Development of composite material with epoxy resin–magnetite for dielectric resonator antenna

Abstract

Composite materials of epoxy resin–magnetite (Fe3O4) are developed with different weight percentages of Fe3O4. Measured permittivity is found to increase with the increasing weight percentage of Fe3O4. Scanning Electron Microscope analysis confirms the uniform dispersion of Fe3O4 nanoparticles within the resin matrix for all compositions. Permittivity, permeability, and loss tangent are measured. The thermal stability for the dielectric properties of the developed materials is confirmed by heating the samples at 100 °C for 2 h. There are no major changes observed after heating the samples. A probe-fed cylindrical dielectric resonator antenna (DRA) is designed using a composite with 48.78 wt.  % of Fe3O4 with a measured permitivity of 6.2. A comparison of the designed DRA with the same antenna geometry using an industry-standard material, TC600—Rogers Corporation® (ɛr = 6.15) shows a wider computed bandwidth of 47.1% as compared to 29.6% for the TC600-based DRA. A prototype of the designed DRA using the developed composite shows a −10 dB bandwidth of 44.4% from 4.89 to 7.68 GHz. The measured results show that the radiation patterns are broadside, in general, and remain relatively consistent at different frequencies over the operating bandwidth. The results indicate that using the developed composite material, in place of the industry-standard material, for DRA design can significantly increase the bandwidth to cater to ultra wideband applications without requiring complex structural modifications and contribute to the low-cost and easy fabrication of DRAs, compared to other ceramics such as alumina (Al2O3).