Antenna array with circularly polarized antenna elements on the head of a body

Abstract

The present invention relates to an antenna arrangement. The antenna arrangement comprises a head of a body; and a plurality M of antenna elements arranged on the head of the body and outside the body.

Description

TECHNICAL AREA OF INVENTION

[0001] The invention relates to antenna arrangements, in particular to an antenna arrangement with circularly polarized antenna elements on a head of a body for applications in radar technology. BACKGROUND OF THE INVENTION

[0002] For guidance, missiles can be equipped with a radar head to enable the acquisition of radar data from the perspective of the missile's radar head. The radar data can be analyzed and used, for example, to guide the missile or to control other objects. The radar head occupies a volume within the missile, usually in its head. A missile's propulsion system can be adapted to the dimensions of the radar head (volume, body, shape, arrangement, weight, etc.) in order to meet one or more performance requirements of the missile. For precise guidance using radar data, the shape and structure of the missile, which includes an antenna array, can be important, for example.

[0003] One of the objects of the invention is to provide antenna arrangements which allow to increase the performance of the radar head or the missile, for example by reducing the complexity of the radar head with regard to an analysis of the acquired radar data, or with regard to a reduction of the volume occupied by the radar head. SUMMARY OF THE INVENTION

[0004] The invention is defined by the independent claims. The dependent claims define advantageous embodiments.

[0005] According to one aspect of the invention, an antenna assembly comprises a head of a body; and a plurality M of antenna elements arranged on the head of the body and outside the body. This increases the volume within the body and reduces the complexity of analyzing the acquired radar data.

[0006] According to a further development, a plurality of antenna elements each comprise a housing, a tip, and an antenna, wherein the antenna has the shape of an elongated helix extending in a longitudinal direction of the antenna array. Polarization losses are thereby reduced.

[0007] According to a further development, a plurality of antenna elements are configured for transmitting and / or receiving circularly polarized electromagnetic radiation, in particular electromagnetic radiation for applications in radar technology. Transmission and / or reception is enabled, and the range of a radar is increased.

[0008] According to a further development, the length of the housing is no less than the length of the antenna. This allows the antenna to be positioned completely outside the head or body.

[0009] According to a further training, the numerous antenna elements are arranged symmetrically around an axis of symmetry of the antenna array. This enables a simplified analysis of the radar data.

[0010] According to further training, the plurality M of antenna elements comprises a plurality E of antenna elements for receiving, a plurality S of antenna elements for transmitting, and / or a plurality B of antenna elements for bidirectional transmitting and receiving, with E + S + B = M and E ≥ 0, S ≥ 0, B ≥ 0. This expands functionality and increases range or reduces complexity.

[0011] According to a further development, the plurality of antenna elements are arranged in a longitudinal direction of the antenna array at an edge of the head of the body. This can increase the radiation and / or reception power or enable an enlarged field of view.

[0012] According to a further development, the plurality of antenna elements each comprises a housing made of a first material, and the head of the body is made of a second material, wherein the first material and the second material are different. This optimizes the radiation and / or reception performance.

[0013] According to a further development, the plurality of antenna elements is configured to generate and / or receive radiation with the same left-handed or right-handed circular polarization. This reduces polarization losses.

[0014] According to one aspect of the invention, a missile comprises the antenna arrangement as described above. This enables a missile with an extended performance spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 Front view of an exemplary antenna arrangement with antenna elements arranged symmetrically on a rotationally symmetrical head of a body. Fig. 2 Side view of the exemplary antenna arrangement of Fig. 1. Fig. 3 Side view of a missile with an example antenna arrangement.

[0016] The accompanying figures are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain the principles and concepts of the invention. Other embodiments and many of the aforementioned advantages become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale. Directional terminology such as "above," "below," "left," "right," "over," "below," "horizontal," "vertical," "front," "back," and similar terms are used for explanatory purposes only and are not intended to limit the general public to specific embodiments as shown in the figures.

[0017] In the figures, the same reference symbols regularly designate identical or functionally identical components, unless otherwise stated. DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

[0018] Fig. Figure 1 shows a front view of an exemplary antenna arrangement 110 with antenna elements on the head of a body and outside the body, for example of a missile 300 as in Fig. Figure 3 shows that, without loss of generality, the head of the body exhibits rotational symmetry; that is, it can be circular when viewed from the front along an axis of rotation x. The head of the body can also be elliptical, for example, when viewed from the front along the axis of rotation x.

[0019] As in the Fig. As shown in Figure 1, the antenna array comprises a plurality M of antenna elements m where 1 ≤ m ≤ M. The plurality M can be an even or odd integer, for example, 4, 6, 8, 10, 12, 14, 16, or 18. The antenna elements can be identical or different. For example, S antenna elements can be configured for transmitting, E antenna elements for receiving, and / or B antenna elements for bidirectional transmission and reception of electromagnetic radiation. The plurality M of antenna elements m can, for example, include 0, 2, 4, or 8 antenna elements for transmitting and 16, 14, 12, or 8 antenna elements for receiving, for a total of 16 antenna elements in each case. The multitude M of antenna elements can also include 4 antenna elements for transmitting and 14 antenna elements for receiving, a total of 16 antenna elements, i.e., 2 antenna elements for transmitting and 2 for receiving.Other combinations are also possible, in particular the case where all antenna elements are configured for transmitting and receiving, B = M. Antenna elements may differ at least in the direction of polarization rotation and otherwise be identical.

[0020] The transmitting and receiving antenna elements can be arranged in sequential groups on the body or head of the device, e.g., 2 of array S and 14 of array E; or 4 of array S and 12 of array E; or 4 of array S, 4 of array E, 4 of array S, 4 of array E; or alternating 1 of array S and 1 of array E. The 16 antenna elements, for example, can all be configured for transmitting and / or receiving. The transmitting configuration can exclude the receiving configuration, and vice versa. In the case of a receive-only arrangement, where all antenna elements are configured for receiving and no transmitting antenna element is configured, the antenna arrangement can, for example, receive radar waves reflected from a target object that were emitted by a transmitter.

[0021] The antenna elements can be configured, in particular, to transmit and / or receive electromagnetic radiation for radar applications. The antenna elements can also be configured to transmit and / or receive in different frequency ranges.

[0022] The multitude M of antenna elements m can be arranged rotationally symmetrically on a circle with radius r. i , arranged in a plane perpendicular to the rotation axis x of the head of, for example, the missile. The position of the antenna elements can be represented, for example, by a rotation angle φ(m) where 1 ≤ m ≤ M. The rotation angle φ(m) for the antenna element m can be given by the relationship φ(m) = (m - 1) × Δφ, with Δp = 360° / M. Different rotation angles are possible for the plurality S and the plurality E. As in the Fig. As shown in Figure 1, the radius is r. i smaller than a radius of the missile r a, if, without loss of generality, the case is concentric circles as the shape of the missile (outer, solid circle in Fig. 1) and the arrangement of the antenna elements (inner, dotted circle in Fig. 1) is considered. A radius d m / 2 of one, several, or all of the antenna elements m can be less than, equal to, or greater than the difference r a - r i the radii r a and r i The position of the antenna elements at the edge of the head of the body can, for example, allow for a larger field of view.

[0023] Fig. Figure 2 shows a side view of an exemplary antenna arrangement 210 with antenna elements mounted on the head of a body outside the body, for example a missile 300 as in Fig. 3. The head of the body, without loss of generality, has a hyperbolic shape when viewed laterally along an axis y that is orthogonal to an axis x. The head of the body can, for example, also have the shape of a circle or a triangle when viewed laterally along an axis y.

[0024] As with reference to Fig. As described in detail in section 1, the antenna arrangement comprises a plurality M of antenna elements m with 1 ≤ m ≤ M. For the sake of simplicity, in Fig. 2. An example with 8 antenna elements is illustrated.

[0025] Alternative solutions, all of which are based on the example in Fig. 2 can be combined, and vice versa, with reference to Fig. 1 described in detail.

[0026] Each of the antenna elements m can comprise a radome (derived from the English "radar dome") with a housing 211 and a tip 212. The housing can have a diameter (cf. d min Fig. 1) have a length in the range of 5 to 50 mm, preferably 10 to 20 mm, more preferably 12 to 15 mm. The housing 211 can have a length l mThe radome may have a diameter of 20 to 200 mm, preferably 50 to 120 mm, and more preferably 70 to 100 mm. The radome may be arranged completely or at least partially outside the head of the body to increase the volume of available space within the head of the body. Each of the antenna elements m may further comprise an antenna 213. The antenna 213 may be a helical antenna configured for transmitting and / or receiving circularly polarized electromagnetic radiation. Other antennas extending in one direction, e.g., in the x-direction, configured for transmitting and / or receiving circularly polarized electromagnetic radiation are also possible. The antenna 213 may, for example, form a helix around a cylinder, a cone, an ellipsoid, etc. The antenna 213 may have a directional characteristic 214 that is rotationally symmetrical in one direction of radiation.

[0027] The antenna 213 can be arranged in the radome. In particular, the length of the antenna 213 can be less than the length l. m of the radome, so that the antenna 213 can be arranged completely outside the head of the body inside the radome.

[0028] The shape and material of each individual radome of an antenna 213 can be independent of the shape and material of the body head to enable optimal performance of the antenna 213. Losses and / or distortions during transmission and reception of a radar signal can thus be minimized. The shape and material of the respective radomes can also be adapted to the configuration of the antenna 213 (transmission, reception, transmission, and reception).

[0029] Due to the shape of the antenna elements and the dimensions of the respective antenna 213, the antenna elements can be mounted on the head of a missile 300 as in Fig. 3. This arrangement allows space to be provided inside the head or missile for, for example, a second instrument for guiding the missile. The second instrument can be an optical seeker head, such as a seeker head for detecting electromagnetic radiation in the infrared frequency range. Antenna arrangements according to the present disclosure can thus enable the use of multiple seekers to improve missile guidance without requiring a comprehensive modification of the missile's shape.

[0030] Each antenna 213 can be configured to generate radiation with the same left- or right-handed circular polarization, regardless of the relative position and orientation of the antenna elements m. This allows a radiated and backscattered radar signal from each transmitting antenna to be received by each receiving antenna without polarization losses. Polarization losses here refer to losses caused by different polarizations.

[0031] Fig. Figure 3 shows a side view of a missile 300 with an antenna assembly 310 and a fuselage 320. The fuselage 320 can comprise a single-stage, two-stage, or multi-stage propulsion module. One or more of the propulsion stages of the propulsion module can be jettisonable. The antenna assembly 310 can surround one or more submodules. The antenna assembly 310 can, for example, surround an active or passive radar, one or more effectors, a control system, and / or means for wireless communication. In particular, an antenna assembly 310 can comprise a plurality of antenna elements, as shown with reference to the Fig. 1 and Fig. 2 described in detail.

[0032] In the foregoing detailed description, various features have been combined into one or more examples for the sake of clarity. It should be understood, however, that the above description is merely illustrative and not restrictive in nature. It is intended to cover all alternatives, modifications, and equivalents of the various features and embodiments. Many other examples will be readily apparent to those skilled in the art based on their skill in the art in light of the above description.

[0033] The exemplary embodiments were selected and described to best illustrate the principles underlying the invention and its practical applications. This enables those skilled in the art to optimally modify and utilize the invention and its various embodiments with regard to the intended purpose. In the claims and the description, the terms "including" and "featuring" are used as neutral language terms for the corresponding terms "comprehensive."

[0034] Furthermore, the use of the terms "ein", "einer" and "eine" should not fundamentally exclude a plurality of such described features and components. REFERENCE MARK LIST x10 Antenna arrangement (x = 1, 2 or 3) 211 Housing of a radome of an antenna element m 212 Tip of a radome of an antenna element m 213 Antenna of an antenna element m 214 Directional characteristic of an antenna element m 300 missiles 320 Fuselage of the missile 300

Claims

[1] Antenna arrangement (110, 210, 310), comprising: a head of a body; and a plurality M of antenna elements (m) arranged on the head (110) of the body and outside the body. [2] The antenna assembly (110, 210, 310) of claim 1, wherein the plurality M of antenna elements (m) each comprise a housing (211), a tip (212), and an antenna (213), the antenna (213) having the shape of an elongated helix extending in a longitudinal direction of the antenna assembly (110, 210, 310). [3] Antenna arrangement (110, 210, 310) according to claim 1 or 2, wherein the plurality M of antenna elements (m) is configured to transmit and / or receive circularly polarized electromagnetic radiation, in particular electromagnetic radiation for applications in radar technology. [4] Antenna arrangement (110, 210, 310) according to claim 2, wherein a length l mof the housing (211) is not smaller than a length of the antenna (213). [5] Antenna arrangement (110, 210, 310) according to any one of claims 1 to 4, wherein the plurality M of antenna elements (m) are arranged symmetrically about an axis of symmetry (x) of the antenna arrangement (110, 210, 310). [6] Antenna arrangement (110, 210, 310) according to any one of claims 1 to 5, wherein the plurality M of antenna elements (m) comprises a plurality E of antenna elements for receiving, a plurality S of antenna elements for transmitting and / or a plurality B of antenna elements for bidirectional transmitting and receiving, with E + S + B = M and E > 0, S ≥ 0, B > 0. [7] Antenna assembly (110, 210, 310) according to any one of claims 1 to 6, wherein the plurality M of antenna elements (m) are arranged in a longitudinal direction of the antenna assembly (110, 210, 310) at an edge of the head of the body. [8] Antenna arrangement (110, 210, 310) according to claim 1, wherein the plurality M of antenna elements (m) each comprises a housing (211) made of a first material and the head of the body is made of a second material, the first material and the second material being different. [9] Antenna arrangement (110, 210, 310) according to any one of claims 1 to 8, wherein the plurality M of antenna elements (m) are configured to generate and / or receive radiation having the same left-handed or right-handed circular polarization. [10] Missile (300), comprising: the antenna assembly (110, 210, 310) of any of claims 1 to 9, wherein the body is the missile (300).

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