RU2622226C1 - Antenna system with direction pattern mechanical scanning - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: in the antenna system, containing the reflector, the feed element in the form of the radiator with the corner reflector, where the radiator is fixed rigidly with respect to the reflector, and the angle reflector is movable relative to the radiator.

EFFECT: reduction of losses, microwave signal, the design simplification and reliability increase, while maintaining the low inertia of the antenna system.

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Description

The invention relates to antenna technology and can be used to create antenna systems in radio navigation and radar.

When creating various radio navigation (radar) devices, the problem arises of creating antennas that provide scanning (swinging) of the beam of the radiation pattern (including scanning of the radiation pattern of a special shape) in a relatively small sector, for example, in radars designed to control air traffic. The antenna must have high reliability, low cost and high manufacturability and withstand heavy mechanical loads.

As an antenna that provides scanning beam pattern, it is possible to use a phased antenna array. However, phased antenna arrays are difficult to manufacture, have a complex monitoring and control system, and as a result have a high cost and high operating costs (Antennas and microwave devices. DM Sazonov. M., Higher School, 1988, p. 396 )

Mirror antennas can also be used to provide beam scanning. The use of such antennas is economically preferable, because these antennas have significantly lower cost and lower operating costs. Scanning in such antennas is usually carried out:

- a change in the position of the entire antenna (mirrors with radiators included in it, a counter-reflector, etc.),

- a change in the position of the antenna part (feed) relative to the antenna mirror;

So, in a remote analogue of the claimed invention, consisting of a scanning device for an irradiator, a reflector, counter-reflectors, made in such a way that the center of the suspension and the axis of rotation of the antenna are aligned with the center of the suspension and the axis of rotation of the scanning device, which is made in the form of two segments of a circular waveguide, one of which are rigidly fixed, and its end is made expanding in the form of a conical horn, the other segment is movable, made in the form of a circular waveguide, at one end of which the walls are beveled to a cone with an external the sides, and at the other end are connected to the horn feed of the antenna, the movable waveguide with beveled walls inserted into the conical horn with a gap, the center of the suspension of the scanning device is aligned with the center of the plane of the end cut of the waveguide with tapering walls, and the axis of rotation passes through this center, while the movable length of the waveguide and the irradiator can be rigidly connected to the reflector and counterreflector of the mirror antenna or elements of any other antenna (RF Patent No. 2109375, H01Q 3/06, 1998).

The specified device has the following disadvantages:

- to scan (swing) the beam of the radiation pattern, it is necessary to “swing” the entire antenna system with its components (horn, a segment of a moving waveguide, reflector), which have a large mass, which leads to an increase in the power of the engines providing “swing” of the antenna system, increase the inertia of the entire system (increase the swing time), reduce the accuracy of setting the position of the antenna and reduce reliability;

- the presence of a gap at the junction of the waveguides leads to radiation and, as a result, to an increase in the loss of the microwave signal in the feeder path and distortion of the radiation pattern.

A closer analogue, selected as a prototype due to the similarity of the technical task being performed, is an antenna system containing a reflector (mirror) and a movable irradiator. As an emitter, you can use almost any kind of antenna, for example a vibrator, consisting of an active vibrator and a counter-reflector in the form of a metal disk or a passive vibrator. (Antennas and microwave device. B.C. Filipov, L.I. Ponomarev, A.Yu. Grinev. Edited by Prof. D.I. Voskresensky. M: Radio and Communications, 1994. P. 91). Scanning (swinging) of the beam of the radiation pattern is carried out “by shifting the irradiator out of focus” (Microwave antennas (microwave antennas), R. Kuhn, translated from German, Leningrad, Sudostroenie ed., 1967, p. 363).

In this antenna system for scanning the radiation pattern there is no need to “pump” the entire antenna system with its nodes, which significantly reduces the power of the engine, which ensures the “swing” of the antenna system, reduces the inertia (shortens the swing period). There are no gaps in the feeder path, which reduces the distortion of the radiation pattern. However, this antenna system has the following disadvantages:

- cumbersomeness, the length of the path and large insertion loss, low manufacturability and low reliability. This is due to the need to shift the irradiator out of focus, which requires the use of devices in the feeder path that provide multiple movement (rotation, bending) of feeder lines, which leads to the use of a large number of high-frequency elements and their compounds. To ensure rotation of the radiation pattern by a certain angle, it is necessary to shift the irradiator exactly along a certain curve, which leads to a complication of the device for shifting the irradiator. Devices providing multiple rotation (bending) of feeder lines have, as a rule, a complex design, high cost due to low manufacturability in manufacturing, and low reliability. In addition, in some devices that are practically implemented, it is necessary to use a switch (Scanning microwave antenna systems, translated from English, edited by G.T. Markov and A.F. Chaplin, M .: ed. "Sov. Radio", 1966 ., p. 303);

- the complexity of scanning a radiation pattern of a special shape without distortion. So, to create a radiation pattern of a special shape, a mirror is used in the form of a double curvature surface (Mirror Scanning Antennas. L.D. Bahrakh, G.K. Galimov. M.: “Nauka”, 1981, pp. 242-246), therefore, the offset irradiator from the focus of the mirror in the form of a surface of double curvature leads to large distortions of the radiation pattern, and the distortion occurs in both planes. Even greater difficulties arise if not a spot irradiator is used to form a radiation pattern of a special shape, but an emitter in the form of a linear array of vibrators (Mirror scanning antennas. L.D. Bakhrakh, G.K. Galimov. M.: “Science”, 1981, p. 243), since in this case there is a shift not of one irradiator, but of a linear array of vibrators having significant dimensions.

The technical result of the invention is to reduce microwave signal loss, simplifying the design and increasing reliability while maintaining low inertia of the antenna system.

The specified technical result is achieved by the fact that in an antenna system containing a reflector, an irradiator in the form of either a single vibrator or a linear array of vibrators, the vibrator (linear array) has an angle reflector, and the irradiator is fixedly mounted relative to the reflector, and the corner reflector has the ability to move relatively linear lattice.

Known antennas with mechanical scanning, in which the counter-reflector is shifted relative to the emitter (Design of lens, scanning, wide-range antennas and feeder devices. Zhuk M.S. and Molochkov Yu.B. M .: "Energy", 1973, pp. 114-115) in which the movement (swinging) of the metal plate (counter-reflector) allows you to "move the image of the irradiator (virtual irradiator)" However, in this device, the virtual irradiator is on the side opposite to the plate, which inevitably leads to shading of the real nym irradiator working surface of the primary mirror, and as a result - in distortion of the radiation pattern. Particularly noticeable distortion of the radiation pattern during scanning is when using an irradiator in the form of a linear array of vibrators, since in this case it is necessary to use a feeder power device made in series or parallel circuits (Antennas and microwave devices. N.T. Bova, GB Reznikov, Kiev: “Vishcha school”, 1982, p. 260-261). Accordingly, the feeder feed device has rather large transverse dimensions (of the order of several wavelengths). Therefore, the shading area will be very significant, in addition, this shading area depends on the rotation angle of the plate (the larger the rotation angle of the plate, the larger the shading area), which leads to the dependence of the distortion of the shape of the radiation pattern on the angle of rotation (the larger the angle of rotation of the plate, the greater the distortion of the shape of the radiation pattern). A reduction in the area of shading is possible due to the movement of the feeder supply device, but this leads to an increase in the power of the engines providing joint movement of the plate and the feeder supply device, an increase in the inertia of the entire system (increase in swing time), in addition, there is a need to use devices providing multiple displacement (rotation, bending) of feeder lines, and all this leads to an increase in microwave signal loss, complicating the design and reducing reliability.

Thus, the considered design features of these devices either do not allow scanning the radiation pattern of a special form without distortion, or lead to an increase in microwave signal loss, complicating the design, increasing the inertia of the entire system and reducing reliability.

This allows us to conclude that the claimed invention meets the patentability criterion of "inventive step".

The invention will be more clear from the above description and the accompanying drawings:

in FIG. 1 shows the proposed antenna system with mechanical scanning of the radiation pattern;

in FIG. 2 shows the principle of operation of the proposed antenna system.

The antenna system with mechanical scanning of the radiation pattern contains: a reflector 1, which can be made in the form of a mirror, an irradiator in the form of a radiator 2 with an angular reflector 3. Moreover, the emitter 2 is fixedly mounted relative to the reflector 1, and the angular reflector 3 has the ability to move (swing) relative to the plane of the emitter 2. The irradiator, consisting of a radiator 2 and an angle reflector 3, is a corner antenna. If the irradiator 2 lies in the bisectoral plane, then a corner antenna with symmetric excitation is formed, if the irradiator 2 is moved away from the bisectoral plane, then a corner antenna with asymmetric excitation is formed (Design of antenna-feeder devices. Zhuk M.S. and Molochkov Yu.B. . M.: "Energy", 1966, p. 330, 342).

The reflector 1 can be made in the form of any reflective surface, for example, in the form of a mirror.

The emitter 2 may have a different design, for example in the form of a multi-vibrator antenna (VHF antennas. G.Z. Aizenberg, V.G. Yampolsky, ON.Tereshin, part 2. M .: Communication, 1977. P. 123) or as a waveguide slot antenna (USSR AS No. 1587612, H01Q 3/10, 1990). In the slot-wave antenna, the role of vibrators is played by transverse slots cut in a rectangular waveguide, and the role of an angular reflector 3 is played by two metal plates located along the axis of the waveguide segment.

The corner reflector 3 is usually made in the form of metal plates located along the axis of the grating of the emitters 2.

The antenna system with mechanical scanning of the radiation pattern works as follows (see Fig 2).

The array of emitters 2 with an angular reflector 3 irradiates the reflector (mirror) 1. The radiation pattern is determined by the shape of the reflector 1 and the radiation pattern of the irradiator, which in this case consists of an emitter 2 with an angular reflector 3.

Let us consider a change in the radiation pattern with a change in the position of the corner reflectors 3 relative to the emitter 2. It is known that the direction of the maximum radiation changes with a change in the position of the corner reflectors 3 (VHF antennas. G.Z. Aizenberg, V.G. Yampolsky, ON.Tereshin, part 2. M .: Communication, 1977. P. 126-127. Designing antenna-feeder devices. Zhuk MS and Molochkov YB M .: "Energy", 1966, p. 342-347). Thus, a change in the position of the corner reflectors 3 leads to a change in the direction of the main beam of the radiation pattern of the irradiator. In FIG. 2 shows a change in the direction of the main beam of the radiation pattern at different positions of the corner reflectors 3 (solid and dashed lines). As can be seen from the figure, a change in the direction of the main beam of the radiation pattern of the irradiator leads to irradiation of another portion of the reflector 3, and this, in turn, leads to a change in the direction of the main beam of the radiation pattern of the antenna system, i.e. to scanning the radiation pattern of the claimed antenna system. Changing the irradiated areas for scanning the radiation pattern is used in various types of antennas, for example an hourglass antenna (Mirror Scanning Antennas L. D. Bakhrakh, G. K. Galimov. M.: “Nauka”, 1981, p. 249). Thus, the proposed technical solution allows you to scan the radiation pattern.

The displacement (rotation) of only the corner reflectors 3 allows not only scanning with a radiation pattern without distortion, but also allows, in comparison with the antenna system taken as a prototype, to reduce losses, simplify the design, increase reliability while maintaining low inertia of the entire system, because:

- scanning with a radiation pattern is carried out by moving the part of the irradiator that is not connected with the feeder path that supplies energy to it. This eliminates the need to use in the feeder path connections that provide multiple movement (rotation, bending) of feeder lines with a large number of high-frequency elements and their connections, causing large losses, having complex design, low manufacturability and low reliability;

- as an irradiator, an angular reflector is used, the movable part (angular reflectors 3) of which has a small mass, which allows for quick scanning of the radiation pattern, and does not require large power to change the position of complex mechanisms and engines.

To form a radiation pattern of a special shape, an emitter is used in the form of a linear array of vibrators, which, as a rule, has significant dimensions (Mirror Scanning Antennas. L.D. Bakhrakh, G.K. Galimov. M.: “Nauka”, 1981, p. 243 ) The proposed technical solution allows you to scan the radiation pattern of a special shape without distortion due to the displacement of the angle reflector 2 of the emitters 2 relative to the fixed array of radiators 3. Moreover, in comparison with the prototype, the microwave signal loss is reduced, the design is simplified, reliability is increased while maintaining the low inertia of the antenna system, and the engine that provides scanning of the radiation pattern can have low power, which reduces the power consumption of the entire device ystva.

The use of a corner reflector, consisting of separate and independent sections, i.e. sites that have the ability to independently move relative to the fixed array of emitters, allows you to get different types of radiation patterns.

The use of this invention allows to create an antenna system with mechanical scanning of the radiation pattern with low losses, while simplifying the design and increasing reliability, while maintaining low inertia of the entire system, low engine power, and also to create an antenna system that provides scanning of the radiation pattern, including special form, without distortion.

Claims (1)

Antenna system with mechanical scanning of a radiation pattern containing a reflector, an irradiator in the form of a radiator with an angular reflector, characterized in that the emitter is mounted stationary relative to the reflector, and the angular reflector has the ability to move relative to the emitters.

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