X-band radar-absorbing structures based on MWCNTs/NiZn ferrite nanocomposites

ABSTRACT

Microwave absorbers present a wide range of applications in radar and telecommunications. To improve the microwave absorption characteristics of radar-absorbing structures (RASs), magnetic and dielectric materials are blended in different proportions because the impedance mismatch of dielectric materials, resulting from poor permeability, can be eliminated by a combination with magnetic loss fillers. Herein, E-glass/epoxy composites were prepared by blending multi-walled carbon nanotubes (MWCNTs) with Ni_0.5Zn_0.5Fe₂O₄ (NZF) nanopowder to enhance the composites’ microwave absorption. Nanocomposite laminates with different filler contents were fabricated by a simple and low-cost process of in situ polymerisation. The dielectric characteristics were estimated in the X-band, and possible loss mechanisms were studied. A two-layered RAS exhibited a reflection loss of −16 dB for a bandwidth of 2.2 GHz with a matching thickness of 3 mm. The resulting mechanical and thermal properties suggest that the proposed MWCNTs/NZF composite exhibiting good microwave absorption properties can be used in high-performance RASs.

KEYWORDS:

• Radar absorption
• X-band
• magnetic and dielectric loss
• complex permittivity and permeability
• thermal stability
• mechanical properties
• reflection loss
• multilayered structures

Acknowledgements

We would like to thank Dr. Ch. Subrahmanyam, professor, Dr. K. Krushna Murthy, research associate, Department of Chemistry, IITH, and Dr.V.V.S.S.Srikanth, professor, SEST, UOH for providing fabrication and testing facilities at their institutes.

Disclosure statement

No potential conflict of interest was reported by the author(s).