An artificial surface plasmon orbital angular momentum beam scanning antenna and method thereof

Abstract

The invention discloses an artificial surface plasmon orbital angular momentum beam scanning antenna and a method thereof. The present invention uses a waveguide feeding device to convert the TEM mode in the coaxial line into an SSP mode, and propagate along the surface of the SSP transmission line; under the diffraction effect of the radiation structure outside the SSP transmission line, the wave vector of the SSP mode is superimposed on the diffraction The generated harmonic wave vector produces a spectrum shifting effect, thereby converting the SSP mode into a free space radiation wave, and at the same time, the intrinsic electric field of the helix of the radiation structure has an OAM mode, thus realizing a space radiation wave with an OAM mode, and Work in different frequency bands; control the radiation direction of the OAM mode by controlling the operating frequency; the rotation direction of the OAM mode is consistent with the chirality of the helix; the invention has a compact structure and does not require multiple unit arrays; the system has strong robustness , it is only necessary to maintain the helical characteristics of the helix; the waveguide feeding device is simple, only the coaxial port feeding is required, and no complicated feeding network is required.

Description

technical field [0001] The invention relates to orbital angular momentum technology, in particular to an artificial surface plasmon orbital angular momentum wave vector scanning antenna and a realization method thereof. Background technique [0002] Orbital angular momentum (OAM) has a spiral wave front and is widely used in various fields. First, different OAM modes are orthogonal to each other and can be applied in communication systems to improve channel capacity. In addition, OAM can be applied to imaging, quantum communication and other fields. Due to the wide application of OAM in many fields, how to efficiently generate OAM patterns has always been a research hotspot. In the optical band, the thickness of the spiral phase plate is different in the angular direction. When the Gaussian mode passes through the spiral phase plate, it can be converted into the OAM mode. In addition, the OAM mode can also be converted through the holographic phase plate. At present, ther...

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Problems solved by technology

Although there are many ways to generate OAM beams, there are still many problems, such as (1) limited working size, the use of an array structure will result in too large a volume, which is not conducive to the miniaturization of the antenna structure, and faces a complex feed structure Design; (2) limited operating bandwidth, due to the resonance effect of the metasurface structure depending on the unit structure, the bandwidth is narrow; (3) mode adjustment is difficult

Structures such as metasurface arrays, antenna arrays, and planar artificial surface plasmons depend on phase changes between adjacent units, and each OAM mode distribution requires a specific array arrangement, which is difficult to adjust; (4) Radiation The direction is difficult to adjust. At present, the adjustment methods to realize the radiation mode are limited, mainly mechanical adjustment, and the adjustment angle is limited

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