The Design of Ternary Nanofibers with Core–Shell Structure for Electromagnetic Stealthy Antenna

Nanoscience Electrical Engineering Chemistry Materials Science Engineering Electromagnetism Physics
electromagnetic wave absorption ternary nanofibers core–shell structure synergistic effect patch antenna

Academic Background

In the information age, the widespread application of electromagnetic waves (EMW) has led to breakthroughs in various fields such as communication, healthcare, and navigation. However, with the proliferation of electronic devices, electromagnetic interference (EMI) issues have become increasingly severe, not only affecting the normal operation of precision equipment but also posing potential threats to human health. Therefore, the development of efficient electromagnetic wave-absorbing materials has become a current research hotspot. Traditional electromagnetic wave-absorbing materials often suffer from narrow absorption bandwidth and high reflection loss, making it difficult to meet the demands of modern communication devices for efficient electromagnetic stealth and signal transmission.

To address this issue, researchers have begun designing new electromagnetic wave-absorbing materials from the perspectives of multi-component composites and microstructure engineering. Among these, the core-shell structure has become a research hotspot due to its ability to cleverly combine the advantages of different materials and significantly increase the contact area. By rationally selecting components and optimizing the microstructure, researchers hope to achieve a synergistic effect between impedance matching and attenuation capabilities, thereby developing high-performance electromagnetic wave-absorbing materials.

Ternary Nanofiber Core-Shell Structure Design for Electromagnetic Stealth Antenna

Paper Source

This paper was co-authored by Xiangwei Meng, Meijie Yu, and Chengguo Wang, who are affiliated with the School of Materials Science and Engineering at Shandong University and the Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education). The paper was published on October 7, 2024, in the journal Advanced Fiber Materials, titled The Design of Ternary Nanofibers with Core–Shell Structure for Electromagnetic Stealthy Antenna.

Research Process

1. Material Preparation

The study first prepared Ni/C@ZrO₂ ternary nanofibers through electrospinning and carbonization processes. The specific steps are as follows:

  1. Electrospinning: Polyvinylpyrrolidone (PVP), nickel acetylacetonate (Ni(acac)₂), and zirconium butoxide (Zr(OBu)₄) were dissolved in N,N-dimethylformamide (DMF) to form a homogeneous solution. The solution was then spun into nanofibers using an electrospinning device and collected on aluminum foil.
  2. Pre-oxidation and Carbonization: The collected nanofibers were pre-oxidized at 180°C and subsequently carbonized at 700°C in a nitrogen atmosphere, ultimately yielding Ni/C@ZrO₂ ternary nanofibers.

2. Material Characterization

The researchers conducted detailed characterization of the prepared nanofibers using various methods:

  1. X-ray Diffraction (XRD): Confirmed the crystal structures of Ni and ZrO₂ in the material.
  2. Raman Spectroscopy: Analyzed the degree of graphitization of the material.
  3. Nitrogen Adsorption-Desorption Test (BET): Determined the specific surface area and average pore size of the material.
  4. X-ray Photoelectron Spectroscopy (XPS): Analyzed the chemical states and electronic properties of the material’s surface.
  5. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM): Observed the morphology and internal microstructure of the material.

3. Electromagnetic Performance Testing

The electromagnetic parameters of the material, including complex permittivity and permeability, were measured using a vector network analyzer (VNA) in the frequency range of 2.0-18.0 GHz. The researchers also calculated the material’s reflection loss (RL) and effective absorption bandwidth (EAB) and simulated the radar cross-section (RCS) characteristics.

Research Results

1. Material Structure and Properties

XRD and TEM results showed that the Ni/C@ZrO₂ ternary nanofibers successfully formed a core-shell structure, with Ni particles uniformly distributed within the nanofibers and ZrO₂ layers approximately 7 nm thick. Raman spectroscopy revealed that the material contained abundant amorphous carbon and defect sites, which helped regulate the material’s conductivity and impedance matching characteristics.

2. Electromagnetic Wave Absorption Performance

The Ni/C@ZrO₂ ternary nanofibers achieved a minimum reflection loss (RL) of -60.1 dB at 11.0 GHz and an effective absorption bandwidth (EAB) of 7.6 GHz. Additionally, simulation results showed that the material’s radar cross-section (RCS) values were less than -20 dBm² at most observation angles, demonstrating excellent electromagnetic stealth performance.

3. Antenna Design

The researchers designed a patch antenna using Ni/C@ZrO₂ ternary nanofibers as the dielectric substrate. Test results showed that the antenna’s reflection coefficient (S11) in the X-band was less than -10 dB, indicating efficient signal transmission capability.

Conclusion and Significance

This study successfully prepared Ni/C@ZrO₂ ternary nanofibers with a core-shell structure through electrospinning and carbonization processes and demonstrated their excellent performance in electromagnetic wave absorption and antenna design. The material not only achieved efficient electromagnetic wave absorption but also provided theoretical guidance for the future design of electromagnetic stealth antennas. The research results indicate that by using multi-component composites and microstructure design, the electromagnetic parameters of materials can be effectively regulated to achieve a synergistic effect between impedance matching and attenuation capabilities.

Research Highlights

  1. High-Performance Electromagnetic Wave Absorbing Material: The Ni/C@ZrO₂ ternary nanofibers achieved a minimum reflection loss of -60.1 dB at 11.0 GHz and an effective absorption bandwidth of 7.6 GHz, demonstrating excellent electromagnetic wave absorption performance.
  2. Core-Shell Structure Design: The core-shell structure design successfully achieved a synergistic effect of multiple loss mechanisms, including conductive loss, magnetic loss, and polarization relaxation.
  3. Antenna Design Application: The application of Ni/C@ZrO₂ ternary nanofibers in patch antenna design showcased their potential value in electromagnetic stealth antennas.

Other Valuable Information

The study also explored the effects of carbonization temperature and filler loading on the material’s electromagnetic performance. The results showed that a carbonization temperature of 700°C and a filler loading of 15% were the optimal conditions for achieving efficient electromagnetic wave absorption. Additionally, the researchers used High-Frequency Structure Simulator (HFSS) and CST Studio Suit 2019 software to simulate the electromagnetic field distribution and power loss of the material, further validating its excellent performance.

Summary

This study not only provided new insights into the development of efficient electromagnetic wave-absorbing materials but also laid a theoretical foundation for the future design of electromagnetic stealth antennas. Through multi-component composites and microstructure engineering, the researchers successfully achieved a synergistic effect between impedance matching and attenuation capabilities, demonstrating the broad application prospects of ternary core-shell structure nanofibers in electromagnetic wave absorption and antenna design.