fabrication. For the antenna design
of wireless communication systems, it is challenging to
miniaturize antenna size while promoting its performance,
such as low cost, high gain, wide impedance bandwidth
and multiple operation bands. One of the most concerns
is focused on the broadband printed quasi-Yagi anten-
nas [7]–[10] or their operating bandwidth enhancement
methods [11]–[13]. In [7] and [8], a coplanar waveguide
and a coplanar stripline fed quasi-Yagi antennas are pre-
sented with the bandwidths of 44% and 41%, respectively.
In order to further improve the bandwidths of the Yagi anten-
nas, some researchers attempt to change the shapes of the
drivers [9]–[11], reflectors [12] or directors [13].
In addition to the growing demand of the broadband anten-
nas, the designs of multi-band antennas are also applied
extensively to accomplish the requirements of multi-band
and multi-service communication systems. Several dual-band
printed Yagi antennas operating at two different frequency
bands have been reported in [14]–[18]. For instance, in [17],
the strip director of the printed Yagi antenna is replaced
by two split ring resonators with two resonant modes for
dual-band applications. In [18], a compact dual-band end-
fire Yagi antenna is presented, where the roles of the driven
dipole and director operating at the first frequency band are
changed into the reflector and driven dipole at the second fre-
quency band, respectively. Moreover, some tri-band printed
quasi-Yagi antennas are proposed to meet the increasingly
rapid-progress requirement of wireless communication sys-
tems [19]–[22]. In [19], a tri-band quasi-Yagi antenna with
coplanar-waveguide-to-coplanar-strip transition is proposed,
where the even-mode E-field at the coplanar-waveguide feed
line can be smoothly transformed to the odd-mode E-field at
the coplanar-strip line. Based on the conventional quasi-Yagi
antennas, in [20]–[22], the additional operating modes are
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
FIGURE 1. Geometry of the dual-mode stub-loaded dipole and voltage
distributions of two resonant modes.
introduced by the changes of the drivers, reflectors or direc-
tors to obtain three desired frequency bands.
Stub-loaded technique is one of the most popular methods
to generate an additional resonant mode in the design of
microwave circuits and antennas [23], [24]. For instance,
a stub-loaded slotline antenna is presented with two reso-
nances in [25] and [26]. In this paper, double dipoles are
employed with this stub-loaded technique for the triple-mode
printed quasi-Yagi antenna applications. Two resonant modes
are introduced by a stub-loaded dipole, named as the lower
dual-mode dipole, and the third resonant mode is generated
by a simple dipole, named as the upper single-mode dipole.
The lower dual-mode dipole is allocated on the underside of
the upper single-mode dipole. Finally, the miniaturized dual-
band, tri-band, and broadband printed quasi-Yagi antennas
using these two dipoles are designed, respectively.
II. ANTENNA STRUCTURE AND ANALYSIS
Fig. 1 shows the geometry of the proposed stub-loaded dipole
whose two arms are positioned on the top and bottom metallic
layers of substrate, respectively. Based on a conventional
dipole, two stubs are loaded at the trisection points (Aand A0)
of the dipole. The voltage distributions of the first two oper-
ating modes are also plotted in Fig. 1, where the red solid
line is the voltage distribution of the fundamental resonant
mode at the frequency f, and the blue dash line represents
the voltage distribution of the second resonant mode whose
operating frequency is 3f0. It can be seen that the voltage
is maximum at the points Aand A0for the second resonant
mode, thus the two open stubs will affect this resonant mode
but they have almost no effect on the fundamental resonant
mode.
Fig. 2 shows the evolution of the triple-mode printed quasi-
Yagi antenna. In Fig. 2(a), a conventional printed quasi-Yagi
antenna is presented, which consists of a driven dipole and
two short strips on the top and bottom metallic layers of the
dielectric substrate as the director. The stepped impedance
section in the input feedline is adopted for improving the
impedance matching of the antenna. Then, a pair of strip lines
are added to connect the driven dipole and the director as
shown in Fig. 2(b), resulting in dual-mode generation. This
is because that the previous director can behave as the driven
dipole of the high-frequency mode while the previous driven
FIGURE 2. The evolution of the proposed triple-mode printed quasi-Yagi
antenna. (a) Conventional printed quasi-Yagi antenna, (b) dual-mode
printed quasi-Yagi antenna, and (c) the proposed triple-mode printed
quasi-Yagi antenna with double concave parabolic reflector Substrate:
FR4 with the relative dielectric constant of 4.4 and thickness of 1 mm.
FIGURE 3. Simulated reflection coefficient of the tri-band printed
quasi-Yagi antenna.
dipole behaves as the reflector. Finally, the third resonant
mode is introduced by employing the stub-loaded technique
as seen in Fig. 2(c). Two resonant modes are introduced
by a stub-loaded dipole, named as the lower dual-mode
dipole, whereas the third resonant mode is generated by a
simple dipole, named as the upper single-mode dipole of the
high-frequency mode. The lower dual-mode dipole and stubs
are bended to minimize the occupied area of the antenna
and keep from the touch of the upper single-mode dipole,
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
FIGURE 4. Simulated reflection coefficients of the tri-band printed
quasi-Yagi antenna against the varied (a) L3, and (b) L1.
respectively. Moreover, in order to increase the effective size
of the ground plane, the symmetrical concave parabolic shape
as the reflector is designed. By adjusting the positions of
these above-mentioned three resonant modes, the printed
quasi-Yagi antennas for dual-band, tri-band and broadband
applications can be obtained.
III. MULTI-BAND PRINTED QUASI-YAGI ANTENNAS
A. TRI-BAND PRINTED QUASI-YAGI ANTENNA
For the design of a tri-band printed quasi-Yagi antenna,
its antenna prototype is shown in Fig. 2(c), whose
dimensions are set as follows (unit: mm): W1=1, W2=
0.1, W3=W4=2, W5=W6=W7=0.5, W8=2, W9
=1, W10 =1.85, L1=10.9, L2=4.5, L3=8.5, L4=1,
L5=3, L6=8.85, L7=3.5, L8=5.4, L9=3.2, W10 =5,
and D=13.9. The overall size of the antenna is 29.1 mm ×
18.1 mm ×1 mm. Fig. 3 shows the reflection coeffi-
cient of the proposed tri-band printed quasi-Yagi antenna.
The center frequency of the 1st passband is mainly deter-
mined by the overall length of the lower dual-mode dipole,
i.e., 2(L5+L6+L7), which can be adjusted to satisfy the
required operating frequency. Then, the operating frequencies
of the 2nd and 3rd passbands can be controlled independently.
In Fig. 4(a), the center frequency of the 2nd passband can
FIGURE 5. Simulated and measured (a) reflection coefficients and
radiation efficiencies, and (b) realized gains at the end-fire direction of
the proposed tri-band antenna. The fabricated photograph is shown in
the inset.
be adjusted by tuning the length of the L3, while the center
frequencies of the 1st and 3rd passbands keep fixed. This
result agrees with the above-mentioned theoretical analysis
in Section II. On the other hand, when the length of L1
is changed, the center frequency of the 3rd passband will
be shifted, but the center frequencies of the 1st and 2nd
passbands have almost no change as shown in Fig. 4(b).
For demonstration, the tri-band printed quasi-Yagi antenna
is fabricated, and a 50 SMA connector is used to feed the
antenna for measurement. As shown in Fig. 5(a), the three
measured impedance bandwidths defined by |S11|<−10 dB
are 3.63423, 5.49-5.75 and 7.94-8.59 GHz, respectively,
which are in good agreement with the simulations. The radi-
ation efficiencies at the frequency range of 3-9 GHz are also
measured, coincident with the simulated results. Fig. 5(b)
illustrates the realized gains at the end-fire direction. Within
the operating frequency ranging from 3.63 to 4.23 GHz,
the simulated gain varies between 2 and 2.65 dBi, while the
measured antenna gain varies between 2.6 and 4.67 dBi. For
the 2nd passband of 5.495.75 GHz, the simulated gain varies
between 1.8 and 2.91 dBi, and the measured counterpart
ranges from 1.8 to 2.83 dBi. The simulated and measured
gain variations in the 3rd passband of 7.94-8.59 GHz are
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
FIGURE 6. Simulated and measured radiation patterns of the proposed
tri-band antenna in E-plane at (a) 4 GHz, (b) 5.6 GHz, (c) 8.2 GHz and in
H-plane at (d) 4 GHz, (e) 5.6 GHz, (f) 8.2 GHz.
2.93.31 dBi and 3.5-4.19 dBi, respectively The photograph
of the fabricated antenna is shown in the inset of Fig. 5(b)
For indicating the radiation performance of the fabricated
tri-band quasi-Yagi antenna, its radiation patterns at different
frequencies are also measured. The comparisons of simu-
lated and measured radiation patterns in E-plane (xoy-plane)
and H-plane (yoz-plane) at 4 5.6, and 8.2 GHz are plotted
in Fig. 6 The measured co-polarizations agree well with the
simulated ones. The antenna achieves a front-to-back ratio
(FBR) of over 18, 15 and 9 dB at 4 5.6 and 8.2 GHz, respec-
tively. It can be observed that the proposed tri-band antenna
has good unidirectional radiations with the main lobe in the
y-axis direction, and low cross-polarization levels in both
E- and H-planes at three different frequencies.
B. DUAL-BAND PRINTED QUASI-YAGI ANTENNA
From Fig. 4(a), it can be seen that the second resonant mode
can be shifted close to the first or third resonant mode, making
two resonant modes adjacent each other. When we change
the parameters of antenna prototype in Fig. 2(c) a dual-band
printed quasi-Yagi antenna can be realized by using the three
resonant modes, where two of them are employed to form
FIGURE 7. Simulated reflection coefficients of the proposed dual-band
quasi-Yagi antenna (a) under the first situation and (b) under the second
situation against the varied L3, where other parameters are set as
W1=2 mmW2=0.2 mm, W3=W4=0.8 mm, W5=W6=W7=1.1 mm,
W8=1.7 mm, W9=1 mm, W10 =1.85 mm, L1=10.9 mm, L2=6 mm,
L4=1 mm, L5=4.5 mm, L6=8 mm, L7=2.9 mm, L8=6.1 mm,
L9=3.2 mm, W10 =5 mm, D=13.2 mm.
one passband, and the remaining one constitutes the other
passband. The bandwidths of these two passbands can be
adjusted flexibly.
Fig. 7 illustrates the reflection coefficients of the proposed
dual-band quasi-Yagi antennas under two situations. As seen
from Fig. 7(a), the first two resonant modes are combined to
form the 1st passband, and the third resonant mode consists of
the 2nd passband. Meanwhile, the bandwidth of the 1st pass-
band can be adjusted by tuning the length of L3, but the 2nd
passband has no change. For the second situation, the dual-
band quasi-Yagi antenna can also be developed with a wider
bandwidth of the 2nd passband as shown in Fig. 7(b). When
the length of L3becomes shorter, the operating frequency
of the second resonant mode will be shifted to the higher
frequency, while the first and third resonant modes are fixed.
Thus, the 2nd passband is achieved by the second and third
resonant modes, and the 1st passband is realized by the first
resonant mode. From Fig. 7(b), it can be also seen that the
bandwidth of the 2nd passband can be adjusted by altering
the length of L3while it is fixed for the first passband.
For demonstration, a printed quasi-Yagi antenna with dual-
band response is fabricated and measured, whose dimensions
in Fig. 2(c) are set as follows: W1=2 mm, W2=0.2 mm,
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
FIGURE 8. Simulated and measured (a) reflection coefficients and
radiation efficiencies, and (b) realized gains at the end-fire direction of
the proposed dual-band antenna. The fabricated photograph is shown in
the inset.
W3=W4=0.8 mm, W5=W6=W7=1.1 mm, W8
=1.7 mm, W9=1 mm, W10 =1.85 mm, L1=10.9 mm,
L2=6 mm, L3=6.3 mm, L4=1 mm, L5=4.5 mm, L6
=8 mm, L7=2.9 mm, L8=6.1 mm, L9=3.2 mm, W10
=5 mm, D=13.2 mm. The overall size of the antenna is
28.3 mm×20.3 mm×1 mm As shown in Fig. 8(a), the two
measured impedance bandwidths with |S11|<−10 dB are
from 3.95 to 4.8 GHz and from 6.35 to 7.35 GHz, respec-
tively, which are in agreement with the simulated ones. The
radiation efficiencies within these two passbands are better
than 70% and 75%, respectively. Fig. 8(b) illustrates the sim-
ulated and measured realized gains of the proposed dual-band
antenna at the end-fire direction Within the two passbands
of 3.95-4.8 GHz and 6.35-7.35 GHz, the measured gains
at the end-fire direction are larger than 4 dBi and 3.8 dBi
respectively The minor differences between simulations and
measurements may be attributed to connector soldering and
fabrication tolerances. The photograph of the fabricated dual-
band antenna can be seen in the inset of Fig. 8(b).
The simulated and measured radiation patterns of the
proposed dual-band antenna in E- and H-planes at 4.2 and
7.1 GHz are illustrated in Fig. 9. The experimental
FIGURE 9. Simulated and measured radiation patterns of the proposed
dual-band antenna in E-plane at (a) 4.2 GHz, (b) 7.1 GHz, and in H-plane
at (c) 4.2 GHz, (d) 7.1 GHz.
TABLE 1. Comparisons of some recent multi-band printed Yagi antennas.
measurements have good agreement with the simulations.
It can be observed that the co-polarized radiation patterns
have good unidirectional radiations, realizing the FBR of
around 19 and 13 dB at 4.2 and 7.1 GHz, respectively. The
cross-polarization levels in the main lobe direction of the
E- and H-planes at 4.2 and 7.1 GHz are all less than -20 dB
Performance comparisons between our work and some
recent reported dual-band/tri-band antennas are tabulated
in Table 1 It can be seen that the proposed dual-band and
tri-band printed quasi-Yagi antennas fulfill the designs with
unidirectional radiations, reasonable bandwidths and very
miniaturized sizes.
IV. BROADBAND PRINTED QUASI-YAGI ANTENNA
The proposed antenna prototype can also be designed
into a broadband printed quasi-Yagi antenna through tun-
ing the parameters shown in Fig. 2(c). For demonstration,
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
FIGURE 10. Simulated and measured (a) reflection coefficients and
radiation efficiencies, and (b) realized gains at the end-fire direction of
the proposed broadband antenna. The fabricated photograph is shown in
the inset.
a broadband antenna is fabricated and measured, whose
dimensions are as follows: W1=2.1 mm, W2=0.3 mm,
W3=W4=1 mm, W5=W6=W7=1.8 mm, W8=
1.7 mm, W9=2.3 mm, W10 =1.85 mm, L1=7.9 mm, L2
=6.9 mm, L3=1.2 mm, L4=0.2 mm, L5=4.3 mm, L6=
5.85 mm, L7=2.2 mm, L8=6.8 mm, L9=5.4 mm, W10
=5 mm, D=10.85 mm. The overall size of the antenna is
24 mm×24.1 mm×1 mm. As shown in Fig. 10(a), the sim-
ulated impedance bandwidth with |S11|<−10 dB is from
3.71 to 8.65 GHz (80%) and the measured counterpart is from
3.8 to 9 GHz (81.3%). The measured radiation efficiencies
within the passband are better than 72%, in good agreement
with the simulated results Fig. 10(b) shows the simulated
and measured gain variations of the broadband antenna with
the frequency In the operating frequency band of 3.8-9 GHz,
the measured gains at the end-fire direction vary from 2.7 to
6 dBi The fabricated photograph is embedded in the inset of
Fig. 10(b).
For illustrating the radiation performance of the fabricated
broadband quasi-Yagi antenna, its radiation patterns are mea-
sured at three different frequencies, i.e. 4.5, 6, and 7.5 GHz.
The simulated and measured radiation patterns including
co-polarizations and cross-polarizations in E- and H-planes,
respectively, are plotted in Fig. 11, where stable radiation
FIGURE 11. Simulated and measured radiation patterns of the proposed
broadband antenna in E-plane at (a) 4.5 GHz, (b) 6 GHz, (c) 7.5 GHz and in
H-plane at (d) 4.5 GHz, (e) 6 GHz, (f) 7.5 GHz.
TABLE 2. Comparisons of some recent broadband printed Yagi antennas.
patterns can be obtained. It can be observed that the proposed
broadband antenna has low cross-polarization levels in both
E and H-planes, and high unidirectional radiations with the
FBR of 15, 17 and 15 dB at 4.5, 6 and 7.5 GHz, respectively.
Performance comparisons between our proposed broadband
antenna and some other reported works are also tabulated
in Table 2 As can be seen, our design has achieved wide
bandwidth, high FBR and very compact size simultaneously.
V. CONCLUSION
Using the same antenna geometry and stub-loaded technique,
three double-dipoles-based printed quasi-Yagi antennas have
been designed for the tri-band, dual-band and broadband
applications, respectively, in this paper. These three antennas
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K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
have been fabricated on the low-cost FR4 substrate with
very compact sizes. The measured results illustrate that all of
the printed quasi-Yagi antennas have reasonable impedance
bandwidths, good unidirectional radiations, high radiation
efficiencies and low cross-polarization levels within the oper-
ating frequency bands
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KAI DA XU (S’13–M’15) received the B.S.
and Ph.D. degrees in electromagnetic field
and microwave technology from the Univer-
sity of Electronic Science and Technology of
China (UESTC), Chengdu, China, in 2009 and
2015, respectively. From 2012 to 2014, he was
a Visiting Researcher with the Department of
Electrical and Computer Engineering, Duke Uni-
versity, Durham, NC, USA, under the financial
support from the China Scholarship Council. From
2016 to 2017, he was a Post-Doctoral Fellow with the State Key Laboratory
of Millimeter Waves, City University of Hong Kong, Hong Kong. He is
currently an Assistant Professor with the Institute of Electromagnetics and
Acoustics and the Department of Electronic Science, Xiamen University,
Xiamen, China. He has authored or co-authored over 80 papers in peer-
reviewed journals and conference proceedings. His current research inter-
ests include RF/microwave and mm-wave circuits, antenna arrays, and
nanoscale memristors. He was the recipient of the UESTC Outstanding
Graduate Awards in 2009 and 2015, respectively. He was a recipient of
the National Graduate Student Scholarship from the Ministry of Education,
China, in 2012, 2013, and 2014. He is serving as a Reviewer for several
IEEE and IET journals, including the IEEE TRANSACTIONS ON MICROWAVE
THEORY AND TECHNIQUES, the IEEE TRANSACTIONS ON ELECTRON DEVICES,
the IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS
AND SYSTEMS,IEEE Microwave Magazine, IEEE ANTENNAS AND WIRELESS
PROPAGATION LETTERS, IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS,
IEEE ACCESS,IET Microwaves Antennas & Propagation, and Electronics
Letters. Since 2017, he has been serving as an Associate Editor for IEEE
ACCESS and Electronics Letters. He is also an Editorial Board member of the
AEÜ-International Journal of Electronics and Communications.
DAOTONG LI (S’15–M’16) received the
Ph.D. degree in electromagnetic field and
microwave technology from the University of
Electronic Science and Technology of China
(UESTC), Chengdu, China, in 2016. Since 2015,
he has been a Visiting Researcher with the
Department of Electrical and Computer Engineer-
ing, University of Illinois at Urbana–Champaign,
Urbana, IL, USA, with the financial support from
the China Scholarship Council. He is currently
with the Center of Aircraft TT&C and Communication, Chongqing Uni-
versity, Chongqing. He has authored or co-authored over 30 peer-reviewed
journal or conference papers. Since 2014, he has been a Reviewer for some
international journals. His current research interests include RF, microwave
and millimeter-wave technology and applications, antennas, devices, circuits
and systems, and passive and active (sub-) millimeter-wave imaging, and
radiometer. He was a recipient of the UESTC Outstanding Graduate Awards
by the Sichuan province and UESTC in 2016. He was also a recipient of
the National Graduate Student Scholarship from the Ministry of Education,
China, and the Tang Lixin Scholarship.
VOLUME 6, 2018 7

K. D. Xu et al.: Printed Quasi-Yagi Antennas Using Double Dipoles and Stub-Loaded Technique
YANHUI LIU (M’15) received the B.S. and
Ph.D. degrees in electrical engineering from the
University of Electronic Science and Technology
of China (UESTC), Chengdu, China, in 2004 and
2009, respectively. From 2007 to 2009, he was a
Visiting Scholar with the Department of Electrical
Engineering, Duke University, Durham, NC, USA.
Since 2011, he has been with Xiamen University,
China, where he is currently a Full Professor with
the Department of Electronic Science. In 2017,
he was a Visiting Professor with the State Key Laboratory of Millimeter
Waves, City University of Hong Kong. He has authored or co-authored over
110 peer-reviewed journal and conference papers. He holds several granted
Chinese patents. His research interests include antenna array design, array
signal processing, and microwave imaging methods. He was the recipient of
the UESTC Outstanding Graduate Award in 2004 and the Excellent Doctoral
Dissertation Award of Sichuan Province of China in 2012. He is serving as a
Reviewer for severalinternational journals, including the IEEE TRANSACTIONS
ON ANTENNAS AND PROPAGATION, the IEEE TRANSACTIONS ON GEOSCIENCES AND
REMOTE SENSING, IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, IEEE
MICROWAVE AND WIRELESS COMPONENTS LETTERS,IET Microwave, Antennas
and Propagation, and Digital Signal Processing. Since 2018, he has been
serving as an Associate Editor for IEEE ACCESS.
QING HUO LIU (S’88–M’89–SM’94–F’05)
received the B.S. and M.S. degrees in physics
from Xiamen University, China, and the Ph.D.
degree in electrical engineering from the Univer-
sity of Illinois at Urbana–Champaign. He was
with the Electromagnetics Laboratory, University
of Illinois at Urbana–Champaign, as a Research
Assistant from 1986 to 1988, and as a Post-
Doctoral Research Associate from 1989 to 1990.
He was a Research Scientist and a Program Leader
with Schlumberger-Doll Research, Ridgefield, CT, USA, from 1990 to 1995.
From 1996 to 1999, he was an Associate Professor with New Mexico
State University. Since 1999, he has been with Duke University, where
he is currently a Professor of electrical and computer engineering. He has
authored or co-authored over 400 papers in refereed journals and 500 papers
in conference proceedings. His research interests include computational
electromagnetics and acoustics, inverse problems, and their application in
nanophotonics, geophysics, biomedical imaging, and electronic packaging.
He is a Fellow of the Acoustical Society of America, the Electromagnetics
Academy, and the Optical Society of America. He was the recipient of the
1996 Presidential Early Career Award for Scientists and Engineers from the
White House, the 1996 Early Career Research Award from the Environmen-
tal Protection Agency, and the 1997 CAREER Award from the National
Science Foundation. He was also the recipient of the ACES Technical
Achievement Award in 2017. He currently serves as the Founding Editor-in-
Chief of the IEEE JOURNAL ON MULTISCALE AND MULTIPHYSICS COMPUTATIONAL
TECHNIQUES, the Deputy Editor-in-Chief of Progress in Electromagnetics
Research, and an Editor of the Journal of Computational Acoustics. He
served as an IEEE Antennas and Propagation Society Distinguished Lecturer
for 2014-2016.
8VOLUME 6, 2018