Microwave wedge absorber design using rice husk - an evaluation on placement variation

Placement variation is one example of parameters that critically affects the performance of RF absorbers. In this work, four designed variation patterns - W, X, Y, and Z were discussed to compare the reflectivity (S
₁₁
) of designed wedge microwave absorbers. Two sub-shapes were investigated in this work - straight wedge and oblique wedge, each type having three variation of top width dimension. The other investigation includes performance comparison between four and nine elements' array of straight wedges and oblique wedges. These wedge absorbers were simulated using CST Microwave Studio software, with rice husk as its material (dielectric constant, ε
_r
= 2.89). The wedge absorbers have been designed to operate effectively between the frequencies of 1 GHz to 20 GHz.