scholarly journals Engineering of dielectric composites on electromagnetic and microwave absorbing properties for operation in the X-band

2020 ◽  
pp. 2150001
Author(s):  
Bhoopendra Singh ◽  
Vivek Pratap ◽  
Mohit Katiyar ◽  
S. M. Abbas ◽  
Y. K. Sharma ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Network Analyzer ◽  
Frequency Range ◽  
Melt Mixing ◽  
Band Frequency ◽  
Microwave Absorbing Properties ◽  
X Band ◽  
Mixing Method ◽  
Microwave Absorbing ◽  
Potential Use

In this study, carbon black (CB) powder-loaded polyurethane (PU) composites (CB–PU composites) were prepared by melt mixing method with different volume percentages (45, 50, 55, 58 and 61 vol.%) of CB in the PU matrix. The prepared CB–PU composites had been further studied for surface morphology using the field-emission scanning electron microscopy (FESEM) technique. Dielectric properties in terms of real permittivity ([Formula: see text] and imaginary permittivity ([Formula: see text] of the fabricated composites were computed using an Agilent E8364B vector network analyzer in the frequency range of 8–12 GHz ([Formula: see text]-band). Dielectric loss factor of the prepared CB–PU composites was computed in terms of the dielectric loss tangent (tan [Formula: see text] = [Formula: see text]/[Formula: see text]. Microwave absorbing properties were appraised in terms of the reflection loss (RL) which in turn was calculated for varying thicknesses of the prepared composites from the measured real and imaginary permittivity data. The minimum RL was observed as −20.10 dB for the absorber with a thickness of 2.2 mm and the bandwidth achieved was 1.92 GHz for RL [Formula: see text]10 dB. Based on the above results these CB–PU composites have potential use as effective microwave absorbers in 8–12-GHz ([Formula: see text]-band) frequency range.

Preparation and Microwave Absorbing Properties of Natural Ferrites from Corrosion Product as Radar Absorber Materials in X-Band

2020 ◽  
Vol 855 ◽  
pp. 286-292
Author(s):  
Mashuri ◽  
M.A. Faisal
Keyword(s):  
Corrosion Product ◽  
Reflection Loss ◽  
Ferrous Metal ◽  
Soft Magnetic ◽  
Band Frequency ◽  
Microwave Absorbing Properties ◽  
X Band ◽  
Microwave Absorbing ◽  
Magnetite Phase ◽  
Maximum Reflection Loss

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.

scholarly journals Structural, Magnetic, and X-Band Microwave Absorbing Properties of Ni-Ferrites Prepared Using Oxidized Mill Scales

2021 ◽  
Vol 21 (1) ◽  
pp. 27
Author(s):  
Ardita Septiani ◽  
Novrita Idayanti ◽  
Tony Kristiantoro ◽  
Dedi Mada ◽  
Nadya Larasati Kartika ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Raw Materials ◽  
Energy Dispersive Spectrometer ◽  
Milling Process ◽  
Microwave Properties ◽  
Heating Process ◽  
Microwave Absorbing Properties ◽  
X Band ◽  
Microwave Absorbing

This study aims to evaluate the structural, magnetic, and microwave absorbing properties at the X-band region of oxidized mill scales as by-product derived from a steel making process by means of a facile solid-state reaction. The oxidized mill scales were heated at 600 °C for 4 h followed by mixing with NiO. A calcination process took place at 900 °C and sintering process were conducted at 1260 °C with a milling process conducted in between the heating process. X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) were employed to evaluate the structural properties of the Ni-ferrites samples. Remacomp measurement were conducted to evaluate the magnetic properties and vector network analyzer (VNA) to measure its microwave properties. A single phase of NiFe2O4 was confirmed by XRD data. The site occupancies derived from the Rietveld refinement shows that the Ni:Fe:O ratio deviates from the 1:2:4 ratio as that suggests vacancies formed in the Ni2+ and Fe3+ that lowers the unit cell density to 5.08 g/cm3 that further confirmed by EDS measurement. The coercivity of 11 kOe is also higher than the bulk NiFe2O4¬ prepared by the chemical grade raw materials. The reflection data of the microwave properties at X-band of 8-12 GHz do not shows significant absorptions. This study suggests that the selected preparation method yields a single phase, however with the significant crystallographic defects and has less ‘soft’ magnetic properties compared to NiFe2O4 prepared using chemical grade by previous study.

Structural Characteristic and Dielectric Properties of Zirconia Toughened Alumina

2020 ◽  
Vol 1010 ◽  
pp. 250-255
Author(s):  
Nik Akmar Rejab ◽  
Nurul Khairunnisa Su ◽  
Wan Fahmin Faiz Wan Ali ◽  
Mohd Fadzil Ain ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Dielectric Resonator ◽  
Cutting Tool ◽  
High Hardness ◽  
Xrd Analysis ◽  
Dielectric Resonator Antenna ◽  
Frequency Range ◽  
Band Frequency ◽  
X Band ◽  
Zirconia Toughened Alumina

Zirconia toughened alumina (ZTA) has shown a great effect in the cutting tool application due to its high hardness and comparable fracture toughness. However, the capability of the materials to be applied in as the dielectric resonator antenna (DRA) is not being discussed in detail. In this study, an attempt is made to further explore the potential of ZTA to be applied in DRA. Various related characterization techniques were applied that is subjected to DRA properties. The addition of CeO2 (0 wt.% to 15 wt.%) on ZTA has been pressed into pellets shape and sintered at 1600 °C for 2 hours under pressureless conditions. Based on the XRD analysis, only corundum and yttria doped zirconia phases were present. Shift in position of the zirconia peaks was observed due to an existence of Ce2Zr3O10 phase. For the DRA measurement, ZTA with 10 wt.% CeO2 addition have resonated at 6.76 GHz which is suitable for X-band applications. Meanwhile the radiation pattern indicated the omnidirectional characteristic, which suggested that the signal could be received by this dielectric antenna in various positions. Therefore, ZTA- 10 wt.% CeO2 have high potential to be used as DRA that operates X-band frequency range applications.

scholarly journals The Preparation of FeCo/ZnO Composites and Enhancement of Microwave Absorbing Property by Two-Step Method

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3259
Author(s):  
Ka Gao ◽  
Junliang Zhao ◽  
Zhongyi Bai ◽  
Wenzheng Song ◽  
Rui Zhang
Keyword(s):  
Single Phase ◽  
Effective Bandwidth ◽  
Frequency Range ◽  
Step Method ◽  
Absorption Properties ◽  
Composite Surface ◽  
Microwave Absorbing Properties ◽  
Microwave Absorbing Property ◽  
Microwave Absorbing ◽  
Absorbing Property

In this paper, the flower-like FeCo/ZnO composites were successfully firstly prepared by a two-step method, and their microstructures and microwave absorbing properties were characterized. The results show that with an increase of temperature, the content of ZnO loaded on a FeCo/ZnO composite surface was increased. The optimal reflection loss (RL) value can be reached around −53.81 dB at 9.8 GHz, which is obviously superior to results of previous studies and reports, and its effective bandwidth (RL < −10 dB) is 3.8 GHz in the frequency range of 8.7–11.8 GHz with a matching thickness of 1.9 mm. We considered that a large number of lamellar and rod-like ZnO loaded on nano-FeCo single-phase solid solution by two-step method can significantly improve the electromagnetic wave absorption properties.

scholarly journals Synthesis of suitable material for microwave absorbing properties in X-band

2020 ◽  
Vol 2 (12) ◽  
Author(s):  
Monika Rani ◽  
Kamaljit Singh Bhatia ◽  
Harjitpal Singh ◽  
Harsimrat Kaur ◽  
Nancy Gupta
Keyword(s):  
Suitable Material ◽  
Microwave Absorbing Properties ◽  
X Band ◽  
Microwave Absorbing

Electromagnetic shielding performance of three-dimensional woven fabrics with copper-based hybrid yarn in X-band frequency range

2018 ◽  
Vol 49 (4) ◽  
pp. 484-502 ◽  
Author(s):  
Dharmendra Nath Pandey ◽  
Arindam Basu ◽  
Pramod Kumar ◽  
Himangshu B Baskey
Keyword(s):  
Cotton Fabric ◽  
Three Dimensional ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Structural Configuration ◽  
Band Frequency ◽  
Hybrid Yarn ◽  
X Band ◽  
Electromagnetic Shielding Effectiveness

This study involves a comprehensive evaluation of electromagnetic shielding characteristics of multilayer three-dimensional conductive fabrics by using cotton/copper wrapped hybrid yarn in X band frequency range. Five, three-dimensional fabrics with different structural configuration, such as orthogonal, angle interlock, cellular spacer, multi-tubular spacer, and contour were produced. Three different series of all five structures was also developed using pure cotton fabric, conductive hybrid yarn in weft and one-third hybrid yarn and two-third cotton yarn in warp Also, the effect of vertical and horizontal polarization of electromagnetic waves on electromagnetic shielding effectiveness was studied. The comparative analysis of reflectance transmittance and absorption behavior was also undertaken. The results indicate that pure cotton fabric (A series) does not have electromagnetic shielding capabilities. The difference between the electromagnetic shielding effectiveness values in vertical and horizontal planes of fabrics, having conductive hybrid yarn in weft direction (B series), showed significantly better results on the vertical plane in comparison to that on the horizontal plane. Fabric containing conductive hybrid yarn in both warp and weft (C series) exhibits consistent electromagnetic shielding effectiveness in both the planes. It is worth mentioning that the structural configuration in all five three-dimensional fabrics in B and C series has shown differential trends of electromagnetic shielding effectiveness in terms of reflectance, transmittance and absorption behavior. They are also found to be statistically significant. Finally, it is concluded that the conductive 3-D multilayer system develops special protective capabilities, mostly due to its larger surface area.

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