Metasurface retroreflector microstructure design method based on topological optimization

Abstract

The invention provides a metasurface retroreflector microstructure design method based on topological optimization. The metasurface retroreflector microstructure design method comprises the following steps: establishing a metasurface multichannel reflector; dividing a design domain into a regular rectangular sub-grid array by using a two-dimensional periodic grid, and describing configurations of different microstructures by using difference combinations of metal layers in the two-dimensional sub-grid array; obtaining the length and the width of the supercell according to the incident angle and the specific frequency of the incident wave obliquely emitted to the multi-channel reflector; constructing a two-dimensional matrix, and enabling each array element in the two-dimensional matrix to represent attachment or deletion of a metal layer in the corresponding design domain sub-grid; modeling the scattering characteristics of a two-dimensional periodic array composed of supercells, and carrying out configuration optimization on a super-surface microstructure in the supercells by taking the maximum ratio of reflection power in the reverse direction of a required specific frequency at an incident angle to total reflection power in all directions as a design target. According to the super-surface retroreflector, the super cell is used as a design domain, and reasonable metal patch distribution is obtained so as to realize the super-surface retroreflector with the maximum retroreflection power ratio.

Description

technical field [0001] The invention relates to the field of retroreflectors, in particular to a microstructure optimization method for metasurface-based retroreflectors. Background technique [0002] Retroreflection is a special physical phenomenon in which the incident wave is reflected toward the incident direction of the wave on the reflecting surface. Since its discovery, it has attracted the attention of relevant researchers in the research field with its unique response characteristics. With the continuous development of electromagnetic field theory and preparation technology, retroreflection is widely used in target recognition, satellite communication, ship navigation and rescue, and radar scattering cross section. Enhancement, remote sensing, traffic guidance and other fields have shown great application potential. For example, in the field of target recognition, the retroreflector is mounted on the target to be identified. When the detection wave scans the retror...

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Problems solved by technology

However, if there are too many copper grid substructures in the supercell, the size of the substructures needs to be much smaller than the working wavelength, which has high requirements for the fabrication accuracy. If there are design and fabrication errors, resulting in gradient phase discontinuity, it will reduce the inverse Reflection efficiency, it is necessary to find a retroreflection realization form with a low number of substructures. At the same time, obtaining the maximum retroreflection power ratio in the retroreflection direction requires finding a reasonable microstructure configuration of the retroreflector, so it is necessary to find a feasible Microstructure topology design method of retroreflector, but there is no topology design method of retroreflector

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