Compact cross orthogonal scanning multilayer millimeter wave multi-beam array antenna

Abstract

The invention discloses a compact cross orthogonal scanning multilayer millimeter wave multi-beam array antenna, which comprises a dual-port common-cavity Rotmann lens feed network structure and a common-caliber antenna layer, and is characterized in that the dual-port common-cavity Rotmann lens feed network structure is located at a bottom layer, and the common-caliber antenna layer is located above the common-cavity Rotmann lens feed network structure; the common-aperture antenna layer comprises a slot antenna layer and a patch antenna layer, the slot antenna layer is located at the bottom layer, and the patch antenna layer is located above the slot antenna layer. According to the invention, the return loss of each port is reduced, the reflection of incident waves at the edge ports is reduced, the isolation degree between the ports and between the two sub-lenses is increased, and the working efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of Rotman lens multi-beam antennas, and in particular relates to a compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna. Background Art

[0002] In wireless communication systems, multi-beam antennas are becoming an increasingly indispensable component. Multi-beam antennas can switch the beam direction along a specific axis. Beam scanning antennas have been used in various scenarios such as wireless communication, radar, and imaging. In recent years, multi-beam scanning antennas fed by circuit-type or quasi-optical beamforming networks have become ideal candidates for future B5G / 6G applications.

[0003] In the field of beam scanning, in addition to one-dimensional and two-dimensional beam scanning, there is also a type of orthogonal beam scanning that is worth noting. Orthogonal beam scanning is achieved by arranging two one-dimensional beam scanning antennas orthogonally and scanning in the azimuth and elevation planes at the same time. It is a two-dimensional plane scanning method. Conventional multi-beam antennas generally achieve one-dimensional linear scanning. To achieve orthogonal scanning, the beam needs to have a certain pointing angle in both the elevation plane and the horizontal plane, which puts forward new requirements for the design of the feed network. Therefore, the integration of the orthogonal scanning system has become a major problem. Summary of the invention

[0004] The purpose of the present invention is to provide a compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna, which reduces the return loss of each port, reduces the reflection of the incident wave at the edge port, increases the isolation between ports and between two sub-lenses, and improves work efficiency.

[0005] In order to achieve the purpose of the present invention, the present invention provides a compact cross-orthogonal scanning multi-layer millimeter-wave multi-beam array antenna, including a dual-port common-cavity Rotman lens feeding network structure and a common-aperture antenna layer, wherein the dual-port common-cavity Rotman lens feeding network structure is located at the bottom layer, and the common-aperture antenna layer is located above the common-cavity Rotman lens feeding network structure.

[0006] The common-aperture antenna layer includes a slot antenna layer and a patch antenna layer, the slot antenna layer is located at the bottom layer, and the patch antenna layer is located above the slot antenna layer.

[0007] The dual-port common-cavity Rotman lens feeding network structure comprises a power-division dual-port feeding structure, a common-cavity Rotman lens structure, a double-layer transition structure and a triple-layer transition structure; the power-division dual-port feeding structure constitutes the feed source profile of the common-cavity Rotman lens; the common-cavity Rotman lens structure is composed of two orthogonal Rotman lens structures; the double-layer transition structure is located on the inner array profile of the common-cavity Rotman lens, and the three-layer transition structure is located on another inner array profile of the common-cavity Rotman lens, so as to realize energy propagation between different layers.

[0008] The slot antenna layer includes a slot antenna, a slot antenna array unit, and an offset hole; the slot antenna is a rectangular slot for radiating energy outward; the slot antenna array unit is formed by an array of ten slot antennas, and the ten slot antenna array units are arranged horizontally; the offset hole is located in a cut resonant cavity in a substrate integrated waveguide.

[0009] The patch antenna layer includes a microstrip line antenna, a radiation cavity, and a horn-shaped transition structure; the microstrip line antenna is arranged longitudinally, and a total of ten microstrip line antennas are arranged; the radiation cavity is embedded in the microstrip line antenna in a 10*10 array; the horn-shaped transition structure is located at the input end of the microstrip line antenna, and there are ten of them, which are used to transition energy from the substrate integrated waveguide to the microstrip line.

[0010] Compared with the prior art, the significant progress of the present invention is as follows: (1) The present invention constructs a power-dividing dual-port excitation, and the input port adopts a dual-port feeding method, which replaces the horn-type transition of the traditional structure, effectively improving the isolation between the input ports. The dual-port excitation improves the concentration of the incident wave and reduces the scattering of electromagnetic energy in the cavity, thereby reducing the coupling between the two sub-lenses, improving the working efficiency of the feeding network, and improving the isolation between the ports of the feeding network, thereby reducing the insertion loss; (2) The present invention proposes a new radiation component, which integrates the patch antenna array and the slot antenna array into a common aperture design to form a new common aperture antenna, so that the entire array antenna is compactly arranged and forms a two-dimensional plane adjustable scanning beam in the orthogonal radiation area direction; (3) The present invention uses multi-layer slot coupling to realize the effective integration of the feeding network and the radiation aperture, and separates the output ports of the two sub-networks through multi-layer conversion respectively. The entire feeding network is hidden under the radiation aperture through the slot coupling design, thereby forming a compact orthogonal scanning system, improving the system integration and reducing the total area of ​​the working system.

[0011] In order to more clearly illustrate the functional characteristics and structural parameters of the present invention, further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 It is a schematic diagram of the structure of the dual-port common-cavity Rotman lens feeding network of the present invention;

[0015] Figure 3 Schematic diagram of the slot antenna layer structure of the present invention, wherein (a) is a schematic diagram of the entire layer structure, and (b) is a schematic diagram of the array unit structure;

[0016] Figure 4 Schematic diagram of the patch antenna layer structure of the present invention, wherein (a) is a schematic diagram of the entire layer structure, and (b) is a schematic diagram of the array unit structure;

[0017] Figure 5 It is a schematic diagram of the overall structure of the common aperture antenna of the present invention;

[0018] Figure 6 1 is a comparison diagram of the electric field distribution brought about by the dual-port excitation of the present invention and the single-port excitation, wherein (a) is the electric field distribution of the dual-port excitation, and (b) is the electric field distribution of the single-port excitation;

[0019] Figure 7 It is the design principle diagram of the present invention;

[0020] Figure 8 1 is a comparison diagram of the reflection coefficients of the simulation and the test of the present invention, wherein (a) is the reflection coefficient when the ports #1 to #5 are fed, and (b) is the reflection coefficient when the ports #6 to #10 are fed;

[0021] Fig. 9 Schematic diagram of the main polarization scanning angle and gain of the antenna radiation of the present invention, wherein (a) is the radiation situation of ports #1 to #5, and (b) is the radiation situation of ports #6 to #10.

[0022] The reference numerals in the figure are: 1. Dual-port common-cavity Rotman lens feeding network structure; 2. Common-aperture antenna layer; 3. Slot antenna layer; 4. Patch antenna layer; 1-1. Power-sharing dual-port feeding structure; 1-2. Common-cavity Rotman lens structure; 1-3. Double-layer transition structure; 1-4. Three-layer transition structure; 3-1. Slot antenna; 3-2. Slot antenna array unit; 3-3. Offset hole; 4-1. Microstrip antenna; 4-2. Radiating cavity; 4-3. Horn-shaped transition structure. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] A compact cross-orthogonal scanning multi-layer millimeter-wave multi-beam array antenna of the present invention comprises a dual-port common-cavity Rotman lens feeding network structure 1 and a common-aperture antenna layer 2, wherein the dual-port common-cavity Rotman lens feeding network structure 1 is located at the bottom layer, and the common-aperture antenna layer 2 is located directly above the common-cavity Rotman lens feeding network structure 1.

[0025] The common-aperture antenna layer 2 includes a slot antenna layer 3 and a patch antenna layer 4, wherein the slot antenna layer 3 is located at the bottom layer and the patch antenna layer 4 is located directly above the slot antenna layer 3; the entire working system has three layers in total, and electrical interconnection is achieved in the vertical direction.

[0026] Combination Figure 2 The dual-port common cavity Rotman lens feeding network structure 1 is the first antenna layer, including a power-dividing dual-port feeding structure core 1, a common cavity Rotman lens structure core 2, a double-layer transition structure core 3, and a triple-layer transition structure core 4; the power-dividing dual-port feeding structure core 1 constitutes the feed source profile of the common cavity Rotman lens core 2, replacing the traditional single port and dividing the energy of the input port into two; the common cavity Rotman lens structure core 2 is composed of two orthogonal Rotman lens structures, the central operating frequency is set at 28GHz, and the focal length of the Rotman lens is F=65mm, focal diameter ratio is 1.1; the double-layer transition structure core 3 is located on the inner array contour of the common cavity Rotman lens, and the triple-layer transition structure core 4 is located on another inner array contour of the common cavity Rotman lens. Double-layer and triple-layer transition layers are designed above the different output ports of the two orthogonal groups of sub-lenses, respectively. Each transition layer consists of a metallized through-hole array with a diameter of 0.508mm and a spacing of 0.8mm and a gap at the bottom, which is used to isolate the transmission channels between different layers and to realize the propagation of energy between different layers.

[0027] Combination Figure 3 (a), the slot antenna layer 3 is the second antenna layer, including a slot antenna 3-1, a slot antenna array unit 3-2, and an offset hole 3-3; the slot antenna 3-1 is a rectangular slot, the size of which is 4.38*0.6mm, and is used to radiate energy outward; the slot antenna array unit 3-2 is formed by an array of ten slot antennas 3-1, which are evenly and evenly arranged in the horizontal direction, and the spacing is 5.40mm; the offset hole 3-3 is located in the cut resonant cavity of the substrate integrated waveguide; combined with Figure 3(b) The structural parameters of the slot antenna layer 3 are: the width of the slot antenna array unit d1 = 5.40, the length of the slot antenna slot d2 = 4.38, the length of the offset hole from the array unit boundary d3 = 0.74, the distance between the slot antenna slots d4 = 5.40, the width of the slot antenna slot d5 = 0.60, the length of the slot antenna unit from the array unit edge d6 = 4.91, the length of the offset hole from the array unit boundary d7 = 3.45, the unit is mm, and there is a row of transition holes with a diameter of 0.508 mm and a spacing of 0.8 mm at the bottom to guide the energy to couple upward.

[0028] Combination Figure 4 (a), the patch antenna layer 4 is the third antenna layer, including a microstrip antenna 4-1, a radiation cavity 4-2, and a horn-shaped transition structure 4-3; the microstrip antenna 4-1 is arranged at equal intervals in the longitudinal direction, with a distance of 5.4 mm, and ten microstrip antennas 4-1 are arranged; the radiation cavity 4-2 is embedded in the microstrip antenna 4-1 in a 10*10 array, and the size of the radiation cavity 4-2 is a metallized rectangular through hole of 4.38mm*0.6mm, the copper thickness inside the through hole is 0.05mm, and the spacing between each rectangular through hole and the adjacent one is 5.4mm; the horn-shaped transition structure 4-3 is located at the input end of the microstrip antenna 4-1, and there are ten of them, and the angle of the horn-shaped transition structure 4-3 is 22.5°, which is used to transition the energy from the substrate integrated waveguide to the microstrip line; combined with Figure 4 (b), the structural parameters of the patch antenna layer 4 are: the line width of the microstrip antenna d8 = 0.40, the length of the microstrip antenna node d9 = 2.00, the distance between the microstrip antenna nodes d10 = 5.40, the width of the microstrip antenna node d11 = 0.60, the width of the microstrip antenna d12 = 1.90, the line length of the microstrip antenna d13 = 2.40, the length of the microstrip antenna tail unit d14 = 3.80, the unit is mm, combined Figure 5 .

[0029] Combination Figure 1 After the three-layer structure consisting of the dual-port common-cavity Rotman lens feeding network structure 1, the slot antenna layer 3, and the patch antenna layer 4 is arranged in a corresponding order, the overall size is 114.6mm*114.6mm, and carbon fiber plates are used for press-fit assembly, where #1 to #10 represent the ten input ports of the system respectively, #3 and #8 are the central ports of the working system, and carbon fiber plates with a thickness of 0.2mm are used for press-fit installation. The three-layer structure is coupled by multi-layer pores to achieve electrical interconnection between different layers. The second layer and the third layer together form a common-aperture antenna array. Taking the central port as an example, the working principle of the antenna system, combined with Figure 7, Taking the center ports #3 and #8 as an example, when energy is input from the center port, it is fed from the two center ports, and the energy is coupled upward along the common cavity Rotman lens to achieve electrical interconnection between different layers.

[0030] Furthermore, the substrate material of the three-layer structure is Rogers RT / duroid 5880, and the thickness is 0.508 mm.

[0031] Furthermore, the metal structures at the top and bottom of the three-layer substrate are made of copper with a thickness of 0.035 mm.

[0032] The present invention is based on substrate integrated waveguide technology, which orthogonalizes two Rotman subnetworks and introduces a new dual port at the feeding arc for feeding. Then, the patch antenna lens array and the slot antenna array are integrated into a common aperture. The input ports are arranged orthogonally, which is compatible with the dual-port common cavity Rotman lens in the vertical direction. The dual-port common cavity Rotman lens and the common aperture antenna array are combined through slot coupling, and different input ports are switched to achieve different beam pointing. In the millimeter wave spectrum, a compact multi-layer cross-orthogonal scanning multi-beam antenna that can switch beams along two orthogonal planes is realized.

[0033] Combination Figure 6 (a) and Figure 6 (b) Comparison of the electric field distribution inside the cavity of the common-cavity Rotman based on power-division dual-port feeding and the traditional common-cavity Rotman. It can be clearly seen that the dual-port feeding effectively concentrates the incident wave, reduces the loss of electromagnetic energy in the cavity, and improves the return loss.

[0034] Combination Figure 8 The reflection coefficient obtained from simulation and test, S 11 To S 99 They represent the return loss from port #1 to port #9 input, S 00 Indicates the return loss from port #1O, in dB. Figure 8 (a) and Figure 8 (b) It can be seen that from 27.8 GHz to 28.2 GHz, the reflection coefficient results of ports #1 to #1O are all less than -10 dB.

[0035] Combination Fig. 9 The simulated and measured main polarization scanning angles and gains of the ten input ports of Fig. 9 (a) represents the main polarization intensity corresponding to #1 to #5, and its coverage angle in the horizontal plane is -29.4° to 29.4°; Fig. 9(b) shows the main polarization intensity corresponding to #6-#10, and its coverage angle in the elevation plane is 59.9° to 149.9°. By switching different input ports, switching of different scanning beams in orthogonal directions can be achieved.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna, characterized in that: It comprises a dual-port common-cavity Rotman lens feeding network structure (1) and a common-aperture antenna layer (2), wherein the dual-port common-cavity Rotman lens feeding network structure (1) is located at the bottom layer, and the common-aperture antenna layer (2) is located above the common-cavity Rotman lens feeding network structure (1).

2. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 1, characterized in that: The common-aperture antenna layer (2) comprises a slot antenna layer (3) and a patch antenna layer (4), wherein the slot antenna layer (3) is located at the bottom layer, and the patch antenna layer (4) is located above the slot antenna layer (3).

3. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 1, characterized in that: The dual-port common-cavity Rotman lens feeding network structure (1) comprises a power-division dual-port feeding structure (1-1), a common-cavity Rotman lens structure (1-2), a double-layer transition structure (1-3), and a triple-layer transition structure (1-4); the power-division dual-port feeding structure (1-1) constitutes the feed source profile of the common-cavity Rotman lens (1-2); the common-cavity Rotman lens structure (1-2) is composed of two orthogonal Rotman lens structures; the double-layer transition structure (1-3) is located on the inner array profile of the common-cavity Rotman lens, and the triple-layer transition structure (1-4) is located on another inner array profile of the common-cavity Rotman lens, so as to realize energy propagation between different layers.

4. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 2, characterized in that: The slot antenna layer (3) comprises a slot antenna (3-1), a slot antenna array unit (3-2), and an offset hole (3-3); the slot antenna (3-1) is a rectangular slot for radiating energy outward; the slot antenna array unit (3-2) is formed by an array of ten slot antennas (3-1), and the ten slot antenna array units (3-2) are arranged horizontally; and the offset hole (3-3) is located in a cut resonant cavity in a substrate integrated waveguide.

5. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 2, characterized in that: The patch antenna layer (4) comprises a microstrip line antenna (4-1), a radiation cavity (4-2), and a horn-shaped transition structure (4-3); the microstrip line antenna (4-1) is arranged longitudinally, and a total of ten microstrip line antennas (4-1) are arranged; the radiation cavity (4-2) is embedded in the microstrip line antenna (4-1) in a 10*10 array; the horn-shaped transition structure (4-3) is located at the input end of the microstrip line antenna (4-1), and there are ten horn-shaped transition structures in total, which are used to transition energy from the substrate integrated waveguide to the microstrip line.

6. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 4, characterized in that: The structural parameters of the slot antenna layer (3) are: the width of the slot antenna array unit d1 = 5.40, the length of the slot antenna slot d2 = 4.38, the length of the offset hole from the array unit boundary d3 = 0.74, the distance between the slot antenna slots d4 = 5.40, the width of the slot antenna slot d5 = 0.60, the length of the slot antenna unit from the array unit edge d6 = 4.91, and the length of the offset hole from the array unit boundary d7 = 3.45, the unit is mm.

7. The compact cross-orthogonal scanning multi-layer millimeter wave multi-beam array antenna according to claim 5, characterized in that: The structural parameters of the patch antenna layer (4) are: the line width d8 of the microstrip line antenna is 0.40, the length d9 of the microstrip line antenna node is 2.00, the distance d10 between the microstrip line antenna nodes is 5.40, the width d11 of the microstrip line antenna node is 0.60, the width d12 of the microstrip line antenna is 1.90, the line length d13 of the microstrip line antenna is 2.40, and the length d14 of the microstrip line antenna tail unit is 3.80, and the unit is mm.

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