ES2694245T3 - Addressable antenna - Google Patents

Abstract

Addressable antenna (1), comprising: - a steerable payload (4, 5); - an electromechanical system (6-10) of movement and support, operatively connected to the payload (4, 5) and adapted to guide the payload in a controlled manner, said electromechanical system comprising a base (6), a first motor (7) attached to the base (6), a transmission pulley (8) operatively connected to the first motor (7) to cause it to rotate about a first axis of rotation, a second motor (9) operatively connected to the pulley of transmission (8) and operatively connected to the payload (4, 5) to cause the payload to rotate about a second axis of rotation; wherein the electromechanical system (6-10) of movement and support further comprises a support arm (10) integral with the base (6), to which the second motor (9) and the transmission pulley (8) are hinged pivotably. is operatively connected to the second motor (9) to cause the second motor (9) to rotate relative to the base (6) and relative to the support arm (10); wherein the electromechanical system (6-10) of movement and support comprises a belt transmission system (18, 19, 48, 49) adapted to operatively couple the first motor (7) to the transmission pulley (8), comprising said drive system a drive pulley (48, 49) coupled to the first motor (7); characterized in that said belt transmission system (18, 19, 48, 49) comprises two crossed belts (18, 19) having a first end portion secured to said drive pulley (48, 49), wherein said belts (8, 19). , 19) are made of a metallic alloy and each of them has a second end portion attached to said drive pulley (8), wherein the drive pulley (48, 49) comprises two parallel pulleys (48, 49), joined together by means of a coupling system that allows the adjustment of the reciprocal orientation of said parallel pulleys (48, 49).

Description

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DESCRIPTION

Addressable antenna

The present description refers to the technical sector of addressable antennas.

It has been known for a long time that the addressable antennas comprise an orientable receiver and / or electromagnetic radiation transmitter whose direction of direction can be controlled by means of an electromechanical system of movement and support which makes it possible to orient the orientable device of the electromagnetic radiation. reception and / or transmission in space, for example to expand the scanning angle of the antenna. The orientable receiver device and / or transmitter of electromagnetic radiation is also known in general as a payload.

In some cases, such as, for example, the case of the addressable antennae of a missile search engine, the electromechanical system of movement and support used is comparable to an altazimut system and can be electronically controlled to allow the orientable receiving device and / or transmission rotate around two axes orthogonal to each other and define a cone angle of aperture of the antenna beam.

Theoretically and according to a first approximation, the electromechanical system of movement and support, or addressing system, must guarantee a highly accurate signaling, it must be capable of imparting relatively high accelerations to the orientable receiver and / or electromagnetic radiation transmitter, and must ensure a conical opening angle of the antenna beam that is as wide as possible.

The electronic control system of the electromechanical system of movement and support, is developed in general on the basis of a theoretical mechanical behavior of the electromechanical system of movement and support, and of several sensors on board of the addressable antenna, for example position sensors and / o speed and / or gyroscopic, associated with the electromechanical system of movement and support that are used to create a closed loop control. The result of the sensor reading is what is happening locally; therefore, it is important that downstream of this reading there are no deformations or behaviors that are undetectable by the sensors, which could lead to an incorrect command of the electromechanical system of movement and support. These deviations from the standard are usually usually mentioned by the term aberrations. In theory, the sensors could be placed as close as possible to the orientable receiver device and / or transmitter of electromagnetic radiation, so that the control system always knows precisely its real position. A distant position of them, with a series of intermediate mechanical controls, could introduce mechanical aberrations due to the imprecision of the pairings, to the elastic deformations of the system due to external stresses and to the imprecision in the mechanization of the mechanical parts.

The ideal solution could be to be able to couple the sensors directly under the orientable receiver device and / or transmitter of electromagnetic radiation, coupled to the latter with rigid connections, without intermediate mechanical controls. The solution, however, tends to limit the cone angle; and the bigger this is, the bigger the sensors (and the motors) are. With this configuration, when desiring to favor the performance in terms of angular acceleration (larger motors), the performance in terms of amplitude of the conical angle will be penalized; conversely, the desire to favor the latter will penalize performance in terms of angular accelerations while making the use of smaller motors more appropriate.

A possible compromise between the performance in terms of angular acceleration and the amplitude of the conic angle, could be achieved by separating the motors out of the useful load, even though they are rigidly connected to the orientable receiver device and / or electromagnetic radiation transmitter; this could, however, determine an increase in the radius of the addressable antenna fingerprint sphere, which is problematic because the available space in the radome is limited. Additionally, the above solution requires, in the case of microwave antennas, a signal connection with shielded cable to the receiver and / or electromagnetic radiation transmitter, which affects the radiofrequency performance and reduces the maximum transportable power.

A different alternative, relatively more generalized than previously described, is to position the motors and sensors outside the orientable receiver and / or electromagnetic radiation transmitter, and to rely on intermediate mechanical controls, often rigid cardan shafts and rods. connection, to move them. This makes it possible to use relatively larger motors with a high torque, and then rely on the quality of mechanical construction and assembly to limit possible aberrations. With this configuration, there is a division between the axes of rotation of the receiver and / or transmitter steerable device and the axes of the motors. The alternative allows wider conic angles and high performance in terms of angular acceleration. However, the addressable antennas of the prior art constructed in accordance with this alternative have high costs, are structurally complex and require delicate adjustments during assembly.

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The prior art also comprises addressable antennas in which the electromechanical system for moving and supporting the useful load comprises a base, a first motor (or external motor) attached to the base, a drive pulley, a belt drive connecting the first the motor and the drive pulley so that it can be rotated in pitch to a first axis of rotation (or external shaft), a second motor (or internal motor) fixed to the drive pulley and supported by it and adapted to do that rotates the useful load around a second axis of rotation (or internal axis). The two axes are decoupled from each other; the movement of one does not affect the other; something difficult to achieve with a system of connection rods that are generally subject to the same drag element (antenna) in spite of being driven by two different actuators. This type of antennas of the prior art have several drawbacks, such as poor transverse stiffness, due essentially, but not exclusively, to the presence of the transmission pulley having a supporting function for the useful load and for the second motor. Such addressable antennas with an electromechanical system for moving and supporting the payload have been disclosed in EP1134839 and US2002 / 0030631.

A general purpose of the present description is to make available an addressable antenna that does not have the drawbacks mentioned above with reference to the prior art.

This and other purposes have been achieved by means of an addressable antenna as defined in the first claim in a more general manner, and in the dependent claims in some of its particular embodiments.

The invention may be understood more clearly from the detailed description that follows of its embodiments, carried out by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 shows a partial and perspective cross section of a portion of a missile, comprising a radome and an addressable antenna;

Figure 2 shows a perspective view of the addressable antenna of Figure 1;

Figure 3 shows a first view, in lateral cross-section, of the addressable antenna of Figure 1;

Figure 4 shows a perspective view of an embodiment of an addressable antenna support arm of Figure 1;

Figure 5 shows a second side cross-sectional view of the addressable antenna of Figure 1, in which the plane of the cross section is perpendicular to the plane of the cross section of the view of Figure 3, and

Figure 6 shows a perspective view of an enlarged detail of the addressable antenna of Figure 1.

In the attached drawings, elements that are the same or similar will be indicated using the same reference numbers.

Figure 1 shows a portion of an embodiment of a missile 1 comprising a radome 2 and an addressable antenna 3 mounted inside the radome 2. In the particular example shown and without thereby introducing any limitations, the addressable antenna 1 is the antenna of a radar and more in particular the antenna of a missile search engine. It should be appreciated, however, that the teachings of the present disclosure are applicable without restriction to the particular type of addressable antenna since the addressable antenna referred to in the present description could be any antenna usable, for example, in telecommunications, terrestrial or by satellite, and in the industries of scientific measurement instruments.

The addressable antenna 1 comprises a steerable useful load 4, 5. For example, the steerable working load 4, 5 comprises at least one receiver device 4 and / or transmitter of electromagnetic radiation. For example, the electromagnetic radiation receiver and / or transmitting device 4 comprises a planar matrix antenna, for example a microwave and disk antenna comprising a plurality of antenna elements, such as patch antenna elements or antenna elements of groove. Preferably, and without thereby introducing any limitations, the electromagnetic radiation receiver and / or transmitter device 4 is a receiver as well as a transmitter device.

According to one embodiment, the payload 4,5 further comprises a section 5 of processing circuit of the signals transmitted and / or received by the receiver device 4 and / or transmitter of electromagnetic radiation.

The addressable antenna 1 further comprises an electromechanical system 6-10 of movement and support, operatively connected to the load 4, 5 and adapted to guide the load 4,5 in a continuous manner.

The electromechanical system 6-10 of movement and support comprises a base 6, a first motor 7 attached to the base 6 (or external motor 6), a transmission pulley 8 operatively connected to the first motor 7 to rotate it around a first rotation shaft (or external rotation shaft), a second motor 9 (or internal motor) operatively connected to the transmission pulley 8 and operatively connected to the load 4, 5 to rotate the useful load 4, 5 around to a second axis of rotation (or axis of internal rotation). The first and second axes of

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rotation are perpendicular to each other.

The electromechanical system 6-10 of movement and support further comprises a support arm 10, for example as shown in Figure 3, fixed stably to the base 6, in which the second motor 9 has been hinged pivotably.

The drive pulley 8 is operatively connected to the second motor 9 to cause the second motor 9 to rotate relative to the base 6 and relative to the support arm 10.

According to an embodiment according to the example shown in the figures, the first motor 7 is located below the transmission pulley 8 and the support arm 10, on the opposite side to the useful load 4, 5. Among other advantages, this makes it possible, in spite of the presence of a powerful first motor and therefore of significant dimensions, to avoid the obstruction of the movement of the useful load 4, 5 and, for example, to optimize the use of the space in which it can be moved the useful load inside a radome.

Preferably, the first motor 7 and the second motor 9 are servomotors.

According to one embodiment, the base 6 is a cylindrical or substantially cylindrical container, provided with an upper opening 12 and a lower opening 13. Preferably, the base 6 comprises a housing 14 inside which the first motor 7 is housed and fixed. Preferably, the addressable antenna 1 comprises an electronic control circuit 15 of the first motor 7, also housed, at least partially, in the housing 14.

According to one embodiment, the base 6 comprises one or more fixing elements 16 adapted to allow the base 6 to be held inside the radome 2. For example, said fixing elements 16 comprise a plurality of defined recesses in the side walls external of the base 6.

According to one embodiment, the upper opening 12 of the base 6 allows the passage of at least one transmission element of the movement from the first motor 7 to the transmission pulley 8.

With reference to Figure 4, according to one embodiment, the support arm 10 comprises a first end portion 20, 21 firmly attached to the base 6, and a second opposite end portion 22, 23 to which the second hinged pivotably is 9. For example, the first end portion 20, 21 is fastened to the base by means of screws crossing through openings provided in the first end portion 20, 21 to engage in corresponding openings or in internally threaded holes provided in the upper wall of the base 6.

Preferably, the support arm 10 is fork-shaped, and said second end portion 22, 23 comprises two end portions between which said second motor 9 is hinged pivotably.

More preferably, the first end portion 20, 21 mentioned above of the support arm 10, comprises at least one fixing foot to the base 6, provided with a through opening 26 traversed by the transmission pulley 8 and which does not interfere with the rotation of the transmission pulley 8. In the example of Figure 3, the aforementioned fixing foot 20, 21 comprises two fixing feet 20, 21 which are separated from each other, and between which the through opening is defined. 26 mentioned above, traversed by the transmission pulley 8.

According to a further embodiment, the support arm 10 comprises two fork arms 24, 25 attached to the fixing foot 20, 21 of the support arm 10, and the second end portions 22, 23 mentioned above are free end portions thereof. said fork arms 24, 25. Preferably, each of the second end portions 22, 23 mentioned above of the support arm 10 comprises a respective through-opening 28, 29 having a circular cross-section. These through openings 28, 29 define a hinge axis and allow the pivoting hinge of the second motor 9 on the support arm 10.

According to an embodiment 8, the support arm 10 comprises a waveguide 30 integrated inside the arm 10.

Preferably, the waveguide 30 is a channel defined in the thickness of the support arm 10 and said arm 10 is constructed of a metal material, for example steel.

With reference to Figure 4, according to an advantageous embodiment, the support arm 10 comprises two half-portions 26, 27 made in two separate pieces and juxtaposed and coupled together, for example by screws. In this way, the execution of the waveguide 30 integrated in the support arm 10 is particularly easy because the waveguide 30 can be constructed by providing a first recess in a wall of one of the two semi-portions 26, 27 provided so that it faces an opposite wall of the other of the two half-portions. Clearly, a second recess may also be provided in said opposite wall that faces and aligns with the first recess when the two half portions 26, 27 are coupled together.

In case the support arm 10 is in the form of a fork with two fork arms 24, 25, the channel

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mentioned above preferably has a portion extending inside one of said fork arms 24, 25. Preferably, the aforementioned channel extends between two openings in the channel from the first end portion 20, 21 of the arm of support 10, to the second end portion 22, 23 of the support arm 10, in order to define a waveguide 30 extending from the base 6 of the addressable antenna 1 to the payload 4, 5. It can be provided a waveguide connector in the base 6 disposed in the respective opening of the channel.

With reference to Figure 3, according to one embodiment, the addressable antenna 1 comprises a first rotary joint in the waveguide 31 having a seal portion attached to the support arm 10, in the second end portion 22, 23 which is operatively coupled to the integrated waveguide 30 and which is in operative communication therewith, and a second gasket portion operatively coupled to the payload 4, 5. Preferably, the second motor 9 is fixed to the second portion of the rotary seal in the waveguide , in the example shown, on the outside of it. With joint reference to Figures 3 and 5, in the particular example shown, the first rotary joint in the waveguide 31 is attached to the arm 25 of the support arm 10 and, in particular, fitted in the through opening 29, and therefore allows that the second motor 9 is pivotally hinged to the arm 25 of the support arm 10. On the other side of the support arm 10, a hinge pin 32 is preferably provided which includes a portion with a smooth surface engaged in the second motor 9. and with a threaded portion screwed into the interior of the through opening 28 of the arm 24 of the support arm 10.

According to one embodiment, the second motor 9 comprises a container body 39, a stator 33 housed inside the container body 39, a rotor 34 and a drive shaft 35 secured, or coupled, to the rotor 33. The container body 39 is fixed to the drive pulley 8 and hinged pivotably to the support arm 10 to rotate about the first axis of rotation. The drive shaft 35 of the second motor 9 is directly or indirectly coupled to the load 4, 5 by means of a first coupling flange 36. In the example shown in the figures, no torque reducer has been provided, so that the coupling flange 36 is coupled directly to the drive shaft 35, for example keyed to the drive shaft 35, and is directly coupled to the load 4, 5. In an alternative embodiment, the aforementioned coupling can be achieved by interposition of a torque reducer.

According to an embodiment, a transducer 45 of speed and / or integral position with the drive shaft 35 in its rotation about the second axis of rotation, is coupled to the drive shaft 35 of the second motor 9.

According to one embodiment, the payload 4, 5 is coupled to the external container 39 of the second motor 9 by means of a second coupling flange 37 and a second rotary joint 41, as shown in Figure 5. Preferably, the second rotary joint 41 and the coupling flange 37 are waveguide devices and make it possible to make a waveguide connection by means of a link waveguide 38, operatively interconnected between the first waveguide seal 31 and the second waveguide seal 41, and integral in terms of rotation with the second motor 9.

With reference to Figure 5, according to one embodiment, the transmission pulley 8 has a central portion 50 of arcuate shape and two lateral arms 41, 42 attached to the container body 39 of the second motor 9. The rotation of the transmission pulley 8 In this way, it determines a rotation of the container body 39 of the second motor 9 around the first axis of rotation.

According to an embodiment, the first motor 7 comprises a container body 70, a stator 71 housed inside the container body 70, a rotor 72 and a drive shaft 73 attached or coupled to the rotor 72. The container body 70 is fixed to the base 6. According to one embodiment, a speed and / or position transducer 74 is coupled to the drive shaft 73 of the first motor 7.

The drive shaft 73 of the first motor 7 is preferably directly coupled, that is, without torque reducer, to the drive pulley 8.

According to the invention, the electromechanical system 6-10 of support and movement comprises a belt transmission system 18, 19, 48, 49, adapted to operatively couple the first motor 7 to the transmission pulley 8, which comprises two belts 18. 19, which intersect each other, having a first end portion subject to the drive pulley 48, 49, wherein said transmission system 18, 19, 48, 49 comprises a drive pulley 48, 49 coupled to the first motor 7, and in particular to its drive shaft 73. The belts 18, 19 mentioned above each have a second end portion attached to the drive pulley 8. Preferably, the second end portions of the belts 18, 19 are fixed to opposite end portions 53, 54 of the rounded central portion 53, 58 of the drive pulley 8.

According to the invention, the belts 18, 19 mentioned above are made of a metal alloy, for example of a super alloy, based on nickel-chromium, of austenitic structure. Preferably, such belts have a reduced thickness, for example in the order of tenths of a millimeter, for example equal to one tenth of a millimeter.

According to the invention, the drive pulley 48, 49 comprises two parallel pulleys 48, 49, joined together by means of

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a coupling system which makes it possible to adjust the mutual orientation of said pulleys 48, 49 to ensure the correct prestressing of the belts 18, 19.

From the foregoing description, it is evident how an addressable antenna 1 of the type described above, makes it possible to achieve the aforementioned purposes with reference to the state of the prior art.

The addressable antenna described above has in fact a very compact structure and a high transverse rigidity. The entire system, in fact, is developed around a rigid central body consisting of the support arm 10 and the base 6. The embodiment in which an integrated waveguide is provided on the support arm 10, appears to be also particularly advantageous since it makes it possible to avoid the provision of a radiofrequency cable that moves during maneuvers of the addressable antenna.

Notwithstanding the principles of the invention, the embodiments and construction details may be widely varied with respect to what has been described and illustrated solely by way of non-limiting example, without thereby departing from the scope of the invention as defined. in the appended claims.

Claims (13)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. - Addressable antenna (1), comprising: - an adjustable load (4, 5); - an electromechanical system (6-10) of movement and support, operatively connected to the useful load (4, 5) and adapted to guide the useful load in a controlled manner, said electromechanical system comprising a base (6), a first motor (7) attached to the base (6), a transmission pulley (8) operatively connected to the first motor (7) to cause it to rotate about a first axis of rotation, a second motor (9) operatively connected to the pulley of transmission (8) and operatively connected to the useful load (4, 5) to cause the useful load to rotate about a second axis of rotation; wherein the electromechanical system (6-10) of movement and support further comprises a support arm (10) integral with the base (6), to which the second motor (9) and the drive pulley (8) are hinged pivotably is operatively connected to the second motor (9) to cause the second motor (9) to rotate relative to the base (6) and relative to the support arm (10); wherein the electromechanical system (6-10) of movement and support comprises a belt transmission system (18, 19, 48, 49) adapted to operatively couple the first motor (7) to the transmission pulley (8), comprising said transmission system a drive pulley (48, 49) coupled to the first motor (7); characterized in that said belt transmission system (18, 19, 48, 49) comprises two crossed belts (18, 19) having a first end portion secured to said drive pulley (48, 49), wherein said belts (8, 19). , 19) are made with a metal alloy and each of them has a second end portion attached to said drive pulley (8), wherein the drive pulley (48, 49) comprises two parallel pulleys (48, 49), joined together by means of a coupling system that allows the adjustment of the reciprocal orientation of said parallel pulleys (48, 49). 2. - Addressable antenna (1) according to claim 1, wherein said support arm (10) comprises a first end portion (20, 21) fixed to the base (6), and a second end portion (22, 23) to which the second motor (9) is hinged pivotably. 3. - Addressable antenna (1) according to claim 2, wherein said support arm (10) is fork-shaped, and wherein said second end portion (22, 23) comprises two end portions between which hinged pivotingly said second motor (9). 4. - Addressable antenna (1) according to claim 3, wherein said first end portion (20, 21) of the support arm (10) comprises a base fixing foot (6), provided with a through opening ( 26) traversed by the transmission pulley (8). 5. - Addressable antenna (1) according to claim 4, wherein said fixing foot (20, 21) comprises two separate fixing feet, between which said through-opening (26) is defined. 6. - Addressable antenna (1) according to claim 4 or 5, comprising two fork arms (24, 25) attached to the fixing foot (20, 21), and wherein said two end portions (22, 23) they are free end portions of said fork arms (24, 25). 7. - Addressable antenna (1) according to any of the preceding claims, wherein the payload (4, 5) comprises a device (4) for transmission and / or reception of electromagnetic radiation. 8. - Addressable antenna according to claim 1, wherein the first motor (7) is positioned below the drive pulley (8) and the support arm (10) on the side opposite the load (4, 5). ). 9. - Addressable antenna (1) according to claim 1, wherein the support arm (10) comprises an integrated waveguide (30). 10. - Addressable antenna (1) according to claim 9, wherein said integrated waveguide (30) is a channel defined in the thickness of the support arm (10), and wherein said channel has a portion extending in the interior of one of said fork arms (24, 25). 11. - Addressable antenna (1) according to any of the preceding claims, wherein the second motor (9) comprises a container body (39), a stator (33) housed inside said container body (39), a rotor (34) and a drive shaft (35) attached or coupled to the rotor (34), and wherein the container body (39) is attached to the drive pulley (8) and hinged pivotally to the support arm (10) of so that it is capable of rotating around said first axis of rotation. 5 10 fifteen twenty 25 30 12. - Addressable antenna (1) according to claim 11, wherein the transmission pulley (8) has a central portion (50) of arched shape, and two side arms (51, 52) fixed to the container body (39) of the second motor (9). 13. - Search engine comprising an addressable antenna (1) according to any of the preceding claims.