Comparison of the Microwave Absorption Properties of Opuntia ficus-indica, Agave atrovirens, and Cocos nucifera L. Husk

In this work, a comparison of the microwave absorption properties of Opuntia ficus-indica cladodes, Agave atrovirens branches, and Cocos nucifera L. husk samples was performed. The study was carried out by inserting dry and powdered samples of these organic materials transversely and in the middle of a rectangular waveguide, for which scattering parameters S21 and S11 were measured to estimate the absorption coefficient. These measurements were compared to determine the material that behaves the best as a microwave absorber with a view to develop future low-cost and eco-friendly products by reusing agricultural waste. Specifically, Agave atrovirens sample showed the best performance, having an average value of absorption coefficient of 0.4218, while its maximum was 0.5792 at 9.706 GHz within the range from 8.005 to 13 GHz.