Communication
Design of a Novel Wideband Leaf-Shaped Printed Dipole
Array Antenna Using a Parasitic Loop for High-Power
Jamming Applications
Eunjung Kang
1
, Tae Heung Lim
1,
* , Seulgi Park
2
and Hosung Choo
1
Citation: Kang, E.; Lim, T.H.; Park,
S.; Choo, H. Design of a Novel
Wideband Leaf-Shaped Printed
Dipole Array Antenna Using a
Parasitic Loop for High-Power
Jamming Applications. Sensors 2021,
21, 6882. https://doi.org/
10.3390/s21206882
Academic Editor: Ángela
María Coves Soler
Received: 21 September 2021
Accepted: 11 October 2021
Published: 17 October 2021
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1
Department of Electronic and Electrical Engineering, Hongik University, Seoul 04066, Korea;
ej0901@mail.hongik.ac.kr (E.K.); hschoo@hongik.ac.kr (H.C.)
2
Hanwha Systems Co., Ltd., Seongnam City 13524, Korea; sg0212.park@hanwha.com
* Correspondence: qpzm0105@mail.hongik.ac.kr
Abstract:
This paper proposes a novel wideband leaf-shaped printed dipole antenna sensor that
uses a parasitic element to improve the impedance matching bandwidth characteristics for high-
power jamming applications. The proposed antenna sensor consists of leaf-shaped dipole radiators,
matching posts, rectangular slots, and a parasitic loop element. The leaf-shaped dipole radiators
are designed with exponential curves to obtain a high directive pattern and are printed on a TLY-5
substrate for high-power durability. The matching posts, rectangular slots, and a parasitic loop
element are used to enhance the impedance matching characteristics. The proposed antenna sensor
has a measured fractional bandwidth of 66.7% at a center frequency of 4.5 GHz. To confirm the array
antenna sensor characteristics, such as its active reflection coefficients (ARCs) and beam steering
gains, the proposed single antenna sensor is extended to an 11
×
1 uniform linear array. The average
values of the simulated and measured ARCs from 4.5 to 6 GHz are
−
13.4 dB and
−
14.7 dB. In
addition, the measured bore-sight array gains of the co-polarization are 13.4 dBi and 13.7 dBi at
4 GHz and 5 GHz, while those of the cross-polarizations are
−
4.9 dBi and
−
3.4 dBi, respectively.
When the beam is steered at a steering angle,
θ
0
, of 15
◦
, the maximum measured array gains of the
co-polarization are 12.2 dBi and 10.3 dBi at 4 GHz and 5 GHz, respectively.
Keywords: jammer antenna; printed dipole; wideband antenna; parasitic element
1. Introduction
In electronic warfare, high-power jamming systems have been widely used to impede
the radio frequency (RF) signal detection of friendly forces by producing interference signals
to jam enemy RF radar systems [
1
]. However, the development of radar design technology
has supported such RF radar systems with multifunctional modes to avoid jamming
signals by using various frequency bands. Thus, it is essential for high-power jamming
applications to also have wideband characteristics in order for antennas to efficiently
interfere with RF radar signals with diverse frequencies. Extensive efforts have been
devoted to enhancing the frequency bandwidth of antennas by employing various design
structures, such as a Vivaldi antenna with a flared-notched shape [
2
], a folded patch
antenna with shorting pins [
3
], a horn antenna with a substrate-integrated waveguide [
4
],
and double exponentially tapered slot antennas [
5
,
6
]. Although these approaches have
achieved the wideband characteristics of a single antenna, the physical antenna size is too
large to mount on jamming applications with multiple antenna elements. To overcome
this problem, many studies have investigated miniaturizing the antenna size by applying
a meander line on a log-periodic dipole antenna (LPDA) [
7
], a hybrid-type antenna with
wideband characteristics antennas, i.e., a horn antenna and Vivaldi antenna [
8
,
9
], and a
printed LPDA on a high dielectric substrate [
10
]. However, these techniques still encounter
the problems of high cost and a complex fabrication process, despite the antenna sensor
Sensors 2021, 21, 6882. https://doi.org/10.3390/s21206882 https://www.mdpi.com/journal/sensors
