Wideband microwave absorber structures based on carbonaceous nanomaterials : from modelling to experimental characterisation
(2019)
Files
PhDthesis_RajkumarJAISWAR_printed_version.pdf
Open Access - Adobe PDF
- 18.8 MB
Details
- Authors
- Supervisors
- Huynen, Isabelle
- Abstract
- This thesis focused on the development of compact wideband microwave absorbers based on carbonaceous nanomaterials, which offers possible solutions to meet the industrial challenge of makinghigh performance thin electromagnetic shielding structures. Our work combinesmodeling and experimental tools for the synthesis of microwave absorbers designed throughmetamaterial-inspired inkjet-printed Frequency Selective-Surfaces, as well as through a multilayer approach combining polymer nanocomposite layers (PNCs)having a graded arrangement of conductivity and dielectric constant. The smart gradient-property arrangement of layers in the envisaged shielding structure plays a crucial role for controlling the propagation and attenuation of electromagnetic wave in thelossy medium, and achieve narrow band to ultra-wide band absorption performance.In this thesis, four different types of microwave absorbers are proposed. At first,multilayers combining PNCs of graded-concentration are optimized for wideband absorption. Secondly, hybrid structures combining Frequency SelectiveSurfacesand PNCsenable a combined control on the level and frequency range of the absorption. Thirdly, metamaterial inspired FSSs structures are printed on thin dielectric layers using a home-made carbon-nanotube based ink. As a variant, a magnetically decorated Fe3O4-carbon nanotube ink-based thin absorber is proposed. Inkjet solutions allows ultra-wideband absorption at reduced thickness. Further adding to the ink development, this thesis also contributed to the understanding about electronic properties of magnetically functionalized graphene-nanoplateletshaving various magnetic nanoparticle loadings,to be used inliquid-phase ink for the design of electronically or magnetically tunable microwave absorbers. As a whole, the thesis demonstrates the benefit of a clever combination of carbonaceousand magnetic nano-inclusionswith polymer thin films for the realizationof broadband thin microwave absorbers.
- Affiliations
Citations
Jaiswar, R. R. (2019). Wideband microwave absorber structures based on carbonaceous nanomaterials : from modelling to experimental characterisation. https://hdl.handle.net/2078.5/170823