RU2701483C1 - Ultra-wideband antenna with adaptive beam pattern correction device - Google Patents

Abstract

FIELD: antenna equipment.

SUBSTANCE: antenna has a dielectric substrate, a metal layer located on a dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction and forming an antenna opening, an adaptive correction of the beam pattern, installed in the antenna opening. At that, device of adaptive correction of directional pattern is made of radar absorbent material and is located on opposite side of dielectric substrate, between divergent walls of slot or in dielectric housing, in which it is possible to place antenna, and, thus, is free from contact with walls of slot for selective correction of main lobe of antenna pattern of antenna in aperture.

EFFECT: technical result consists in the possibility of selective adaptation of the main lobe antenna pattern, minimizing power loss when using antenna for radio frequency coverage of target areas.

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Description

The invention relates to antenna technology, in particular to ultra-wideband antennas, and can be used in various broadband radio systems, in particular in 3G, 4G communication standards systems. 5G, Wi-Fi.

The Vivaldi antenna design was first proposed by Gibson (Gibson PJ., "The Vivaldi aerial", Proceeding 9th European Microwave Conference, 1979, pp. 101-105). The Vivaldi antenna contains a dielectric substrate, a metal layer located on the dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction, forming the opening of the antenna. An antenna of the TSA type (abbreviation from the English. Tapered Slot Antenna - an antenna with an expanding slot) has a shape resembling a tuning fork, therefore, because of the musical association, the TSA is commonly called the Vivaldi antenna.

The established TSA patterns are as follows. Its slit width determines the lower frequency, like a dipole.

The length of the expanding walls of the slit determines the gain in the middle and on the upper edge of the strip, as in a log-periodic antenna or horn.

The shape of the slit determines the frequency band. The shape may be different, but it has been established that the exponential increase in the width of the gap gives the widest band.

Where power is applied to the supply gap affects the matching at the bottom of the frequency band.

The classic Vivaldi antenna design has the following disadvantages: a high level of side lobes and a wide radiation pattern. A wide antenna pattern (BOTTOM) is due to the spherical shape of the wave front.

Vivaldi antenna designs are known, characterized by powering means located in the power slot (US Pat. No. 4,837,004; US Pat. No. 5,014,466).

The disadvantage of these designs is the expansion of the DND, symmetrical with respect to the horizontal axis, in the aperture of the antenna between the expanding walls, which leads to a significant level of the lower radiation of the antenna in the plane of the electric field lines.

Close to the proposed technical solution is the Vivaldi antenna, containing a dielectric substrate, a metal layer located on the dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction and forming the antenna opening, a lens installed in the antenna opening and made of diffusers ( Bin Zhou, Yan Yang, Hui Li, and Tie Jun Cui, "Beam-steering Vivaldi antenna based on partial Luneburg lens constructed with composite materials", Journal of Applied Physics, V. 110, no. 8, pp. 084908-084908- 6, 2011).

The known device contains a circular Luneberg lens in the aperture between the expanding walls of the slit from the outer and inner surfaces of the dielectric substrate, and outside the aperture. This antenna device consists of a Vivaldi antenna tuned to operate in the frequency band 8-11 GHz, and a Luneberg lens. A Luneberg lens is made in the form of several disks of dielectric material and diffusers, in the form of perforation of disks with round holes, due to which the necessary distribution of the refractive index is realized. In addition, the Luneberg lens disks are located on both sides of the E-polarization plane of the antenna, and the use of eight Luneberg lens disks (four above and below the E-polarization plane of the antenna) is required to satisfactorily reduce the side lobe level and improve the gain.

The advantages of this technical solution when compared with the known ones (Gibson PJ, "The Vivaldi aerial", Proceeding of the 9th European Microwave Conference, 1979, pp. 101-105; US patent No. 483704; US patent No. 5081466) are reduced side lobe levels and an increase in gain due to the use of a Luneberg lens.

The disadvantages of the known device are: the complexity of manufacture and the bulkiness of the design, the lack of the possibility of selective correction of the sides of the main lobe of the bottom, large longitudinal and transverse dimensions.

Closest to the proposed technical solution is a Vivaldi antenna containing a dielectric substrate, a metal layer located on the dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction and forming the antenna opening, a lens mounted in the antenna opening and made of diffusers characterized in that the diffusers are made in the form of conductive plates located on a dielectric substrate between the expanding walls, and made free from contact with the walls of the slit for correcting phase distortion in the aperture (RF Patent No. 2593910).

The known device is a lens, due to the compensation of phase distortion helps to focus electromagnetic energy in the direction of the main lobe of the bottom.

The disadvantages of the known device are: the difficulty in manufacturing, the lack of the possibility of selective correction of the sides of the main lobe of the bottom.

The problem solved by the invention is the improvement of technical and operational characteristics.

The technical result obtained by using the invention is to simplify the device, reduce the longitudinal and transverse (in height) dimensions, realize the possibility of selective correction of the sides of the main lobe of the bottom.

To solve the problem with achieving the specified technical result in the known Vivaldi antenna containing a dielectric substrate, a metal layer located on the dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction and forming the antenna opening, an adaptive bottom correction device, placed in the aperture of the antenna. According to the invention, the adaptive DND correction device is a selective DND correction device. The adaptive DND correction device is made of a special radio-absorbing material, is located on the opposite side of the dielectric substrate and, thus, is free from contact with the walls of the slit for correcting the DND in the aperture.

Possible additional embodiments of the device:

- the device for adaptive correction of the bottom of the antenna was located in a dielectric housing in which it is possible to place the antenna perpendicular to the axis of the longitudinal direction of the slit;

- the adaptive DND correction device was located in a dielectric housing in which it is possible to place the antenna parallel to the axis of the longitudinal direction of the slit;

- the adaptive DND correction device consists of several parts, it was located in a dielectric casing in which it is possible to place the antenna parallel or perpendicular to the axis of the longitudinal direction of the slit.

These advantages, as well as features of the present invention are illustrated by a variant of its implementation with reference to the accompanying drawings.

FIG. 1 - view of the declared antenna, view from the outside;

FIG. 2 - view of the claimed antenna, inside view, with the image of the adaptive correction device BOTTOM;

FIG. 3 is a view of the radiation pattern of the claimed antenna at a frequency of 2.4 GHz without an installed adaptive correction device BOTTOM;

FIG. 4 is a view of the DND at a frequency of 2.4 GHz with the adaptive DND correction device installed;

FIG. 5 is a view of the claimed antenna with a device for adaptive correction of the bottom;

The claimed antenna (Fig. 5) contains a dielectric substrate 2, a metal layer 1 located on the dielectric substrate 2, a slot 3 made in a metal layer 1 with expanding walls along its longitudinal direction and forming an opening 4 of the antenna. Adaptive correction device DND 5 is installed in the aperture 4 of the antenna. In accordance with the invention, an adaptive DND correction device 5 (FIG. 5) is a selective DND correction device. The adaptive DND correction device is made in the form of a special radar absorbing material located on the dielectric substrate 2 between the expanding walls of the slit 3, on the opposite side of the antenna and, thus, is made free from contact with the walls of the slit 3 to correct the radiation pattern in aperture 4.

The term "device adaptive correction of the bottom" 5 means a special radar absorbing material.

The adaptive correction device DND 5 is perpendicular to the axis of the longitudinal direction of the slit 3.

The adaptive correction device DND 5 can be located in rows relative to the axis of the longitudinal direction of the slit 3.

The adaptive correction device DND 5 is not a lens and is not a device for correcting phase distortions in the aperture.

Adaptive correction device DND 5 is applicable for Vivaldi type antennas.

As in analogs, a slot 3 made in a metal layer 1 with expanding walls along its longitudinal direction, in the place of its narrowing is paired with a power gap 6, which is narrow (Fig. 4).

The device for adaptive correction of DNA 5 can be made in the form of a separate structural element 5 (Fig. 5), or can be applied in the form of a coating (for example, on an epoxy or paint base).

The claimed antenna works (Fig. 1, 2, 4) as follows. An electromagnetic wave propagates from the power gap 6 along the aperture 4 of the antenna. In the area where the distance between the expanding walls of the gap 3 is small compared to the wavelength in free space, electromagnetic waves are well “connected” with the walls of the gap 3. But as the distance between the conducting surfaces of the expanding walls of the gap 3 increases, the radiation resistance increases, and when threshold wavelengths are emitted by the antenna.

It can be noted that different parts of the walls emit at different frequencies

antennas, so theoretically it can have a very wide frequency band. In practice, the frequency band is limited by the size of the antenna.

In a classic Vivaldi antenna, the width of the bottom of the bottom is determined by the shape of the wave front, characterized by a high level of side lobes and a wide bottom.

The DND can be narrowed due to the concentration of the wave in the longitudinal direction using the Luneberg lens, as is done in the closest analogue. However, it does not allow selective adjustment of the DNA in the necessary part. Such a lens should extend beyond the aperture of 4 antennas, as it is this part that makes a significant contribution to the formation of DND.

In the claimed technical solution, a device for adaptive correction of DND 5 is used (Fig. 5), which are located in the aperture 4 of the antenna. The adaptive DND correction device 5 is made in the form of a special radar absorbing material, which is located on the dielectric substrate 2 between the expanding walls of the slit 3, and is necessarily placed on the opposite side of the dielectric plate, free from contact with the walls of the slit 3 (not in contact with the expanding walls). In this case, the radar absorbing material serves to correct the main lobe of the DND due to the physical mechanisms of radar absorption occurring in its microstructure.

The experiments showed that the shape of the adaptive DND correction device can be made in the form of a rectangle 5 (Fig. 5), or in another form. The shape of the adaptive DND correction device depends on the size of the Vivaldi antenna, the frequency range, the required selective correction of the DND. In this case, the device for adaptive correction of the DND can be placed at different distances from the edge of the dielectric plate, which affects the appearance of the radiation pattern. The adaptive DND correction device can be made as a separate structural element 5 (Fig. 5), or it can be applied in the form of a coating. Moreover, the composition and properties of the radar absorbing material depend on the aim pursued in the selective correction of DND.

The use of the claimed device gives a gain in selective correction of the flooring layer of the bottom (Fig. 4), as a result of the rational use of the power supplied to the antenna. Also received radiation patterns in the vertical plane at a frequency of 2.4 GHz for Vivaldi antenna with adaptive correction device DND 5 (Fig. 4) and without it (Fig. 3). As can be seen from figures 3 and 4, the presence of a device for adaptive correction of DND 5 promotes selective focusing of electromagnetic energy in the direction of the main lobe of the DND, correction of the underlying layer of the DND (Fig. 4).

The most successfully announced "Ultra-wideband antenna with adaptive beam correction device" is industrially applicable in broadband radio engineering systems both as a stand-alone antenna device and in antenna arrays.

Claims (4)

1. Vivaldi ultra-wideband antenna containing a dielectric substrate, a metal layer located on the dielectric substrate, a slot made in a metal layer with expanding walls along its longitudinal direction and forming an aperture of the antenna, an adaptive radiation pattern correction device installed in the antenna aperture, characterized in that the adaptive radiation pattern correction device is made of a radar absorbing material, located on the opposite side of the dielectric substrate between the expanding walls of the slit or in a dielectric housing into which it is possible to place the antenna, and, thus, is made free from contact with the walls of the slot for selective correction of the main lobe of the antenna pattern in the aperture. 2. Vivaldi ultra-wideband antenna according to claim 1, characterized in that the adaptive radiation pattern correction device is made of radar absorbing material. 3. The Vivaldi ultra-wideband antenna according to claim 1, characterized in that the adaptive radiation pattern correction device can be located either perpendicular to the axis of the longitudinal direction of the slit or parallel to the axis, while it can consist of several parts. 4. The Vivaldi ultra-wideband antenna according to claim 1, characterized in that the adaptive radiation pattern correction device can be made in the form of a separate structural element or can be applied in the form of a coating.

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