RU2314611C2 - Multichannel lens antenna having stabilizable/controllable angle directivity pattern - Google Patents

Abstract

FIELD: communication and radar systems; transceiving equipment disposed on mobile carriers.

SUBSTANCE: proposed multichannel lens antenna has Luneberg lens, base, radiator unit, supporting-rotating mechanism, radiator unit, drive motors for rotating radiator unit and supporting-rotating mechanism bow, supporting-rotating mechanism frame, and drive motor for setting the latter in rotary motion. Such antenna design makes it possible to render services to users of multichannel communication system residing in wide coverage area, as well as under vibration conditions of antenna carrier, such as spacecraft, aircraft, ships, and land-based vehicles.

EFFECT: enlarged functional capabilities of antenna.

1 cl, 2 dwg

Description

The invention relates to the field of communication and radar systems, in particular to radio-technical transceivers located on mobile carriers.

Known multi-beam antenna system with auxiliary antenna elements (patent US 6252560 VA, CL 7 H 01 Q 21/00, 2000), containing the antenna array and feeder system based on the Butler matrix. In this antenna system, a multi-beam antenna pattern is formed using a Butler beamforming circuit or other schemes for generating phase shifts of signals emitted or received by the device emitters.

An antenna array with several scanning beams is also known (US Pat. No. 6,055,515 A, cl. 6 H 01 Q 3/02, 1999), in which the formation of a multi-beam radiation pattern is carried out in digital form by appropriate processing of the emitted or received signals in the intermediate frequency range.

The disadvantages of these antennas are a significant amount of equipment in the case of the implementation of a beam-forming circuit at a carrier frequency or a significant amount of computation and a high sampling rate of signals when implementing a beam-forming circuit in digital form. In addition, when using a phased antenna array in the antenna, the antenna gain, beam width, and side lobe level strongly depend on the angle of deviation of the beam from the normal to the surface of the array φ. In particular, the antenna gain is proportional to cosφ and at φ = 30 deg decreases by about 14% compared with the value that takes place at φ = 0. At φ = 45 deg, the decrease in antenna gain is about 30%, and at φ = 60 deg - 50%. In practice, this means that the angle φ is limited to about 30 degrees. In the case of a working area corresponding to deviations of the beam by angles substantially exceeding this value, to maintain a high antenna gain and a low level of the side lobes of the radiation pattern, it is necessary to use several antenna arrays or an antenna array with a cylindrical or spherical surface, which leads to an increase in mass and dimensions antennas.

Of the known technical solutions, the closest prototype is a Luneberg lens antenna with several emitters on cardan joints (patent US 6266029 VA, CL 7 H 01 Q 19/06, 2000). The lens antenna is fixedly mounted on a base to which several arcuate tracks are attached. Attaching the tracks to the base allows each track to rotate separately from other tracks around the lens. Each track turns its engine in accordance with the control signals. Emitters providing radiation or receiving electromagnetic radiation move along the tracks, remaining at a fixed distance from the lens surface. Each radiator moves its engine in accordance with the control signals. This lens antenna allows, for example, to continuously communicate with satellites moving relative to the earth’s surface, and when one of the satellites leaves the line of sight, others remain in communication.

The disadvantage of the prototype is the use of two drives and a separate arcuate track to control the position of each of the feeders. In this case, the total number of tracks is equal to the number of rays formed by the lens antenna, and the total number of engines is twice the number of rays. With a large number of rays, this leads to a significant mass and dimensions of the lens antenna or even the inability to accommodate the required number of tracks with engines, which significantly limits the number of rays and, therefore, simultaneously serviced subscribers when using a multi-beam antenna in multi-channel communication systems or the number of simultaneously observed objects at use of the antenna in radar systems.

Thus, the aim of the invention is to provide the possibility of simultaneous servicing of subscribers of a multi-channel communication system located in a wide coverage area, or radar observation of objects located in a wide field of view, under conditions of movement and oscillations of the antenna carrier, which can be used in space and air vehicles, ships and land vehicles.

This goal is achieved by the fact that the following are introduced into the lens antenna containing the Luneberg lens mounted on the base:

a block of emitters, including a spherical frame with emitters placed thereon, emitting and receiving electromagnetic radiation;

rotary support device consisting of a frame and an arc pivotally interconnected;

a rotation motor for the emitter unit mounted on an arc of a slewing ring;

a rotation motor of an arc of a slewing ring mounted on a frame of a slewing ring;

the rotation motor of the frame of the slewing ring mounted on the base.

Figure 1 shows a sketch (side view and top view) of a multi-channel lens antenna with a stabilized and angle-controlled multi-beam radiation pattern, where

1 - Luneberg lens,

2 - spherical frame,

3 - emitters,

4 - frame slewing device

5 - arc of the slewing device,

6 - motor rotation of the arc of the slewing device,

7 - the rotation motor of the frame of the slewing device,

8 - engine rotation block emitters,

9 - base

10 - block emitters,

11 - rotary support device.

The arc 5 of the slewing device 11 is pivotally connected to the frame 4 of the slewing device. The rotation motor of the block of emitters 8 is located in the center of the arc of the slewing device 5. The frame of the slewing device 4 is pivotally connected to the base 9 on which the antenna is mounted. A Luneberg lens 1 is also fixed on the base 9. The rotation motor of the arc of the slewing device 6 is fixed to the frame of the slewing device 4, and the rotation motor of the frame of the slewing device 7 is mounted on the base 9. The emitters 3 are mounted on the spherical frame 2 and form a block emitters 10, while the aperture of the emitters are located on the focal surface of the Luneberg lens 1.

The inventive device operates as follows. Each of the emitters 3 located in the block of emitters 10, together with the Luneberg lens 1 forms a beam with a beam pattern width of 3 dB equal to:

where λ is the radiation wavelength, D is the diameter of the Luneberg lens, γ is the coefficient determined by the radiation pattern of the emitter.

The lens antenna provides a complete overlap of the solid angle Ω defining the field of view. The total number of antenna beams in this case is:

For example, with Ω = 2π, λ = 15 cm, D = 1 m and γ = 1, the total number of rays is over 350.

The rotation motor of the frame of the slewing device 7 provides the rotation of the frame 4 around the Luneberg 1 lens (rotation around the CC ′ axis), and the rotation motor of the arc of the slewing rotary device 6 ensures the rotation of the arc 5 around the Luneberg 1 lens (rotation around the BB ′ axis). The rotation motor of the block of emitters 8 provides rotation of the block of emitters 10 around its axis of symmetry (axis AA ′). All engines are controlled by the mismatch signals between the required and current values of the corresponding angles measured by the sensors.

The process of angular pointing and stabilization of the antenna pattern is illustrated in Fig. 2, which shows an orthogonal coordinate system, the Oz axis of which is directed along the axis of rotation of the rotary support frame, the Ox axis is horizontally perpendicular to the Oz axis, and the Oy axis is vertical. It is assumed that in the initial position the axis of the antenna pattern is generally directed along the Oy axis, and the axis of the radiation patterns of individual emitters are offset relative to it by fixed angles determined by the position of the emitter in the block of emitters. When the rotary support frame is rotated by the rotation motor of the rotary support frame by a certain elevation angle β, the axis of the antenna pattern is shifted by this angle in the xOy plane (axis Oy ′). The axis of rotation of the arc of the slewing ring (axis Ox ′) is shifted by the same angle. When the arc of the support-rotary device is turned by the rotation motor of the arc of the support-rotary device by a certain angle of inclined azimuth α, the axis of the antenna pattern is shifted by this angle and occupies the position Oy ′ ′, which also coincides with the axis of rotation of the emitter unit. The rotation of the emitter unit by the engine of rotation of the emitter unit provides rotation of the antenna pattern around its axis. As a result, angular stabilization and guidance of the multipath diagram of the lens antenna are carried out.

To perform the inventive device, Luneberg lenses made of pressed foam or perforated dielectric can be used (A.Z. Fradin. Antenna-feeder devices, “Communication”, 1977, p.337), and electric motors of direct or alternating current.

As emitters, active transceiver modules or passive emitters, including horn, slot-hole, etc. can be used. If the generation of the emitted signals for each emitter and the processing of the electromagnetic radiation received by each emitter are performed independently, each channel of the antenna operates autonomously, which provides, for example, spatial selection of subscribers when using the antenna in a communication system. If necessary, the emitted signals can coincide, and the processing of the received signals is carried out autonomously. This reduces the amount of transmitting equipment, and a multi-channel antenna can, for example, provide spatial selection of detected objects when used in a radar device. Finally, the emitted signals of the emitters can coincide, and the received signals are summed, which, for example, allows us to solve the problem of detecting an object in the entire field of view.

Using the invention will allow for simultaneous servicing of subscribers of a multichannel communication system located in a wide coverage area, as well as radar monitoring of objects located in a wide field of view, including when placing the antenna on moving and oscillating carriers - space vehicles, airplanes and helicopters, ships and land vehicles.

An example of the application of the claimed antenna is its use as part of an aviation communication system, which includes a transceiver device of a communication system located on an airplane, and ground-based mobile and stationary communication terminals. The inventive multichannel antenna is part of the transceiver device of the communication system placed on the aircraft. Each of the beams of the multi-beam radiation pattern of the antenna provides communication with communication terminals located in a certain fixed area of the coverage area. With a Luneberg lens diameter D = 1 M and a wavelength of λ = 15 cm, the width of the partial beam is Δφ = 0.15 rad. At a carrier flight height of H = 10 km, the diameter of the portion of the coverage zone located in the nadir is d = N · Δφ = 1.5 km. If the radius of the coverage zone is R = 50 km, the number of rays generated by the multichannel antenna should be

Claims (1)

A multi-channel lens antenna with a stabilized and angularly controlled multi-beam radiation pattern, comprising a Luneberg lens mounted on the base, characterized in that a block of emitters is introduced into the antenna, including a spherical frame with emitters placed thereon, emitting and receiving electromagnetic radiation, rotary support a device comprising a frame and an arc pivotally interconnected with rotation motors of a block of emitters and an arc of a support-rotary device mounted on them properties, the rotation motor of the frame of the slewing device mounted on the base, while the frame of the slewing device is pivotally connected to the base and can rotate around the Luneberg lens, providing rotation of the axis of the antenna pattern in elevation by the rotation motor of the frame of the slewing device, and the rotation motor of the slewing ring is mounted on the frame of the slewing ring, rotates the axis of the antenna pattern in oblique azimuth and together with the with a rotator of the frame of the rotary support device provides movement of the emitter unit around the Luneberg lens on a spherical surface, in addition, the rotation motor of the emitter unit mounted on the arc of the rotary support device rotates the emitter unit around its axis of symmetry, providing angular movement of the axes of the radiation patterns around the axis of the antenna pattern.

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