An effective methodology to design scale model for magnetic absorbing
coatings based on ORL
Liming Yuan
a,
⇑
, Bin Wang
b
, Wei Gao
a
, Yonggang Xu
a
, Xiaobing Wang
a
, Qilin Wu
c
a
Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438, PR China
b
Shanghai Radio Equipment Research Institute, Shanghai 200090, PR China
c
Key Laboratory of High Performance Fibers & Products, Ministry of Education, Donghua University, Shanghai 201620, PR China
article info
Article history:
Received 18 October 2016
Received in revised form 20 April 2017
Accepted 6 May 2017
Available online 10 May 2017
Keywords:
A magnetic absorbing coating
Scale measurement
Reflective loss
Monostatic RCS
abstract
The scale measurement has a great significance in studying electromagnetic scattering properties. But
there still exist great difficulties in constructing an accurate scale model including nonmetallic materials
such as magnetic absorbing coatings. Based on the reflective loss of a coating irradiated obliquely by
plane microwave, a method is proposed to solve the problem of designing the scale coating. The commer-
cial simulation software FEKO is used to investigate the use of the method. According to simulating
monostatic RCS of coating plate models, coating sphere models and coating spherecone models, results
reveal that the monostatic RCS of the designed scale model have a great agreement with that of the the-
oretical scale model in the whole incidence angle range. Furthermore, the coating SLICY models, which
include many electromagnetic scattering mechanisms, are constructed to verify the proposed method.
The simulated result of the designed scale SLICY model is very close to that of the theoretical scale
SLICY model. All the simulated results indicate that the method proposed in this paper is valid.
Ó 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND
license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
Radar cross section (RCS) is one of the most important electro-
magnetic scattering properties. It has a great significance in radar
system development, object recognition, electronic warfare tech-
nology and so on. RCS of a target could often be obtained by the full
scale measurement or the scale measurement. For there exist
many difficulties in the full scale measurement, such as it is diffi-
cult to acquire the real full-scale target, the controllability is poor,
the cost is very expensive and so on, the scale measurement has
been increasingly concerned and widely applied to study electro-
magnetic scattering properties [1]. On the basis of the linear theory
of Maxwell’s equations, a classic scale theory was proposed by J.A.
Stratton and J.A. Sinclair [2,3]. The basic principle of the theory is
that the scale system has the same electrical size with the full scale
system, and then there differs a constant value between the scale
model RCS and the full scale model RCS. This principle requires
that the ratio of the geometric length to the microwave wavelength
in the scale system is the same with that in the full scale system;
meanwhile, electromagnetic parameters of model materials are
identical in the both systems. Table 1 gives the relationships of
physical quantities between the full scale system and the scale
system.
In Table 1, p is the scale ratio, then there exists the following
relation between the scale model RCS and the full scale model RCS.
r
0
¼
r
þ 20 log p ð1Þ
where
r
0
is the scale model RCS at scale frequency, and
r
is the full
scale model RCS at full scale frequency.
In the scale measurement, one of the keys is to construct an
accurate scale model. For metallic object or perfect electric conduc-
tor (PEC), there is little difficulty in constructing a satisfactory
model. However, engineering targets always contain electric or/
and magnetic materials. The permittivity or/and permeability of
these materials are typically frequency dependent [4,5]. In partic-
ular, when a target contains a magnetic material, such as a mag-
netic absorbing coating on a stealth aircraft, for permeability of a
regular material tends to be a constant for the existence of Snoek
limitation [6,7], it would be very difficult to obtain the scale mate-
rial which has the same permeability at scale frequency.
In this study, a scale-designing method for a magnetic absorb-
ing coating is proposed based on the reflective loss of a coating
irradiated obliquely by plane microwave. The optimization proce-
dure base on the method is introduced in details. Monostatic RCS
of coating plate models, coating sphere models and coating sphere-
cone models as well as coating SLICY models are evaluated by the
http://dx.doi.org/10.1016/j.rinp.2017.05.007
2211-3797/Ó 2017 The Authors. Published by Elsevier B.V.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
⇑
Corresponding author.
E-mail address: lming_y@163.com (L. Yuan).
Results in Physics 7 (2017) 1698–1704
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