Cylindrical cavity resonator for complex permittivity estimation at 1.2853 GHz: Coir and skins of rice, banana, lemon, watermelon, pineapple, and papaya

Abstract

The knowledge of dielectric properties of organic materials at microwave frequencies is important for different applications in agriculture, food, or other similar research areas. The method of the low-cost disturbed cylindrical cavity resonator is a common measurement technique that considers resonant frequency shift when inserting samples of materials inside the cavity. Frequency shifts together with the knowledge of the complex permittivity of a reference material allow the estimation of the permittivity of a material under test. In this paper, the complex permittivity, and the loss tangent of dried and powdered agricultural wastes from the state of Colima in Mexico are obtained at 1.2853. The materials under test are coir and skins of rice, banana, lemon, watermelon, pineapple, and papaya since they are one of the most abundant agricultural wastes in the state of Colima in Mexico.