Engineering of dielectric composites on electromagnetic and microwave absorbing properties for operation in the X-band

Abstract

In this study, carbon black (CB) powder-loaded polyurethane (PU) composites (CB–PU composites) were prepared by melt mixing method with different volume percentages (45, 50, 55, 58 and 61 vol.%) of CB in the PU matrix. The prepared CB–PU composites had been further studied for surface morphology using the field-emission scanning electron microscopy (FESEM) technique. Dielectric properties in terms of real permittivity ([Formula: see text] and imaginary permittivity ([Formula: see text] of the fabricated composites were computed using an Agilent E8364B vector network analyzer in the frequency range of 8–12 GHz ([Formula: see text]-band). Dielectric loss factor of the prepared CB–PU composites was computed in terms of the dielectric loss tangent (tan [Formula: see text] = [Formula: see text]/[Formula: see text]. Microwave absorbing properties were appraised in terms of the reflection loss (RL) which in turn was calculated for varying thicknesses of the prepared composites from the measured real and imaginary permittivity data. The minimum RL was observed as −20.10 dB for the absorber with a thickness of 2.2 mm and the bandwidth achieved was 1.92 GHz for RL [Formula: see text]10 dB. Based on the above results these CB–PU composites have potential use as effective microwave absorbers in 8–12-GHz ([Formula: see text]-band) frequency range.

FDTD-Based Electromagnetic Modeling of Dielectric Materials with Fractional Dispersive Response

“…Meanwhile, the attention of researchers has been focused on modeling dielectric response over broader frequency ranges [51][52][53]. The resulting models allow evaluating performance indexes as well as optimizing the dielectric response so as to meet given design specifications or to generate unusual electromagnetic properties [54,55]. The right knowledge of the dielectric response over broad frequency ranges is of utmost importance for the development of accurate theoretical models and computational techniques aimed at determining the electromagnetic field propagation properties inside complex and disordered dielectric materials.…”

Constructing magneto-dielectric dual absorption performance of epoxy based nanocomposites filled with polyaniline-manganese zinc ferrite

“…Overall, the use of microwaves in wireless telecommunications has signi cantly expanded our ability to communicate over long distances, providing fast, reliable, and versatile connectivity solutions for individuals, businesses, and society as a whole Radar Absorbing Materials (RAMs) have been designed and intensively explored to address various military and civilian applications. Here are some key purposes and areas of exploration for RAMs [8][9][10][11]. This introduction sets the stage for an exploration of the remarkable EM and absorption characteristics of such types of nanocomposites.…”

Design of a lattice dielectric cylinder based on multiwalled carbon nanotube-epoxy composite for microwave absorption in the X-band

“…The excellent absorption performance of the Dallenbach absorber depends on the electromagnetic properties of the composite. Therefore, various composites composed of the non-conductive polymer such as epoxy, silicone rubber, acrylonitrile butadiene styrene, etc, embedded with conductive fillers like carbon black [3,4], carbon nanotubes [5,6], carbon fibers [7], and other magnetic powders [8,9] have been investigated by many researchers. In addition, composite based on metal-organic framework has also been reported [10].…”