Ultralight Broadband Microwave Absorbing Materials Basing on Short Fibers of the Glass-Coated Amorphous Magnetic Microwires

Abstract

Glass-coated amorphous magnetic microwires (GAWs) has typical structure with glass skin and amorphous metal alloy inner core, which makes it have special electromagnetic (EM) properties. It not only has multiple EM losses and proper impedance matching, but also has the conductive core with magnetic property. In the paper, the filament fiber samples (named LFs) and the short fiber samples (named SFs) of GAWs were prepared and discussed respectively. They showed completely different EM performance. LFs with GAWs filament closely arrayed one by one could reflect the EM waves and could be the EM shielding material. While to our surprise, the SFs with GAWs short fibers randomly distribution showed excellent microwave absorbing (MA) properties. The single-layer SFs with the content of only 3 g/m 2 and the length of 5mm of the short fiber in, presented a minimum reflectivity (R L ) of -20.4 dB at 12.3 GHz, and the effective absorption bandwidth (EAB) for R L < -10 dB was 5.36 GHz with a thickness of only 1 mm. What’s more, MA property of the SFs could be obtained and controlled by adjusting the length and the content of the short fiber and lamination of the SFs, according to the multiple microwave absorbing mechanisms. The double-layer structure SFs with 2 mm thickness can furtherly get an EAB (R L < -10 dB) over the 10 GHz. All these show that the GAWs short fiber is an excellent microwave absorber, which could obtain a broadband, ultralight MA fabric material depends on novel and effective strategy provided in this study.

Keywords: Glass-coated amorphous magnetic microwires, Short fiber, Microwave absorbing material, Broadband, Resonance effect, Multiple electromagnetic loss