Design and development of electromagnetic wave absorbing composites effective at microwave frequencies /

Hamat, Özgür
In the scope of this study, EM wave absorbing composites effective at microwave frequencies having crucial properties for their structural applicability will be designed and developed making use of a novel approach originating from our research group. For this purpose, surfaces of glass and polymeric fiber woven fabrics were modified via metal coatings with nm order thickness, where EM wave absorbing structural composites were formed by incorporating multilayered combinations of these surface-modified woven fabrics within polymer matrices. EM wave reflection and transmission properties, and hence absorption characteristics of surface-modified single layer and multilayer fiber woven fabrics were investigated using Free-Space test method. Based on the experimental data achieved on single layer woven fabrics, simulation studies were conducted in order to predict the EM wave absorption characteristics of multilayered reinforcement structures. In the last phase of the study, structural prototype EM wave absorbing polymer matrix composite is produced by placing surface modified multilayer fiber woven reinforcement materials with the highest EM wave absorption. More than 90% EM wave absorption was achieved with the fabricated composites in 18-40 GHz frequency range. Critical design principles required to reach to this challenging target were presented using simulations and experimental studies.