Parametric studies of the pyramidal microwave absorber using rice husk

Abstract

Agriculture waste has potential to be used as an alternative material for the microwave absorber used in the anechoic chamber. Compared to the current materials used, such as polystyrene and polyurethane, agricultural waste has low cost and is environmental friendly. In this paper, rice husks from paddy are used as the material in the pyramidal microwave absorber design, to operate effectively in the frequency range from 1 GHz to 20 GHz. Urea Formaldehyde (UF) and Phenol Formaldehyde (PF) are the resins investigated and are used to make the rice husk particle board. There are four main stages in designing the rice husk pyramidal microwave absorber. They are fabricating the rice husk particle board, deriving the dielectric constant value of the resin-rice husk mixture particle board, simulating the rice husk pyramidal microwave absorber using CST Microwave Studio software, and analyzing the performance of the rice husk pyramidal microwave absorber. Various parameters that affect the performance of the pyramidal microwave absorber are investigated, such as the dielectric constant of the material used, mixed resin percentages, source-port distance and angles between the signal source and the surface of the pyramidal microwave absorber. The excellent reflection loss results show that the rice husks can be potentially used as the material in a microwave pyramidal absorber.