Multi-beam antenna (variants)

Abstract

A multi-beam telecommunications antenna system with a focusing device including a two-dimensional radiator array generating a plurality of beams simultaneously by setting amplitude-time parameters of the signals for each radiator. The antenna includes: a focusing system having an amplifying lens; a radiating device, for irradiating the amplifying lens and having a two-dimensional radiator array, is disposed at a distance from the amplifying lens and covers a projection area of beams at this distance; and a beam forming system. At least one sub-array of the radiators provides a beam in a set direction. For each beam, the beam forming system provides, for each radiator in the corresponding sub-array, amplitude-time parameters of the signal being transmitted to form a non-planar wavefront, which is equidistant across the amplifying lens to a planar wavefront of the beam. The radiating surface of the radiator array is outside a region of self-intersection of the non-planar wavefronts.

Claims

1. A multi-beam antenna comprising: a focusing system; an irradiating device designed to irradiate the focusing system, comprising a two-dimensional array of feeders, placed at a distance from the focusing system and overlapping a zone of beam projections at this distance; and a beamforming system, which serves at least one subarray of feeders of the two-dimensional array of feeders, providing one beam in a given direction, wherein the focusing system is designed as an amplifying lens, and for each such beam, the beamforming system provides amplitude-time parameters of a transmitted signal for each feeder in the corresponding subarray, to form a non-planar wave front, which is equidistant across the amplification lens to a planar wave front of the beam, while the radiating surface of the irradiation device is outside a self-intersection zone of non-planar wave fronts.

2. A multi-beam antenna comprising: a focusing system; an irradiating device designed to irradiate the focusing system, comprising a two-dimensional array of feeders, placed at a distance from the focusing system and overlapping an area of beam projections at this distance; and a beamforming system, which serves at least one sub-array of feeders of the two-dimensional array of feeders, providing one beam in a given direction, wherein the focusing system is designed as an amplifying lens with partial feeders, containing photodetectors on a side of the irradiation device, and the irradiating device contains feeders in the form of light sources are amplitude-modulated by a radio signal, and for each such beam, the beamforming system provides amplitude-time parameters for each feeder in the corresponding sub-array, to form a non-planar wave front of an amplitude-modulated signal, which is equidistant across the amplifying lens to a plane wave front of such a beam, and wherein a radiating surface of the irradiation device is outside a self-intersection zone of non-planar wave fronts.

3. The multi-beam antenna according to claim 1, wherein a refractive surface of the amplifying lens is designed as a surface of revolution with a continuous second derivative and an axis of revolution that does not coincide in at least one of an angle or a position with axes of at least one of the amplifying lens or the irradiating device.

4. The multi-beam antenna according to claim 1, wherein a refractive surface of the amplifying lens is designed as a pulling surface of forming curves with a continuous second derivative.

5. The multi-beam antenna according to claim 2, wherein a refractive surface of the amplifying lens is designed as a surface of revolution with a continuous second derivative and an axis of revolution that does not coincide in at least one of an angle or a position with axes of at least one of the amplifying lens or the irradiating device.

6. The multi-beam antenna according to claim 2, wherein a refractive surface of the amplifying lens is designed as a pulling surface of forming curves with a continuous second derivative.

7. The multi-beam antenna according to claim 4, wherein the refractive surface of the amplifying lens is designed as a pulling surface of a variable forming curve along a guiding curve.

8. The multi-beam antenna according to claim 6, wherein the refractive surface of the amplifying lens is designed as a pulling surface of a variable forming curve along a guiding curve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further, the invention is disclosed in more detail using graphic materials, where:

(2) FIG. 1—is front view of the antenna (Variant 1);

(3) FIG. 2—is an enlarged fragment of A;

(4) FIG. 3—is front view of the antenna (Variant 2);

(5) FIG. 4—is an enlarged fragment of B;

(6) FIG. 5—is a diagram of the transformation of the electrical signal to ensure the interference of the amplitude-modulated optical signal.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(7) For ease of perception, the following designations are common for both antenna variants:

(8) The irradiating device 1, its feeders 2 and the radiating surface 3, formed by the phase centers of the feeders 2;

(9) Apertures 4, 5 for deviation angles 0, α;

(10) Plane wave fronts 4a, 5a, corresponding to apertures 4, 5;

(11) Non-flat wave fronts equidistant to the front 5a:

(12) 5b—at the exit from the radiating surface 3 (the wave front touches the surface 3 at the point K1); 5c—at the entrance to the radiating surface 3 (the wave front touches the surface 3 at the point K2); 5d—in the zone of self-intersection of wave fronts;
Feeder 2n and distance Tn, which determines its time delay.
Amplifying lens 6, its radiating surface 7, receiving surface 8 and refracting surface 9, approximating the length of the delay lines of the partial feeders of the lens.

(13) FIGS. 1 and 2 show an antenna according to Variant 1, consisting of an irradiating device 1 with feeders 2 and an amplifying lens 6. The irradiating device is made in the form of a concave sphere and the feeders 2 are directed so as to irradiate the surface 8 as effectively as possible.

(14) FIGS. 3 and 4 shows the antenna according to Variant 2, consisting of an optical irradiating device 1 with feeders 2 and an amplifying lens 6. In this embodiment, due to the simplicity of optical feeders 2, it is quite easy to ensure the individual direction of each feeder to the surface 8.

(15) FIGS. 2 and 4 shows the principle of the formation of a wave front 5c, equidistant to wave front 5a in a given direction of the beam.

(16) Front 5c can be constructed, for example, by reverse tracing from an arbitrary (up to a constant) plane 5a by the Monte Carlo method. In this case, the segment Tn determines the time delay for the partial feeder 2n, and the number of tracing rays in a certain neighborhood of its phase center, for example, at a distance of λ/2, its amplitude. Thus, it is possible to determine the amplitude-time parameters of the entire subarray of feeders for a given direction of the beam.

(17) In both cases, the refractive surface 7 of the focusing system is designed as a surface with a continuous second derivative. If the continuity condition of the second derivative is not met, the refracted wave front will immediately intersect itself and cannot be reproduced by ID feeders.

(18) It should be noted that in the context of the present invention, the concepts of “focal point” and “focal surface” lose their meaning. In this case, the refracting surface of the lens can be a surface of revolution, with a revolution axis that does not coincide both in angle and in position with the axes of the lens and/or the ID. Moreover, the refracting surface can be formed, for example, by pulling one, perhaps variable, curve along the other, guiding curve. The only requirement is that the self-intersection region of the non-planar front 5d must be outside the radiating surface 3. At the same time, a sufficiently large flexibility is provided in optimizing the scheme of the antenna for various configurations of the service area and spacecraft layout.

(19) The implementation of the invention can be performed as follows:

(20) Structurally, the antennas in both variants practically do not differ from the known schemes of lens antennas. At the same time, wider possibilities for optimizing the geometry of the antenna facilitate its integration into the layout of the spacecraft.

(21) In the process of optimization, ray tracing is performed from arbitrary planes 5a in directions from given subscriber positions and the following are determined: the geometry of the lens 6, its refracting surface 9, and the irradiating device 1; amplitude-time parameters for each feeder 2 in each direction.
In the future, these tables of amplitude-time parameters, after some adjustments as a result of testing and operating the antenna, are used by the beam forming system.

(22) All of the above is quite obvious, in the context of geometric optics and radio wave interference, for Variant 1.

(23) In Variant 2, optical radiation amplitude-modulated by a radio signal is involved in the area between surfaces 3 and 8. FIG. 5 shows the principle of conversion of an electrical signal to ensure the interference of an amplitude-modulated optical signal:

(24) 501—incoming signals:

(25) receiving antenna—radio emission from a given direction at the input of receivers of partial feeders of the lens; transmitting antenna—electrical signals at the input of the feeders of the irradiating device from the beamforming system for a given direction;
502—electrical signals before conversion;
503—is the signal offset by the value of ΔV1 . . . ΔVn;
504—amplitude-modulated radiation of optical feeders;
505—light radiation between the lens and the irradiating device;
506—light radiation on the photodetector (interference by the amplitude of the light flux);
507—electrical signal from the photodetector;
508—signal shift by minus ΔVs;
509—output signal: receiving antenna—an electrical signal from a given direction to the input of the repeater; transmitting antenna—radio emission from each partial feeder of the lens for a given direction.

(26) Of course, the signals 501 and 509 in this scheme are interpreted taking into account the time delays of the focusing system and the beamforming system for a given beam direction. If there is a discrepancy in phase (in the context of the invention—in time) of signals 501, then due to the offset minus ΔVs, signals 508 and 509 will approach zero (in accordance with the antenna pattern).

(27) Thus, the principles of interference and geometrical optics in Variant 2 completely coincide with Variant 1.

(28) The use of an active phased array as an irradiation device for an amplifying lens with the formation of non-planar wave fronts equidistant to flat wave fronts in given directions will allow to achieve the following advantages: simplification of the beamforming system; reducing the size of the antenna due to the “short focus” of the lens; providing a large service area, with minimal loss of gain and beam width; providing a large number of active beams; provision of favorable thermal conditions for the antenna and the spacecraft; providing great flexibility in optimizing the scheme of the antenna.

(29) Thus, all the tasks of this invention are completed.

(30) Although the present disclosure has been described with reference to one or more examples, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the disclosure and/or the appended claims.