A multi-beam feed structure with multi-frequency bands and its design method

Abstract

The present invention relates to a multi-beam feed structure with multiple frequency bands and a design method thereof. The multi-beam feed structure with multiple frequency bands comprises: a rotating mechanism and a plurality of feed arrays, wherein the plurality of feed arrays are arranged on the periphery of the rotating mechanism along the circumference of the rotating mechanism, and the frequency bands of at least two feed arrays are different; the distances from the focal plane of each feed array in the plurality of feed arrays to the axis of the rotating mechanism are the same; the rotating mechanism can rotate under the drive of a driving mechanism, and drive the plurality of feed arrays to rotate. By arranging a plurality of feed arrays on the periphery of the rotating mechanism, and driving the feed arrays to rotate by rotating the rotating mechanism, the focal plane of the feed array with the required frequency band coincides with the focal plane of the reflector, so as to realize the replacement of the antenna frequency band and meet the multi-band working requirements of the parabolic antenna.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and in particular relates to a multi-beam feed structure with multiple frequency bands and a design method thereof. Background Art

[0002] The parabolic antenna is one of the earliest antenna types in the field of antennas. The parabolic antenna reflects the electromagnetic waves emitted by the feed source at the focus straight ahead and keeps them in phase, thereby forming a highly directional beam, or converging parallel beams at the focus. High directivity is its most significant feature, so it is often used in high-gain occasions, such as radio telescopes, satellite ground receiving stations, radars, microwave relay transmissions, etc.

[0003] The frequency band covered by the parabolic antenna depends on the frequency band of the feed source, and the feed source in the prior art can only be used for a single frequency band, which limits the frequency band covered by the parabolic antenna. With the growing demand for space radio signal detection, the parabolic antenna with a single frequency band can no longer meet the detection needs. Therefore, providing a feed source structure with multiple frequency bands has become an urgent problem to be solved. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a multi-beam feed structure with multiple frequency bands and a design method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] A first aspect of the present invention provides a multi-band multi-beam feed structure, comprising: a rotating mechanism and a plurality of feed arrays, wherein:

[0006] The plurality of feed source arrays are arranged on the outer periphery of the rotating mechanism along the circumferential direction of the rotating mechanism, and at least two of the plurality of feed source arrays have different frequency bands;

[0007] The distance from the focal plane of each feed array in the plurality of feed arrays to the axis of the rotating mechanism is the same;

[0008] The rotating mechanism can rotate under the drive of the driving mechanism and drive the plurality of feed source arrays to rotate.

[0009] In one achievable manner, one of the plurality of feed arrays includes a plurality of horn feeds sequentially arranged along the axial direction of the rotating mechanism.

[0010] In one achievable manner, the feed array includes 5 to 15 horn feeds.

[0011] In one achievable manner, the horn feed source includes: a standard horn or a ridged horn.

[0012] In one achievable manner, the horn feed source is a 2-octave horn feed source.

[0013] In an achievable manner, the one feed source array is fixedly connected to the rotating mechanism via a threaded adjustment structure;

[0014] The one feed source array is movable along the threaded adjustment structure to move closer to or farther away from the rotating mechanism.

[0015] In one achievable manner, the angle between every two adjacent feed arrays in the plurality of feed arrays is greater than 30 degrees.

[0016] In an achievable manner, it further includes: a fixed frame and a connecting block, wherein:

[0017] Two ends of the rotating mechanism are movably connected to the fixed frame;

[0018] The fixed end of the driving mechanism is connected to the fixed frame, and the movable end is connected to the rotating mechanism;

[0019] The connecting block is fixedly connected to the fixed frame, and the connecting block is used to connect the reflector.

[0020] A second aspect of the present invention provides a method for designing a multi-beam feed structure with multiple frequency bands, which is used to design the multi-beam feed structure with multiple frequency bands provided by the first aspect of the present invention, comprising the following steps:

[0021] S1: Determine the number of feed arrays and the frequency band of each feed array in the plurality of feed arrays according to frequency band requirements;

[0022] S2: Determine the structural parameters of each feed array according to the frequency band and design requirements of each feed array.

[0023] In one practicable manner, the design requirements include the aperture, focal length and beam width of the reflector;

[0024] The structural parameters of each feed array include the aperture, ridge curve, length and number of the horn feeds in each feed array.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a multi-beam feed structure with multiple frequency bands. A plurality of feed arrays are arranged on the periphery of a rotating mechanism, and the rotating mechanism is rotated to drive the feed arrays to rotate, so that the focal plane of the feed array with the required frequency band coincides with the focal plane of the reflector, thereby realizing the replacement of the antenna frequency band and meeting the multi-band working requirements of the parabolic antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a multi-beam feed structure with multiple frequency bands provided by an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the installation of a feed structure and a reflector provided in an embodiment of the present invention;

[0029] Figure 3 is a structural schematic diagram of another multi-beam feed structure with multiple frequency bands provided by an embodiment of the present invention;

[0030] Figure 4 is a horn feed pattern provided by an embodiment of the present invention;

[0031] Figure 5 This is the feed array pattern provided by an embodiment of the present invention.

[0032] Reference numerals:

[0033] 1: feed array; 101: horn feed; 2: rotating mechanism; 21: threaded adjustment structure; 3: driving mechanism; 4: fixed frame; 5: connecting block; 6: reflector; 7: connecting rod; 11: first feed array; 12: second feed array; 111: first horn feed; 121: second horn feed. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0035] Embodiment 1

[0036] See also Figure 1 , Figure 1 It is a structural schematic diagram of a multi-beam feed structure with multiple frequency bands provided in an embodiment of the present invention.

[0037] An embodiment of the present invention provides a multi-band multi-beam feed structure, comprising: a rotating mechanism 2 and a plurality of feed arrays 1. The plurality of feed arrays 1 are arranged on the periphery of the rotating mechanism 2 along the circumference of the rotating mechanism 2, and at least two of the plurality of feed arrays 1 have different frequency bands. The distance from the focal plane of each feed array 1 in the plurality of feed arrays 1 to the axis of the rotating mechanism 2 is the same. The rotating mechanism 2 can rotate under the drive of the driving mechanism 3, and drive the plurality of feed arrays 1 to rotate.

[0038] Specifically, see Figure 2, the axis of the rotating mechanism 2 is arranged parallel to the focal plane of the reflector 6. When the frequency band of the antenna is changed, the rotating mechanism 2 is driven to rotate by the driving mechanism 3 to drive the feed array 1 to rotate, and the feed array 1 with the required frequency band is rotated to a position facing the focal plane of the reflector 6, so that the focal plane of the feed array 1 coincides with the focal plane of the reflector 6, thereby changing the frequency band of the antenna. It should be understood that among the multiple feed arrays 1, only the feed array 1 facing the focal plane of the reflector 6 is in working state, and the other feed arrays 1 are in idle state. The frequency band of the feed array 1 in working state is the frequency band covered by the antenna.

[0039] In this embodiment, one of the plurality of feed arrays 1 includes a plurality of horn feeds 101 sequentially arranged along the axial direction of the rotating mechanism 2. In an achievable manner, one feed array 1 includes 5 to 15 horn feeds 101.

[0040] Specifically, the horn feed 101 at the center of the feed array 1 in the working state is located at the focus of the reflector 6. The focal plane of the feed array 1 is the plane formed by the focus of each horn feed 101 in the feed array 1.

[0041] In this embodiment, the feed array 1 is fixedly connected to the rotating mechanism 2 via a threaded adjustment structure 21, and the feed array 1 can move along the threaded adjustment structure 21 to get closer to or farther away from the rotating mechanism 2. Specifically, the distance between the feed array 1 and the rotating mechanism 2 is adjusted via the threaded adjustment structure 21, so that the distance from the focal plane of each feed array 1 to the axis of the rotating mechanism 2 is the same.

[0042] In this embodiment, the angle between every two adjacent feed arrays 1 among the plurality of feed arrays 1 is greater than 30 degrees. Specifically, when the angle between two feed arrays 1 is less than 30 degrees, there is mutual interference between the two feed arrays 1 .

[0043] In this embodiment, the feed structure further includes: a fixed frame 4 and a connecting block 5. The two ends of the rotating mechanism 2 are movably connected to the fixed frame 4. The fixed end of the driving mechanism 3 is connected to the fixed frame 4, and the movable end is connected to the rotating mechanism 2. The connecting block 5 is fixedly connected to the fixed frame 4, and the connecting block 5 is used to connect the reflector 6.

[0044] Specifically, see Figure 2 The fixed frame 4 is arranged parallel to the focal plane of the reflector 6 , and the connecting block 5 is connected to the reflector 6 through the connecting rod 7 .

[0045] In one achievable manner, the driving mechanism 3 is a motor driving structure, the motor of the driving mechanism 3 is fixedly connected to the fixed frame 4, the output shaft of the driving mechanism 3 is connected to the rotating mechanism 2 through a coupling, and both ends of the rotating mechanism 2 are connected to the fixed frame 4 through bearing assemblies. The output shaft of the driving mechanism 3 rotates to drive the rotating mechanism 2 to rotate.

[0046] In one achievable manner, the driving mechanism 3 is an electric push rod structure, the base of the driving mechanism 3 is fixedly connected to the fixed frame 4, the push rod of the driving mechanism 3 is rotatably connected to the rotating mechanism 2, and both ends of the rotating mechanism 2 are connected to the fixed frame 4 through bearing assemblies. The push rod of the driving mechanism 3 reciprocates to drive the rotating mechanism 2 to rotate. It should be understood that when the driving mechanism 3 is an electric push rod structure, the rotating mechanism 2 has a maximum rotation angle limit; when the driving mechanism 3 is a motor drive structure, the rotating mechanism 2 can rotate 360 ​​degrees.

[0047] The present embodiment provides a multi-beam feed structure with multiple frequency bands, by arranging a plurality of feed arrays 1 on the periphery of a rotating mechanism 2, and driving the feed arrays 1 to rotate by rotating the rotating mechanism 2, so that the focal plane of the feed array 1 with the required frequency band coincides with the focal plane of the reflector 6, thereby realizing the replacement of the antenna frequency band and meeting the multi-band working requirements of the parabolic antenna.

[0048] Embodiment 2

[0049] Based on Example 1, see Figure 3 , Figure 3 It is a structural schematic diagram of another multi-beam feed structure with multiple frequency bands provided in an embodiment of the present invention.

[0050] Another multi-band multi-beam feed structure provided in this embodiment includes: a first feed array 11, a second feed array 12, a rotating mechanism 2, a driving mechanism 3, a fixed frame 4 and a connecting block 5. Among them, the first feed array 11 and the second feed array 12 are arranged on the outer periphery of the rotating mechanism 2 along the circumference of the rotating mechanism 2. Both ends of the rotating mechanism 2 are connected to the fixed frame 4 through a bearing assembly. The driving mechanism 3 is an electric push rod structure, the base of the driving mechanism 3 is fixedly connected to the fixed frame 4, and the push rod of the driving mechanism 3 is rotatably connected to the rotating mechanism 2. The push rod of the driving mechanism 3 reciprocates to drive the rotating mechanism 2 to rotate. Four connecting blocks 5 are respectively arranged at the four corners of the fixed frame 4, and each connecting block 5 is fixedly connected to the reflector 6 through a connecting rod 7.

[0051] In this embodiment, the first feed array 11 includes 11 first horn feeds 111 arranged along the axis of the rotating mechanism 2, and the second feed array 12 includes 11 second horn feeds 121 arranged along the axis of the rotating mechanism 2. The angle between the first feed array 11 and the second feed array 12 is 45 degrees, which enables the rotating mechanism 2 to switch the feed array by rotating a smaller angle. Exemplarily, when the first feed array 11 is in working state, the push rod of the driving mechanism 3 is retracted to drive the rotating mechanism 2 to rotate clockwise, thereby rotating the focal plane of the second feed array 12 to coincide with the focal plane of the reflector 6, so that the second feed array 12 is in working state and the frequency band switching is completed. Here, the coverage frequency band of the parabolic antenna is the frequency band of the second feed array 12. Optionally, a pin limiting structure is provided on the rotating mechanism 2 to limit the maximum rotation angle of the rotating mechanism 2.

[0052] In this embodiment, the first horn feed 111 and the second horn feed 121 are both ridged horns, and a dielectric block is disposed at the top of the second horn feed 121. The second horn feed 121 is a 2-octave horn feed, that is, the maximum frequency of the second horn feed 121 is twice the minimum frequency.

[0053] In one achievable manner, the second horn feed source 121 is a 2-octave horn feed source, and the frequency band of the first horn feed source 111 and the frequency band of the second horn feed source 121 are continuous.

[0054] In another achievable manner, the second horn feed source 121 is a 2-octave horn feed source, and the frequency band of the first horn feed source 111 and the frequency band of the second horn feed source 121 are discontinuous.

[0055] In this embodiment, the bottom end of the first horn feed 111 is fixed to the first fixed plate by a pin, and the bottom end of the second horn feed 121 is fixed to the second fixed plate by a pin. Both ends of the first fixed plate and both ends of the second fixed plate are fixedly connected to the rotating mechanism 2 by a threaded adjustment structure 21. The threaded adjustment structure 21 includes a threaded rod, a first nut and a second nut. Both ends of the first fixed plate and both ends of the second fixed plate are connected to the threaded adjustment structure 21 in the same way. Taking one end of the first fixed plate as an example, the bottom end of the threaded rod is fixedly connected to the rotating mechanism 2, and a through hole matching the threaded rod is provided on the first fixed plate. The threaded rod passes through the through hole on the first fixed plate. The first nut and the second nut are sleeved on the threaded rod, and the first nut and the second nut are respectively located on both sides of the first fixed plate. The first fixed plate can be fixed by locking the first nut and the second nut; loosening the first nut and the second nut, the first fixed plate can slide along the threaded rod, and the position of the first fixed plate can be adjusted to adjust the distance between the focal plane of the first feed array 11 and the axis of the rotating mechanism 2. It should be understood that the focal plane of the first feed array 11 is the plane where the top of the first horn feed 111 is located.

[0056] Embodiment 3

[0057] On the basis of the first embodiment, this embodiment provides another multi-band multi-beam feed structure, comprising: a first feed array, a second feed array, a third feed array and a rotating mechanism 2, wherein the first feed array, the second feed array and the third feed array are arranged on the periphery of the rotating mechanism 2 along the circumference of the rotating mechanism 2. In this embodiment, the first feed array, the second feed array and the third feed array each include 5 standard horns arranged along the axis of the rotating mechanism 2.

[0058] In one implementable manner, the frequency band of the first feed array, the frequency band of the second feed array, and the frequency band of the third feed array are continuous.

[0059] In another achievable manner, the frequency band of the first feed array, the frequency band of the second feed array, and the frequency band of the third feed array are discontinuous.

[0060] Embodiment 4

[0061] On the basis of the first embodiment, this embodiment provides another multi-band multi-beam feed structure, including: a first feed array, a second feed array and a rotating mechanism 2, wherein the first feed array and the second feed array are arranged on the periphery of the rotating mechanism 2 along the circumference of the rotating mechanism 2. In this embodiment, the first feed array and the second feed array each include 15 horn feeds arranged along the axis of the rotating mechanism 2. The horn feeds in the first feed array are standard horns, and the horn feeds in the second feed array are ridged horns.

[0062] Embodiment 5

[0063] This embodiment provides a design method for a multi-beam feed structure with multiple frequency bands, which is used to design the multi-beam feed structure with multiple frequency bands provided in Embodiments 1 to 4 of the present invention. The design method includes the following steps:

[0064] S1: Determine the number of feed arrays 1 and the frequency band of each feed array 1 among the multiple feed arrays 1 according to frequency band requirements.

[0065] Specifically, the frequency band requirements are determined by users based on actual usage needs, including the number of frequency bands and the coverage of each frequency band.

[0066] S2: Determine the structural parameters of each feed array 1 according to the frequency band and design requirements of each feed array 1.

[0067] Specifically, the design requirements include the aperture, focal length and beam width of the reflector 6. The structural parameters of each feed array 1 include the aperture, ridge curve, length and number of the horn feeds 101 in each feed array 1.

[0068] Furthermore, when the frequency band requirement of the feed array 1 is not high, the design requirements can be met by an ordinary horn feed 101 without a ridge. When the frequency band requirement of the feed array 1 increases, such as reaching a 2-octave frequency, it is difficult for a standard horn to meet the design requirements. A ridge can be added to the horn feed 101 to form a ridged horn to widen the operating frequency band. The aperture of the horn feed 101 includes a horizontal length and a vertical length. Step S2 is explained by taking the horn feed 101 as an example in which a ridge is required. In this embodiment, step S2 includes the following steps:

[0069] S201: According to the aperture, focal length and beam width of the reflector 6, the original aperture, original length and original ridge curve of the horn feed 101 are proposed. In the design software, an initial model is established with the original aperture, original length and original ridge curve of the horn feed 101, and the following can be obtained: Figure 4 The single horn feed pattern shown is based on the single horn feed pattern, taking antenna aperture efficiency as the optimization target, optimizing the aperture, length and ridge curve of the horn feed 101, and obtaining the structural parameters after preliminary optimization.

[0070] S202: Determine the number of horn feeds 101 in each feed array 1 according to the antenna gain reduction limit.

[0071] Specifically, the more the number of horn feeds 101 in the feed array 1, the more the antenna gain decreases, and the larger the multi-beam scanning range. In the application of parabolic antennas, the larger the multi-beam scanning range, the wider the range of information that can be received. However, the larger the multi-beam scanning range, the more the antenna gain decreases. Therefore, after comprehensive consideration of the multi-beam scanning range and the antenna gain decrease, the antenna gain decrease limit in this embodiment is 2.5dB. When the antenna gain decrease limit is 2.5dB, the multi-beam scanning range is a maximum of 4 to 6 times the beam width, which can meet the application of most situations. The number of horn feeds 101 in each feed array 1 can be determined according to the maximum multi-beam scanning range. For example, when the multi-beam scanning range is 4 times the beam width, the number of horn feeds 101 in each feed array 1 is 9; when the multi-beam scanning range is 5 times the beam width, the number of horn feeds 101 in each feed array 1 is 11.

[0072] S203: In HFSS software, a feed array model is established using the structural parameters of the speaker feed 101 after preliminary optimization and the number of the speaker feeds 101 in a feed array 1, and the following can be obtained: Figure 5 According to the feed array radiation pattern shown in the figure, the structural parameters of the horn feed 101 after preliminary optimization are optimized again with feed standing wave ratio, antenna gain, crossover level between beams, number of beams, antenna gain reduction limit and phase center stability as optimization targets.

[0073] For example, Figure 5 The multi-beam scanning range in the feed array pattern shown is 4 times the beam width. The feed array 1 includes 9 horn feeds 101. The feed array 1 has a high gain, a reasonable crossover level, and a good sidelobe level within a 2-octave frequency band. In this embodiment, the horn feeds 101 in a feed array 1 are arranged compactly, that is, the outer walls of two adjacent horn feeds 101 are in contact with each other. Furthermore, the phase center stability is controlled within ±2%~4% of the center frequency of the feed array.

[0074] This embodiment provides a design method for a multi-beam feed structure with multiple frequency bands. The feed structure obtained by the design method has multiple frequency bands, and each feed array 1 has a high gain, a reasonable crossover level and a good sidelobe level.

[0075] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A multi-beam feed structure with multiple frequency bands, characterized in that: include: A rotating mechanism and several feed source arrays, wherein: The plurality of feed source arrays are arranged on the outer periphery of the rotating mechanism along the circumferential direction of the rotating mechanism, and at least two of the plurality of feed source arrays have different frequency bands; The distance from the focal plane of each feed array in the plurality of feed arrays to the axis of the rotating mechanism is the same; The rotating mechanism can rotate under the drive of the driving mechanism, and drive the plurality of feed source arrays to rotate; One of the plurality of feed source arrays comprises a plurality of horn feed sources sequentially arranged along the axial direction of the rotating mechanism; The axis of the rotating mechanism is arranged parallel to the focal plane of the reflector.

2. A multi-band multi-beam feed structure according to claim 1, characterized in that: The feed array includes 5 to 15 horn feeds.

3. The multi-band multi-beam feed structure according to claim 1, characterized in that: The horn feed source includes: a standard horn or a ridged horn.

4. The multi-band multi-beam feed structure according to claim 3, characterized in that: The speaker feed source is a 2-octave speaker feed source.

5. The multi-band multi-beam feed structure according to claim 4, characterized in that: The one feed source array is fixedly connected to the rotating mechanism via a threaded adjustment structure; The one feed source array is movable along the threaded adjustment structure to move closer to or farther away from the rotating mechanism.

6. The multi-band multi-beam feed structure according to claim 1, characterized in that: The angle between every two adjacent feed arrays in the plurality of feed arrays is greater than 30 degrees.

7. The multi-band multi-beam feed structure according to claim 1, characterized in that: Also includes: Fixed frame and connection block, where: Two ends of the rotating mechanism are movably connected to the fixed frame; The fixed end of the driving mechanism is connected to the fixed frame, and the movable end is connected to the rotating mechanism; The connecting block is fixedly connected to the fixed frame, and the connecting block is used to connect the reflector.

8. A design method for a multi-beam feed structure with multiple frequency bands, characterized in that: The method for designing a multi-band multi-beam feed structure according to any one of claims 1 to 7 comprises the following steps: S1: Determine the number of feed arrays and the frequency band of each feed array in the plurality of feed arrays according to frequency band requirements; S2: Determine the structural parameters of each feed array according to the frequency band and design requirements of each feed array.

9. The design method of a multi-beam feed structure with multiple frequency bands according to claim 8, characterized in that: The design requirements include the aperture, focal length and beam width of the reflector; The structural parameters of each feed array include the aperture, ridge curve, length and number of the horn feeds in each feed array.

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