A terahertz-encoded metasurface with reduced radar cross-section over wide frequency bands

Abstract

The invention discloses a novel flexible terahertz 2bit code metasurface for wide-frequency-band radar scattering cross section reduction. The novel flexible terahertz 2bit code metasurface involves the following steps that electromagnetic field software is used for designing the structural shapes and parameters of four elements of '00', '01', '10' and '11' under optimization of the structural parameters, and the 2bit code metasurface achieving terahertz broadband nondirectional scattering, namely diffuse reflection, is optimized; on the basis of optimizing the 2bit code metasurface, a silicon wafer is coated with a polyimide film with a needed thickness; a needed code metasurface is prepared on the polyimide film through traditional micromachining technology, the silicon wafer is removed on the basis of the prepared 2bit code metasurface, and on the basis that the silicon wafer is removed, a gold film with a needed thickness is evaporated on the polyimide film on the other surface of a metal-free structure; terahertz broadband radar scattering cross section reduction is achieved, and simulation and experiment results show that the radar scattering cross section reduction can reach above 10 dBsm within the range from 0.66 THz to 1.26 THz.

Description

technical field [0001] The invention relates to a terahertz coding metasurface with reduced wide-band radar scattering cross-section, in particular to a novel meta-surface capable of reducing the terahertz wide-band radar scattering cross-section. Background technique [0002] Terahertz waves have the characteristics of broadband, low energy, and strong penetration, and show broad application prospects in high spatial resolution, military radar, and high-sensitivity detection. In these applications, not only stable terahertz radiation sources and detectors are required, but also terahertz devices with various functions are required to regulate the reflection, scattering, and transmission of terahertz waves, especially in military radar stealth. [0003] In order to achieve radar stealth, mainly by reducing the target radar echo signal. The physical quantity to measure the strength of target radar echo signal is radar cross section. The methods to reduce the radar cross sec...

AI Technical Summary

Problems solved by technology

In addition, metasurface absorbers still have defects such as narrow bandwidth, especially in the terahertz band. Using multi-layer metamaterials can broaden the bandwidth of the frequency band, but it is difficult to process

For the use of new wave-absorbing coating materials to reduce the radar cross-section, it is difficult to obtain coating materials that respond in the terahertz band

Images