The Effects of Layer Thickness of Radar Absorbing Materials Prepared by Double Layer Method on X-Band Wavelength Frequency

2019 ◽  
Vol 966 ◽  
pp. 35-40
Author(s):  
Mochamad Zainuri ◽  
Rahma Fitri Puspitasari ◽  
Deril Ristiani ◽  
Triwikantoro

Double layer coating with variations in layer thickness on radar absorbent material (RAM), and Polyaniline dobed by DBSA as a dielectric material has been successfully synthesized. As well as Barium M-Hexaferrite doped by Zn2+ at x=0.9 as magnetic material successfully synthesized. Polyaniline has been synthesized by polymerization method and Barium M-Hexaferrite has been synthesized by solid state method. Characterization results obtained the conductivity of Polyaniline and Barium M-Hexaferrite respectively 4.4 × 10-1 S/m and 2.09 × 10-3 S/m, both of which are in range of semiconductor materials conductivity. The presence of Zn2+ doping successfully reduced hard magnetic properties of Barium M-Hexaferrite to be soft magnetic, with coercivity field (Hc) equals 0.0181 Tesla. Based on research that has been done, represent that double layer design with variations PANi : PANi + BaM (3:1) has maximum reflection loss value about -29,6003 dB, and 96.69% of energy absorbed. Whereas in variation of PANi: PANi + BaM (3: 1) has minimum reflection loss value about -15.2937 dB, and 82.21% of energy absorbed. In addition, the coating thickness variations also affect the absorption band width, with the most effective absorption peaks in “D” variation with bandwidth equals 1.81 GHz in range of frequency 8 to 9.81 GHz.

2019 ◽  
Vol 966 ◽  
pp. 54-59 ◽  
Author(s):  
Mochamad Zainuri ◽  
Dina Andryani

Behavioral characterization of radar absorbent material consisting of Polyaniline (PaNi) and Barium M-Hexaferrite (BaM) has been successfully synthesized by solid state method. Polyaniline conductive material was synthesized using the polymerization method with DBSA dopant. A Radar Absorbing Materials (RAM) is characterized by X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Four Point Probe (FPP), Scanning Electron Microscope (SEM) and Vector Network Analyzer (VNA). The ion Zn 2+ is dopping into the BAM structure, where Zn 2+ ions replace Fe2+ ions in Hexaferrite barium so that the phase becomes soft magnetic materials . RAM and PANi particles are combined with ship paint to form radar wave absorbent coatings. The layer is coated with multilayer geometry on AH 36 type A steel, with thicknesses of 2.4 mm, 3.6 mm, 4.8 mm and 6 mm respectively. The X-band wave absorption was identified by VNA testing, where the maximum reflection loss value was found at 6mm thickness with a reflection loss value - 32.6 dB at 8.4 GHz frequency. Reflection loss values of multilayer variations with a thickness of 2.4 mm, 3.6mm and 4.8mm each have reflection loss values of -8.02 dB, -19.13 dB and -28.9 dB respectively in the x band frequency range.


2018 ◽  
Vol 929 ◽  
pp. 109-115 ◽  
Author(s):  
Erfan Handoko ◽  
Iwan Sugihartono ◽  
Mangasi Alion Marpaung ◽  
Maulana Randa ◽  
Mudrik Alaydrus ◽  
...  

Microwave absorption characteristics of double layer of barium hexaferrite attached on the silica to from a composite on the basis of wave propagation theory have been investigated. Barium hexaferrite, BaFe12O19, was synthesized through ceramic method from stoichiometric mixtures of BaCO3 and Fe2O3 as precursors. The mixture was pelletized under the pressure of 10 MPa and sintered at 1100 °C for 5 hours. Silica in the forms of powder was purified by using HCl. The crystal structure of the samples was characterized using X-ray diffraction (XRD), microstructure was examined using scanning electron microscope (SEM), hysteresis curves recorded by PERMAGRAPH techniques, whereas the microwave absorbing properties for X-band was recorded using a vector network analyzer (VNA). Relative complex permeability and permittivity, and reflection loss values were calculated at given thickness according to transmittance line theory within the range 8.2–12.4 GHz. Based on this study, the layer dimension and frequency that results in low reflection loss can be estimated from the material properties of the barium hexaferrite/silica composite material.


2020 ◽  
Vol 855 ◽  
pp. 286-292
Author(s):  
Mashuri ◽  
M.A. Faisal

Rust is the by product of oxidation on ferrous metal. Rust is extremely harmful and can’t be avoided. Due to that reason for added values on rust a research titled utilizing corrosion product as absorber for microwave on X-band frequency is done. This research goals are to determine the ability of rust to absorb radar waves by maximum reflection loss values. The study was conducted by taking a powder natural ferrites of rust from corroded ferrous metal in Surabaya, Malang, Bangkalan and then later separated by using a 0.1 T hard magnet. The XRF, XRD and VSM characterization showed that rust powder sample has chemical compound of ferrites (Fe3O4) with magnetite phase and a soft magnetic with Ms = 8 emu/g. Based on the measurement microwave absorbing by VNA showed that maximum reflection loss of natural ferrites Surabaya, Malang, Bangkalan respectively-20.15 dB, -12.64 dB and-6.75 dB, at matching frequency 11 GHz and width frequency 3 GHz.


2021 ◽  
Vol 933 ◽  
Author(s):  
Yu Liang ◽  
Xisheng Luo

Shock-induced light-fluid-layer evolution is firstly investigated experimentally and theoretically. Specifically, three quasi-one-dimensional helium gas layers with different layer thicknesses are generated to study the wave patterns and interface motions. Six quasi-two-dimensional helium gas layers with diverse layer thicknesses and amplitude combinations are created to explore the Richtmyer–Meshkov instability of a light-fluid layer. Due to the multiple reflected shocks reverberating inside a light-fluid layer, the speeds of the two interfaces gradually converge, and the layer thickness saturates eventually. A general one-dimensional theory is adopted to describe the two interfaces’ motions and the layer thickness variations. It is found that, for the first interface, the end time of its phase reversal determines the influence of the reflected shocks on it. However, the reverberated shocks indeed lead to the second interface being more unstable. When the two interfaces are initially in phase, and the initial fluid layer is very thin, the two interfaces’ spike heads collide and stabilise the two interfaces. Linear and nonlinear models are successfully adopted by considering the interface-coupling effect and the reverberated shocks to predict the two interfaces’ perturbation growths in all regimes. The interfacial instability of a light-fluid layer is quantitatively compared with that of a heavy-fluid layer. It is concluded that the kind of waves reverberating inside a fluid layer significantly affects the fluid-layer evolution.


2017 ◽  
Vol 50 (3) ◽  
pp. 701-711 ◽  
Author(s):  
Qi Zhong ◽  
Lars Melchior ◽  
Jichang Peng ◽  
Qiushi Huang ◽  
Zhanshan Wang ◽  
...  

Iterative phase retrieval has been used to reconstruct the near-field distribution behind tailored X-ray waveguide arrays, by inversion of the measured far-field pattern recorded under fully coherent conditions. It is thereby shown that multi-waveguide interference can be exploited to control the near-field distribution behind the waveguide exit. This can, for example, serve to create a secondary quasi-focal spot outside the waveguide structure. For this proof of concept, an array of seven planar Ni/C waveguides are used, with precisely varied guiding layer thickness and cladding layer thickness, as fabricated by high-precision magnetron sputtering systems. The controlled thickness variations in the range of 0.2 nm results in a desired phase shift of the different waveguide beams. Two kinds of samples, a one-dimensional waveguide array and periodic waveguide multilayers, were fabricated, each consisting of seven C layers as guiding layers and eight Ni layers as cladding layers. These are shown to yield distinctly different near-field patterns.


1983 ◽  
Vol 132 ◽  
pp. 337-347 ◽  
Author(s):  
E. J. Hinch ◽  
J. D. Sherwood

We study the primary electroviscous effect in a suspension of spheres when the double layer thickness κ−1 is small compared with the particle radius a. The case of a 1–1 symmetric electrolyte is examined using the methods of Dukhin & coworkers (1974), whilst the asymmetric electrolyte is studied along lines similar to those of O'Brien (1983). Sherwood's (1980) asymptotic results for high surface potentials and high Hartmann numbers are extended and complemented.


2020 ◽  
Vol 8 (13) ◽  
pp. 6183-6189 ◽  
Author(s):  
Fei Shen ◽  
Kaiming Wang ◽  
Yuting Yin ◽  
Le Shi ◽  
Dingyuan Zeng ◽  
...  

A PAN fiber/PI sphere double-layer coating serves as an interfacial functional layer to guide uniform Li deposition.


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