Nanoferrite-Based Structural Materials for Aerospace Vehicle Radomes

Abstract

The fundamental role of an aerospace vehicle radome is to create a sheltered enclosure between the vehicle’s antenna system and the environment, with minimum effects on the antenna’s performance. Radome applications include civil, military, aerospace, surveillance, telecommunications, satellite communications, and microwave radars. Excellent electrical and mechanical properties are the fundamental requirements for maximized performance and strength parameters of the radomes. Consequently, the material selection must be carefully made to optimize critical properties such as the dielectric constant, loss tangent, impermeability to water, thermal resistance, aerodynamic and structural load tolerance for specific radome applications. Materials like Alumina and Silicon nitride display optimum thermal shock resistance, rain erosion resistance, and favorable mechanical properties - however, their usability is prohibited due to their high loss tangent and lower thermal shock resistance at high temperatures. The use of nanoferrite materials offers a promising position to curb such technological limitations faced while using conventional materials. It is concluded that ZnFe2O4@SiO2@PPy nanocomposite with varying SiO2 content exhibits the highest bandwidth of 9.56 GHz in the Ka-band, with a thickness of 1 mm. In contrast, cobalt-zinc ferrite nanofiber (Co0.6Zn0.4Fe2O4) covers the X band and ~80% of the Ku band, offering a bandwidth of 9 GHz with a thickness of 2.9 mm. Scope of improvements in fundamental properties, such as dielectric constant, dielectric loss tangent, permittivity dispersion, and permeability dispersion to optimize microwave absorption, are discussed. It is recommended that research on radome materials should intensively focus on their stability at high temperatures, flexibility, and usability as coating materials, corrosion resistance, ease of fabrication, and lightweight characteristics. This chapter reports the suitability of various nanoferrite materials for radome applications while detailing their comparison, technological developments in the past decade, and research prospects. We conclude that nanostructured ferrites and polymer-ferrite composites offer excellent potential and must be explored extensively.