CN115064866A

CN115064866A - Circularly polarized antenna array for generating high-purity vortex wave

Info

Publication number: CN115064866A
Application number: CN202210575635.9A
Authority: CN
Inventors: 刘丹丹; 柳森涛; 吴巍; 肖金石; 孙沁沁
Original assignee: Naval University of Engineering PLA
Current assignee: Naval University of Engineering PLA
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2022-09-16

Abstract

The invention discloses a circularly polarized antenna array for generating high-purity vortex waves, and belongs to the technical field of wireless communication. The invention includes a circularly polarized antenna array that radiates high purity vortex waves. The circularly polarized antenna array consists of an antenna array with N array elements, a dielectric substrate and a grounding plate, wherein the antenna array consists of circularly polarized antennas, and N is more than or equal to 4. The invention realizes the radiation of high-purity vortex waves by using the circularly polarized antenna array which has a planar structure, a simple principle and a compact structure. The invention designs two antenna arrays capable of radiating high-purity vortex waves, can provide an antenna foundation for improving the spectrum capacity of a communication system, and has important significance in practical application.

Description

Circularly polarized antenna array for generating high-purity vortex wave

Technical Field

The invention belongs to the field of wireless communication, and particularly relates to a circularly polarized antenna array for generating high-purity vortex waves.

Background

With the increase of wireless communication data services, the demand of people for transmission speed and capacity is sharply increased, however, the frequency spectrum is a limited resource, so that the increase of the frequency spectrum capacity is an effective means for improving the performance of the wireless communication system. In this context, vortex waves with mode orthogonality gradually walk into the field of view of people. The vortex waves have infinite mode numbers, and the vortex waves with different mode numbers are orthogonal to each other. If vortex waves in different modes are used as orthogonal sub-channels of wireless communication, and different information is loaded on each sub-channel for transmission, the spectrum capacity can be multiplied.

The frequency spectrum capacity improvement based on the vortex wave technology mainly depends on the orthogonality among vortex wave modes, but based on the research on the purity of the vortex wave modes by scholars, the purity of the vortex wave modes generated by the existing method is not high. Chen et al used super-surfaces to generate different modes of OAM waves with a modal purity of 83%, see J.Chen, J.Song, et al, Dual-band vortex beam generation with differential OAM modes using single-layer meter surface. Zhang et al design cavity antennas to generate OAM waves that produce OAM wave mode purities for both modes-3 and-9 of less than 80%, see Z.Zhang, S.ZHING, W.Zhang, et al, experimental demodulation of frequency gain of plane specific OAM-based MIMO systems, IEEE Microwave and Wireless Components Letters,2017,27(8):757 and 759. The problem of low mode purity can affect the ability of vortex waves to improve spectral capacity.

Aiming at the problem that the vortex wave mode is not high in purity, the invention provides a circularly polarized sky array for generating vortex waves, and the vortex waves generated by the antenna array have the advantage of higher mode purity. And the circularly polarized antenna array has a planar patch structure, the principle is simple, and the implementation is easy. The vortex wave generator is beneficial to improving the application prospect of vortex waves.

Disclosure of Invention

The invention provides a circularly polarized antenna array for generating high-purity vortex waves, which solves the problem of low purity of a vortex wave mode.

The invention provides a circularly polarized antenna array for generating high-purity vortex waves, which comprises a circularly polarized antenna array, a dielectric substrate and a grounding plate, and is characterized in that:

the radius of the circularly polarized antenna array is R, and the dielectric substrate and the grounding plate have the same shape and can be square or circular;

the number of the circularly polarized antenna array units is N, N is more than or equal to 4, and the N circularly polarized antenna units are uniformly distributed on a circumference with the radius of R;

the circularly polarized antenna array feeds power through a coaxial line;

the feed excitations of the circularly polarized antenna array have the same amplitude, and the phase difference between the circularly polarized antenna units is 2 pi ln/N;

the antenna unit of the circularly polarized antenna array is a right-hand circularly polarized antenna;

the antenna unit of the circularly polarized antenna array is a left-handed circularly polarized antenna.

When the circularly polarized antenna array works, when the antenna units of the circularly polarized antenna array are right-hand circularly polarized antennas, the excitations of the feed ports of the N antenna units have the same amplitude, the same frequency and the phase difference of 2 pi ln/N. The vortex wave generated by the circularly polarized antenna array has the following characteristics: the x-component and the y-component of the electric field present the radiation characteristic of the vortex wave with the mode of l, and the z-component of the electric field presents the radiation characteristic of the vortex wave with the mode of l + 1. When the antenna elements of the circularly polarized antenna array are left-handed circularly polarized antennas, the excitations of the feed ports of the N antenna elements have the same amplitude, the same frequency and a phase difference of 2 pi/N. The vortex wave generated by the circularly polarized antenna array has the following characteristics: the x-component and the y-component of the electric field present the radiation characteristic of the vortex wave with the mode l, and the z-component of the electric field presents the radiation characteristic of the vortex wave with the mode l-1.

Compared with the existing method for generating vortex waves, the circularly polarized antenna array adopted by the invention has the advantages that 3 components of the electric field radiated by the circularly polarized antenna array have vortex wave characteristics, the principle of the antenna array is simple, and the structure is compact. Is favorable for improving the application prospect of the vortex wave.

Drawings

Fig. 1 is a side view of a circularly polarized antenna array according to embodiment 1 of the present invention;

FIG. 1B is a top view of example 1;

FIG. 1C is a bottom view of embodiment 1;

FIG. 2A is a phase distribution diagram of an x-component of an electric field of example 1;

FIG. 2B is a phase distribution diagram of the y-component of the electric field of example 1;

FIG. 2C is a phase distribution diagram of the z-component of the electric field of example 1;

fig. 3A is a side view of a circularly polarized antenna array according to embodiment 2 of the present invention;

FIG. 3B is a top view of the preferred embodiment 2;

FIG. 3C is a bottom view of the preferred embodiment 2;

FIG. 4A is a phase distribution diagram of an x-component of an electric field in example 2;

FIG. 4B is a phase distribution diagram of the y component of the electric field of example 2;

FIG. 4C is a phase distribution diagram of the z-component of the electric field of example 2.

Detailed Description

The invention is further illustrated below with reference to examples and figures.

As shown in fig. 1, embodiment 1 of the present invention includes a circularly polarized antenna array 10, a dielectric substrate 20, and a ground plate 30. The radius of the circular polarized antenna array 10 is 15mm, the circular polarized antenna unit is a right-hand circular polarized antenna, and the size of the antenna unit is shown in table 1. The dielectric substrate 20 is FR4, the dielectric constant is 4.3, the thickness is 1.6mm, the shape is square, and the side length is 50 mm. The ground plate 30 is square with a side length of 50 mm.

TABLE 1 parameters for right-hand single circularly polarized patch antenna

In the working of embodiment 1 of the present invention, the phase difference of the antenna elements in the circularly polarized antenna array 10 is pi/4. The vortex wave generated in this particular example 1 has the following characteristics: the electric field x-component and the electric field y-component exhibit a vortex wave characteristic of mode 1, and the electric field z-component exhibits a vortex wave characteristic of mode 2.

The phase distribution map of the embodiment of the invention observes a distance of 50mm from the antenna, and the observation plane is parallel to the circularly polarized antenna array. Fig. 1 and 1B are phase distribution diagrams of an x component and a y component of an electric field in this embodiment, which show a vortex wave characteristic of mode 1. FIG. 1C is a phase distribution diagram of the z-component of the electric field in this embodiment, which shows the vortex wave characteristic of mode 2.

Embodiment 2 of the present invention is shown in fig. 3, and includes a circularly polarized antenna array 10, a dielectric substrate 20, and a ground plate 30. The radius of the circular polarized antenna array 10 is 15mm, the circular polarized antenna unit is a left-handed circular polarized antenna, and the size of the antenna unit is shown in table 2. The dielectric substrate 20 is FR4, the dielectric constant is 4.3, the thickness is 1.6mm, the shape is square, and the side length is 50 mm. The ground plate 30 is square with a side length of 50 mm.

TABLE 2 parameters for left-handed single circularly polarized patch antenna

Parameter(s)	Numerical value (mm)
		l ₁	11
l ₂	6.5
		b	2.4
r	1.3
		a	2.75
r ₁	1.3
		r ₂	1.8

Fig. 3A and 3B are phase distribution diagrams of the x-component and the y-component of the electric field in this embodiment, which show the vortex wave characteristic of mode 1. FIG. 3C is a phase distribution diagram of the z-component of the electric field in this embodiment, which shows a vortex wave characteristic with a mode of 0.

Claims

1. A circularly polarized antenna array for generating high purity vortex waves, comprising a circularly polarized antenna array (10), a dielectric substrate (20), a ground plate (30), characterized in that:

the radius of the circularly polarized antenna array (10) is R, and the dielectric substrate (20) and the grounding plate (30) have the same shape and can be square or circular;

the number of the units of the circularly polarized antenna array (10) is N, N is more than or equal to 4, and the N circularly polarized antenna units are uniformly distributed on the circumference with the radius of R.

2. The circularly polarized antenna array for generating high purity vortex waves of claim 1, wherein:

the circularly polarized antenna array (10) is fed by a coaxial line;

the feed excitations of the circularly polarized antenna array (10) have the same amplitude, and the phase difference between the circularly polarized antenna elements is 2 pi ln/N.

3. The circularly polarized antenna array for generating high purity vortex waves of claim 1 or 2, wherein:

the antenna unit of the circularly polarized antenna array (10) is a left-handed circularly polarized antenna;

the antenna unit of the circularly polarized antenna array (10) is a right-hand circularly polarized antenna.