Extinction performance of microwave by core-shell spherical particle

A new method was presented for calculating extinction cross-section of electromagnetic wave by the core-shell spherical granule. An equivalent method was used to calculate the equivalent permittivity of the core-shell spherical granule. A concentric core-shell spherical granule can be replaced by a solid granule possessing the same radius with the original coating shell, and the equivalent permittivity is equal to that of the product of equivalent coefficient and the kernel permittivity. Based on the electromagnetic wave theory and the equivalent method, the scattering and absorption characteristics of the electromagnetic wave by a core-shell spherical particle were analyzed under the condition that wavelength was far greater than the particle diameter. The influence of geometrical and dielectric parameters on the scattering and absorption of microwave was discussed numerically in detail.