Main IEEE Access Differential Probe Fed Liquid Crystal-Based Frequency Tunable Circular Ring Patch Antenna

Differential Probe Fed Liquid Crystal-Based Frequency Tunable Circular Ring Patch Antenna

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10.1109/access.2017.2786870
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SPECIAL SECTION ON MULTI-FUNCTION RF COMPONENTS FOR CURRENT AND
FUTURE 5G WIRELESS COMMUNICATIONS

Received October 25, 2017, accepted December 8, 2017, date of publication December 27, 2017,
date of current version February 14, 2018.
Digital Object Identifier 10.1109/ACCESS.2017.2786870

Differential Probe Fed Liquid Crystal-Based
Frequency Tunable Circular Ring
Patch Antenna
GUANGHUI XU 1 , HONG-LI PENG1 , (Member, IEEE), CHANGLI SUN2 , JIAN-GANG LU2 ,
YAOPING ZHANG1 , (Fellow, IEEE), AND WEN-YAN YIN1,3 , (Fellow, IEEE)
1 Key

Laboratory of Ministry of Education for Design and Electromagnetic Compatibility of High Speed Electronics Systems, Shanghai Jiao Tong University,
Shanghai 200240, China
2 Center for Opto-electronic Materials and Devices, Shanghai Jiao Tong University, Shanghai 200240, China
3 College of Information and Electronic Engineering, Zhejiang University, Hangzhou 310058, China

Corresponding author: Hong-Li Peng (hl.peng@sjtu.edu.cn)
This work was supported by the Major National S&T Program of China under Grant 2016ZX03001015-005.

ABSTRACT A differential probe-fed liquid crystal (LC)-based frequency tunable circular-ring patch
antenna is presented. Besides, cavity model is extended to analyze the LC-based antenna for the differential
operation. According to the cavity model, the permittivity and loss tangent of the LC are extracted from the
measured differential reflection coefficients. Acceptable agreements among the measurement, simulation,
and calculation for differential impedances, reflection coefficients, and radiation patterns are obtained and
also validate the extraction method and model. More importantly, the extended cavity model can provide a
deep physical insight into the LC-based antenna.
INDEX TERMS Circular ring patch antennas, cavity model, nematic liquid crystal, differential probe fed.

I. INTRODUCTION

In modern wireless communication systems, the frequency
reconfigurable antennas have caused considerable attention.
There have been some techniques developed in anten; nas
to realize frequency tunability, such as the tunable lumped
elements [1], [2], micromechanical structures [3] and tunable materials. The lumped and micromechanical devices
need to design complicated structures which generate the
parasitic effect and lead to radiation pattern degradation.
Recently, some voltage-controlled tunable materials such as
(Ba,Sr)TiO3 (BST) [4] and LC [5]–[7] have been considered
as antenna substrates to realize the frequency tunability and
improve the radiation performance. When the permittivity of
tunable material is varied by different bias voltages, the effective antenna size with resonant frequency will be changed.
The frequency tunable principle should greatly reduce parasitic effects. Among these materials, LC will be an important
potential candidate for the frequency tunable antenna due to
no DC power consumption and simple fabrication process [6].
To date, the reported LC-based patch antennas adopted
the single-end microstrip feed structure which will lead
to a larger planar size and asymmetrical E-plane radiation
pattern [5]–[7]. The radiation pattern and gain as key
VOLUME 6, 2018

parameters for LC-based frequency tunable antennas in
S-band have not been measured [5]–[7]. In addition, permittivity properties of many LC materials are still unclear,
especially in the low frequency band and are frequency
dependent [8]–[11]. Therefore, it is necessary to extract
the LC permittivity for study and analysis of the LC-based
antenna at the early stage. For example, Polycarpou et al. [6]
showed that the simulated frequency tunable range of 7%
disagrees with the measurement range of 4% due to uncertain
permittivity of the E7 type LC material.
Considering the above problems, a differential probe fed
LC-based frequency tunable circular ring patch antenna is
proposed in this paper. The differential probe feed exhibits
more advantages such as easy 3D-integration with other
differential RF components, compact planar size, symmetrical E-plane radiation pattern and lower cross-polarized
field [12]–[16]. Here, the circular ring patch is used due to its
smaller size compared with the rectangle and circular patches
for a given frequency while operating in the fundamental
mode [17].
In measurement, the differential reflection coefficients,
radiation patterns and gain for the LC-based antenna are
given. In theory, we extend cavity model and derive the

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3051

G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

mutual, differential impedance and radiation pattern expressions to analyze the LC-based circular ring patch antenna
for the differential operation. The expressions for the resonant frequency, permittivity, losses and Q-factor are also
shown to extract permittivity and loss tangent of the LC for
further investigating the antenna. According to the extracted
LC parameters, the measured, simulated and calculated
impedances, reflection coefficients and radiation patterns
are compared and acceptable agreements also validates the
extraction method and model.
In this paper, the LC-based antenna is described and the
extended cavity model theory is presented in Section II,
respectively. Results will be discussed in Section III. The
conclusions are drawn in Section IV.

network, the DC voltage is input into an SMA connector
by using bias tee, and then the electrostatic field will be
generated between the patch and GND2 .
A. LC-FILLED CAVITY

LC as the tunable anisotropic material (εLC = [εx , εy , εz ])
is filled into the cavity [11]. For the electrically-thin patch
antenna, we can neglect the transversal electrostatic field
components (Et = 0) and only consider the z-direction one
(Ez 6 = 0) [18]. Therefore, the permittivity tensor of LC is just
considered the component in the z-direction. In other words,
the permittivity component in the z-direction (εz ) is used for
the following analysis. When no DC bias voltage is applied
between the ground and the patch, the LC directors are
almost perpendicular to the z-direction due to the effect of the
surface anchoring and the corresponding permittivity in the
z-direction is εLC⊥ . If the DC (or 1kHz low frequency AC)
bias voltage increases from zero to the saturation case for
creating an electrostatic field, the LC directors will turn from
perpendicular to parallel direction to the z-direction (the DC
bias electric field direction), and the corresponding permittivity component in the z-direction εz will vary from perpendicular permittivity εLC⊥ to parallel permittivity εLC|| [8].

FIGURE 1. The exploded view and feed network of the differential probe
fed LC-based frequency tunable circular ring patch antenna.

II. THE LC-BASED ANTENNA AND CAVITY
MODEL THEORY

Fig. 1 shows the exploded view and feed network of the
differential probe fed LC-based frequency tunable circular
ring patch antenna. The antenna has three layers of RT/duriod
5880 (εr = 2.2, tan δ = 0.0009, thickness t = 0.787 mm)
material. Double-side metallized bottom layer has two holes
of diameter 0.9mm for two probes and openings of diameter
2 mm for insulation. Each hole is rounded by eight metalized
solid vias of diameter 0.6 mm for interconnection of the
double-side grounds. The middle layer is etched to form a
circular cavity extended 2 mm beyond the area of the patch
and filled with the E7 type LC from injection hole. The ring
patch is printed on the top layer which is inverted and placed
on top of the cavity. Two bonding pads on the top layer are
connected with the radiated patch by using two metallized
vias so that the patch can be fed by the probe. The screw
holes of the three layers are used for the fixation. In the feed
3052

FIGURE 2. The simplified structure of the antenna for cavity model
analysis.

B. EXTENDED CAVITY MODEL OF CIRCULAR RING
PATCH ANTENNA

A simplified structure of the antenna for cavity model analysis is shown in Fig.2. The patch of the outer radius b and
inner radius a is fed by two probes at (d1 , ϕ1 ) and (d2 , ϕ2 ),
respectively. According to the existing single-end cavity
model theory [17], [18], the electric field under the patch is
given by
X
X
Ez =
Anm ψnm =
Anm Xnm (knm ρ) cos nϕ
m,n

=

X

m,n

Anm Jn (knm ρ)Yn0 (knm a) − Jn0 (knm a)Yn (knm ρ)



m,n

× cos nϕ

(1)
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G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

where
Anm

R
I ψ ∗ ds
jωu0
R z nm
.
= 2
∗ ds
2
ψnm ψnm
keff − knm

(2)

In (1) and (2), ψmn is the eigenmode function, Jn is the
n-order Bessel function, Yn is the n-order Bessel function of
the second kind, knm is the roots of the characteristic equation
(X (knm b) = 0), j is the imaginary unit, µ0 is the vacuum
permeability, ω is the angular frequency, keff is the effective
wave number [18], Iz is the input current density in the
z-direction.
The input current ribbon for two ports can be given

The radiation fields can be derived as:
X Rnm
Eθ = jn+1 k0 FE (θ )
k
m,n nm


J 0 (knm a)
× Jn0 (k0 a sin θ ) − Jn0 (k0 b sin θ) n0
J (knm b)
! n
2
X
×
I cos(n(ϕ − ϕi ))e−jφi
Eϕ = −jn+1

ϕ1 − w < ϕ < ϕ1 + w,
ϕ2 − w < ϕ < ϕ 2 + w
elsewhere.
(3)

In (3), w is the effective angular width of the z-directed
source current, δ(ρ) is the impulse function. For the differential operation, the two probe position satisfies the following
relation:
d1 = d2

and ϕ2 − ϕ1 = π.

(4)

According to the impedance definition, the two port mutual
(transfer) impedances Zij (ij = 1, 2) can be derived as:
X  sin(nw) 2
Zij = jωµ0 t
(nw)
m,n
2 X (k d )X (k d ) cos(n(ϕ − ϕ ))
π knm
nm i
nm j
j
i
·

i
 h 02
2
Jn (knm a)
n2
2
2
2ε0n keff − knm
(1− k 2 b2 )−(1 − k 2n a2 )
02
Jn (knm b)

nm

nm

X nRnm
cos θ
FH (θ )
sin θ
knm
m,n

Jn (k0 a sin θ ) Jn (k0 b sin θ) Jn0 (knm a)
×
a
b
J 0 (knm b)
!n
2
X
×
I sin(n(ϕ − ϕi ))e−jφi


Iz
 


I δ(ρ − d1 ) + δ(ρ − d2 )
d1
d2
=


0

= Z11 − Z21 − Z12 + Z22
X  sin(nw) 2
= jωµ0 t
(nw)
m,n


2
ε0n keff

2 X (k d )2 [1 − cos(nπ )]
π knm
nm 1
 h 02
2
J
n (knm a)
2
− knm
(1 − k 2n b2 ) − (1 −
02
Jn (knm b)

where k0 is the free space wave number, the input current
phase φi is firstly introduced in the radiation pattern expressions for the differential operation. The current phase for
the differential operation satisfies φ1 = 0 and φ2 = π.
FE (θ ) and FH (θ ) have the same approximate value of 2 when
considering the radiated field effects of substrate and the
ground plane [17], and
Rnm
=
2
rnε0n (keff

2 sin(nw)X (k d )
e−jk0 r 2tωµ0 knm
nm 1
h 02
Jn (knm a)
n2
2
(1 − k 2 b2 ) − (1 −
− knm ) 0 2
Jn (knm b)

n2
2 a2
knm

nm

nm

i.
)
(9)

C. RESONANT FREQUENCY, PERMITTIVITY AND LOSSES

The resonant frequency of these modes can be written as [18]
fnm =

cknm
√
2π εe

(10)

where c is the velocity of light, the effective permittivity [18]
(11)

In (11), the modified radii (ae and be ) which respectively
substitute a and b for considering the fringing fields in this
work can be given by
i

n2
2 a2 )
knm

(6)
which implies that if the mode order is even (n = 0, 2, 4, . . .),
the corresponding mode impedance is zero. The differential
operation excites the fundamental TM11 mode but will not
excite higher order modes such as TM21 and TM02 mode, etc.
Therefore the differential operation has much lower crosspolarization level due to canceling the spurious radiation from
high modes. In addition, two symmetrical feed probes lead to
a symmetrical radiation field.
VOLUME 6, 2018

(8)


− 1
2
10t
1
1
.
εe = (εLC + 1) + (εLC − 1) 1 +
2
2
be − ae

Zdd11

·



i=1

(5)
where ε0n is 1 for n 6 = 0 and 2 for n =0. Based on the mixedmode theory [19], the differential impedance can be derided
as

(7)

i=1

3
ae = a − t
4

3
and be = b + t.
4

(12)

The effective loss δeff which mainly comprises the LC
substrate material, copper and radiation losses can be written
as [18]
1
δeff = tan δLC + √
t σ π µ0 f
2ωµ0 tPr
+
h 02
2
Jn (knm a)
η0 εr 0 2
(1 − k 2n b2 ) − (1 −
Jn (knm b)

nm

i

n2
2 a2 )
knm

(13)

3053

G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

where√σ is the conductivity of the patch and the ground plane,
η0 = µ0 /ε0 and


Z π
2 n cos2 θ
Jn (k0 a sin θ) Jn (k0 b sin θ ) Jn0 (knm a) 2
Pr =
−
2
2
a
b
Jn0 (knm b)
0 k0 sin θ


Jn0 (knm a) 2
0
0
+ sin θ Jn (k0 a sin θ ) − Jn (k0 b sin θ ) 0
dθ.
Jn (knm b)
(14)
The relationship among total Q-factor, effective loss and
relative bandwidth (BW) can be written as [18]
1
1
Q=
=
(15)
δeff
BW
where BW = 1ω/ω0 , 1ω is the half power bandwidth of the
input impedance magnitude [20].

FIGURE 3. Measured and simulated differential reflection coefficients of
the air-filled cavity antenna.

III. RESULTS AND DISCUSSION

The extended cavity model theory is employed to analyze
the LC-based antenna. By using Eqs.10-15, the unknown
permittivity and loss tangent of LC can be extracted from
the measured differential reflection coefficients. According
to the extracted LC parameters, the impedances, reflection
coefficients and radiation patterns of the antenna can be
respectively obtained by HFSS simulation and the cavity
model calculation. The differential reference impedance is
100  [21]. The main geometrical parameters are summarized in Table 1.
TABLE 1. Geometrical parameters of the antenna.

FIGURE 4. Experimental setup for S-parameter (a) and radiation
pattern (b).

A. EXTRACTION FOR PERMITTIVITY AND LOSS
TANGENT OF LC

Firstly, in order to obtain the resolution of the extracted
method, the measured and simulated differential reflection coefficients of the air-filled cavity antenna are given
in Fig.3 [9]. The measured resonant frequency is 4.02 GHz
and the corresponding simulated resonant frequency is
3.997 GHz. Their frequency deviation is just 0.023 GHz. The
extracted permittivity and loss tangent of the air-filled cavity
are 1.013 and 0.0018. Therefore, the extraction resolution
of relative permittivity and loss tangent are limited to 0.013
and 0.0018, respectively, which is sufficient to permittivity
(εLC > 2) and loss tangent (tan δLC > 0.01) of the E7 LC
material [9].
Fig.4 shows the experimental setup of the LC-based
antenna for S-parameter and radiation pattern measurements.
In Fig.4, the bias tee is used to apply DC voltage from a feed
port to the LC-filled cavity. In Fig.4 (b), the differential signal
is generated by employing a balun for the radiation pattern
measurement. In the S-parameter measurement, the bias tee
need be calibrated. In the radiation pattern measurement,
3054

FIGURE 5. Measured differential reflection coefficients of the LC-based
antenna under different bias voltages.

the insertion loss of both bias tee and balun are considered
for reducing their influences.
Fig.5 gives the measured differential reflection coefficients of the LC-based antenna under different bias voltages. It is observed that the good impedance match can
be obtained in the tunable process. When increasing the
bias voltage, the differential reflection coefficients moves
from high to low frequency due to the increase of the LC
VOLUME 6, 2018

G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

FIGURE 6. The extracted permittivity (a) and loss tangent (b) of the E7 LC.
FIGURE 7. Normalized differential impedance comparisons for the
measurement, simulation and calculation under bias voltages of 0 V (a)
and 25 V (b).

permittivity. The measured resonant frequency versus bias
voltage is shown in Fig.9. The frequency tunable range from
2.532 to 2.427 GHz, the threshold voltage of 3 V and the
saturation voltage of 23 V can be obtained. The measured
frequency tunable range ratio of 4.2% is close to 4% of the
reported work which also used the E7 LC material [6].
According to the measured reflection coefficients, the permittivity and loss tangent of LC under different bias voltages
can be extracted by using Eqs.10-15, and the results are
shown in Fig.6. At bias voltage of 0 V, the LC directors
are nearly perpendicular to the z-direction (static electric
field direction), and the extracted perpendicular permittivity
εLC⊥ and loss tangent tan δLC⊥ are approximate 2.696 and
0.0656, respectively. When increasing the bias voltage to
the saturation case, the LC directors will turn to the direction parallel to the z-direction, and the corresponding parallel permittivity εLC|| of 2.95 and loss tangent tan δLC||
of 0.0295 can be extracted. It is noted that when the bias
voltage increases, the permittivity increases and loss tangent
decreases.
From above results, we can observe that the permittivity
of the E7 type LC has a small tunability range with the
large loss tangent. As a result, the frequency tunable range is
small. In fact, some LC materials (e.g. GT3-23001) with lager
tunablity range and low loss tangent have been produced by
Merck for microwave and millimeter-wave applications [22].
However, we can only use the type E7 LC material to model
VOLUME 6, 2018

and analyze properties of the LC-based antenna under our
laboratory conditions.
B. COMPARISONS OF THE MEASURED, SIMULATED AND
CALCULATED DIFFERENTIAL IMPEDANCES AND
REFLECTION COEFFICIENTS

The above extracted permittivity and loss tangent of LC
under different bias voltages are introduced into the HFSS
simulation and the cavity model calculation, respectively.
Fig.7 compares the measured, simulated and calculated normalized differential impedances under bias voltages of 0 V
and 25 V. In order to uniformly compare the results, the
normalized operation is adopted. The measured and calculated results are very close. The simulated results show
smaller frequency deviation and slightly larger reactance
value.
Similarly, the measured, simulated and calculated differential reflection coefficients under the bias voltages of 0 V, 10 V
and 25 V are compared in Fig.8. The measured and calculated
results are also very close. The simulated results have smaller
frequency deviation. To further analyze the frequency deviation, the resonant frequency variations for the measurement,
simulation and calculation are shown in Fig.9. These resonant
frequencies versus bias voltage has the same variation trend.
3055

G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

FIGURE 8. Measured, simulated and calculated differential reflection
coefficients under bias voltages of 0 V, 10 V and 25 V.

FIGURE 9. Resonant frequency comparisons for the measurement,
simulation and calculation.

The maximum resonant frequency difference between the
measurement and simulation is only 0.019 GHz.
C. RADIATION PERFORMANCE

Fig.10 compares the measured, simulated and calculated
co-polar radiation patterns under the bias voltages of 0 V and
25 V. Pattern differences among calculation, simulation and
measurement are acceptable. The calculated E-plane patterns
have a slightly wider upper half plane due to an infinite
ground size considered in the cavity model [14]. However,
the simulation and measurement use a finite ground size.
A good performance can be found that the patterns basically
maintain the same shape under bias voltages of 0 V and
25 V. This is because the permittivity and loss tangent of
the LC-filled cavity uniformly vary under the electrostatic
field. Due to a larger inherent loss tangent of the E7 LC in
the S-band, the simulated realized gain at resonant frequency
under bias voltage of 25 V can achieve the maximum value
of 1.2 dBi and the corresponding measured value is 0.1 dBi.
Their difference is acceptable when considering tolerance in
measurement. Therefore, the LC-based antenna can be used
in many low-power wireless communications.
From Eqs.7-8, when operating in the fundamental TM11
mode, higher order modes such as TM21 and TM02 mode
3056

FIGURE 10. Measured, simulated and calculated radiation patterns: in the
H-plane (a) and E-plane (b) at resonant frequency under bias voltage
of 0V; in the H-plane (c) and E-plane (d) at resonant frequency under bias
voltage of 25V.

are not excited and the spurious radiation from high modes is
reduced. In addition, the differential operation cancels cross
polar components from feed probes [14]. Therefore, lower
VOLUME 6, 2018

G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

cross-polarization levels can be obtained. The simulated and
measured cross-polarization levels are at least 25 dB lower
than their peak co-polarization levels.
IV. CONCLUSION

The extended cavity model is presented to analyze the differential probe fed LC-based frequency tunable circular ring
patch antenna. The impedance and radiation pattern expressions for the differential operation are derived. Expressions
for resonant frequency, permittivity, losses and Q-factor are
shown for extracting the permittivity and loss tangent of
the LC. According to the extracted LC parameters, simulation and calculation of the antenna can be performed for
analyzing properties of the differential impedances, reflection
coefficients and radiation patterns under the different bias
voltages. Comparisons among measurement, simulation and
calculation validates the extraction method and model. Therefore, the cavity model can provide a deep physical insight
into the LC-based antenna. Similarly, the cavity model can
be also applied to analyze the LC-based rectangular, circular
patch antennas and their arrays. It is believed that the LC
is an important candidate material for realizing frequency
tunability in antennas.
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[22] S. Bildik, S. Dieter, C. Fritzsch, W. Menzel, and R. Jakoby, ‘‘Reconfigurable folded reflectarray antenna based upon liquid crystal technology,’’
IEEE Trans. Antennas Propag., vol. 63, no. 1, pp. 122–132, Jan. 2015.

GUANGHUI XU is currently pursuing the
Ph.D. degree with the Department of Electronic
Engineering, Shanghai Jiao Tong University,
Shanghai, China. His research interests include
liquid crystal-based reconfigurable patch antennas
and arrays.

HONG-LI PENG (M’10) was born in Shangluo,
China, in 1966. He received the B.S., M.S.,
and Ph.D. degrees in electromagnetic field and
microwave technique from Xidian University,
Xi’an, China, in 1988, 1991, and 2005, respectively.
From 1994 to 1999, he was a Senior Researcher
and the Project Leader for conformal antenna and
its system designing with the National Telemeter
Center, Xi’an. In 1999, he joined the ZTE Corporation, Shanghai, China, as a Scientific Researcher and the Project Leader,
where he contributed 11 essential patents. Since 2008, he has been an Associate Professor in electromagnetic fields and microwave techniques with the
School of Electronic Information and Electrical Engineering, Shanghai Jiao
Tong University. He has authored or coauthored over 65 technical papers
and a book on MIMO indoor channel modelling. He holds over 25 patents.
His current research interests mainly include the tunable RF and microwave
passive circuits research, reconfigurable compact antennas/array analysis
and design, and spatial wireless channel modeling.

CHANGLI SUN is currently pursuing the Ph.D.
degree with the Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai,
China. Her research interests include liquid crystal
technologies and liquid crystal display modes.

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G. Xu et al.: Differential Probe Fed LC-Based Frequency Tunable Circular Ring Patch Antenna

JIAN-GANG LU received the Ph.D. degree from
the College of Information Science and Engineering, Zhejiang University, Hangzhou, China,
in 2003. He focused on LC displays with the NextGeneration LCD Research Center, LCD business,
Samsung Electronics, from 2003 to 2009. Since
2009, he has been an Associate Professor with the
National Engineering Laboratory for TFT-LCD
Materials and Technologies, Shanghai Jiao Tong
University, Shanghai, China. His research interests
include liquid crystal materials, polymer materials, liquid crystal display
modes, and 3-D displays.

YAOPING ZHANG (M’03–SM’07–F’10) received the B.E. and M.E. degrees in electronic engineering from the Taiyuan Polytechnic Institute and
the Shanxi Mining Institute, Taiyuan University
of Technology, China, in 1982 and 1987, respectively, and the Ph.D. degree in electronic engineering from The Chinese University of Hong Kong,
Hong Kong, in 1995.
He was with Shanxi Electronic Industry Bureau,
China, from 1982 to 1984; with the Shanxi Mining
Institute from 1987 to 1990; with the University of Liverpool, Liverpool,
U.K., from 1990 to 1992; and also with the City University of Hong Kong,
Hong Kong, from 1996 to 1997. He was promoted to a Full Professor with
the Taiyuan University of Technology in 1996. He was with The University
of Hong Kong from 1997 to 1998. He is currently a Professor with the School
of Electrical and Electronic Engineering, Nanyang Technological University,
Singapore. He has delivered scores of invited papers/keynote addresses at
international scientific conferences. He has organized or chaired dozens of
technical sessions of international symposia. His current research interests
include radio science and technology.
Dr. Zhang received the Sino-British Technical Collaboration Award
in 1990 for his contribution to the advancement of subsurface radio science
and technology, the Best Paper Award from the Second International Symposium on Communication Systems, Networks and Digital Signal Processing,
Bournemouth, U.K., in 2000, the Best Paper Prize from the Third IEEE
International Workshop on Antenna Technology, Cambridge, U.K., in 2007,
the William Mong Visiting Fellowship from The University of Hong Kong
in 2005, and the IEEE AP-S Schelkunoff Prize 2012. He was a Guest Editor
of the International Journal of RF and Microwave Computer-Aided Engineering and an Associate Editor of the International Journal of Microwave
Science and Technology. He serves as an Editor for ETRI Journal and an
Associate Editor for the IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
and the International Journal of Electromagnetic Waves and Applications.
He serves on the editorial boards of a large number of journals, including
the IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES and the IEEE
Microwave and Wireless Components Letters.

3058

WEN-YAN YIN (M’99–SM’01–F’13) received
the M.Sc. degree in electromagnetic field and
microwave technique from Xidian University,
Xi’an, China, in 1989, and the Ph.D. degree in
electrical engineering from Xi’an Jiao Tong University, Xi’an, in 1994.
He was an Associate Professor with the Department of Electronic Engineering, Northwestern
Polytechnic University, Xi’an, from 1993 to 1996.
From 1996 to 1998, he was a Research Fellow with
the Department of Electrical Engineering, Duisburg University, Duisburg,
Germany. Since 1998, he has been a Research Fellow with the Monolithic
Microwave Integrated Circuit Modeling and Package Laboratory, Department of Electrical Engineering, National University of Singapore (NUS),
Singapore . In 2002, he joined Temasek Laboratories, NUS, as a Research
Scientist and the Project Leader of high-power microwave and ultrawideband
electromagnetic compatibility (EMC)/electromagnetic interference. Since
2005, he has been a Professor of electromagnetic fields and microwave techniques with the School of Electronic Information and Electrical Engineering,
Shanghai Jiao Tong University, Shanghai, China, where he is currently the
Director and the Adjunct Ph.D. Candidate Supervisor with the Center for
Microwave and RF Technologies. In 2009, he joined the National State
Key Laboratory of Modern Optical Instrumentation, Centre for Optical and
Electromagnetic Research, Zhejiang University, Hangzhou, China, as a Qiu
Shi Chair Professor. As the Lead Author, he has authored over 230 international journal articles (more than 100 IEEE papers), including one international book and 17 book chapters. His current research interests include
passive and active RF and millimeter-wave device and circuit modeling,
ultrawideband interconnects and signal integrity, nanoelectronics, EMC and
electromagnetic protection of communication platforms, and computational
multiphysics and its application.
Dr. Yin received the Science and Technology Promotion Award of the First
Class from the Local Shanghai Government of China in 2005, the National
Technology Invention Award of the Second Class from the Chinese Government in 2008, the National Technology Progress Award of the Second
Class from the Chinese Government in 2012, and the best paper awards from
the Asia–Pacific Symposium on Electromagnetic Compatibility in 2008 and
2012. He was also the Technical Chair of EDAPS in 2006. He was an
IEEE EMC Society Distinguished Lecturer from 2011 to 2012, and the
General Co-Chair of the IEEE Electrical Design of Advanced Packaging
and Systems Symposium (EDAPS) in 2011, technically sponsored by the
IEEE Components, Packaging and Manufacturing Technology Committee.
He has been an Associate Editor of the IEEE TRANSACTIONS ON COMPONENTS,
PACKAGING AND MANUFACTURING TECHNOLOGY and the International Journal of
Numerical Modeling: Electronic Networks, Devices and Fields since 2011.
He is a reviewer for many international journals, including eight IEEE
Transactions and IEEE Letters.

VOLUME 6, 2018