Enhanced Microwave-Absorbing Property of Honeycomb Sandwich Structure with a Significant Interface Effect

Abstract

Honeycomb sandwich structures (HSSs) are excellent candidates for light and efficient microwave-absorbing materials. In this work, we design an HSS using SiO2 fiber-reinforced epoxy resin (SiO2f/ER) composites as both the top and bottom layers to improve the impedance matching with free space. Target dielectric properties of the honeycomb and coated lossy material of the HSS were calculated based on the multilayer transmission line theory, metal backplane model, and homogenization theory. In addition, the interface effect between the SiO2f/ER and honeycomb of the HSS was discussed theoretically, experimentally, and numerically, indicating a 1–4% contribution of microwave absorption resulting from the interface. By analyzing the equivalent resistance, equivalent capacitance, as well as equivalent inductance, the enhanced microwave absorption of HSS is attributed to the formation of the interfacial transition zone, which benefits both impedance matching and electromagnetic loss.

A Split-Ring Resonator-Loaded Honeycomb Sandwich Structure for Broadband Microwave Absorption

“…The aramid honeycomb sandwich structure (AHSS) plays a structural-functionintegration role in stealth aircraft due to its high flexural strength/mass ratio and easy-toadjust electrical properties [1,2]. However, the rapid development in omnidirectional radar detection technology has required the AHSS to have a wider effective microwave-absorbing bandwidth as well as insensitivity to polarization and the microwave incidence angle to effectively reduce radar cross-section (RCS) [3][4][5][6].…”