Three-dimensional fully-polarized super-surface invisible cloak

Abstract

The invention discloses a three-dimensional fully-polarized super-surface invisible cloak. The three-dimensional fully-polarized super-surface invisible cloak is formed by seamlessly splicing phase-shift resonant units, wherein each phase-shift resonant unit is composed of an upper-layer medium, a middle-layer medium and a lower-layer medium, the dimensions of each contour line of each phase-shift resonant unit are less than a wavelength of a working electromagnetic wave, the upper-layer medium is a resonant structure with a full-polarization function, the upper-layer medium is fixed on the upper surface of the middle-layer medium, the middle-layer medium is a non-metal layer, the lower-layer medium is a metal layer, and the upper surface of the lower-layer medium and the lower surface of the middle-layer medium are tightly bonded and completely fitted; and a changed reflected wave phase of each phase-shift resonant unit meets the condition defined in the description, wherein delta is the changed reflected wave phase, theta is the complementary angle of an included angle between the working electromagnetic wave of the invisible cloak and a horizontal plane, h is a height of the geometric centre of each phase-shift resonant unit from the ground, and kb is a wave number of the working electromagnetic wave of the invisible cloak. The super-surface invisible cloak disclosed by the invention is insensitive to a polarization direction of the working electromagnetic wave, and suitable for all electromagnetic wave frequency bands.

Description

technical field [0001] The invention belongs to the field of electromagnetic wave cloaking, and in particular relates to a metasurface cloak that maintains full polarization amplitude and phase. Background technique [0002] From the famous Chinese novel Journey to the West to Greek myths and even Harry Potter, people have never stopped their fantasy of invisibility. In recent years, with the development of heterogeneous media, electromagnetic wave invisibility is no longer just a beautiful fantasy. Electromagnetic wave refers to a wave in which energy and momentum are transmitted in the form of periodic fluctuations in space by electric and magnetic fields that oscillate in phase and are perpendicular to each other. The electromagnetic spectrum includes all possible frequencies of electromagnetic radiation, from low to high frequencies of the electromagnetic spectrum are radio waves, microwaves, infrared light, visible light, ultraviolet light, X-rays and gamma rays. Gene...

AI Technical Summary

Problems solved by technology

[0006] 1. Most traditional cloaks can only be applied to specific polarized electromagnetic waves. To achieve full polarization of traditional body cloaks, six electromagnetic parameters need to be controlled, namely, the three spatial components of the permittivity and the three components of the magnetic permeability. spatial components, which makes it very difficult to implement

[0007] 2. Most cloaks use optical path approximation, that is, keep the refractive index of the parameter unchanged and change the impedance so that it can be realized by using existing materials. However, if the impedance does not match, it will cause strong reflection, and the cloaked object can still be cloaked. detected

[0008] 3. Existing fully polarized cloaks are designed using the quasi-conformal transformation method, but this method will introduce a lateral offset to the reflected wave, so the object is not perfectly invisible

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