RU2699936C1 - Antenna device with switched beam pattern - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to the field of antenna equipment and can be used, for example, in corporate, mobile communication systems, as well as special purpose communication systems. Antenna device with switchable beam pattern comprises passive and active electric vibrators and switching elements. At that, excitation source is permanently connected to power supply line of active vibrator surrounded by uniformly located at distance of 0.25 λ from it N (N = 1, 2, …) by commutated passive vibrators with length of 0.5 λ, consisting of M (M = 4, 5, …) of collinear conductors connected by switching elements, controlling the beam pattern of the antenna device by imparting to the passive vibrators either a reflector property or an invisibility property for the active vibrator, wherein passive vibrators are configured to switch the beam pattern with the operating transmission device operating with considerable power, wherein number of partitions of passive vibrators is selected depending on required degree of their invisibility for active vibrator.

EFFECT: technical result consists in the possibility of switching the beam pattern, reducing the current load on the switching elements and reducing the number of elements to be matched with the supply line.

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Description

The proposed device relates to the field of antenna technology and can be used, for example, in corporate, mobile communications systems, as well as in communication systems for special purposes.

The use of directional radiation in communication systems makes it possible to increase the energy of a radio line in a given direction while simultaneously suppressing interfering emissions from other directions, increase the range of radio communications, increase the noise immunity of a communication channel, improve the parameters of electromagnetic compatibility, and increase the secrecy of information transfer.

In this case, when working with subscribers located randomly in the azimuthal plane, as well as in mobile communication systems, the use of directional antennas is required with the possibility of reversing the direction of radiation.

For these purposes, various methods can be used: mechanical scanning, frequency control of the beam, phased arrays, SMART antennas, or solutions based on the use of emitter arrays with switching their power supply, which makes it possible to form a specific beam or rotate it.

A number of antenna devices of this kind are known.

An antenna device with a controlled radiation pattern and a planar directional antenna [1] includes planar directional antennas, each of which is made in the form of a dielectric plate on which the active element of the antenna is mounted. The plate surface facing the active element is metallized and serves as an antenna reflector. The plates are connected along the ribs so that they form the side faces of the hollow body of the device. The end face is made in the form of a dielectric plate with a metallized outer surface and may also have an active antenna element. On the inner surface of the end face of the housing there is an antenna switch connected to the control unit of the switch and connected to the active elements of the antennas. The active element is attached using pins made of the body of the active element by its notching with subsequent bending.

In [2], a six-element ring antenna array (CAR) was implemented for a Wi-Fi data transmission system with a controlled radiation pattern based on planar emitters with a flat screen, the radiation of each element of which covers a certain sector of angles. By switching the elements, the antenna provides operation in all azimuthal directions with the required gain (KU).

The Super Scanner M-119 Electronic Sector-Phased Omni-beam antenna [3] of The antenna specialist co., Represents three dipoles mounted vertically on one mast in different sectors of space and switched remotely by a switching device on the RF relay. During operation, the dipoles are switched on in such a way that one excitation source and two reflectors are obtained. Thus, a switchable radiation pattern in three directions can be obtained.

The closest analogue in technical essence to the proposed device is "Vibrator antenna with switchable radiation patterns" [4], adopted as a prototype.

In FIG. 1 is a diagram of a prototype antenna; FIG. 1 a ) is a plan view, FIG. 1b) - side view), where it is indicated:

1.1, 1.2, 1.3 - “thin” shoulders of vibrators;

7 - a cylindrical screen;

8 - microstrip line (MPL).

Antenna prototype (Fig 1 a.) - plan view, and FIG. 1b) - side view) contains a cylindrical screen 7, which is one arm of the vibrator.

The second arm is the “thin” arms of the vibrators 1.1, 1.2, 1.3 that are connected by means of switching elements - controlled contactors. The power circuit is based on a microstrip line (MPL) 8 and controlled contactors (jumpers) on pin diodes (not shown in Fig. 1).

The cylindrical screen 7 has a generatrix length of about a quarter wavelength λ and a diameter such that the distances between the arms of the vibrators 1.1, 1.2, 1.3 are about 0.3 λ. The electric distance along the MPL 8 from the center of the power circuit to the power points of the arms of the vibrators 1.1, 1.2, 1.3 in which controlled contactors are included is 0.25 λ.

If at the given moment two contactors are in the “closed” state, then the idle mode is implemented at the inputs of the corresponding segments of MPL 8: the entire signal is transmitted to the connection point of one active arm of the vibrator. The active arm of the vibrator emits an electromagnetic wave that propagates in all directions. Since the distances to the currently passive arms of the vibrators and their lengths are selected in a certain way, waves reradiated by these arms of the vibrators, folding in the space with the primary wave, realize a radiation pattern with a width of ~ 120 ° with one main beam in the direction of the active arm. By making the other shoulders active alternately, you can direct the main beam to two other positions. The radiation pattern in the H-plane is shown in FIG. 1c). Having the ability to control the NAM, the prototype antenna, as well as the above analog antennas, however, have disadvantages.

The rotation of the beam in the prototype antenna is made by switching the supply currents in the radiating elements. For transmitting antennas at high power transmitting devices, the supply currents are noticeable, which leads to increased requirements for switching elements. In addition, since when rotating the beam, all elements of the antenna array become alternately active, they all require coordination with the supply line.

The task is to reduce the current load on the switching elements, reducing the number of elements to be coordinated with the supply line.

The proposed device is illustrated in graphic materials.

In FIG. 1 a ) is the prototype antenna, FIG. 1 b) is a side view, FIG. 1 c) is the radiation pattern of the prototype antenna. In FIG. 2 - the proposed antenna device, in FIG. 3-7 - dependences of radiation patterns for antenna structures from one active vibrator and N driven passive vibrators.

To solve the problem, in an antenna device with a switchable radiation pattern containing passive and active electric vibrators and switching elements, according to the invention, the excitation source is an active vibrator constantly connected to the power line, surrounded by N uniformly located at a distance of 0.25 λ from it (N = 2 , 3, ...) switched passive vibrators 0.5 λ long, consisting of M (M = 4, 5, ...) collinearly located conductors connected by switching elements that control the diag the directivity frame of the antenna device by giving the passive vibrators either the reflector property or the invisibility property for the active vibrator, while the passive vibrators are configured to switch the radiation pattern when the transmitting device is operating, operating with significant powers, and the number of partitions of the passive vibrators is selected depending on the required degree their invisibility to the active vibrator.

In FIG. 2 shows the proposed antenna device, where it is indicated:

1 - active vibrator;

2 - switching elements (jumpers);

3 - controlled passive vibrators.

The switching elements (jumpers) 2 in the passive vibrator operate synchronously and can be implemented, for example, on an RF relay, reed switches, pin diodes.

The functioning of the proposed device is as follows.

If the jumpers 2 in the passive vibrator 3 are closed, then the passive vibrator is a conductor with a length of 0.5 λ, and, due to the fact that it is located at a distance of about 0.25 λ from the active vibrator, it plays a role with respect to the active vibrator 1 reflector.

When the jumpers 2 are open, the passive element 3 splits into a series of short conductors with a length much shorter than the working wavelength. The natural resonance frequency of the resulting short conductors goes beyond the operating frequency of the antenna, and the passive vibrator becomes “invisible” to the active vibrator.

Since the currents induced in passive vibrators have a significantly smaller value of the supply currents in the active vibrator 1-source of excitation, the radiation pattern can be switched when the transmitting device is operating, including at significant powers. Only one active vibrator 1 is subject to coordination with the supply line with such an antenna device structure.

Some types of H-plane patterns are shown in FIG. 3-7.

In FIG. Figure 3 shows the directivity pattern for open jumpers for any number N of passive vibrators. The shape of the radiation pattern for this case is circular with KU = 2.53 dB.

In FIG. 4 shows the radiation pattern for one active vibrator and two passive, located opposite each other through 180 ° at a distance, and in one passive vibrator the jumpers are closed, in the other open. Directional diagram with KU = 4.56 dB.

In FIG. Figure 5 shows the radiation pattern for one active vibrator and three passive vibrators, arranged uniformly in a circle at a distance of 0.25 λ from the active vibrator with two passive vibrators closed and one open. Directional diagram with KU = 6.56 dB.

In FIG. Figure 6 shows the radiation pattern for one active vibrator and four passive vibrators, arranged uniformly in a circle at a distance of 0.25 λ from the active vibrator with three passive vibrators closed and one open. Directional diagram with KU = 5.98 dB.

In FIG. 7 shows the directivity pattern for one active vibrator and four passive, arranged uniformly in a circle at a distance of 0.25 λ from the active vibrator with two passive vibrators closed and two open. Directional diagram with KU = 6.55 dB.

Thus, the use of the structure of the antenna device, in which the excitation source is an electric vibrator 1 constantly connected to the power line, surrounded by uniformly located switched passive vibrators 3, allows you to control the radiation pattern by turning on and off the currents induced in them, as a result of which the passive vibrator 1 can either play the role of a reflector for the source of excitation, or be invisible to him.

The distance between the excitation source and passive vibrators is about 0.25 λ. The number of passive vibrators N is selected depending on the requirements for the DN and the angle of rotation (N = 2, 3, ...). The number of partitions of passive vibrators M into shorter parts is selected from four or more, depending on the desired degree of manifestation of their “invisibility” for the active vibrator, that is, on the severity of the directivity effect of the antenna device.

Compared with the prototype, the proposed antenna device can reduce the current load on the switching elements and reduce the number of vibrators to be coordinated with the supply line.

Information sources.

1. Abramov O.Yu., Kashkarov A.G., Nagaev F.I., Antenna device with a controlled radiation pattern and a planar directional antenna, patent 223017, H01Q 1/00 filing date 02.12.2002, publication date 20.07.2004 .

2. Kostikov G.A., Terentyeva P.V. Antenna array with switchable radiation pattern for mobile communication systems // Izv. Russian universities. Radio Electronics 2017. No1. S. 29-35.

3.http: //radiochief.ru/antenny/antenna-pereklyuchaemoj-diagrammoj-napravlennosti /.

4. Slezkin V.G., Evenko V.V. Vibrator antenna with switchable radiation patterns. In the book: 13th Intern. conf. KryMiKo, 2003. Materials conf. - Sevastopol: "Weber", 2003 - S. 404-405.

Claims (1)

An antenna device with a switchable radiation pattern containing passive and active electric vibrators and switching elements, characterized in that the excitation source is an active vibrator constantly connected to the power line, surrounded by N uniformly spaced at a distance of 0.25 λ (N = 1, 2, ... ) switched passive vibrators with a length of 0.5 λ, consisting of M (M = 4, 5, ...) collinearly located conductors connected by switching elements that control the antenna radiation pattern devices by giving the passive vibrators either the reflector property or the invisibility property for the active vibrator, while the passive vibrators are configured to switch the radiation pattern when the transmitting device is operating, operating with significant powers, and the number of partitions of the passive vibrators is selected depending on the required degree of invisibility of them for active vibrator.

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