RU2703926C1 - Waveguide reflective antenna array - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: invention relates to the antenna equipment. Antenna grid consists of metal reflector and metal layer with round holes of equal radius of different depth. Thickness of metal layer, depth of holes, their mutual arrangement and radius satisfy condition of focusing of irradiation field at working frequency. Metal layer is made in form of a set of plates of equal thickness, depth of holes of metal layer varies with pitch equal to thickness of metal plates, and to metal layer with round holes adjoins dielectric layer with cylinders protruding from it of different height and identical radii, coinciding with radii of round holes in metal layer, and such mutual arrangement that protruding cylinders of dielectric layer are completely embedded into metal layer. Depth of holes of metal layer and height of cylinders of dielectric layer satisfy condition of focusing of irradiation field at working frequency.

EFFECT: technical result consists in improvement of operational stability and reduction of cross dimensions of structure.

1 cl, 16 dwg

Description

The invention relates to antenna technology and is intended for use as a transmitting and receiving antenna in high-speed information transmission systems, in 5G systems.

A metal OAR is known with grooves of the same geometry cut through it, partially filled with a dielectric, and the depth and method of filling cavities with a dielectric satisfy the condition of focusing the irradiation field at the operating frequency (Ghalamkari, Behbod & Tavakoli, Ahad. (2016). A fast solution of TE wave scattering by a 2D partially dielectric filled and coated rectangular crack. Journal of Electromagnetic Waves and Applications. 30.1-15. 10.1080 / 09205071.2016.1157047.)

The disadvantages of this solution is the ability to work on only one polarization.

Known metal OAR with holes cut in it of the same radius, but of different depths, while the size and relative position of the recesses satisfy the condition of focusing the irradiation field at the operating frequency (KR 101084225 B1 "Cassegrain antenna for high gain")

The disadvantages of this solution are a slight decrease in the working frequency band, the need for additional climate protection to prevent clogging of the recesses, and significant transverse dimensions (thickness) of the antenna.

A metal OAR is known consisting of a set of metal plates of different thicknesses with holes of the same size cut in them so that when they are combined in the metal layer, recesses of different depths are formed, while the dimensions and relative position of the recesses satisfy the condition of focusing the irradiation field at the operating frequency. (KR 100932921 B1 "Antenna using a laminate plate")

The disadvantage of this solution is the large transverse dimensions (thickness) of the structure.

The closest in the totality of existing features to the proposed device is a waveguide reflective antenna array consisting of a metal reflector and a metal layer with round holes of the same radius of different depths, and the thickness of the metal layer, the depth of the holes, their relative position and radius satisfy the condition of focusing the radiation field on the working frequency (SV Polenga, A.V. Stankovsky, R.M. Krylov, AD Nemshon, Y.A. Litinskaya and YP Salomatov, "Millimeter-wave waveguide reflectarray," 2015 International Siberian Conference on Control and Communications (SIBCON), Omsk, 2015, pp. 1-4. Doi: 10.1109 / SIBCON.2015.714733 5).

The advantage of the prototype is the ability to work on circular polarization.

The disadvantages of the prototype are:

- the complexity of manufacturing associated with the need to use milling technology;

- the need for additional climate protection to increase the operational stability of the device, which increases the overall dimensions of the structure.

- significant transverse dimensions of the antenna, due to the limited ability to adjust the phase of the reflected signal by a single element of the antenna array.

The task of the invention is to increase operational stability, reducing the transverse dimensions of the structure, improving the manufacturability of the device.

The problem is solved due to the fact that the claimed device, as well as the known one, consists of a metal reflector and a metal layer with round holes of the same radius of different depths, and the thickness of the metal layer, the depth of the holes, their relative position and radius satisfy the focus condition of the irradiation field at the operating frequency. But, unlike the known one, in the present invention, the metal layer is made in the form of a set of plates of the same thickness, the depth of the holes of the metal layer varies in steps equal to the thickness of the metal plates, and a dielectric layer with protruding cylinders of different heights adjoins the metal layer with round holes and the same radii coinciding with the radii of round holes in the metal layer, and such a mutual arrangement that the protruding cylinders of the dielectric layer are completely contributions into the metal layer, and the depth of the holes of the metal layer and the height of the cylinders of the dielectric layer satisfy the condition of focusing the irradiation field at the operating frequency.

The technical result achieved is an increase in operational stability, a decrease in the transverse dimensions of the structure, and an improvement in the manufacturability of the device.

The technical result is achieved by performing a metal layer in the form of a set of metal plates of the same thickness so that the depth of the holes of the metal layer changes in increments equal to the thickness of the plates. In addition, a dielectric layer is inserted into the structure of the reflective antenna array adjacent to the metal layer with holes, cylinders of different heights protruding from it and the same radii coinciding with the radii of the circular holes in the metal layer and such a mutual arrangement that the protruding cylinders of the dielectric layer is completely are embedded in a metal layer, and the depth of the holes of the metal layer and the height of the cylinders of the dielectric layer satisfy the condition for focusing the irradiation field at the operating frequency. A possible method of manufacturing a dielectric layer is 3D printing. A possible method of manufacturing a metal layer is laser cutting. In this case, the holes in the metal layer are reliably protected from climatic influences or clogging due to the closed structure and do not require additional climate protection, which could increase the mass of the structure. The dielectric layer performs the functions of both climate protection and focusing of the irradiator field at the operating frequency.

The invention is illustrated by 16 drawings.

FIG. 1 - view of the antenna system

FIG. 2 - section of the antenna system

FIG. 3 is a view of a first metal plate.

FIG. 4 is a view of a 2nd metal plate.

FIG. 5 is a view of a third metal plate.

FIG. 6 is a view of a fourth metal plate.

FIG. 7 is a view of a 5th metal plate.

FIG. 8 is a view of a dielectric layer with cylinders protruding from it.

FIG. 9 - unit cell of the antenna array with cylindrical holes partially filled with a dielectric.

FIG. 10 - unit cell of the antenna array with cylindrical holes and a dielectric shelter.

FIG. 11 - unit cell of the antenna array with cylindrical holes completely filled with a dielectric.

FIG. 12 - dependence of the phase of the reflected signal within the unit cell of the antenna array on the height of the protruding cylinders of the dielectric layer and the hole depth of the metal layer.

FIG. 13 - dependence of the phase of the reflected signal within the unit cell of the antenna array on the depth of the holes of the metal layer.

FIG. 14 - dependence of the phase of the reflected signal within the unit cell of the antenna array on the height of the protruding cylinders of the dielectric layer and the depth of the hole of the metal layer.

FIG. 15 - frequency dependence of the gain of various geometries of waveguide reflective antenna arrays.

FIG. 16 are radiation patterns of a dielectric reflective antenna array at various frequencies.

The following notation is introduced in the drawings:

1 - irradiator.

2 - metal reflector.

3 - metal plates with holes cut through them.

4 - a dielectric layer with cylinders of different heights protruding from it.

5 - air gaps.

6 - phase dependence of the reflected signal within the unit cell of the antenna array for a small step of changing the depth of the holes in the metal layer, the depth of the holes coincides with the height of the cylindrical protrusions in the dielectric layer.

7 - phase dependence of the reflected signal within the unit cell of the antenna array for the depth of the holes in the metal layer is 2.5 mm.

8 - phase dependence of the reflected signal within the unit cell of the antenna array for the depth of the holes in the metal layer is 2.0 mm.

9 - phase dependence of the reflected signal within the unit cell of the antenna array for the depth of the holes in the metal layer is 1.5 mm.

10 - dependence of the phase of the reflected signal within the unit cell of the antenna array for the depth of the holes in the metal layer is 1.0 mm.

11 - phase dependence of the reflected signal within the unit cell of the antenna array for the depth of the holes in the metal layer is 0.5 mm.

12 - phase dependence of the reflected signal within the unit cell of the antenna array for the prototype with a dielectric shelter, the height of the metal layer is 2.5 mm

13 - phase dependence of the reflected signal within the unit cell of the antenna array for the prototype with a dielectric shelter, the height of the metal layer is 3.5 mm

14 - phase dependence of the reflected signal within the unit cell of the antenna array for the prototype with a dielectric cover, the height of the metal layer is 4.0 mm

15 - phase dependence of the reflected signal within the unit cell of the antenna array for the prototype with a dielectric shelter, the height of the metal layer is 5.0 mm.

16 - phase dependence of the reflected signal within the unit cell of the antenna array for the proposed waveguide reflective antenna array, the grid spacing is 0.55 wavelength.

17 - dependence of the phase of the reflected signal within the unit cell of the antenna array for the prototype in the presence of a dielectric shelter (climate protection), the grid pitch is 0.8 wavelengths.

18 - frequency dependence of the gain for the proposed waveguide reflective antenna array.

19 is a frequency dependence of the gain for a prototype with dielectric shelter (climate protection).

20 - frequency dependence of the gain for the proposed waveguide reflective antenna array, a fixed depth of the holes in the metal layer.

21 - frequency dependence of the gain for the proposed waveguide reflective antenna array, a small step of changing the depth of the holes in the metal layer, the depth of the holes coincides with the height of the cylindrical protrusions in the dielectric layer.

The antenna works as follows.

To explain the operation of the device, an irradiator 1 is additionally introduced into its structure (Fig. 1-2). When the antenna is in transmission mode, the wave from the feed 1 falls on the waveguide reflective antenna array consisting of a metal layer made of a metal reflector 2, a set of metal plates 3 (Fig. 3-7), a dielectric layer 4 (Fig. 8) with cylinders of different heights protruding from it and the same radii coinciding with the radii of round holes in the metal layer. At the same time, the depth of the holes in the metal layer and the heights of the protruding cylinders are selected in such a way that air gaps can be formed 5. Thus, when designing an antenna using a known method based on the analysis of the phase of the reflected wave within the unit cell (Fig. 9-11) (Thornton J., Huang K.- C. Modern Lens Antennas for Communications Engineering. Wiley-IEEE Press, 2012. P.272) a greater number of degrees of freedom is achieved compared to the known counterparts, thereby reducing the transverse dimensions of the antenna. Due to the fact that the holes in the metal layer and the dielectric protrusions are arranged in such a way that the set of elements corresponds to an equivalent Fresnel lens (N. D. Hristov, Fresnel zones in wireless links, zone plate lenses and antennas, Artech House, 2000) for focusing the field irradiation, when the incident wave is reflected from the antenna, the spherical wave front from the irradiator 1 is converted to a flat front of the reflected wave.

When the antenna is in the receiving mode, the incident field from the source in the far zone after reflection from the antenna is focused at the point where the irradiator 1 is located.

In this case, both direct focus and offset arrangement of the irradiator can be implemented. Depending on the desired shape of the radiation pattern and the arrangement of the irradiator, the law of the relative position of the holes in the metal layer and the protrusions of the dielectric layer will also change.

The operation of the device is confirmed by the data of electrodynamic modeling of a direct-focus waveguide reflective antenna array with dimensions of 43 × 43 mm for operation at a center frequency of 71 GHz with a hexagonal grid pitch of 0.55 wavelength cylindrical cavities at the operating frequency and a dielectric plate thickness of 15 mm, made of a dielectric with permittivity 2.33 and a loss tangent of 0.0025. The antenna sample was designed based on its implementation by laser cutting of 5 sheets of metal with a thickness of 0.5 mm and using 3D printing technology for the dielectric layer. The geometry of the layers was obtained by a known method (Thornton J., Huang K.- C. Modern Lens Antennas for Communications Engineering. Wiley-IEEE Press, 2012. P. 272).

The synthesis of the reflective antenna array is based on the dependences of the phase of the reflected field on the size of the holes in the metal layer and the protrusions of the dielectric layer obtained from modeling in the unit cell of the antenna array (Fig. 12-14). Namely, a set of dependences of the phase of the reflected field on the dimensions of the protrusion of the dielectric layer was used for different depths of the holes of the metal layer (Fig. 12).

From the above dependences of the phase of the reflected signal on the dimensions of the protrusion of the dielectric layer and the hole depth of the metal layer in FIG. 12 it follows that

- the variation of the phase of the reflected signal has the largest range of variation of the proposed design of the present invention, with a small step of changing the depth of the holes in the metal layer and the cavity full filling with a dielectric (Fig. 9) - the depth in the metal layer of the holes completely coincides with the size of the protrusions of the dielectric layer, with a gain by the band of operating frequencies and the maximum value of the gain relative to the proposed solution, it turns out to be small (Fig. 15);

- when using the geometry of the prototype, in the presence of only a dielectric shelter without protrusions (Fig. 10), phase reconstruction at the same height of the structure is possible only with an increase in the pitch of the hexagonal grid of the arrangement of elements to 0.8 wavelength (Fig. 14), which is due to diffraction lobes, leads to a decrease in gain in the operating frequency band.

- if you use a fixed depth of the holes and change only the height of the cylindrical protrusions, then there will also be a decrease in the values of the gain in the operating frequency band (Fig. 15).

A design variant of the proposed antenna with a step equal to the thickness of the plates (0.5 mm metal plates in this example) is preferred for implementation using laser cutting technology. The radiation patterns in the operating frequency band for a given antenna are shown in FIG. 16.

Thus, the achievability of the technical result is shown — expanding the operating frequency band, increasing operational stability, increasing mechanical strength during operation, reducing the size of the structure.

Claims (1)

A waveguide reflective antenna array consisting of a metal reflector and a metal layer with round holes of the same radius of different depths, and the thickness of the metal layer, the depth of the holes, their relative position and radius satisfy the condition of focusing the irradiation field at the operating frequency, characterized in that the metal layer is made in in the form of a set of plates of the same thickness, the depth of the holes of the metal layer varies with a step equal to the thickness of the metal plates, and to the metal layer adjacent to the round holes is a dielectric layer with protruding cylinders of different heights and equal radii coinciding with the radii of the round holes in the metal layer and such a mutual arrangement that the protruding cylinders of the dielectric layer are completely embedded in the metal layer, with the depth of the holes of the metal layer and the height the cylinders of the dielectric layer satisfy the condition of focusing the irradiation field at the operating frequency.

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