Small array of folding multi-mode structure

Abstract

The invention discloses a small array with a folding multi-mode structure, which belongs to the technical field of satellite communication, is based on a passive beam forming network and comprises a radiation array and a folding multi-mode beam forming network, the lower layer structure and the upper layer structure of the folding multimode beam forming network are in close contact, and energy coupling transmission is achieved. The multimode beam forming network does not need to use a large number of couplers, and the problems of huge size and high structural complexity caused by passive networks such as a Blass matrix and a Butler matrix are fundamentally solved. Compared with a traditional multi-mode beam forming network, the multi-mode beam forming network has the advantage that the size is halved through the elaborate optimization design of the folding structure. The design has a wide application prospect in the current miniaturized and portable mobile satellite communication equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communications, and more specifically, relates to a small array with a folded multi-mode structure. Background Art

[0002] Satellite communications are widely used in various fields because of their wide coverage and unconstrained geographical conditions. However, due to the long communication distance, especially in the millimeter wave frequency band, the path loss and shielding caused by electromagnetic waves will significantly reduce the signal-to-noise ratio. In order to ensure stable and effective communication, satellite communications must rely on high-gain terminal equipment to concentrate the radiation and reception of weak signals. To achieve this goal, satellite communication antenna design needs to adopt a relatively narrow beam width while ensuring a wide coverage range.

[0003] The millimeter-wave multi-beam antenna based on the passive beamforming network has the advantages of low cost and low loss. It can generate multiple high-gain independent directional beams to cover the expected large angle range and has broad application prospects in the field of satellite communications. Butler matrix and BLASS matrix are the current mainstream passive beamforming network architectures. The traditional Butler matrix consists of fixed phase shifters, cross couplers and 90° bridges. These components work together in the Butler matrix to generate multiple orthogonal beams. With the development of technology, the modern Butler matrix has been optimized and improved in many ways, such as introducing 180° couplers and substrate integrated waveguide (SIW) structures, to meet the high frequency and wide coverage application requirements of today's satellite communications. A large number of couplers and phase shifters are required in the Butler matrix, and its layout and structure are relatively complex. In contrast, the BLASS matrix, as a more flexible beamforming network, can generate any number of beams with any direction. It uses a multi-channel traveling wave feeding method and cooperates with directional couplers on the feeder path to achieve power and phase distribution, thereby realizing multi-beam function. However, despite the use of planar transmission technologies such as SIW to help the above-mentioned multi-beam antennas achieve miniaturization and integration, there is still the problem of large size in their design and implementation. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention proposes a small array of a folded multi-mode structure.

[0005] To achieve the above-mentioned purpose, the present invention provides a small array of a folded multi-mode structure, based on a passive beamforming network, including a radiation array and a folded multi-mode beamforming network; the lower structure and the upper structure of the folded multi-mode beamforming network are in close contact to realize energy coupling transmission.

[0006] In some optional embodiments, the radiation array is N radiation units arranged in an equidistant linear array with a half-wavelength length.

[0007] In some optional embodiments, the radiating unit is a circularly polarized antenna.

[0008] In some optional implementations, the circularly polarized antenna is an X-shaped slot circularly polarized antenna.

[0009] In some optional embodiments, the folded multimode beamforming network is a folded multimode beamforming network structure having N input ports and N output ports; the multimode beamforming network structure distributes equal power values ​​to the signals input to each port, and outputs equal power signals with fixed phase differences at the N output ports.

[0010] In some optional embodiments, the folded multi-mode beamforming network structure refers to spatially folding the multi-mode beamforming network, where a portion of the entire multi-mode network is located in the lower structure and the other portion is located in the upper structure, and energy coupling transmission is performed between the lower structure and the upper structure.

[0011] In some optional embodiments, the multimode beamforming network structure consists of two waveform converters, a multimode cavity and a supplementary phase shifter, wherein the waveform converter is located in the lower structure, the waveform converter and the supplementary phase shifter are located in the upper structure, half of the multimode cavity is located in the lower structure, and the other half is located in the upper structure.

[0012] In some optional embodiments, the energy coupling refers to coupling gaps of the same shape at the same positions on the top of the lower structure and the bottom of the upper structure.

[0013] In some optional embodiments, the coupling gap is a rectangular coupling gap.

[0014] In some optional embodiments, the close contact can be close contact between the copper layers of two PCB boards; the folded multimode beamforming network is a substrate integrated waveguide SIW structure, which is composed of a lower PCB board and an upper PCB board; the top copper layer of the lower PCB board and the bottom copper layer of the upper PCB board are dug out with a coupling gap, and the two copper layers are tightly connected under force.

[0015] In some optional embodiments, the close contact can be that the outer walls of the waveguides of the two-layer rectangular waveguide structure are in close contact; the folded multimode beamforming network is a waveguide structure, which consists of an upper waveguide structure and a lower waveguide structure; a coupling gap is dug out at the bottom of the upper waveguide and the top of the lower waveguide, and the two waveguides are tightly connected by force.

[0016] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0017] 1) Compared with the existing technology, the multimode beamforming network does not need to use a large number of couplers, which fundamentally solves the problems of large size and high structural complexity brought by passive networks such as Blass matrix and Butler matrix.

[0018] 2) Through the careful optimization of the folding structure, the size is halved compared to the traditional multi-mode beamforming network. This design has broad application prospects in today's miniaturized and portable mobile satellite communication equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an example of a small array of a folded multi-mode structure provided by an embodiment of the present invention;

[0020] Figure 2 It is a structural schematic diagram of a folded multi-mode feeding network provided by an embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of a small array structure of a folded multi-mode structure provided by an embodiment of the present invention;

[0022] Figure 4 It is the far-field pattern characteristic of a small array with a folded multi-mode structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] The present invention provides a small array of folded multi-mode structure, which is designed for use in the 29 GHz Ka satellite frequency band. Figure 1 As shown, the array is a double-layer folded structure, including a radiation array 1 and a folded multi-mode beamforming network 2; the lower structure 21 and the upper structure 22 of the folded multi-mode beamforming network are in close contact to achieve energy coupling transmission.

[0025] Furthermore, the radiation array 1 is composed of N radiation units 11 arranged in an equidistant linear array with a half-wavelength length.

[0026] Furthermore, the multimode beamforming network 2 consists of two waveform converters, a multimode cavity and a supplementary phase shifter, wherein the waveform converter 24 is located in the lower structure 21, the waveform converter 25 and the supplementary phase shifter 26 are located in the upper structure 22, and half of the multimode cavity 27 is located in the lower structure 21, and the other half is located in the upper structure 22.

[0027] Furthermore, energy coupling refers to coupling gaps 23 of the same shape at the same positions on the top of the lower structure 21 and the bottom of the upper structure 22 .

[0028] The small array of folded multimode structure in the embodiment of the present invention adopts substrate integrated waveguide structure 3, which is composed of two single-layer PCB boards. Figure 2 As shown, the folded multimode beamforming network performs spatial folding processing on the multimode beamforming network, and has 4 input ports and 4 output ports. Half of the structure of the entire multimode network is located on the lower PCB board 31, and the other half is located on the upper PCB board 32. The top copper layer 311 of the lower PCB board 31 and the bottom copper layer 321 of the upper PCB board 32 are dug out to remove the coupling gap, and the two copper layers are closely connected by force. Through the coupling gap structure of the aligned positions on the two PCB boards, the electromagnetic wave energy transmission between the two PCB boards is realized, and the overall design of the folded multimode network is completed. In order to offset the impact of performance degradation caused by assembly errors in the actual assembly process, the two PCB boards are treated with differentiated rectangular gap notches. The energy input by the port is fed from the bottom PCB board 31 to the top PCB board 32 through the coupling gap through the folded multimode network, and is distributed to the four channels of the upper layer with equal power amplitude. Subsequently, the phase shift adjustment is performed through the SIW phase shifter 322 to form a phase gradient, and then distributed to the four output ports.

[0029] like Figure 3 As shown, the radiating array of the present invention example is composed of four identical 1×4 linear arrays, which is a 4×4 unit SIW slot antenna array 4. The antenna unit adopts an X-shaped slot circularly polarized antenna design. These four linear array antennas are arranged in an equidistant linear array with a half-wavelength length. Each linear array antenna is designed as a single-ended feeding traveling wave antenna structure. The signals input from the four ports are distributed to the input ports of the radiating array through a folded multimode beamforming network, and radiate four beams with different directions and independent of each other, such as Figure 4 shown.

[0030] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0031] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A small array of folded multi-mode structures, characterized in that: Based on a passive beamforming network, it comprises a radiation array (1) and a folded multimode beamforming network (2); the lower structure (21) and the upper structure (22) of the folded multimode beamforming network (2) are in close contact to achieve energy coupling transmission.

2. The small array of folded multi-mode structures according to claim 1, characterized in that: The radiation array (1) comprises N radiation units (11) arranged in an equidistant linear array with a half-wavelength length.

3. The small array according to claim 2, characterized in that: The radiation unit (11) is a circularly polarized antenna.

4. The small array of folded multi-mode structures according to claim 3, characterized in that: The circularly polarized antenna is an X-shaped slot circularly polarized antenna.

5. The small array of folded multi-mode structures according to claim 1, characterized in that: The folded multimode beamforming network (2) is a folded multimode beamforming network structure having N input ports and N output ports; the multimode beamforming network structure distributes equal power values ​​to the signals input to each port, and outputs equal power signals with fixed phase differences at the N output ports.

6. The small array of folded multi-mode structures according to claim 5, characterized in that: The folded multi-mode beamforming network structure refers to a multi-mode beamforming network that is spatially folded, wherein a portion of the entire multi-mode network is located in a lower structure (21) and another portion is located in an upper structure (22), and energy coupling transmission is performed between the lower structure (21) and the upper structure (22).

7. The small array of folded multi-mode structures according to claim 6, characterized in that: The multimode beamforming network structure consists of two waveform converters, a multimode cavity and a supplementary phase shifter, wherein the waveform converter (24) is located in the lower structure (21), the waveform converter (25) and the supplementary phase shifter (26) are located in the upper structure (22), and half of the multimode cavity (27) is located in the lower structure (21) and the other half is located in the upper structure (22).

8. The small array of folded multi-mode structures according to claim 6, characterized in that: The energy coupling refers to coupling gaps of the same shape at the same positions on the top of the lower structure (21) and the bottom of the upper structure (22).

9. The small array of folded multi-mode structures according to claim 8, characterized in that: The coupling gap (23) is a rectangular coupling gap.

10. The small array of folded multi-mode structures according to claim 1, characterized in that: The close contact may be close contact between copper layers of two PCB boards; the folded multimode beamforming network (2) is a substrate integrated waveguide (SIW) structure (3), which is composed of a lower PCB board (31) and an upper PCB board (32); a coupling gap is dug out between the top copper layer (311) of the lower PCB board (31) and the bottom copper layer (321) of the upper PCB board (32), and the two copper layers are closely connected under force.

11. The small array of folded multi-mode structures according to claim 1, characterized in that: The close contact may be that the outer walls of the waveguides of the two rectangular waveguide structures are in close contact; the folded multimode beamforming network (2) is a waveguide structure, which is composed of an upper waveguide structure and a lower waveguide structure; coupling gaps are dug out at the bottom of the upper waveguide and the top of the lower waveguide, and the two waveguides are closely connected under force.

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