Absorption Bandwidth Research Articles

Construction of a 3D spider web structure with spherical Ho2O3 wrapped by carbon nanofibers for high-efficiency microwave absorption and corrosion protection

Reasonable composition control and microstructure design are the effective ways to realize multi-functional high-performance absorbing materials. In this work, a three-dimensional (3D) spider web structure was designed by the electrospinning and high temperature carbonization technology, where Ho2O3 spheres were wrapped by carbon nanofibers. Herein, the spherical Ho2O3 were surrounded by layers of carbon nanofibers (spider silk), which were like the preys inside the spider's web. This unique bionic structure working in conjunction with the tuned components enables the as-prepared composites with improved impedance matching and enhanced loss capacity. The superior electromagnetic wave absorption performance was obtained as the minimum reflection loss of −61.37 dB at 2.90 mm and the maximum effective absorption bandwidth of 6.88 GHz (11.12–18 GHz) at 2.64 mm. At a thickness of 3.44 mm, the effective absorption bandwidth is 4.80 GHz (8–12.80 GHz), covering the entire X-band. At the same time, the composite soaked in the corrosive medium for 7 days owns a low corrosion current density (10−4 ∼10−6 A cm−2) and a high polarization resistance (105∼107 Ω), which exhibits the obvious anticorrosion ability. This work designs a specific spider web structure with high-performance microwave absorption and corrosion protection.

CNTs/lamellar VSe2/Fe3O4 self-assembled a variety of unique three-dimensional multilayer interface structures and microwave absorption properties

Fabrication of microwave absorption (MA) materials of matched small thickness, low density, broad effective absorption bandwidth (EAB), as well as high absorption performance remains a technical challenge to be solved today. In this paper, three-dimensional (3D) VSe2/CNTs/Fe3O4 ternary composites with a variety of self-assembled structures were fabricated by a two-step hydrothermal and one-step carbothermal reduction method. Via varying the content of Fe3O4 in the composites, different 3D multilayer interfacial structures, such as star fruit-, bitter melon-, goldfish-, starfish-, peony- and chrysanthemum-shaped structures were self-assembled, and excellent MA absorption characteristics were obtained. The best reflection loss (RLmin) was −50.96 dB at 1.8 mm thickness. The maximum EAB was 4.93 GHz at 2.0 mm thickness. Carbon nanotubes mainly contributed to conduction and polarization losses. In situ generated VSe2 nanosheets and Fe3O4 nanoparticles promoted the assembly of multilevel interfacial structures, thus contributing to interfacial polarization loss and dipole polarization loss. Fe3O4 also created magnetic losses. This study lays the foundation for fabricating highly efficient MA materials in special self-assembled heterostructures with ternary synergistic effects at the nanoscale.

Mesoporous carbon spheres modified with atomically dispersed iron sites for efficient electromagnetic wave absorption

Carbon materials have obtained some achievements in electromagnetic wave (EMW) absorption owing to their excellent electrical conductivity and low density. However, poor impedance matching and high electrical conductivity limit their EMW absorption properties. Metal single atoms absorbers have garnered considerable attention in EMW absorption, largely due to the high metal availability and special coordination structure, but the modulation of the EMW absorption properties still needs to be improved. Herein, atomically dispersed Fe sites embedded into the N-doped mesoporous carbon spheres (Fe–SAs/NC) were synthesized through a facile coordination-assisted polymerization assembly strategy without acid leaching treatment. Benefitting from abundant mesoporous structure, the Fe–SAs/NC displays large specific surface area (339 m2 g−1) and optimized impedance matching, which results in an effective reduction of the absorber density. The homogeneously dispersed Fe single atoms (Fe–SAs) on the carbon skeleton lead to the improvement in conduction and dipole polarization losses of Fe–SAs/NC, which endows Fe–SAs/NC with exceptional EMW absorption properties. Experimental results indicate that Fe–SAs/NC displays desirable EMW absorption properties with the minimal reflection loss of −52.5 dB at 2.8 mm and the effective absorption bandwidth of 4.8 GHz. The study provides valuable insights for the development of carbon materials modified with atomically dispersed metal sites to achieve high-efficient EMW absorbers.

Metamaterial-inspired infrared electrochromic devices with wideband microwave absorption for multispectral camouflage

Infrared (IR) electrochromic devices, capable of dynamically controlling thermal radiation, hold promising applications in adaptive camouflage. However, the strong microwave reflective properties inherent in the device’s electrodes present a significant challenge, rendering them susceptible to radar detection and weakening their camouflage effect. Inspired by the remarkable electromagnetic control capabilities of metamaterials, the integration of frequency selective surfaces into IR electrochromic devices is proposed to address this multispectral compatibility challenge. The designed integrated metadevices simultaneously exhibit large and reversible IR emissivity tunability (Δε≥0.55 at 3–5 μm, Δε≥0.5 at 7.5–13 μm) and wideband microwave absorption (reflection loss ≤−10 dB at 8.5–18 GHz). Furthermore, the monolithic integrated design of the shared barium fluoride substrate offers a simple device architecture, while careful design considerations mitigate coupling between IR electrochromism and microwave wideband absorption. This work introduces opportunities for the development of multispectral adaptive camouflage systems, offering potential advancements in concealment technology.

Excellent Low-Frequency Microwave Absorption and High Thermal Conductivity in Polydimethylsiloxane Composites Endowed by Hydrangea-Like CoNi@BN Heterostructure Fillers.

The advancement of thin, lightweight, and high-power electronic devices has increasingly exacerbated issues related to electromagnetic interference and heat accumulation. To address these challenges, a spray-drying-sintering process is employed to assemble chain-like CoNi and flake boron nitride (BN) into hydrangea-like CoNi@BN heterostructure fillers. These fillers are then composited with polydimethylsiloxane (PDMS) to develop CoNi@BN/PDMS composites, which integrate low-frequency microwave absorption and thermal conductivity. When the volume fraction of CoNi@BN is 44 vol% and the mass ratio of CoNi to BN is 3:1, the CoNi@BN/PDMS composites exhibit optimal performance in both low-frequency microwave absorption and thermal conductivity. These composites achieve a minimum reflection loss of -49.9dB and a low-frequency effective absorption bandwidth of 2.40GHz (3.92-6.32GHz) at a thickness of 4.4mm, fully covering the n79 band (4.4-5.0GHz) for 5G communications. Meanwhile, the in-plane thermal conductivity (λ∥) of the CoNi@BN/PDMS composites is 7.31W m-1 K-1, which is ≈11.4 times of the λ∥ (0.64W m-1 K-1) for pure PDMS, and 32% higher than that of the (CoNi/BN)/PDMS composites (5.52W m-1 K-1) with the same volume fraction of CoNi and BN obtained through direct mixing.

Architectural Design of a Multichannel Porous Carbon Fiber for Efficient Electromagnetic Microwave Absorption.

An ingenious microstructure of electromagnetic microwave absorption materials is crucial to achieve strong absorption and a broad bandwidth. Herein, one-dimensional (1D) carbon fibers with implantation of zero-dimensional (0D) ZIF-8-derived carbon frameworks and construction of a three-dimensional (3D) microcosmic multichannel porous structure are fabricated by electro-blown spinning, solvent-thermal reaction, and high-temperature pyrolysis techniques. The 1D carbon fiber skeleton with a multichannel structure provides a direct axial conductive pathway for charge transport, which plays an important role in dielectric loss. The 0D surface carbon frameworks offer plenty of heterogeneous interfaces to trigger intensive interfacial polarization loss and act as dihedral angles for microwave scattering. The 3D microcosmic multichannel pores can not only generate multiple reflections as much as possible to dissipate electromagnetic microwave energy but also supply huge interior cavities to improve impedance matching. Thanks to the synergistic effect of a strong electrically conductive pathway for enhancing the conductive loss, a plenteous heterogeneous interface for triggering intensive interfacial polarization loss, microcosmic multichannel pores for generating multiple reflections and improving impedance matching, and N and O atom doping for inducing dipole polarization, the optimal sample with an ingenious microstructure delivers an excellent absorption performance of a minimum reflection loss of -35.5 dB at a thickness of 5.0 mm and an effective absorption bandwidth of 6.72 GHz (10.96-17.68 GHz) at a thickness of 2.0 mm. Such a well-designed multichannel porous carbon fiber may pave the way for the exploitation of high-performance microwave absorbing materials.

Genome engineering of materials based on Ce doping, high-performance electromagnetic wave absorber for marine environment

Traditional microwave absorbing materials (MAM) are difficult to meet the current increasingly complex electromagnetic environment, MAM began to functionally integrated development to meet the needs of diversified applications. For the high humidity and high salt spray environment of the ocean, the development of electromagnetic absorber integrating microwave absorption (MA) and corrosion protection functions is imminent. In this work, high-quality genes were screened through materials genome engineering, and in-situ doping strategies of Ce gene were designed to synergistically enhance MA properties using composition modulation and structure modulation, the effective absorption bandwidth (EAB) of composite material WC@FCC1 can reach 5.62 GHz at an ultra-thin thickness of 1.66 mm. Thanks to the unique 4f orbital mechanism of Ce element, CeO2 is endowed with excellent redox property, forming an oxide protective film on the surface, which prevents the entry of external corrosive media. The excellent corrosion protection performance of the composite material has been verified through electrochemical testing and molecular dynamics simulation. This work provides new design ideas for high-performance MAM, as well as new strategies and insights for functionally integrated electromagnetic absorber.

Excellent C-band microwave absorption properties of Ni@nitrogen-doped porous carbon nanocomposite via polymer bubbling technique

Nitrogen-doped porous carbon nanocomposites are highly sought-after materials for electromagnetic wave absorption due to their unique combination of electrical and magnetic properties. However, achieving optimal absorption performance within the critical C-band (4–8 GHz) frequency range remains a significant challenge. Ni@NPC nanocomposites, synthesized through the polymer bubbling technique, demonstrated exceptional microwave absorption (MWA) performance in the C-band. These materials exhibited a reflection loss (RL) of −65.20 dB at a thickness of 4.8 mm. When carbonized at 600 °C, a thickness of 2.0 mm achieved an effective absorption bandwidth (EAB) of 5.74 GHz. The remarkable absorption performance is ascribed to the combined effect of their porous composition and the addition of nitrogen dopants, which efficiently foster various microwave attenuation processes. Furthermore, the material’s effectiveness in real-world applications was evaluated using computer simulation technology (CST). This work highlights the potential of the one-pot fabrication method for developing high-performance MWA materials with practical applications.

Vanadium-dioxide-assisted multifunctional switchable terahertz metamaterial devices

A multifunctional, switchable terahertz (THz) metamaterial (MM) device with wideband absorption and polarization conversion capabilities has been developed, based on the insulator-metal phase transition of vanadium dioxide (VO2). In its metallic state, the device operates as a wideband absorber within the range of 2.56–6.74 THz, achieving a bandwidth of 4.18 THz and an absorption rate of ≥90%. The wideband absorption is insensitive to both oblique incident angles and polarization. When VO2 is in its insulating state, the device switches to a polarization converter, facilitating linear-to-cross polarization (LTX) conversion between 1.04 and 4 THz, and linear-to-circular polarization (LTC) conversion between 1 and 1.04 THz, with a conversion efficiency exceeding 90%. Additionally, the effects of incident angle and polarization angle on the device’s performance were analyzed. This THz device offers advantages of wide angle, wide bandwidth, and high efficiency, making it a valuable reference for research into new multifunctional THz devices. It has great potential applications in short-range wireless THz communication, ultrafast optical switches, high-temperature resistant switches, transient spectroscopy, and optical polarization control devices. In specific application scenarios, particularly in fields requiring efficient detection, transmission, and analysis—such as security and non-destructive testing, secure communication systems, imaging and sensing, multidimensional spectral analysis, pollutant detection, smart stealth coatings, dynamic optical control devices, and integrated optical systems—these devices offer multifunctional capabilities. They enhance system performance and flexibility, meeting diverse application needs.

Electron Migratory Polarization of Interfacial Electric Fields Facilitates Efficient Microwave Absorption

AbstractHigh‐performance microwave absorption materials (MAM) are often accompanied by synergistic effects of multiple loss mechanisms, but the contribution share of various loss mechanisms has been neglected to provide a template and reference for the design of MAM. Here, a highly conductive 2D structure is designed through a functional group‐induced structure modulation strategy, composite L‐Ni@C can reach an effective absorption bandwidth of 6.45 GHz at 15% fill rate, with a maximum absorption efficiency of 99.9999%. Through the layer‐by‐layer analysis of the loss mechanism, it is found that the strong loss originates from the polarization loss at the heterogeneous interface. The movement of space charge between the two‐phase interface forms an interfacial electric field, and the in situ doping of nitrogen is cleverly achieved by the introduction of amino functional groups, which significantly enhances the rate of space charge transfer between the two‐phase interface and greatly facilitates the electron migration polarization. The space charge motion law of the interfacial electric field is also simulated using COMSOL simulation software to illustrate the electron migration polarization mechanism at heterogeneous interfaces. This work fills the gap of functional group‐induced structural modulation and presents new theories into the mechanism of space charge movement at heterogeneous interfaces.

Hierarchical Engineering on Built‐In Electric Field of Bimetallic Zeolitic Imidazolate Derivatives Towards Amplified Dielectric Loss

AbstractConstruction of built‐in electric field (BIEF) in nanohybrids has been demonstrated as an efficacious strategy to boost the dielectric loss by facilitating oriented transfer and transition of charges, thus optimizing the electromagnetic wave absorption property. However, the specific influence of BIEF on interface polarization needs to explore thoroughly and the BIEF strength should be further augmented. Herein, several dielectric systems incorporated Mott–Schottky heterojunctions and hollow structures are designed and constructed, where bimetallic zeolitic imidazolate framework are employed to derive Cu‐ZnO Mott–Schottky heterojunctions, and hierarchical structures and BIEF are further enriched by introducing hollow structure and reduced graphene oxide. The well‐established “double” BIEF verified by theoretical calculation and hollow engineering can regulate the conductivity, and enhance the polarization relaxation effectively. Especially, there always coexisted both enhanced charge separation and reversed charge distribution in this “double” BIEF, boosting the interface polarization. Attributing to the synergy of well‐matched impedance and amplified dielectric loss, the obtained hybrids exhibited superior absorption (reflection loss of −46.29 dB and an ultra‐wide effective absorption bandwidth of 7.6 GHz at only 1.6 mm). This work proves an innovative model for dissecting dielectric loss mechanisms and pioneers a novel strategy to explore advanced absorbers through enhancing BIEF.

Defect introduction and interfacial strategies for enhancing microwave absorption in carbon-based materials

Poor impedance matching and a single loss mechanism are typical challenges for carbon-based materials to become efficient microwave absorbers. To address these issues, defect introduction and interfacial strategies are effective methods for enhancing microwave absorption through the micro-mechanism of material interaction with microwaves. Additionally, forming a homogeneous composite material is crucial for achieving good impedance matching. In this study, we used a controlled solvent-thermal method to achieve self-assembled interfacial intercalation, yielding amorphous VOPO4/rGO nanohybrids, which show significantly enhanced microwave absorption properties. The abundant defects introduced by VOPO4 within the amorphous layered composites disrupt the charge distribution, contributing to polarization loss. The graphene nanosheets expose more VOPO4 structural units, facilitating increased conductivity and enriching the microwave absorption mechanism. As a result, the prepared VOPO4/rGO nanohybrids demonstrate outstanding microwave absorption, with the effective absorption bandwidth covering the entire Ku-band (11.6–18.0 GHz) at a thickness of 2.3 mm. This research provides an important reference for understanding the mechanisms that enhance the electromagnetic wave absorption of carbon-based materials.

Upcycling Spent Graphite from Li-ion Batteries into Cu/Expanded Graphite Composites as high-performance electromagnetic wave absorbers.

With the widespread adoption of lithium-ion batteries and modern electronic components in both daily life and industrial production, there is a growing focus on the high-value recycling of spent lithium-ion batteries and the development of absorbents with high electromagnetic wave absorption capabilities. Efficiently regenerating recycling graphite from spent batteries through low-cost methods and utilizing it to prepare high-performance electromagnetic wave absorbing materials holds significant importance in addressing both the utilization of waste graphite and electromagnetic pollution issues simultaneously. This work presents a method to transform spent graphite into expanded graphite with a three-dimensional conductive structure using an enhanced Hummer's treatment and thermal reduction process. Subsequently, Cu/EG composite materials were efficiently prepared through straightforward mechanical ball milling and calcination. The unique honeycomb-like porous structure of expanded graphite facilitates the reflection and scattering of electromagnetic waves, electron transfer, and defect polarization. Additionally, the incorporation of copper nanoparticles improves the conduction loss and enhances interface polarization, allowing for precise tuning of the composite material's absorption performance. The results demonstrate that Cu/EG composite materials exhibit excellent electromagnetic wave absorption performance. The Cu/EG(1:3) sample exhibits effective absorption in the C, X, and Ku bands, achieving a minimum reflection loss (RLmin) of -54 dB and a maximum effective absorption bandwidth (EABmax) of 5.28 GHz. This performance is attained with a thickness of just 2.2 mm and a filler content of only 15 wt.%.

Micro-perforated plates constructions with approaching the theoretical limits of its sound absorption performance

Micro-perforated plates resonant absorbers have a considerable theoretical sound absorption bandwidth upper limit. Three types of MPPs with straight holes, including circular holes on thick plate, circular holes on thin plate, and slotted holes on thin plate, are investigated with approaching the theoretical limits of its sound absorption performance. It is demonstrated that thin plates are easy to obtain satisfactory sound absorption performance but hard to get high mechanical strength. Slotted holes are beneficial for extending the sound absorption bandwidth of MPP absorbers. MPPs with straight holes usually require a combination of thin plates, minute holes and high perforation ratios, which is practically difficult to apply on a large scale. Two other types of MPPs with variable cross-sectional holes, fabricated using the subtractive processing method and superposition processing method, are then proposed to achieve perfect sound absorption performance and good engineering feasibility.

Biomimetic Multi-Interface Design of Raspberry-like Absorbent: Gd-doped FeNi3@Covalent Organic Framework Derivatives for Efficient Electromagnetic Attenuation.

Structural design and interface regulation are useful strategies for achieving strong electromagnetic wave absorption (EMWA) and broad effective absorption bandwidth (EAB). Herein, a monomer-mediated strategy is employed to control the growth of covalent organic framework (COF) wrapping flower-shaped Gd-doped FeNi3 (GFN), and a novel raspberry-like absorbent based on biomimetic design is fabricated by thermal catalysis. Further, a unique dielectric-magnetic synergistic system is constructed by utilizing the COF-derived nitrogen-doped porous carbon (NPC) as the shell and anisotropic GFN as the core. The electromagnetic parameters of the GFN@NPC composites can be tuned by adjusting the proportions of GFN and NPC. Off-axis electron holography results further clarify the interface polarization and microscale magnetic interactions affecting the EMW loss mechanism. As a result, the GFN@NPC samples exhibit broad EMWA performance. The EAB values of all GFN@NPC composites reach up to 6.0 GHz, with the GFN@NPC-2 sample showing a minimum reflection loss (RLmin) of -69.6 dB at 1.68 mm. In addition, GFN@NPC-2 achieves a maximum radar cross-section (RCS) reduction of 29.75 dB·m2. A multi-layer gradient structure is also constructed using metamaterial simulation to achieve an ultra-wide EAB of 12.24 GHz. Overall, this work provides a novel bio-inspired design strategy to develop high-performance EMWA materials.

Self-assembly Ti3C2Tx MXene/ZnCo2O4@ZnO heterostructure with Schottky junction for regulating BIEF to enhance microwave absorption

Currently, heterogenous interface engineering on absorbers is shown to boost the electromagnetic wave absorption (EMA) performance effectively. However, challenges remain in investigating the mechanisms by studying heterojunctions between heterogeneous interfaces. Herein, a self-assembly Ti3C2Tx MXene/ZnCo2O4@ZnO (MZCZ) heterostructure with abundant Schottky heterogenous interfaces generating a controllable built-interface electric field (BIEF) effect is fabricated to achieve exceptional EMA ability. The formative BIEF between the unbalanced distribution charges promotes charge separation and migration, increasing polarization loss. Fortunately, the obtained MZCZ1 exhibits the reflection loss (RL) value of −69.78 dB under the ultralow thickness of 1.501 mm and the optimal minimum RL (RLmin) value of −74.41 dB, respectively. The excellent performance can be ascribed to the multiple polarization loss, conduction loss, natural resonance, and exchange resonance characteristics. Moreover, by the Computer Simulation Technology (CST) software, the designed circular cone and circular truncated cone periodicity structure with the MZCZ1 absorber both exhibit a super-wide effective absorption bandwidth (EAB) covering the whole C, X, and Ku band. This study can pioneer a novel approach to developing functional EMA materials and provide a valuable direction for further study of EMA mechanisms at heterogeneous interfaces.

Synthesis and high electromagnetic wave absorption performance of carbon-enriched porous SiOC ceramics

The carbon-enriched porous SiOC ceramics with enhanced electromagnetic wave (EMW) absorption properties were synthesized through the hydrothermal method followed by a polymer-derived ceramics (PDCs) process. As the annealing temperature rises from 1200 °C to 1500 ℃, SiC and SiO2 crystals are gradually separated from the porous amorphous SiOC matrix, and the degree of graphitization of free carbon increases. The porous SiOC ceramics annealed at 1400 °C exhibit the presence of SiC, SiO2, turbostratic graphite, and amorphous SiOC phases, which significantly impact the impedance matching and attenuation constant of the material. The minimum reflection loss (RLmin) value of the SiOC ceramics reaches −67.98dB with a matching thickness of 3.19mm and the effective absorption bandwidth (EAB) is 4.45GHz at 1.39mm. The carbon-enriched porous SiOC ceramics with strong absorption capacity and wide absorption bandwidth are primarily owing to appropriate impedance matching and multiple attenuation mechanisms, such as conduction loss, interfacial polarization, and defect-induced polarization, indicating that the SiOC ceramics exhibit significant potential as a high-performance EMW absorbing material.

Lightweight composite from graphene-coated hollow glass microspheres for microwave absorption

In developing the effective and lightweight materials for microwave absorption, graphene holds a bright promise because of its excellent electrical properties and low density, but it suffers from poor impedance matching; while the hollow glass microspheres on the other hand have extremely low density and are dielectric. Their synergistic combination could achieve a perfect impedance matching and thus create a novel lightweight absorption composite. The metamaterial structure absorber can efficiently absorb electromagnetic waves over a wide frequency range. This study employs a hydrothermal method to deposit graphene onto the surfaces of hollow glass microspheres, followed by the design of a metamaterial absorber. Upon coating with graphene flakes, the composite material effectively dissipates electromagnetic wave energy through mechanisms such as interfacial polarization, dielectric loss, and the multiple scattering effects of hollow glass microspheres and graphene flakes. The composite exhibits an effective absorption bandwidth up to 4.02 GHz under a graphene flakes mass fraction of 30 %. More importantly, the incorporation of the metamaterial absorber design further significantly enhances the absorption bandwidth to 7.7 GHz. This material demonstrates significant advantages in terms of lightweight and broadband absorption performance, providing new insights for the research of high-performance lightweight and wideband absorbing materials in the future. However, further investigation is required to examine its long-term stability and performance in complex environments.

Synthesis of hierarchical carbon Nanofibers-CoNi/C composites for enhanced microwave absorption efficiency

Developing lightweight, highly absorption and broadband microwave absorbents to combat severe electromagnetic radiation pollution poses a significant challenge. In this study, we designed a novel chain-like CNFs-CoNi/C nanocomposite by in-situ growth of bimetallic MOFs on the CNFs followed by calcination. The resulting CoNi/C composite with hollow structure was uniformly distributed along the 1D CNFs. The unique porous structure and heterogeneous interface derived from MOFs facilitated efficient scattering and multiple reflections of microwaves. By harnessing interfacial polarization loss, dipole polarization loss, and conduction loss mechanisms synergistically, the chain-shaped porous multi-stage CNFs-CoNi/C composite exhibited exceptional microwave absorption performance at a filling ratio of 10 %. It achieves a maximum reflection loss of −70 dB and an absorption bandwidth (EAB) for RL ≤ -10 exceeding 4.82 GHz with a corresponding thickness as low as 1.25 mm. This study introduced a lightweight and highly absorptive material that offers valuable insights into developing high-performance electromagnetic wave absorbing materials through organic composite comprising MOF and carbon materials.

Design and performance of 3D-Printed ABS@rGO/CF/CeO2 composites for microwave absorption and mechanical strength

Traditional microwave absorbing materials struggle to balance wideband absorption with mechanical properties, particularly in multifunctional applications. This study explores the effects of short carbon fibers (CF), cerium dioxide (CeO2), and reduced graphene oxide (rGO) on the electromagnetic and mechanical properties of 3D-printed composites. The ABS@CF/CeO2/rGO composite with a thickness of 2.2 mm exhibited exceptional microwave absorption, achieving an effective absorption bandwidth (EAB) of 6.6 GHz and a minimum reflection loss (RLmin) of −40.9 dB. The Whale Optimization Algorithm (WOA) was employed to design a load-bearing, microwave-absorbing superstructure, which significantly improved wideband absorption. Experimental results confirmed the superstructure’s isotropy and wide-angle absorption capabilities. The calculated electromagnetic parameters were applied to evaluate the radar cross-section (RCS) of large targets, demonstrating enhanced stealth performance for unmanned aerial vehicles (UAVs). Mechanical tests revealed that rGO improved interlayer bonding strength, while CF negatively impacted bending performance. The superstructure also showed excellent mechanical stability in load-bearing tests, underscoring its potential for practical engineering applications. This study offers insights into designing advanced composite materials with balanced electromagnetic and mechanical properties, guiding future multifunctional material development.