The Scattering Analysis of Elastic Wave Approximate Directional  Cloak Based on Fractional Fourier Transform

In order to reduce the complexity of designing control material of elastic wave mechanics equation with the transformation method, the first and the zero order approximation method of elastic wave mechanics equation is used. Due to the approximate design method itself, and the impedance matching material parameters, and requirements of dielectric materials those are kept intact, etc, the scattering effect is produced when the elastic wave makes the spread in the design of material. The design directional cloak of homogeneous elastic wave approximation is as the research object, with fractional Fourier transform (FRFT) on the sensitivity of the frequency change, the waveform signal in material is transmitted from the space to the fractional domain. This could intuitively, quantitatively reflect the frequency variation that caused by scattering effect, and reduce the blindness of the cognition of the degree of scattering, and provide the basis for the design the material medium parameters simplify.