MINIMIZING THE EFFECTIVE AREA OF SCATTERING BY MEANS OF CHANGING THE RELATIVE MAGNETIC PERMEABILITY

Author(s):  
А.В. Володько ◽  
С.М. Фёдоров ◽  
Е.А. Ищенко ◽  
М.А. Сиваш ◽  
Л.В. Сопина ◽  
...  

Исследуется зависимость эффективной площади рассеяния (ЭПР) от относительной магнитной проницаемости материала, из которого изготавливается структура. В качестве тела моделирования был выбран шар, который изготовлен из диэлектрического материала, у которого возможно выполнять изменение относительной магнитной проницаемости. По полученным результатам моделирования построены графики зависимости максимального значения моностатической ЭПР от частоты, а также от относительной магнитной проницаемости среды. Было показано, что с увеличением относительной магнитной проницаемости материала изготовления происходит увеличение значения ЭПР объекта, а также обнаружена зависимость эффективной площади рассеяния от соотношения размеров шара и длиной волны, так при превышении порогового значения, после которого шар становится крупным объектом, ЭПР резко возрастает. По результатам исследования был построен график зависимости эффективной площади рассеяния шара от относительной магнитной проницаемости материала изготовления. Доказана возможность применения материала с частотозависимой относительной магнитной проницаемостью в качестве стелс-покрытия. В статье содержится исследуемая модель, графики полученных результатов, по которым можно легко определить зависимость ЭПР от частоты и от относительной магнитной проницаемости материала изготовления The article investigates the dependence of the effective scattering area (ESA) on the relative magnetic permeability of the material from which the structure is made. We chose a sphere as the modeling body, which is made of a dielectric material, in which it is possible to change the relative magnetic permeability. Based on the obtained simulation results, graphs of the dependence of the maximum value of monostatic ESA on frequency, as well as on the relative magnetic permeability of the medium, were constructed. It was shown that with an increase in the relative magnetic permeability of the material of manufacture, an increase in the value of the ESA of the object occurs, and the dependence of the effective scattering area on the ratio of the size of the ball and the wavelength was found, so when the threshold value is exceeded, after which the ball becomes a large object, ESA rises sharply. Based on the results of the study, a graph of the dependence of the effective scattering area of the sphere on the relative magnetic permeability of the material of manufacture was built. The possibility of using a material with a frequency-dependent relative magnetic permeability as a stealth coating was proven. The article contains the investigated model, graphs of the results obtained, by which it is easy to determine the dependence of the ESA on the frequency and on the relative magnetic permeability of the material of manufacture

Author(s):  
Andris Martinovs ◽  
Josef Timmerberg ◽  
Konstantins Savkovs ◽  
Aleksandrs Urbahs ◽  
Paul Beckmann

The paper describes methods developed to determine specific electrical conductivity and relative magnetic permeability of cylindrical steel items and nano-coatings deposited on them by sputtering. Research enables development of a new method for determination of thickness of vacuum deposited nano- coating that is based on application of skin effect.


Kursor ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Candra Dewi ◽  
Muhammad Sa’idul Umam ◽  
Imam Cholissodin

Disease of the soybean crop is one of the obstacles to increase soybean production in Indonesia. Some of these diseases usually are found in the leaves and resulted to the crop become unhealthy. This study aims to identify disease on soybean leaf through leaves image by applying the Learning Vector Quantization (LVQ) algorithm. The identification begins with preprocessing using modified Otsu method to get part of the diseases on the leaves with a certain threshold value. The next process is to identify the type of disease using LVQ. This process uses the minimum value, the maximum value and the average value of the red, green and blue color of the image. The testing conducted in this study is to identify two diseases called Peronospora manshurica (Downy Mildew) and phakopsora pachyrhizi (Karat). The result of testing by using 60 training data and the value of all recommendations parameters obtained the highest accuracy of identification is 95% %, but the more stable accuracy is 90%. This result shows that the method perform quite well identification of two mentioned disease.


2014 ◽  
Vol 6 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Mark Clemente Arenas ◽  
Anne Claire Lepage ◽  
Xavier Begaud ◽  
Paul Henri Tichit ◽  
André de Lustrac

In this paper, the design methodology of a flat reflector composed with standard dielectric material and using transformation electromagnetics (TE) is presented. First, the mathematical relation between a flat reflector and a parabolic one is described. The TE principle is then described. Some realization issues are highlighted, leading to approximations and compromises in order to design a more realistic structure. In this way, a flat reflector made only with standard dielectric materials is presented, using an original method to achieve the desired spatial permittivity variation. The simulation results of different configurations for the flat reflector are presented and compared to classical solutions in order to prove the thickness reduction and the improvement of radiation characteristics in terms of gain and half-power beamwidth.


1981 ◽  
Vol 24 (5) ◽  
pp. 351-353
Author(s):  
A. A. Zima ◽  
S. G. Serebryakova ◽  
A. V. Serov ◽  
B. P. Filimonov ◽  
N. N. Chernousova

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed M. Soliman ◽  
Ramy A. Saad

Two new configurations for realizing ideal floating frequency-dependent negative resistor elements (FDNR) are introduced. The proposed circuits are symmetrical and are realizable by four CCII or ICCII or a combination of both. Each configuration is realizable by eight different circuits. Simulation results are included to support the theory.


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