Effect of filler loading and thickness parameters on the microwave absorption characteristic of double-layered absorber based on MWCNT/BaTiO3/pitted carbonyl iron composite

In this work, single- and double-layer electromagnetic wave absorbers were prepared by as-prepared MWCNTs/BaTiO₃/pitted carbonyl iron composites. MWCNT/BaTiO₃ (MW/BTO) was prepared via sol-gel method whereas the carbonyl iron particles (CI) were corroded via pitting corrosion method. The structural, microstructural, magnetic and microwave absorption properties of the composites were evaluated via X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA) methods. CST studio software was employed to simulate the microwave absorption characteristics of double-layer absorbers. Moreover, the effects of changing matching and absorbing layer thickness (3 mm in total) and filler loading (10, 20 and 30 wt%) of the as-prepared composite on the microwave absorption properties were investigated. According to the results, maximum RL value for single layer absorber with 20 wt% filler loading can reach ?11.5 dB at 9.7 GHz with 3 mm thickness and 0.4 GHz bandwidth. In contrast, double-layered absorber using 10 wt% of the composite in the upper layer (as matching layer) and 30 wt% of the composite in lower layer (as absorbing layer) can increase the reflection loss and absorption bandwidth values to ?15.5 dB and 1 GHz respectively. Improving in absorption characteristics can be attributed to coupling interactions, impedance matching and multiple scattering. The main advantages of the prepared double layer absorber than single layer absorber are tuning the intensity and effective absorption bandwidth by adjusting the layer order, thickness and filler loading of each layer which shown good potential for practical application.     

Tunable microwave absorption band via rational design of C@TiC nanospheres

To effectively tune material's microwave absorption band, it is necessary to build a special structure and composition. Titanium carbide nanoparticles decorated carbon nanospheres (C@TiC) were prepared by using carbon nanospheres as a initial structure-directing agent, and their absorption band was tuned by rational design of TiC content. With increasing dosage of tetrabutyl titanate (TBT), absorption band of C@TiC dispersed in paraffin (30 wt%) gradually shifted from Ku to S-band, realizing the adjustment of absorption band. For example, when the amount of TBT was 1.0, 1.5 and 2.0 mL, the minimum reflection loss (RL) of C@TiC was about ?49.8, ?52.4 and ?50.3 dB at 17.4, 13.1 and 6.6 GHz, respectively. Excellent performance was attributed to good impedance match and synergistic effect between carbon spheres and TiC nanoparticles. This in-situ phase transition induced nanoheterostructure would provide a way for microwave absorbers with tunable band.     

Dielectric and microwave absorption properties of CB doped SiO2f/PI double-layer composites

Carbon black (CB) with contents of 5.5?wt% and 15?wt% filled quartz glass fiber reinforced polyimide (SiO_2f/PI) composite were designed and prepared. A double-layer absorbing material was designed using the two composites materials as a matching layer and an absorption layer, respectively. The microwave absorption property of single-layer and double-layer composites is calculated according to transmission line theory. The results show that the microwave absorbing property of double-layer composite is better than that of single-layer at the same thickness. When the 5.5?wt%CB doped SiO_2f/PI composite is used as the matching layer with a thickness of 0.7?mm and 15?wt%CB doped SiO_2f/PI composite is used as the absorption layer with a thickness of 0.9?mm, the RL (reflection loss) of the composite reaches a minimum value of ?46.18?dB at 16.07?GHz. Meanwhile, the bandwidth of RL?≤??5?dB is 5.87?GHz and the bandwidth of RL?≤??10?dB is 3.95?GHz.     

A new multicomponent material based on carbonyl iron/carbon nanofiber/lanthanum–strontium–manganite as microwave absorbers in the range of 8–12 GHz

We report the design of a new multicomponent microwave absorber in the X band based on carbonyl iron (CI)/carbon nanofiber (CNF)/lanthanum–strontium manganese oxide (LSMO). The citrate precursor method has been used to synthesize LSMO nanopowder. The phase identification has been investigated using XRD patterns. Scanning electron microscope (SEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA) are used to analyze the morphology of the different components and the magnetic, electromagnetic and microwave absorption properties of the final composite absorbers. To the best of our knowledge, the use of this class of multicomponent microwave absorber, has not been explored before. The results indicate that substituting CI by increasing amounts of CNF and LSMO, not only decreases the weight of the designed absorber, but also has a synergistic effect that promotes its attenuation properties. The absorber of 2 mm thickness and only 30 wt% of loading ratio exhibits an average reflection loss of −8.75 dB over the range 9–12 GHz, while its corresponding absorber without LSMO has only a RL around −5 dB.     

3D printed SiC nanowire reinforced composites for broadband electromagnetic absorption

SiC nanowire/acrylic resin (SiC_nw/ACR) composites with broadband electromagnetic (EM) absorption capabilities were fabricated by a novel procedure using 3D stereolithography (3D-SL) printing technology. The EM absorption abilities of the composites can be adjusted by tuning the SiC_nw content and the thickness of the printing layer. When the SiC_nw content is 3?wt% and the thickness of the printing layer is 25?μm–50?μm, the SiC_nw/ACR composite has an optimally broad effective absorption bandwidth (EAB) and a high efficiency for EM absorption, whether assessing the C, X or Ku band, because of the high dielectric loss and proper impedance matching between the materials and free space. In the C band (4–8?GHz), the EAB reaches 2.9?GHz, and the reflection loss (RL) reaches ?34.1?dB; in the X band (8–12?GHz), the EAB reaches 4?GHz, which covers the entire X band, and the RL reaches ?34.5?dB; in the Ku band (12–18?GHz), the EAB exceeds 6?GHz, which covers the whole Ku band, and the RL reaches ?34.7?dB. This research is of great importance to the rapid preparation of parts, shells or devices with arbitrarily complex shapes and high efficiency broadband EM absorption abilities.     

Fabrication of hexagonal cerium oxide nanoparticles decorated nitrogen-doped reduced graphene oxide hybrid nanocomposite as high-performance microwave absorbers in the Ku band

With the aim to obtain microwave absorbers simultaneously possessing broad absorption bandwidth, strong absorption intensity and thin matching thickness, nitrogen-doped reduced graphene oxide decorated by cerium oxide particles (NRGO/CeO₂) hybrid nanocomposite was prepared through a hydrothermal and calcination two-step route. Results of micromorphology analysis showed that numerous hexagonal CeO₂ nanoparticles were evenly anchored on the crumpled surfaces of NRGO. Moreover, both nitrogen doping and hybridization with RGO could notably strengthen the microwave absorption capacity of CeO₂. Remarkably, the NRGO/CeO₂ hybrid nanocomposite exhibited the minimum reflection loss of ?57.2 dB at 13.4 GHz (Ku band) under a matching thickness of 1.66 mm and maximum absorption bandwidth of 4.6 GHz (from 13.2 to 17.8 GHz) at an ultrathin thickness of only 1.5 mm. Meanwhile, the hybrid nanocomposites displayed strong absorption intensity (≤-20 dB, 99% absorption) in almost the whole measured thicknesses range. Furthermore, the relationship between absorption intensity and filler loadings was uncovered. The potential microwave absorption mechanisms were further revealed. Therefore, this work opened a novel idea for designing RGO-based hybrid nanocomposites as high-performance microwave absorbers.     

Tunable microwave absorption features in bi-layer absorber based on mesoporous CuS micro-particle with 3D hierarchical structure and nanosphere like NiCo2O4

There has been a growing demand for materials with superior absorption capabilities, such as strong absorbing capacity, thin thickness, and light weight, to solve challenges related to EM radiation pollution. While the majority of the research is focused on optimizing material compositions, component microstructure and absorber structure are also critical factors for improving microwave absorption performance. In this research, we show how the microstructure of components and absorber design may increase dissipation features. Solvothermal and hydrothermal methods were utilized for synthesizing mesoporous CuS micro-particles with a 3D hierarchical structure as a dielectric component and nanospheres like NiCo₂O₄ as magnetic components respectively. The formation of pure phases with the mentioned microstructures was confirmed via XRD, FTIR, UV–Vis, XPS, VSM, FESEM and BET analysis. According to VNA results, the minimum reflection loss can be achieved to ?33 dB at 11 GHz with a total thickness of 2 mm in which each layer thickness was considered 1 mm (CuS placed at top layer and NiCo₂O₄ placed at bottom layer). The RL values of bilayer absorber were strongly affected by both the microstructure of the components and tuning the thickness and arrangement of each layer. We offer a potential technique for enhancing microwave dissipation performance by combining the synergistic effects between the microstructure, thickness and arrangement of layers in a bilayer absorber.     

Single and double-layered Tri-band Microwave absorbing materials

Absorbers at microwave frequencies with multiple frequency-band response are particularly important for use in military for stealth technology. Specially, ferrite based absorbing materials are significant for electromagnetic shielding and signal attenuation. The enhancement of reflection loss of ferrites along with carbonaceous materials are even more beneficial. Recently double-layer absorbers have extensively studied to meet the requirements of advanced absorbing materials in multiple frequency-band response. It still remains a challenge how to determine the type and thickness to couple the impedance-matching-layer to the absorption-layers for a double-layer absorber. We applied hydrothermal method to prepare Fe₃O₄ nanoparticle and combine them with either graphene oxide (GO) or reduced graphene oxide (rGO) to prepare a composite of specific quality to obtain Fe₃O₄@GO and Fe₃O₄@rGO nanocomposite. We studied microwave attenuation capabilities of single and double-layer absorbers containing these two materials. We have demonstrated that with a thin impedance matching layer as a first layer and an absorbing layer behind this layer for the double-layered absorber has much higher reflection loss (RL) than a single-layer. The Fe₃O₄@rGO composite as a single-layer absorber shows the best microwave absorption performance with RL close to −30 dB in all three microwave bands (X, Ku and K bands). The use of a double-layer structure as Fe₃O₄@GO as impedance matching layer and Fe₃O₄@rGO as absorbing layer exhibits the best absorption of −50 dB. This is much larger than the single-layered absorbers at all three frequency-bands. Such a performance is superior to many reported ferrite-based carbonaceous composites. Therefore, a double-layer absorber is best suited to coat the whole body of the aircraft or missiles to evade satellite detection, a preparation towards new-generation weapons for future warfare. Before performing the absorption studies we have characterized the ferrites, GO and rGO materials with various microstructural and magnetic characterizations.     

Design of double-layer ceramic absorbers for microwave heating

We propose a guide for designing double-layer ceramic absorbers in microwave heating by optimizing the thickness based on the analysis of reflection loss (RL) of a double-layer absorber consisting of a high-loss SiC layer and a low-loss Al₂O₃ layer. The calculated reflection losses for individual layers of SiC and Al₂O₃ show that the former with a thickness of 0.0054 m has the maximum microwave absorption while the latter in the thickness range up to 0.1 m is identified as a poor microwave absorbing material with RL larger than −0.4 dB. By using a 0.0054-m-thick SiC layer as the susceptor, the absorption in the Al₂O₃ layer and of the entire double-layer absorber increases significantly. The results demonstrate that high microwave absorption throughout the heating process can only be achieved in a sample with a small thickness in which a slight absorption peak shift during heating (less than one eighth-wavelength in the medium) occurs.     

Multi-interface-induced by regulating nanocomposite morphology and absorber design to achieve wideband electromagnetic wave absorber

The current study describes the fabrication of a bilayer microwave absorber made of magnetic Sr₂FeReO₆ (SRO) powder and a magnetoelectric nanocomposite formed of rod-like magnetic Sr₂FeReO₆ powder wrapped in polygonal SnS₂ powder (SRSS), which was then annealed and analyzed. The analysis of phase constituents, as well as morphological and magnetic measurements, revealed that rod and polygonal particles with soft magnetic properties were successfully synthesized. Additionally, our findings showed that 30:70 wt ratio nanocomposite powders were unable to exhibit broad X-band frequency absorption capabilities. Due to the bi-layer absorber's rational design, the reflection loss was found to be increased and reached -33 dB at 10.3 GHz by covering practically the whole X-band frequency with only 2.5 mm of thickness. The prepared absorber's optimum design included SRSS nanocomposite powder as an absorbing layer with a 1.5 mm thickness and SnS₂ powder as a matching layer. The exceptional electromagnetic wave dissipation performance of bi-layer samples compared to single-layer absorber samples may be the result of multiple interfaces being formed as a result of controlling component morphology and composition as well as the absorber's design, which enhanced critical absorbing factors like various polarization phenomena and relaxation losses. The research presented here suggests a simple method for enhancing microwave dissipation performance with a broad absorption band based on the development of heterojunction structures and the integration of various loss processes.     

Electromagnetic wave absorbing properties of Cr2AlB2 powders and the effect of high-temperature oxidation

The electromagnetic (EM) wave absorbing properties of Cr₂AlB₂ powders and those after high-temperature oxidation were investigated. Coupling of magnetic and dielectric loss enables Cr₂AlB₂ with good absorption properties. The minimum reflection loss (RL) value is −44.9 dB at 8.5 GHz with a thickness of 2.7 mm, and the optimized effective absorption bandwidth (E_AB) is 4.4 GHz (13.0-17.4 GHz) with a thickness of 1.6 mm. After oxidation at 750, 900, and 1000°C for 2 h, the minimum RL values, respectively, are −23.9 dB (17.5 GHz, 1.5 mm), −41.4 dB (16.5 GHz, 1.5 mm), and −39.5 dB (8.0 GHz, 3.0 mm); and the corresponding E_AB values, respectively, are 3.8 GHz (13.6-17.4 GHz, 1.7 mm), 4.1 GHz (13.5-17.6 GHz, 1.6 mm), and 4.4 GHz (13.0-17.4 GHz, 1.7 mm). With an absorber thickness of 1.5-4.0 mm, the E_AB with a RL value of less than −10 dB can be tuned in a broad-frequency range 5.0-18.0 GHz, which basically covers C (4-8 GHz), X (8-12 GHz), and Ku (12-18 GHz) bands. These results demonstrate that Cr₂AlB₂, as a high-efficient and oxidation-resistant absorber, is a promising candidate for microwave absorption applications and can retain good EM wave absorbing properties after high-temperature oxidation.     

Design of controlled-morphology NiCo2O4 with tunable and excellent microwave absorption performance

In recent years, the high-performance microwave absorbers with strong loss, broad frequency bandwidth, thin thickness and light weight have been intensively investigated to address the problem of electromagnetic pollution and improve stealth technology. Considering the fact that microwave absorption performance is quite sensitive to morphology, studying NiCo₂O₄ with different morphologies is a valuable step towards developing a high-performance microwave absorber. The different morphologies are prepared by adjusting the addition of the structure-directing agent NH₄F. When the amount of added NH₄F is 1 mmol, a flower-like NiCo₂O₄ morphology (NC–F1) is obtained with a large specific surface area of 158.97 m²/g and pore volume of 0.3525 cm³g^-1, which easily generates conductive loss, polarization loss, and multiple scattering, thereby enhancing its microwave absorption performance. The maximum reflection loss reaches −50.3 dB at 3 mm, and the effective bandwidth is 4 GHz with the matching thickness of 2 mm when the fill ratio is only 30 wt% in the epoxy resin. As the thicknesses range from 1.5 mm to 5 mm, the effective bandwidth is 14.2 GHz (3.8 GHz–18 GHz) and covers the entire C, X, and Ku bands. Therefore, the defined-morphology NiCo₂O₄ is expected to be a novel wide-band and strong-loss microwave absorber.     

Electromagnetic wave absorption of inexpensive C/ZnO composites derived from zinc-based acrylate resins

Based on the abundant and low-cost zinc-based acrylate resins, C/ZnO composites were fabricated via one-step carbonization at 700 °C in a N₂ atmosphere for 2 h. Zinc-based acrylate resins, which were synthesized by free-radical polymerization of butyl acrylate (BA), acrylic acid (AA) and vinyl acetate (VAc) and dehydration condensation of Zn(OH)₂, provided a common source for carbon and ZnO. These materials demonstrate enhanced electromagnetic wave absorption (EMWA) behavior with tunable microwave absorption bands at 2–18 GHz, which is related to the molar ratio (mol%) of Zn(OH)₂ to acrylate monomers in zinc-based acrylate resins. Remarkably, the 0.11 mol% C/ZnO composite exhibits outstanding absorption properties: the minimum reflection loss (RL_min) at 16.7 wt% loading of −34.66 dB is observed at 3.0 mm and 10.32 GHz, and an RL_min of −24.83 dB is observed at a small thickness of 1.5 mm with an effective absorption bandwidth (EAB) of 3.61 GHz. Moreover, the EAB (RL ≤ −10 dB) from the C band to Ku band is achieved by simply adjusting the thickness of the absorbers, which are superior to the other hybrids of organic carbon and ZnO. These results provide a new strategy for the preparation of carbon-based composites containing metal oxides and their application in high-performance microwave absorption.     

Dielectric regulation of high-graphitized fine ash wrapped cube-like ZnSnO3 composites with boosted microwave absorption performance

Intrinsic dielectric properties and tuning conductivity play important roles in microwave absorption. Novel multi-interfaced ZnSnO₃@ fine ash (ZSFA) composite was successfully synthesized by coating cube-like ZnSnO₃ particles with highly graphitized gasification fine ash. After hydrothermal reaction and Ostwald ripening process, fine ash was tightly wrapped around the assembly of ZnSnO₃ particles. Related electromagnetic parameters and dielectric dissipation ability were discussed with different mass additions. Owing to the strong polarization relaxation, special conductive network, and multi-interface structural design, the as-synthesized ZSFA exhibited adjustable dielectric loss behaviors and efficient microwave absorption ability. When 50% mass added, the maximum reflection loss value of the obtained ZSFA-2 is ?47.8 dB at 2.5 mm thickness, showing the enhanced dielectric loss ability. Meanwhile, the widest effective absorption bandwidth (RL ≤ ?10 dB) can cover 7.0 GHz (11.0–18.0 GHz) at a thickness of only 2.2 mm, which included the entire Ku band. This unique pure dielectric composite exhibited high-performance electromagnetic wave attenuation property and broadband frequency response, thereby providing a new approach to the production of a superior microwave absorber.     

Substituted nickel ferrite coated MWCNT/PVDF based epoxy nanocomposite for microwave absorption

Metal-substituted spinel ferrite-based microwave absorbing materials (MAMs) are attracting significant attention due to their varied soft magnetic behaviour, and ease of synthesis. This work established the efficiency of Cd²⁺ substituted nickel ferrite coated MWCNT (with varied MWCNT loading) for X-band microwave absorption, in the presence of PVDF. The substituted ferrite was prepared with a facile solvothermal process. X-ray diffraction and vibrating sample magnetometer analysis confirmed the spinel structure of substituted ferrites and tuned magnetic behaviour of Cd²⁺ substituted ferrite structure, respectively. FESEM revealed a uniform coating of substituted ferrite on MWCNT and XPS confirmed Cd²⁺ substitution. Hybrid nanocomposites of ferrite coated MWCNT with PVDF, in the epoxy matrix, revealed superior microwave absorption for NiF-150_10 PV and CdNiF-150_10 PV with an absorber thickness of 3 mm in the X band. The absorption bandwidth with the RL below ?10 dB reached 3.9 GHz and 3.6 GHz for NiF-150_10 PV and CdNiF-150_10 PV, respectively. The microwave absorption mechanism was discussed in detail. The developed NiF-150_10 PV and CdNiF-150_10 PV composites can be used as lightweight, low thickness microwave absorbers in the defense and telecommunication industries.     

Enhanced microwave absorption properties of Y-Co2Z/PANI hexaferrites composites in the frequency range of 0.1–18 GHz

We prepared Ba_3−xY_xCo₂Fe₂₄O₄₁ (Y-Co₂Z, x = 0, 0.2, and 0.4) by the solid-state reaction method. Y-Co₂Z and polyaniline (PANI) composites (named as Y-P0, Y-P2, and Y-P4) were prepared by using the in-situ polymerization method. The Y-doping played an important role in the variation of lattice parameters, a and c. The combination of Y-doping and PANI modified the magnetic properties of the composites, which could be observed by the changing of the saturation magnetization and coercivity. This combination had also affected the electromagnetic properties of composites through the measurements of complex permittivity and permeability. Using the transmission line theory, we calculated refection loss (RL) of composites with the variation thickness of 1.00–2.50 mm. Our composites tuned the minimum RL from the X band (RL = −29.6 dB at 11.4 GHz for Y-P2) to Ku band (RL = −16.3 dB at 15.7 GHz for Y-P4 and RL = −26.4 dB at 16.6 GHz for Y-P4). For maximum effective bandwidth, our composites covered a huge range from the S and C bands (Y-P0 with 3.9 GHz in the range of 3.4–7.3 GHz) through the X band (Y-P2 with 3.9 GHz in the range of 9.0–12.9 GHz) to the Ku band (Y-P4 with 4.0 GHz in the range of 13.8–17.8 GHz). Those properties proved that the composites could act as promising absorbers in the S, C, X, and Ku bands.     

Synergistic effect of polyindole decoration on bismuth neodymium ferrite powder for achieving wideband microwave absorber

Recently, composite materials with outstanding absorption properties, like extraordinary absorbing capability, light weight, and thin in size, are required to solve the challenges of electromagnetic pollution. In addition, most of the work is based on the optimization of absorber material structure, and microstructure. In the current work, we improved the reflection loss feature of Bi_0.5Nd_0.5FeO₃ nanopowders via decoration with polyindole polymer by tuning the filler loading of the nanocomposite in the matrix. XRD, UV–Vis, XPS, and FESEM were used to determine the physicochemical features of the as-prepared nanocomposite. The minimum RL was lowered further with the increasing filler loading at 25 wt%. The lower RL of ?22 dB was noticed for 2.2 mm thickness at 11.5 GHz. The maximum value of the SE_R for a 25 wt% sample was 5.5, whereas 19 dB and 24.5 dB values were recorded for SE_A and SET, respectively. The resonance peak above 11.5 GHz demonstrated the better outcome of the absorber at high frequency. Good impedance matching characteristics, conductive features, dielectrics, and magnetic losses were all credited with the excellent reflection loss and electromagnetic interference shielding efficiency. The as-prepared nanocomposite materials that have been proven are interesting prospects for electromagnetic reflection loss and interference shielding that is lightweight, flexible, and extremely effective.     

Enhanced dielectric and microwave absorption properties of Cr/Al2O3 coatings deposited by low‐power plasma spraying

Low‐power plasma‐sprayed Cr/Al₂O₃ coatings have been developed for their potential application as broad bandwidth, thin thickness, lightweight, and strong microwave‐absorbing materials. The dielectric and microwave absorption properties of the as‐sprayed coatings were studied in the X‐band (from 8.2 to 12.4 GHz). High complex permittivity of the coatings was obtained because of a large number of internal boundaries and the conductive networks. Meanwhile, a significant enhancement of microwave absorption properties of the coating was achieved due to the enhanced interfacial polarization and conductance loss. The reflection loss (RL) <?10 dB of the Al₂O₃–15Cr coating was obtained from 9.8 to 11.4 GHz by choosing an appropriate coating thickness, and an optimal minimum reflection loss (RL_min) of ?45.35 dB was achieved at 10.3 GHz with a thin thickness of 1.32 mm.     

Fabrication of novel silicon carbide-based nanomaterials with unique hydrophobicity and microwave absorption property

Novel SiC-based nanomaterials, namely the nitrogen and aluminum co-doped SiC@SiO₂ core-shell nanowires and nitrogen-doped SiO₂/Al₂O₃ nanoparticles, have been fabricated through a facile thermal treatment process based on the chemical vapor deposition and vapor-liquid reaction. These nanomaterials show remarkable hydrophobicity with a water contact angle (CA) over 140°, which are aroused by the surface zigzag morphology of the nanostructures and the hydrocarbyl groups generated during the preparation process. Moreover the nanocomposites also exhibit relatively prominent microwave absorption (MA) properties in the frequency range of 2.0-18.0 GHz. The minimum reflection loss (RL) value as low as −23.68 dB can be observed at 14.16 GHz when the absorber thickness is 2.6 mm with a loading rate of 16.7 wt%. And the nanocomposites-based absorbent can achieve an effective absorption bandwidth (RL < −10 dB) of 4.48 GHz with the absorbent thickness of 2.5 mm. This enhanced microwave attenuation performance can be attributed to multiple polarizations and perfect impedance matching conditions, as well as multiple internal reflections. These marvelous properties make these N and Al co-doped SiC@SiO₂ core-shell nanowires and N-doped SiO₂/Al₂O₃ nanoparticles display extensive application potential as MA materials in harsh environment.     

High temperature anti-oxidative and tunable wave absorbing SiC/Fe3Si/CNTs composite ceramic derived from a novel polysilyacetylene

With the rapid development of high power electromagnetic (EM) equipment and high-speed aircraft, the powerful and high oxidation-resistance absorbers are fundamentally desirable for the EM field. Herein, a novel high temperature anti-oxidative SiC/Fe₃Si/CNTs composite is synthesized by a facile polymer derived ceramic (PDC) route from a Fe-containing polysilyacetylene (PSA). The microstructure of as-prepared SiC/Fe₃Si/CNTs composite absorber is featured by micro-sized SiC ceramic grains with spherical Fe₃Si nanoparticles and carbon nanotubes (CNTs) attached to. The vector network analyzer tests show a tunable wave-absorbing performance by adjusting the thickness of layer, and the effective bandwidth (the reflection loss < −10 dB) is 3.3–16.8 GHz for the sample S-1400 (heat treatment at 1400 °C in nitrogen flow). The minimal RL value is −41.2 dB at 10.5 GHz at a thickness of 2 mm and an effective bandwidth is nearly 4 GHz (12.9–16.9 GHz) at the thickness of only 1.5 mm. Moreover, after the oxidation treatment at 800 °C in the air, this absorber maintains the main structure and shows a good high temperature oxidation resistance. This absorber still remains excellent wave absorption property, in view of a minimal RL value of −40 dB at the thickness of 3 mm and a bandwidth of 4.8 GHz (10.4–15.2 GHz) at the thickness of 2.5 mm. The mechanism of high EM wave absorption performance is studied and attributed to the impendence matching, polarization, and the magnetic properties. Thus, the SiC/Fe₃Si/CNTs composite is a promising EM absorber for high-temperature EM wave-absorbing applications.