An AMC-based cavity-shared dual-frequency circularly polarized co-axial antenna and system

Abstract

The application discloses a cavity-shared dual-frequency circularly polarized co-boresight antenna based on AMC, which comprises an antenna main body, a ground plate, a high-frequency antenna and a low-frequency antenna, a low-frequency cavity, a high-frequency cavity, a low-frequency oscillator and a high-frequency oscillator, and a coupling sheet. The low-frequency cavity comprises a plurality of first short-circuit columns which are arranged in a cross shape. The high-frequency cavity comprises a plurality of second short-circuit columns which are arranged in a cross shape based on the low-frequency cavity. The low-frequency oscillator and the high-frequency oscillator each comprise a pair of inverted L-shaped oscillator units, and the pair of inverted L-shaped oscillator units integrally present a cross shape. The coupling sheet comprises a plurality of groups, and one group of the coupling sheet corresponds to one high-frequency oscillator. The cavities of the high-frequency antenna and the low-frequency antenna are arranged through reasonable array spacing to realize the sharing of part of cavity arms, and the low-frequency oscillator utilizes the high-frequency coupling sheet to reduce the profile and improve the complexity of the structure through the AMC principle, and meanwhile, high isolation is realized.

Description

Technical Field

[0001] This application relates to the fields of communication and antenna technology, and in particular to a cavity-shared dual-frequency circularly polarized common-aperture antenna and system based on AMC. Background Technology

[0002] With the rapid development of modern wireless communication technology and the ever-expanding applications of various communication devices, the performance requirements for antenna systems are becoming increasingly stringent, leading to a growing demand for multi-band, multi-polarization, and miniaturized antenna systems. However, various platforms often face the challenge of limited space and irregular shapes, placing high demands on the utilization of this limited space. This significantly restricts the weight, shape, and physical dimensions of the antenna. Furthermore, installing multiple antennas within such a confined space often results in strong electromagnetic coupling between them, leading to mutual interference and impacting antenna performance.

[0003] A common-aperture antenna refers to an antenna configuration where multiple antennas are located within the same aperture. Through a rational spatial arrangement, common-aperture antennas reduce electromagnetic coupling between antennas operating at different frequencies, allowing multiple antennas with different functions to operate without interference, thus saving space. This invention embeds the cavity of the high-frequency unit and the radiating plate together below the low-frequency unit, selecting an appropriate ratio to achieve a shared cavity, and utilizing the cavity to achieve isolation between high and low frequencies.

[0004] For common-aperture antennas, the design challenge lies in reducing the mutual influence between high-frequency and low-frequency antennas, including ensuring that the antennas do not block each other when radiating energy and that the feeding structures do not overlap. Therefore, the selection of high-frequency and low-frequency antenna types is very important.

[0005] Generally speaking, the choice of low-frequency antenna type is relatively important because low-frequency antennas have longer operating wavelengths and larger antenna sizes compared to high-frequency elements. Therefore, choosing an appropriate low-frequency antenna type can leave suitable array area for the high-frequency antenna. Common low-frequency antenna types include square patches with square windows and cross-shaped patches. High-frequency antenna elements are placed at the positions of the square windows and the four corners of the cross-shaped patches.

[0006] Existing dual-band common-aperture antennas require the selection of an appropriate low-frequency antenna to leave suitable array area for the high-frequency antenna. During the design process, mutual blocking of radiation can occur, resulting in a very complex antenna structure that is difficult to apply in engineering. If a multi-point feeding method is chosen to achieve circular polarization, there are drawbacks such as complex feeding networks leading to network overlap. Summary of the Invention

[0007] This application provides a cavity-shared dual-frequency circularly polarized common-aperture antenna and system based on AMC, which simplifies the antenna feeding structure by utilizing a single-feed circularly polarized unit, and achieves the sharing of some cavity arms by arranging the cavities of high and low frequency antennas through reasonable array spacing, thereby improving the complexity of the structure and achieving a high degree of isolation.

[0008] This application provides a cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC, including: The antenna body is a multi-layer board structure; Floor 3 is a continuous metal layer printed on the bottom layer of the multilayer board structure, used for the common ground of high-frequency antenna and low-frequency antenna; The low-frequency cavity 4 includes multiple first short-circuit pillars arranged in a square shape, and the height of the first short-circuit pillars is consistent with the height of the layer where the low-frequency oscillator 6 is located. The high-frequency cavity 5 includes multiple second short-circuit posts, which are arranged in a cross shape based on the low-frequency cavity 4, so that the low-frequency cavity 4 and the high-frequency cavity 5 are nested in each other in the horizontal direction, and the height of the second short-circuit posts is consistent with the height of the layer where the high-frequency cavity 5 is located. The low-frequency oscillator 6 and the high-frequency oscillator 7 each include a pair of inverted L-shaped oscillator units. Each inverted L-shaped oscillator unit includes mutually perpendicular radiating arms. The pair of inverted L-shaped oscillator units are in a cross shape and are printed on a designated layer of the microwave substrate 1 of the multilayer board structure. The coupling plate 8 includes multiple sets, with each set of coupling plates 8 corresponding to a high-frequency oscillator 7. The coupling plate 8 has a chamfered rectangular structure, arranged around the center of the high-frequency oscillator 7, and located in the gap between the radiating arms of the high-frequency oscillator 7. Each coupling plate 8 is connected to the floor 3 through a short-circuit post 9.

[0009] This application provides a communication system including a cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC, as described above.

[0010] This application embodiment utilizes a single-fed circularly polarized unit to simplify the antenna feeding structure, suppresses surface waves by adding cavities, and achieves partial cavity arm sharing by arranging the cavities of high- and low-frequency antennas through reasonable array spacing. Furthermore, it utilizes the AMC principle to reduce the profile of the low-frequency vibrator using a high-frequency coupling plate, thereby improving the complexity of the structure and achieving higher isolation.

[0011] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0012] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic view of the cavity-shared dual-frequency circularly polarized common-aperture antenna according to an embodiment of this application. Figure 2 This is a partial oblique view of the cavity-shared dual-frequency circularly polarized common-aperture antenna according to an embodiment of this application; Figure 3 This is a schematic side view of a cavity-shared dual-frequency circularly polarized common-aperture antenna according to an embodiment of this application. Figure 4 This is a partial schematic side view of a cavity-shared dual-frequency circularly polarized common-aperture antenna according to an embodiment of this application. Figure 5 This is a partial schematic diagram of the cavity-shared dual-frequency circularly polarized common-aperture antenna vibrator and feeder in an embodiment of this application. Detailed Implementation

[0013] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0014] This application provides a cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC, such as... Figure 1 , Figure 2 As shown, it includes: The antenna body is a multi-layer board structure; in some embodiments, such as... Figure 3 As shown, the multilayer board structure includes a microwave substrate 1 and an adhesive sheet 2, which are stacked alternately. The cross-section of the multilayer board structure is a regular shape, for example, a rectangular cross-section. Figure 1 The cross-section shown is square. In some embodiments, the multilayer board structure extends horizontally to form an outwardly expanding edge, and its four corners are provided with through mounting holes 14. The antenna body of this application embodiment uses a multilayer board, which simplifies the processing method and completes the antenna feeding based on a coaxial direct feed structure, thereby improving the reliability of the antenna.

[0015] Floor 3 is a continuous metal layer printed on the bottom layer of the multilayer board structure, used for the common ground of high-frequency antenna and low-frequency antenna; The low-frequency cavity 4 includes multiple first short-circuit pillars arranged in a square shape, and the height of the first short-circuit pillars is consistent with the height of the layer where the low-frequency oscillator 6 is located.

[0016] The high-frequency cavity 5 includes multiple second short-circuit posts, which are arranged in a cross shape based on the low-frequency cavity 4, so that the low-frequency cavity 4 and the high-frequency cavity 5 are nested in each other in the horizontal direction, and the height of the second short-circuit posts is consistent with the height of the layer where the high-frequency cavity 5 is located.

[0017] Low-frequency oscillator 6, high-frequency oscillator 7, such as Figure 4 As shown, each includes a pair of inverted L-shaped oscillator units, each of which includes mutually perpendicular radiating arms. The pair of inverted L-shaped oscillator units are in a cross shape and are printed on a designated layer of the microwave substrate 1 of the multilayer board structure.

[0018] The coupling plate 8 includes multiple sets, with each set of coupling plates 8 corresponding to a high-frequency oscillator 7. The coupling plate 8 has a chamfered rectangular structure. The set of coupling plates 8 is arranged around the center of the high-frequency oscillator 7 and located in the gap between the radiating arms of the high-frequency oscillator 7. Each coupling plate 8 is connected to the floor 3 through a short-circuit post 9.

[0019] The antenna in this application suppresses surface waves by adding cavities, and the cavities of the high- and low-frequency antennas are arranged with reasonable array spacing to achieve the sharing of some cavity arms, thereby improving the complexity of the structure while achieving a high degree of isolation.

[0020] In some embodiments, such as Figure 1 , Figure 4 As shown, the low-frequency oscillator 6 and the high-frequency oscillator 7 comprise a pair of inverted L-shaped oscillator units, which are arranged in a cross shape after being rotated 90 degrees relative to each other; wherein, The low-frequency oscillator 6 and the high-frequency oscillator 7 are printed on different layers of the microwave substrate 1. The upper-layer oscillator is connected to the low-frequency inner conductor 11 or the high-frequency inner conductor 13, and the lower-layer oscillator is connected to the low-frequency outer conductor 10 or the high-frequency outer conductor 12. In a specific example, such as... Figure 1 , Figure 4 As shown, the low-frequency oscillator 6 is divided into an upper oscillator and a lower oscillator. The upper oscillator of the low-frequency oscillator 6 is connected to the low-frequency inner conductor 11, and the lower oscillator of the low-frequency oscillator 6 is connected to the low-frequency outer conductor 10. Similarly, the high-frequency oscillator 7 is divided into an upper oscillator and a lower oscillator. The upper oscillator of the high-frequency oscillator 7 is connected to the high-frequency inner conductor 13, and the lower oscillator of the high-frequency oscillator 7 is connected to the high-frequency outer conductor 12.

[0021] In some embodiments, the low-frequency inner conductor 11, the low-frequency outer conductor 10, the high-frequency inner conductor 13, and the high-frequency outer conductor 12 constitute a power supply network based on a coaxial direct feed structure.

[0022] In a specific example, the low-frequency oscillator is 6, and the high-frequency oscillator is 7, such as... Figure 5 As shown, the elements are arranged in a cross shape and printed at the corresponding frequency band height. Both the low-frequency oscillator 6 and the high-frequency oscillator 7 include an upper oscillator and a lower oscillator. The inner conductor is connected to one oscillator, and the outer conductor is connected to the other oscillator. The coupling piece 8 is printed in the gap of the high-frequency oscillator wall and is grounded through a short-circuit post.

[0023] In some embodiments, the number of a set of coupling plates 8 is 4, and the set of coupling plates 8 is coupled with a pair of high-frequency oscillators 7, and the heights are consistent.

[0024] In some embodiments, the coupling plate 8 is used in conjunction with the high-frequency oscillator 7 to broaden the impedance bandwidth and axial ratio bandwidth of the high-frequency oscillator 7; and the coupling plate 8 is used in conjunction with the low-frequency oscillator 6 to reduce the profile height of the low-frequency oscillator 6 based on the artificial magnetic conductor AMC.

[0025] In some embodiments, the length and width of the radiating arm of the low-frequency vibrator 6 or the high-frequency vibrator 7 are changed, as well as the positions of the first short-circuit post and the second short-circuit post are changed, to adjust the operating frequency and axial bandwidth of the antenna.

[0026] In some embodiments, the feed line of the inverted L-shaped dipole element is an L-shaped microstrip line. By adjusting the radius of the ring in the L-shaped microstrip line, the matching characteristics within the antenna's operating frequency band are adjusted. Furthermore, the profile height of the low-frequency antenna is adjusted by changing the height and position of the coupling plate.

[0027] This application's cavity-shared dual-frequency circularly polarized common-aperture antenna utilizes a single-feed circularly polarized unit, simplifying the antenna feeding structure and enabling integrated fabrication using multilayer board technology. By adding cavities, surface wave suppression is achieved. The cavities of the high- and low-frequency antennas are arranged with reasonable array spacing to share some cavity arms. Furthermore, the low-frequency vibrator utilizes the AMC principle to reduce its profile using a high-frequency coupling plate, thus improving structural complexity while achieving high isolation. The high-frequency vibrator design employs coupling plate grounding and chamfered rotation to achieve a wider impedance bandwidth and axial ratio bandwidth. The low-frequency vibrator cleverly utilizes the grounding coupling plate of the high-frequency vibrator to achieve a profile reduction effect based on the AMC principle.

[0028] This application also proposes a communication system, including the aforementioned cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC.

[0029] It should be noted that, in the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0030] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0031] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC, characterized in that, include: The antenna body is a multi-layer board structure; The floor (3) is a continuous metal layer printed on the bottom layer of the multilayer board structure and is used for the common ground of high frequency antenna and low frequency antenna. The low-frequency cavity (4) includes multiple first short-circuit pillars arranged in a square shape, and the height of the first short-circuit pillars is consistent with the height of the layer where the low-frequency oscillator (6) is located. The high-frequency cavity (5) includes multiple second short-circuit posts, which are arranged in a cross shape based on the low-frequency cavity (4) so ​​that the low-frequency cavity (4) and the high-frequency cavity (5) are nested in each other in the horizontal direction. The height of the second short-circuit posts is consistent with the height of the layer where the high-frequency cavity (5) is located. The low-frequency oscillator (6) and the high-frequency oscillator (7) each include a pair of inverted L-shaped oscillator units. Each of the inverted L-shaped oscillator units includes mutually perpendicular radiating arms. The pair of inverted L-shaped oscillator units are in a cross shape and are printed on a designated layer of the microwave substrate (1) of the multilayer board structure. The coupling plate (8) includes multiple sets, with each set of coupling plates (8) corresponding to a high-frequency oscillator (7). The coupling plate (8) is a chamfered rectangular structure, arranged around the center of the high-frequency oscillator (7), and located in the gap between the radiating arms of the high-frequency oscillator (7). Each coupling plate (8) is connected to the floor (3) through a short-circuit post (9).

2. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 1, characterized in that, The multilayer board structure includes a microwave substrate (1) and an adhesive sheet (2), which are stacked alternately. The cross-section of the multilayer board structure is a regular shape. The multi-layer board structure extends horizontally to form an outwardly expanding edge, and its four corners are provided with through mounting holes (14).

3. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 2, characterized in that, The low-frequency oscillator (6) and the high-frequency oscillator (7) comprise a pair of inverted L-shaped oscillator units, which are arranged in a cross shape after being rotated 90 degrees relative to each other; wherein, The low-frequency oscillator (6) and the high-frequency oscillator (7) are printed on different layers of the microwave substrate (1). The upper oscillator is connected to the low-frequency inner conductor (11) or the high-frequency inner conductor (13), and the lower oscillator is connected to the low-frequency outer conductor (10) or the high-frequency outer conductor (12).

4. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 3, characterized in that, The low-frequency inner conductor (11), low-frequency outer conductor (10), high-frequency inner conductor (13), and high-frequency outer conductor (12) constitute a power supply network based on a coaxial direct feed structure.

5. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 1, characterized in that, The number of a set of coupling plates (8) is 4. A set of coupling plates (8) is matched with a pair of high-frequency oscillators (7) and the height is consistent.

6. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 5, characterized in that, The coupling plate (8) is used in conjunction with the high-frequency oscillator (7) to broaden the impedance bandwidth and axial ratio bandwidth of the high-frequency oscillator (7); and, The coupling plate (8) is used in conjunction with the low-frequency oscillator (6) to reduce the profile height of the low-frequency oscillator (6) based on the artificial magnetic conductor (AMC).

7. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 3, characterized in that, The operating frequency and axial bandwidth of the antenna are adjusted by changing the length and width of the radiating arm of the low-frequency vibrator (6) or the high-frequency vibrator (7), and by changing the positions of the first short-circuit post and the second short-circuit post.

8. The cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in claim 1, characterized in that, The feed line of the inverted L-shaped vibrator element is an L-shaped microstrip line. By adjusting the radius of the ring in the L-shaped microstrip line, the matching characteristics within the antenna's operating frequency band can be adjusted.

9. A communication system, characterized in that, Including the cavity-shared dual-frequency circularly polarized common-aperture antenna based on AMC as described in any one of claims 1-8.

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