Structural multiplexing microwave / millimeter wave dual-band broadband co-aperture antenna

Abstract

The application provides a microwave / millimeter wave dual-frequency broadband common-aperture antenna with structural multiplexing, which comprises a metal floor, a waveguide power divider, a Г-shaped feeding structure, two substrate integrated waveguide arrays, a coaxial joint and a coaxial-waveguide adapter. The waveguide power divider is a power divider with two branches, the Г-shaped feeding structure is located between the two branches of the waveguide power divider, and the T-shaped joint part of the waveguide power divider is located below the metal floor, and the two output branches extend upwards through the metal floor; the two substrate integrated waveguide arrays are arranged at the ends of the two output branches of the waveguide power divider, and the two substrate integrated waveguide arrays are identical in structure and size and are symmetrically arranged about the x-axis; the coaxial joint is used for feeding a dipole antenna, and the coaxial-waveguide adapter is used for feeding the two substrate integrated waveguide arrays. The application has the advantages of simple structure, high structural multiplexing rate, wide band, stable in-band performance, high isolation and the like.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure. Background Technology

[0002] In contemporary wireless communication systems, the coexistence of microwave and millimeter-wave frequencies is a significant development trend. On one hand, the abundant spectrum resources of the millimeter-wave band are needed to achieve higher data transmission rates, greater bandwidth, and lower latency. On the other hand, the microwave band, considered the "golden band" for wireless communication, continues to be highly valued for its low loss, high efficiency, and stability. Against this backdrop, antennas in wireless communication systems are no longer single units or simple arrays, but rather multi-antenna, multi-frequency coexisting antenna systems. This presents a significant challenge to the miniaturization and integration of the entire antenna system. To address this issue, a common-aperture antenna scheme utilizing the principle of structural reuse has been proposed. This scheme organically combines two antennas operating in the microwave and millimeter-wave bands respectively, achieving dual-band microwave and millimeter-wave functionality. Because the two antennas are structurally reused, the miniaturization and high integration of the antenna system can be effectively achieved.

[0003] Key issues to consider in the design of such antennas include: 1) Aperture reuse rate. This is a key parameter for measuring the reuse of microwave and millimeter-wave antennas, and it also indicates the miniaturization and integration of the antenna system; 2) Antenna performance. This is the core issue in the design of co-aperture antennas. Ideally, the performance of the reused antenna should be basically the same as or higher than that before reuse, and the microwave and millimeter-wave antennas should not affect each other (high isolation); 3) Due to the high atmospheric loss in the millimeter-wave band, a high-gain antenna array should be used in this band to ensure communication quality. Currently, there are some research reports on co-aperture antennas with structural reuse. References [1-4] propose patch / dielectric resonator arrays, patch / substrate integrated waveguide slot arrays, metasurface / substrate integrated waveguide slot arrays, and dipole / horn reuse co-aperture antenna schemes, respectively. Although they can effectively realize microwave and millimeter-wave dual-band, they have some shortcomings in terms of aperture reuse rate and antenna performance (bandwidth, isolation, millimeter-wave band gain, etc.), and cannot meet people's usage needs.

[0004] [1]X.-H. Ding, W.-W. Yang, W. Qin, and J.-X. Chen, “A broadside shared aperture antenna for (3.5, 26) GHz mobile terminals with steerable beam in millimeter-waveband,” IEEE Transactions on Antennas and Propagation, vol. 70, no. 3, pp. 1806–1815, Mar. 2022.

[0005] [2]J. F. Zhang, Y. J. Cheng, Y. R. Ding, and C. X. Bai, “A dual-band shared-aperture antenna with large frequency ratio, high aperture reuse efficiency, and high channel isolation,” IEEE Transactions on Antennas and Propagation, vol. 67, no. 2, pp. 853–860, Feb. 2019.

[0006] [3]T. Li and Z. N. Chen, “Metasurface-based shared-aperture 5G S / K-band antenna using characteristic mode analysis,” IEEE Transactions on Antennas and Propagation, vol. 66, no. 12, pp. 6742–6750, Dec. 2018.

[0007] [4]Y. Cheng and Y. Dong, “Dual-broadband dual-polarized shared-aperture magnetoelectric dipole antenna for 5G applications,” IEEE Transactions on Antennas and Propagation, vol. 69, no. 11, pp. 7918–7923, Nov. 2021. Invention Content

[0008] To address the problems existing in the prior art, this invention provides a microwave / millimeter-wave dual-band broadband common-aperture antenna with a reusable structure. Utilizing the equivalent principle of substrate-integrated waveguide arrays and metal patches, a dipole antenna and a substrate-integrated waveguide array are organically combined through structural reuse, proposing a microwave / millimeter-wave dual-band common-aperture antenna scheme. Compared to reported traditional designs, this invention has advantages such as simple structure, high structural reuse rate, broadband and stable in-band performance, and high isolation.

[0009] To achieve the objectives of this invention, the present invention provides a microwave / millimeter-wave dual-band broadband common-aperture antenna with a reusable structure, comprising a metal ground plane, a waveguide power divider, a U-type feed structure, two substrate integrated waveguide arrays, a coaxial connector, and a coaxial-waveguide adapter.

[0010] The waveguide power divider is a one-to-two power divider. The Г-type feed structure is located between the two paths of the waveguide power divider, and the T-junction of the waveguide power divider is located below the metal ground plane. The two output paths bend 90 degrees and extend upward through the metal ground plane.

[0011] Two substrate integrated waveguide arrays are respectively set at the ends of the two output paths of the waveguide power divider. The two substrate integrated waveguide arrays are identical in structure and size and are placed symmetrically about the x-axis.

[0012] Coaxial connectors are used to feed dipole antennas, while coaxial-waveguide adapters are used to feed two substrate integrated waveguide arrays.

[0013] Furthermore, the Г-type power supply structure is a microstrip line structure based on a PCB.

[0014] Furthermore, the waveguide power divider employs an air-filled rectangular waveguide structure.

[0015] Furthermore, it also includes a first support structure, which is used to support the fixed Г-type power supply structure.

[0016] Furthermore, a second support structure is provided at the end of each of the two output paths of the waveguide power divider, and the two substrate integrated waveguide arrays are respectively fixed on the two second support structures.

[0017] Furthermore, the metal floor, waveguide power divider, first support structure, and second support structure are integrally formed using metal 3D printing technology.

[0018] Furthermore, each substrate integrated waveguide array includes, from bottom to top, a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a third dielectric substrate, and a fourth metal layer. The first metal layer has two rectangular slots parallel to the y-axis. A first power divider is disposed on the first dielectric substrate, and a first coupling slot is disposed on the second metal layer at the end of each path of the first power divider. A second power divider is disposed on the second dielectric substrate, and a second coupling slot is disposed on the third metal layer at the end of each path of the second power divider. The fourth metal layer is a 4*4 patch array, and the patches correspond one-to-one with the second coupling slots.

[0019] Furthermore, the first power divider is a substrate integrated waveguide power divider that splits from one to four channels.

[0020] Furthermore, the second power divider is a substrate-integrated waveguide power divider that splits from one to four channels, and it is arranged in a 2*2 configuration on the second dielectric substrate.

[0021] Furthermore, both the substrate-integrated waveguide array and the Γ-type feed structure are manufactured using printed PCB technology.

[0022] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0023] (1) This invention proposes a microwave / millimeter-wave dual-frequency co-aperture antenna scheme that reuses a dipole / substrate integrated waveguide array. This scheme fully considers the key issues in the design of structurally reused co-aperture antennas. By treating the substrate integrated waveguide array as an equivalent metal patch and replacing the two arms of the dipole antenna, microwave / millimeter-wave dual-frequency radiation is achieved. Specifically, in the microwave band, the antenna operates as a dipole, while in the millimeter-wave band, the antenna operates as a substrate integrated waveguide array. The reuse scheme in this invention allows the two antennas in the microwave and millimeter-wave bands to operate relatively independently, thus achieving high isolation while preserving the excellent performance of both antennas as much as possible. Compared to previously reported conventional designs, this invention has advantages such as simple structure, high structural reuse rate, wide bandwidth and stable in-band performance, and high isolation. No similar designs have been proposed in the previously reported literature.

[0024] (2) The present invention proposes a microwave / millimeter-wave dual-band broadband common-aperture antenna with structural reuse. Structurally, the antenna structure is simple and has a high structural reuse rate based on the combination of dipole antenna and substrate integrated waveguide array. In terms of performance, the present invention has the advantages of dual-band broadband (32.5%, 2.73~3.79GHz; 22.5%, 31.25~39.19GHz), high isolation (better than -30dB), and stable in-band performance. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural schematic diagram of a microwave / millimeter-wave dual-frequency broadband common-aperture antenna with structural reuse provided in an embodiment of the present invention.

[0026] Figure 2 This is a top view of a microwave / millimeter-wave dual-band broadband common-aperture antenna with a reusable structure provided in an embodiment of the present invention.

[0027] Figure 3 This is a side view of a microwave / millimeter-wave dual-band broadband common-aperture antenna with a reusable structure provided in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the Г-type power supply structure and the first support structure in an embodiment of the present invention.

[0029] Figure 5 This is a top view of the waveguide power divider and the second support structure in an embodiment of the present invention.

[0030] Figure 6 This is an exploded view of one of the substrate integrated waveguide arrays in an embodiment of the present invention.

[0031] Figure 7 This is a top view of the first metal layer, the second metal layer, and the first dielectric substrate in the substrate integrated waveguide array of this invention.

[0032] Figure 8 This is a top view of the second metal layer, the third metal layer, and the second dielectric substrate in the substrate integrated waveguide array of this invention.

[0033] Figure 9 This is a top view of the third metal layer, the fourth metal layer, and the third dielectric substrate in the substrate integrated waveguide array of this embodiment of the invention.

[0034] Figure 10 This is a schematic diagram showing the relationship between the reflection coefficient and frequency of the antenna provided in the microwave band according to an embodiment of the present invention.

[0035] Figure 11 This is a schematic diagram of the gain characteristics of the antenna provided in the microwave frequency band according to an embodiment of the present invention.

[0036] Figure 12 These are the radiation patterns of the antenna provided in the embodiment of the present invention in the microwave frequency band E-plane (Figure a) and H-plane (Figure b).

[0037] Figure 13 This is a schematic diagram showing the relationship between the reflection coefficient and frequency of the antenna provided in the millimeter-wave band according to an embodiment of the present invention.

[0038] Figure 14 This is a schematic diagram of the gain characteristics of the antenna provided in the millimeter-wave band according to an embodiment of the present invention.

[0039] Figure 15 These are the radiation patterns of the antenna provided in the millimeter-wave band in the E-plane (Figure a) and H-plane (Figure b) of the embodiments of the present invention.

[0040] Figure 16 This is an antenna port isolation curve provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] This invention provides a structure-reused microwave / millimeter-wave dual-band broadband common-aperture antenna. Figures 1 to 3 The images show a full view, a top view, and a side view of the antenna structure, which includes a metal ground plane 11, a Γ-shaped feed structure 12, a waveguide power divider 13, and two substrate integrated waveguide arrays 14.

[0043] The Γ-type feed structure 12 is a PCB-based microstrip line structure used for feeding a dipole antenna. In some embodiments of the present invention, the dielectric material of the Γ-type feed structure 12 is Rogers 5880, the thickness is 0.508 mm, and the dielectric constant and loss tangent are 2.2 and 0.0009, respectively.

[0044] The waveguide power divider 13 is a one-to-two power divider, employing an air-filled rectangular waveguide structure for feeding two substrate-integrated waveguide arrays. The Γ-shaped feed structure 12 is located between the two paths of the waveguide power divider 13 and is fixed to the first support structure 41 by screws. Figure 4 As shown. Figure 5 The diagram shows a top view of the waveguide power divider 13. The T-junction portion of the waveguide power divider 13 is located below the metal ground plane 11. The two output paths bend at 90 degrees and extend upwards through the metal ground plane 11. At their ends, two second support structures 51 are respectively provided to fix and support the two substrate integrated waveguide arrays 14. The two substrate integrated waveguide arrays 14 are identical in structure and size and are placed symmetrically about the x-axis.

[0045] Figure 6The diagram shown is an exploded view of one of the substrate integrated waveguide arrays. The substrate integrated waveguide array includes four metal layers and three dielectric substrates, which are arranged from bottom to top as follows: first metal layer 61, first dielectric substrate 62, second metal layer 63, second dielectric substrate 64, third metal layer 65, third dielectric substrate 67 and fourth metal layer 66. Figure 7 The diagram shows a top view of the first metal layer 61, the second metal layer 63, and the first dielectric substrate 62. Two rectangular slots 71 parallel to the y-axis are formed on the first metal layer 61 for feeding electromagnetic waves to the first power divider 73. The first power divider 73 is a substrate integrated waveguide power divider that splits one channel into four. At the end of each of its four channels, four rectangular first coupling slots 72 parallel to the y-axis are formed. The first coupling slots 72 are located on the second metal layer 63, and the first power divider 73 is located on the first dielectric substrate 62. Figure 8 The diagram shows a top view of the second metal layer 63, the third metal layer 65, and the second dielectric substrate 64. The second dielectric substrate 64 is provided with four second power dividers 82 arranged in a 2×2 configuration. Each second power divider 82 is a substrate integrated waveguide power divider that splits one channel into four. At the end of each of its four channels, four rectangular second coupling slots 81 parallel to the x-axis are respectively provided. Figure 9 The diagram shows a top view of the third metal layer 65, the fourth metal layer 67, and the third dielectric substrate 66. The fourth metal layer 67 is a 4×4 patch array, with adjacent columns placed alternately parallel to the x-axis. Each patch corresponds to a second coupling slot 81, and the patch is placed directly above the second coupling slot 81.

[0046] In some embodiments of the present invention, the dielectric material in the substrate integrated waveguide array 14 is Rogers 5880, with a thickness of 0.787 mm, a dielectric constant of 2.2 and a loss tangent of 0.0009.

[0047] In some embodiments of the present invention, the antenna is processed in two parts during manufacturing. The metal ground plane 11, waveguide power divider 13, first support structure 41, and second support structure 51 are integrally formed using metal 3D printing technology. The material can be any good conductor material suitable for 3D printing, such as aluminum, aluminum alloy, or stainless steel. The substrate integrated waveguide array 14 and the Γ-type feed structure 12 are both manufactured using printed PCB technology, with the substrate integrated waveguide array 14 using a multi-layer PCB board lamination process. After processing, all components are fixed with screws. Microwave and millimeter-wave feeds are provided by coaxial connector 42 and coaxial-waveguide adapter 21, respectively.

[0048] In terms of operating principle, due to the high frequency ratio between microwave and millimeter-wave bands (in some embodiments of this invention, taking 3.5GHz and 38GHz as examples, the frequency ratio can reach 10.8), some structures in the substrate integrated waveguide array, such as patches, vias, slots, and multilayer board spacing, can be considered as small polarimetric structures in the microwave band. Therefore, they will not affect the radiation in the microwave band. The decisive factor is the large-area metal part in the array. Thus, the substrate integrated waveguide array can be used as equivalent to a metal patch, and the two arrays constitute the two arms of the dipole antenna. At the same time, since the substrate integrated waveguide array is a unidirectional radiating antenna pointing towards the z-axis, and most of the structure of the dipole antenna is located below the array, the dipole antenna in the microwave band will not affect the millimeter-wave band either. The antennas in the two bands are relatively independent.

[0049] In the microwave band, the antenna is fed by coaxial connector 42, and electromagnetic energy is coupled to the dipole by the Γ-shaped feeding structure 12, and then radiated to the atmosphere by the dipole. In the millimeter-wave band, the substrate integrated waveguide array is fed by the WR-28 standard waveguide, and electromagnetic energy is distributed to the two substrate integrated waveguide arrays in equal amplitude and phase via the waveguide power divider 13. Taking one of the substrate-integrated waveguide arrays as an example, when an electromagnetic wave enters the first dielectric substrate 62, it is coupled to the first power divider 73 by rectangular slots 71 with equal amplitude and opposite phase. Then, the electromagnetic wave is split into four paths in the first power divider 73 and coupled to the four second power dividers 82 in the second dielectric substrate 64 by four rectangular first coupling slots 72 with equal amplitude and opposite phase. In order to ensure that the radiation phase of the array is consistent, the rectangular first coupling slots 72 and second coupling slots 81 on the second metal layer 63 and the third metal layer 65 are all alternately staggered. Finally, the electromagnetic wave is coupled to the patch array 67 through the second coupling slot 81 and then radiates the electromagnetic energy to the atmosphere.

[0050] Regarding antenna performance, when operating in the microwave band, the antenna's reflection coefficient is less than -10dB within the 2.73–3.79GHz range, with a bandwidth of 32.5%. Figure 10 As shown, this indicates that the antenna has good impedance matching in the microwave band; Figure 11 The gain characteristics of the microwave band antenna are shown. Within a -10dB bandwidth, the antenna gain is between 6.68 and 7.9dBi, indicating that the antenna has good gain characteristics in the microwave band. The E-plane and H-plane radiation patterns are shown below. Figure 12 As shown, the radiation pattern is basically consistent with that of a traditional dipole antenna, indicating that the antenna can be equivalent to a dipole working normally in the microwave band. When the antenna operates in the millimeter-wave band, its reflection coefficient is less than -10dB in the range of 31.25–39.19 GHz, with a bandwidth of 22.5%. Figure 13As shown, this demonstrates that the antenna can achieve good impedance matching within this frequency band; the antenna's millimeter-wave band gain characteristics are as follows. Figure 14 As shown, the maximum gain can reach 21.8 dBi, and the antenna gain is located in the range of 19.84 to 21.8 dBi within the -10 dB bandwidth, indicating that the antenna has good gain characteristics in the millimeter wave band and stable gain within the operating frequency band. Figure 15 The E-plane and H-plane radiation patterns for the millimeter-wave band show that the antenna sidelobes are below -13dB and both have low back lobes; the port isolation curve of this common-aperture antenna is shown below. Figure 16 As shown, the curve is less than -30dB within the frequency band, indicating that the isolation between the two ports is good and the antennas of the two frequency bands work independently.

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure, characterized in that, It includes a metal ground plane (11), a waveguide power divider (13), a Γ-type feed structure (12), two substrate integrated waveguide arrays (14), a coaxial connector (42), and a coaxial-waveguide adapter (21). The waveguide power divider (13) is a one-to-two power divider. The Г-type feed structure (12) is located between the two output paths of the waveguide power divider (13), and the T-junction part of the waveguide power divider (13) is located below the metal floor (11). The two output paths bend 90 degrees and extend upward through the metal floor (11). Two substrate integrated waveguide arrays (14) are respectively set at the ends of the two output paths of the waveguide power divider (13). The two substrate integrated waveguide arrays (14) are identical in structure and size and are placed symmetrically about the x-axis. When operating in the microwave band, the antenna works as a dipole and is fed through a coaxial connector (42); when operating in the millimeter wave band, the antenna works as a substrate integrated waveguide array and is fed through a coaxial-waveguide adapter (21).

2. The microwave / millimeter-wave dual-band broadband common-aperture antenna with multiplexed structure according to claim 1, characterized in that, The Г-type power supply structure (12) is a microstrip line structure based on PCB.

3. The microwave / millimeter-wave dual-band broadband common-aperture antenna with multiplexed structure according to claim 1, characterized in that, The waveguide power divider (13) adopts an air-filled rectangular waveguide structure.

4. The microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to claim 1, characterized in that, It also includes a first support structure (41), which is used to support the fixed Г-type power supply structure (12).

5. The microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to claim 4, characterized in that, The two output paths of the waveguide power divider (13) are each provided with a second support structure (51), and the two substrate integrated waveguide arrays (14) are respectively fixed on the two second support structures (51).

6. The microwave / millimeter-wave dual-band broadband common-aperture antenna with multiplexed structure according to claim 5, characterized in that, The metal floor (11), waveguide power divider (13), first support structure (41) and second support structure (51) are integrally formed using metal 3D printing technology.

7. The microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to claim 1, characterized in that, Each substrate integrated waveguide array (14) includes, from bottom to top, a first metal layer (61), a first dielectric substrate (62), a second metal layer (63), a second dielectric substrate (64), a third metal layer (65), a third dielectric substrate (66), and a fourth metal layer (67). The first metal layer (61) has two rectangular slots (71) parallel to the y-axis. The first dielectric substrate (62) has a first power divider (73). The second metal layer (63) has a first coupling slot (72) at the end of each path of the first power divider (73). The second dielectric substrate (64) has a second power divider (82). The third metal layer (65) has a second coupling slot (81) at the end of each path of the second power divider (82). The fourth metal layer (67) is a 4*4 patch array, and the patches correspond one-to-one with the second coupling slots (81).

8. A microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to claim 7, characterized in that, The first power divider (73) is a substrate integrated waveguide power divider that splits one power into four.

9. A microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to claim 7, characterized in that, The second power divider (82) is a substrate integrated waveguide power divider that splits one channel into four channels, and is arranged in a 2*2 configuration on the second dielectric substrate (64).

10. A microwave / millimeter-wave dual-band broadband common-aperture antenna with a multiplexed structure according to any one of claims 1-9, characterized in that, Both the substrate integrated waveguide array (14) and the Γ-type feed structure (12) are manufactured using printed PCB technology.

Images