Three-waveband terahertz wave absorber based on Salisbury screen structure

The invention relates to a three-waveband terahertz wave absorber based on Salisbury screen structure. The three-waveband terahertz wave absorber comprises a plurality of wave absorbing units arranged in sequence, and each wave absorbing unit comprises a conductive reflecting layer, a dielectric layer and a microstructure unit layer which are tightly attached in sequence from bottom to top; and each microstructure unit layer comprises a square center and four large branches which are respectively connected with four sides of the square center and are completely the same in shape and size, the tail end of each large branch is a trapezoid, the long side of the trapezoid is connected with one side of the square center, each large branch is symmetrically provided with three groups of small branches, the small branches of the group C, the group B and the group A are arranged in sequence from near to far away from the center of the square, the small branches of the group A, the group B and the group C are arranged