Wideband spirally-coding radar cross-section (RCS) reducing metasurface insensitive to polarization and design method thereof

Abstract

The invention belongs to the technical field of radar stealth, and particularly relates to a wideband spirally-coding radar cross-section (RCS) reducing metasurface insensitive to polarization and a design method thereof. The metasurface is of a two-dimensional limited size structure and is formed by arranging eight types of linear super-elements having different gradient directions in 8 by 8 according to a spiral sequence, the gradient directions of eight types of linear super-elements are respectively 0 degree, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees and 315 degrees, each linear super-element is of a two-dimensional limited size structure and is formed by six types of artificial electromagnetic structure units having different sizes in 6 by 6 according to linear gradient, the six types of artificial electromagnetic structure units realize 360-degree coverage, the phase gradient is 60 degrees, the spiral sequence is a single spiral circulation arrangement mode from outside to inside, each artificial electromagnetic structure unit is of a rotary symmetric reflection structure and comprises an upper-layer internal closed ring, an external Jerusalem metal structure, an intermediate-layer dielectric plate and a bottom-layer metal copper plate. The RCS reducing metasurface has the excellent characteristics of thin thickness, good robustness, ultra-wideband working and the like and is easy to process.

Description

technical field [0001] The invention belongs to the technical field of radar stealth, and in particular relates to an ultra-wideband, polarization-insensitive RCS reduction metasurface and a design method thereof based on a single spiral cyclic code arrangement and a linear phase gradient. Background technique [0002] With the rapid development of radar detection technology, stealth characteristics have gradually become an important indicator to measure the performance of flying targets. The detection of radar targets mainly depends on the radar cross section (RCS) of the detected object. Therefore, reducing the RCS becomes the most important means to achieve stealth. The traditional stealth technology mainly realizes the reduction of RCS by changing the shape of the flying target and coating the radar absorbing material (RAM). 4 layers of RAM to maximize RCS reduction. F-22 Raptor is also used in a similar way to achieve radar stealth. However, due to the aerodynamic lim...

AI Technical Summary

Problems solved by technology

In 2007, the artificial magnetic conductor (AMC) metasurface with checkerboard structure was first applied in the field of RCS reduction. Although its narrow-band characteristics, polarization sensitivity and specific region (backward) RCS reduction limit its practical application, the method It has greatly stimulated people's research upsurge on broadband, polarization insensitivity, large-angle incidence and dual-station RCS reduction. It is expected that this technology can be used in practice one day and become a new stealth material to replace traditional RAM.

[0004] The present invention discloses an ultra-wideband RCS reduction metasurface and its design method based on a single helical cyclic encoding arrangement and a linear phase gradient. The method is simple and efficient, and solves the time-consuming problem caused by the need for a large number of optimizations in the existing RCS reduction metasurface design At the same time, it has excellent performance such as large-angle incidence and polarization insensitivity, and has important potential application prospects in the field of radar electromagnetic stealth

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