Dual-frequency multi-beam antenna array realized based on dual-mode Butler matrix design

Abstract

The invention provides a dual-frequency multi-beam antenna array realized based on dual-mode Butler matrix design, which comprises a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a third dielectric substrate, a fourth metal layer, a fourth dielectric substrate and a fifth metal layer which are sequentially stacked from bottom to top, the overlapping area of the first metal layer, the first dielectric substrate, the second metal layer, the second dielectric substrate and the third metal layer in the vertical direction is sequentially divided into a first area, a second area and a third area in the length direction of the overlapping area, a port mode separator is arranged in the first area, and a dual-mode Butler matrix is arranged in the second area; and the third region is internally provided with a dual-frequency feeder line, a third dielectric substrate, a fourth metal layer, a fourth dielectric substrate and a fifth metal layer to form a broadband dual-polarized antenna array. The dual-frequency multi-beam antenna array has the beneficial effects that dual-frequency operation can be realized, and receiving and transmitting capabilities can be simultaneously obtained in a 5G millimeter wave wireless communication system.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-beam antenna arrays, and in particular to a dual-frequency multi-beam antenna array designed and implemented based on a dual-mode Butler matrix. Background Art

[0002] Multi-beam antenna arrays achieve spatial diversity by generating multiple radiation beams in different directions, thereby effectively improving spectrum efficiency and utilization. It is an important technology in 5G millimeter wave applications.

[0003] Generally speaking, a multi-beam antenna array is mainly composed of a multi-beam forming network and an antenna. The multi-beam forming network is the key to realizing multiple beams with different pointing directions. As one of the implementation methods of a multi-beam forming network, the Butler matrix has the advantages of simple structure, orthogonal beams, and high isolation.

[0004] For example, patent CN114094350B discloses a microwave millimeter-wave slot gap waveguide multi-port fed multi-beam antenna array, whose feeding layer includes: a 4×4 Butler matrix feeding structure formed by four couplers, four phase shifters, and two cross bridges. The input end of the feeding interface is connected to four input ports, and the end is connected to four output ports. The signal input through each input port can output four signals through the 4×4 Butler matrix feeding structure, and the signal is output from each output port to the coupling layer respectively, and then radiated from the radiation layer. Among them, each device in the Butler matrix feeding structure is formed by periodic metal pins, and the two cross bridges also include tuning matching pins. The above scheme can improve space division multiplexing, reduce path loss, and thereby improve the broadband data transmission speed in 5G mobile communications.

[0005] With the continuous advancement of wireless communication and sensor technology, the dual-frequency architecture that can adapt to both receiving and transmitting links has been a research trend in recent years. However, just like the microwave millimeter-wave slot gap waveguide multi-port fed multi-beam antenna array mentioned above, most of the published multi-beam antenna arrays based on the Butler matrix are single-frequency and cannot operate in two frequency bands. The main reason is that there are more passive devices in the Butler matrix, such as couplers, phase shifters, cross junctions, etc. To obtain a dual-frequency Butler matrix, all these devices need to support dual-frequency operation. It is very difficult to achieve this function simply and compactly with the existing technology. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a dual-frequency multi-beam antenna array with a compact structure, capable of dual-frequency operation and simultaneously obtaining receiving and transmitting capabilities in a 5G millimeter-wave wireless communication system. In order to overcome the defects of the above-mentioned prior art (or related technology), the present invention provides a dual-frequency multi-beam antenna array based on a dual-mode Butler matrix design.

[0007] The present invention provides a dual-frequency multi-beam antenna array based on a dual-mode Butler matrix design, comprising a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a third dielectric substrate, a fourth metal layer, a fourth dielectric substrate and a fifth metal layer stacked in sequence from bottom to top, wherein the overlapping areas of the first metal layer, the first dielectric substrate, the second metal layer, the second dielectric substrate and the third metal layer in the vertical direction are divided into a first area, a second area and a third area in sequence along their own length direction, a port mode separator is arranged in the first area, and a dual-mode Butler matrix is ​​arranged in the second area. A Butler matrix, a dual-frequency feeder is arranged in the third area, the dual-mode Butler matrix is ​​electrically connected to the port mode separator and the dual-frequency feeder respectively, the third dielectric substrate, the fourth metal layer, the fourth dielectric substrate and the fifth metal layer constitute a broadband dual-polarization antenna array, the external input signal is received through the port mode separator to stimulate the low-frequency band and high-frequency band of the dual-mode Butler matrix to output dual-frequency signals, and the dual-frequency signal is fed to the broadband dual-polarization antenna array through the dual-frequency feeder to stimulate the broadband dual-polarization antenna array to radiate electromagnetic waves to form a plurality of beams with different directions.

[0008] Compared with the prior art, the dual-frequency multi-beam antenna array implemented based on the dual-mode Butler matrix design in this application has the following advantages: In view of the traditional Butler matrix that can only support single-frequency operation, in this application, two layers of dielectric substrate and three layers of metal layers are used to stack and form a compact antenna array structure, and a port mode separator, a dual-mode Butler matrix and a dual-frequency feeder are arranged in the overlapping area of ​​the dielectric substrate and the metal layer. The third dielectric substrate, the fourth metal layer, the fourth dielectric substrate and the fifth metal layer on the top layer constitute a broadband dual-polarized antenna array. The port mode separator is responsible for receiving the input signal, and the dual-frequency signal is produced through the dual-mode Butler matrix. The dual-frequency signal is fed to the broadband dual-polarized antenna array through the dual-frequency feeder for excitation to achieve dual-frequency operation, so that the receiving and transmitting capabilities can be simultaneously obtained in the millimeter wave wireless communication system.

[0009] In a possible implementation, the port mode separator is provided with eight input ports, namely input port #1, input port #2, input port #3, input port #4, input port #5, input port #6, input port #7, and input port #8. The input port #1, the input port #3, the input port #6, and the input port #8 are used to receive the input signal to excite the low frequency band of the dual-mode Butler matrix, and the input port #2, the input port #4, the input port #5, and the input port #7 are used to receive the input signal to excite the high frequency band of the dual-mode Butler matrix.

[0010] In a possible implementation manner, the port mode separator includes at least one mode separator, and the mode separator includes: a first signal line, disposed at the top of the first metal layer, wherein input ends of the first signal line are respectively connected to the input port #1, the input port #3, the input port #6 and the input port #8, and at least one metal through hole is provided on the first dielectric substrate for the first signal line to pass through; a second signal line, disposed on the top of the second metal layer, wherein an input end of the second signal line is connected to an output end of the first signal line; a first curved path, disposed at the top of the second metal layer, wherein one end of the first curved path is electrically connected to the output end of the second signal line, and the other end of the first curved path is electrically connected to the dual-mode Butler matrix; a third signal line, disposed on the top of the first metal layer, wherein input ends of the third signal line are respectively connected to the input port #2, the input port #4, the input port #5 and the input port #7; a straight transmission path, provided at the top of the first metal layer, one end of the straight transmission path being electrically connected to the output end of the third signal line, and the other end of the straight transmission path being electrically connected to the dual-mode Butler matrix; The first signal line, the second signal line and the first curved path constitute a low-frequency transmission path to feed the dual-mode Butler matrix, and the third signal line and the straight transmission path constitute a high-frequency transmission path to feed the dual-mode Butler matrix.

[0011] In a possible implementation manner, the diameter of the metal through hole is 0.4 mm.

[0012] In a possible implementation, the dual-mode Butler matrix includes four dual-mode couplers, two dual-mode cross junctions and four dual-mode phase shifters, the four dual-mode couplers are respectively a first dual-mode coupler, a second dual-mode coupler, a third dual-mode coupler and a fourth dual-mode coupler, the two dual-mode cross junctions are respectively a first dual-mode cross junction and a second dual-mode cross junction, the four dual-mode phase shifters are respectively a first dual-mode phase shifter, a second dual-mode phase shifter, a third dual-mode phase shifter and a fourth dual-mode phase shifter, the input end of the first dual-mode coupler is connected to the output end of the port mode separator, the output end of the first dual-mode coupler is respectively connected to the input end of the first dual-mode phase shifter and the input end of the first dual-mode cross junction, the input end of the second dual-mode coupler is connected to the output end of the port mode separator, and the second The output end of the dual-mode coupler is respectively connected to the input end of the first dual-mode cross junction and the input end of the second dual-mode phase shifter, the input end of the third dual-mode coupler is respectively connected to the output end of the first dual-mode phase shifter and the output end of the first dual-mode cross junction, the output end of the third dual-mode coupler is respectively connected to the input end of the third dual-mode phase shifter and the input end of the second dual-mode cross junction, the input end of the fourth dual-mode coupler is respectively connected to the output end of the first dual-mode cross junction and the output end of the second dual-mode phase shifter, the output end of the fourth dual-mode coupler is respectively connected to the input end of the second dual-mode cross junction and the input end of the fourth dual-mode phase shifter, and the output end of the fourth dual-mode phase shifter, the output end of the second dual-mode cross junction and the output end of the fourth dual-mode phase shifter are connected to the dual-frequency feeder.

[0013] In a possible implementation, the dual-frequency feed line includes a fourth signal line, a fifth signal line, a sixth signal line, a seventh signal line, a first forked signal line, a second forked signal line, a third forked signal line, and a fourth forked signal line, and an eighth signal line, a ninth signal line, a tenth signal line, an eleventh signal line, a fifth forked signal line, a sixth forked signal line, a seventh forked signal line, and an eighth forked signal line, and a first cross-shaped gap, a second cross-shaped gap, a third cross-shaped gap, and a fourth cross-shaped gap opened on the third metal layer, the fourth signal line is electrically connected to the first forked signal line, the fifth signal line is electrically connected to the second forked signal line, the sixth signal line is electrically connected to the third forked signal line, the seventh signal line is electrically connected to the fourth forked signal line, and the eighth signal line is electrically connected to the fifth forked signal line. The ninth signal line is electrically connected to the sixth fork signal line, the tenth signal line is electrically connected to the seventh fork signal line, and the eleventh signal line is electrically connected to the eighth fork signal line, and the dual-frequency signal output by the dual-mode Butler matrix is ​​received through the fourth signal line, the fifth signal line, the sixth signal line, the seventh signal line, the eighth signal line, the ninth signal line, the tenth signal line and the eleventh signal line, and the dual-frequency signal is fed to the first cross-slot, the second cross-slot, the third cross-slot and the fourth cross-slot through the first fork signal line, the second fork signal line, the third fork signal line, the fourth fork signal line, the fifth fork signal line, the sixth fork signal line, the seventh fork signal line and the eighth fork signal line to excite the broadband dual-polarization antenna array.

[0014] In a possible implementation, the fourth metal layer and the fifth metal layer each include a plurality of metal patches, and the metal patches included in the fourth metal layer are sequentially arranged between the third dielectric substrate and the fourth dielectric substrate along the width direction of the overlapping area, and the metal patches included in the fifth metal layer are sequentially arranged on the top of the fourth dielectric substrate along the width direction of the overlapping area.

[0015] In a possible implementation, each of the metal patches included in the fourth metal layer is a square metal patch with a side length of 2.9 mm, and each of the metal patches included in the fifth metal layer is a square metal patch with a side length of 2.8 mm.

[0016] In a possible implementation manner, the thickness of the first dielectric substrate and the second dielectric substrate is 0.127 mm, and the thickness of the third dielectric substrate and the fourth dielectric substrate is 0.508 mm.

[0017] In a possible implementation, the first metal layer, the second metal layer, the third metal layer, the fourth metal layer and the fifth metal layer are made of copper and have a thickness of 0.018 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the overlapping area of ​​the present invention; Figure 3 It is a schematic diagram of the structural layering of the mode separator of the present invention; Figure 4 Schematic diagram of the top view of the dual-mode Butler matrix of the present invention; Figure 5 It is a schematic diagram of the structure layering of the dual-mode coupler of the present invention; Figure 6 It is a schematic diagram of the structure layering of the dual-mode phase shifter of the present invention; Figure 7 It is a schematic diagram of the structure layering of the dual-frequency feeder of the present invention; Figure 8 is a schematic diagram of the layered structure of the fourth metal layer and the fifth metal layer of the present invention; Fig. 9 Schematic diagram of reflection coefficient and isolation of each input port of the present invention; Fig.10 A normalized radiation pattern simulated when the dual-frequency multi-beam antenna array of the present invention operates at 24 GHz; Fig.11 A normalized radiation pattern simulated when the dual-frequency multi-beam antenna array of the present invention operates at 30 GHz; Fig.12 Gain diagrams of each input port simulated for the dual-frequency multi-beam antenna array of the present invention operating at 24 GHz and 30 GHz; Description of the accompanying drawings: 1. first metal layer; 2. first dielectric substrate; 3. second metal layer; 4. second dielectric substrate; 5. third metal layer; 6. third dielectric substrate; 7. fourth metal layer; 8. fourth dielectric substrate; 9. fifth metal layer; 10. port mode separator; 11. dual-mode Butler matrix; 12. dual-frequency feed line; 13. first mode separator; 14. second mode separator; 15. third mode separator; 16. fourth mode separator; 17. first signal line; 18. metal through hole; 1 9. Second signal line; 20. First curved path; 21. Third signal line; 22. Straight transmission path; 23. Second curved path; 24. First dual-mode coupler; 25. Second dual-mode coupler; 26. Third dual-mode coupler; 27. Fourth dual-mode coupler; 28. First dual-mode cross junction; 29. ​​Second dual-mode cross junction; 30. First dual-mode phase shifter; 31. Second dual-mode phase shifter; 32. Third dual-mode phase shifter; 33. Fourth dual-mode phase shifter; 34. Twelfth signal line; 35. Thirteenth signal line 14th signal line; 15th signal line; 16th signal line; 17th signal line; 18th signal line; 19th signal line; 20th signal line; 21st signal line; 22nd signal line; 23rd signal line; 24th signal line; 25th signal line; 26th signal line; 27th signal line; 28th signal line; 29th signal line; 30th signal line; 31st signal line; 32nd signal line; 33rd signal line; 34th signal line; 35th signal line; 36th signal line; 37th signal line; 38th signal line; 39th signal line; 40th signal line; 41th signal line; 42th signal line; 43th signal line; 44th signal line; 45th signal line; 46th signal line; 47th signal line; 48th signal line; 49th signal line; 50th signal line; 51th signal line; 52th signal line; 53th signal line; 54th signal line; 55th signal line; 56th signal line; 57th signal line; 58th signal line; 59th signal line; 60th signal line; 61st signal line; 62nd signal line; 63rd signal line; 64th signal line; 65th signal line; 66th signal line; 67th signal line; 68th signal line; 69th signal line; 70th signal line; 71st signal line; 72nd signal line; 73rd signal line; 74th signal line; 75th signal line; 76th signal line; 77th signal line; 78th signal line; 79th signal line; 80th signal line; 81st signal line; 82nd signal line; 83 Signal line; 54, fifth forked signal line; 55, sixth forked signal line; 56, seventh forked signal line; 57, eighth forked signal line; 58, first cross gap; 59, second cross gap; 60, third cross gap; 61, fourth cross gap; 62, first metal patch; 63, second metal patch; 64, third metal patch; 65, fourth metal patch; 66, fifth metal patch; 67, sixth metal patch; 68, seventh metal patch; 69, eighth metal patch. DETAILED DESCRIPTION

[0019] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0020] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] See also Figure 1 , Figure 2The embodiment of the present application discloses a dual-frequency multi-beam antenna array designed and implemented based on a dual-mode Butler matrix, which includes four dielectric substrates and five metal layers printed on the four dielectric substrates respectively, wherein a port mode separator 10, a dual-mode Butler matrix 11 composed of dual-mode transmission lines and a dual-frequency feed line 12 are integrated in the overlapping area of ​​the first dielectric substrate 2, the second dielectric substrate 4 and the first metal layer 1, the second metal layer 3 and the third metal layer 5 printed on the two dielectric substrates, which can realize the amplitude and phase response of multiple beams at two frequencies, and a cross-shaped gap is etched at the dual-frequency feed line 12 of the third metal layer 5 to feed the broadband dual-polarization antenna array, and the broadband dual-polarization antenna array is located on the third dielectric substrate 6, the fourth dielectric substrate 8 and the fourth metal layer 7 and the fifth metal layer 9 printed on the two dielectric substrates, and it is connected to the dual-frequency feed line 12 through the cross-shaped gap on the third metal layer 5.

[0022] Continue to see Figure 1 Compared with the existing technology, the beneficial effects of this application are: (1) In view of the traditional Butler matrix that can only support single-frequency operation, this application proposes a dual-mode Butler matrix based on a dual-mode transmission line, which uses two layers of dielectric substrate and three layers of metal layers and realizes dual-frequency operation, that is, it can provide amplitude and phase response of multiple beams at two frequencies, so as to obtain the ability of receiving and transmitting simultaneously in the millimeter wave wireless communication system; (2) In addition, the present application can modify the dual-mode transmission lines constituting the dual-mode Butler matrix, thereby realizing a dual-frequency Butler matrix with different frequency ratios to meet different receiving and transmitting frequency requirements in the millimeter wave wireless communication system; (3) In view of the traditional antenna array design, this application proposes a dual-polarization antenna with broadband and compact structure, which is used to form a four-unit dual-frequency multi-beam antenna array to meet the requirements of multi-beam scanning coverage at two frequencies.

[0023] See also Figure 1 and Figure 3The dual-frequency multi-beam antenna array in the present application is composed of four dielectric substrates and five metal layers, including a port mode separator 10, a dual-mode Butler matrix 11 composed of a dual-mode transmission line, a dual-frequency feed line 12 and a broadband dual-polarization antenna array, wherein the dual-mode transmission line supports two quasi-TEM modes, namely a first quasi-TEM mode and a second quasi-TEM mode, the two quasi-TEM modes are respectively controlled by the second metal layer 3 and the first metal layer 1, the third metal layer 5 is used as a metal ground to form a loop, and the first dielectric substrate 2 and the second dielectric substrate 4 are used as carriers of the three metal layers, that is, the three metal layers are respectively located on the two dielectric substrates. On both sides, the two quasi-TEM modes work at two different frequencies respectively, wherein the first quasi-TEM mode works at a lower frequency, and the second quasi-TEM mode works at a higher frequency. The dual-mode Butler matrix is ​​realized by these two dual-mode transmission lines working at different frequencies, thereby obtaining dual-frequency operation. It should be noted that densely packed metal through holes 18 are arranged on both sides of the dual-mode transmission line to suppress energy leakage. The broadband dual-polarization antenna array is composed of a third dielectric substrate 6, a fourth dielectric substrate 8, a fourth metal layer 7 and a fifth metal layer 9, which can radiate electromagnetic waves into free space and form four multi-beam forms with different directions.

[0024] See also Figure 1 , Figure 2 and Figure 3 , the overlapping area of ​​the first dielectric substrate 2, the second dielectric substrate 4, the first metal layer 1, the second metal layer 3, and the third metal layer 5 includes a total of three parts, namely, a port mode separator 10, a dual-mode Butler matrix 11 and a dual-frequency feeder 12. The port mode separator 10 has 8 input ports, namely, input port #1, input port #2, input port #3, input port #4, input port #5, input port #6, input port #7, and input port #8. Among them, input port #1, input port #3, input port #6, and input port #8 excite the low frequency band of the dual-mode Butler matrix 11, and input port #2, input port #4, input port #5, and input port #7 excite the high frequency band of the dual-mode Butler matrix 11. In addition, in the port mode separator 10, there are 4 mode separators, namely, a first mode separator 13, a second mode separator 14, a third mode separator 15, and a fourth mode separator 16, which have the same structure, as shown in FIG. Figure 3As shown, the signal in the low frequency band is fed by the first signal line 17 on the first metal layer 1, connected to the second signal line 19 of the second metal layer 3 through the metal through-hole 18, and passes through a first curved structure 20 to form a low-frequency transmission path of the dual-mode transmission line and feed the dual-mode Butler matrix 11; the signal in the high frequency band is fed by the third signal line 21 on the first metal layer 1, forms a high-frequency transmission path of the dual-mode transmission line along the straight transmission path 22 and feeds the dual-mode Butler matrix 11. On one side of the straight transmission path 22 of the first metal layer 1, there is another second curved path 23. The second curved path 23 can make the low-frequency and high-frequency transmission signals have a higher isolation, thereby maintaining good signal purity.

[0025] See also Figure 4 , Figure 5 and Figure 6 The dual-mode Butler moment 11 is composed of four dual-mode couplers (a first dual-mode coupler 24, a second dual-mode coupler 25, a third dual-mode coupler 26, and a fourth dual-mode coupler 27), two dual-mode cross junctions (a first dual-mode cross junction 28, a second dual-mode cross junction 29) and four phase shifters (a first dual-mode phase shifter 30, a second dual-mode phase shifter 31, a third dual-mode phase shifter 32, and a fourth dual-mode phase shifter 33). The four dual-mode couplers have the same structure, as shown in FIG. Figure 5 As shown, the structure of the dual-mode coupler is axially symmetrically distributed along the two directions of the dielectric substrate, wherein the twelfth signal line 34 located in the first metal layer 1 and the thirteenth signal line 35 located in the second metal layer 3 have similar structures, but the thirteenth signal line 35 is dug out with many notches. The purpose of these notches is to adjust the frequency of the low frequency while keeping the frequency of the high frequency unchanged, thereby changing the required frequency ratio. When the length of the notch is longer, the frequency of the low frequency will move to a lower frequency, thereby increasing the frequency ratio of the dual frequency. When the input port of the dual-mode coupler is fed, the two output ports will output signals with equal amplitude and 90° phase difference. The two dual-mode cross junctions have the same structure, both of which are cascaded by two identical dual-mode couplers. The four dual-mode phase shifters are divided into two groups, wherein the first dual-mode phase shifter 30 and the second dual-mode phase shifter 31 achieve a phase shift value of -45°, while the third dual-mode phase shifter 32 and the fourth dual-mode phase shifter 33 achieve a phase shift value of 0°, thereby ensuring the theoretical output of the entire dual-mode Butler matrix 11, as shown in FIG. Figure 6As shown, similar to the dual-mode coupler, the fourteenth signal line 36 located on the first metal layer 1 and the fifteenth signal line 37 located on the second metal layer 3 have similar structures, but many gaps are dug out of the fifteenth signal line 37 to ensure the required dual-frequency frequency ratio. In order to achieve the required phase shift value, it is achieved by loading two curved branches, namely the first curved branch 38 and the second curved branch 39 located on the first metal layer 1, and the third curved branch 40 and the fourth curved branch 41 located on the second metal layer 3. The difference between the two groups of dual-mode phase shifters with different phase shift values ​​lies in the different lengths of the curved branches. A phase shift value of -45° requires longer curved branches to achieve.

[0026] See also Figure 7 The dual-frequency feed line 12 is used to feed the dual-frequency signal output by the dual-mode Butler matrix 11 to the broadband dual-polarized antenna array. The fourth signal line 42, the fifth signal line 43, the sixth signal line 44, and the seventh signal line 45 located in the first metal layer 1 transmit the high-frequency signal to four forked signal lines through the signal line path, namely the first forked signal line 50, the second forked signal line 51, the third forked signal line 52, and the fourth forked signal line 53, while the eighth signal line 46, the ninth signal line 47, the tenth signal line 48, and the eleventh signal line 49 located in the second metal layer 3 transmit the low-frequency signal to the fifth forked signal line through the signal line path. Line 54, the second forked signal line 55, the third forked signal line 56 and the fourth forked signal line 57, the forked signal lines on the same metal layer have the same structure, and the forked signal lines located on the first metal layer 1 and the second metal layer 3 are orthogonal to each other. These forked signal lines feed the high-frequency and low-frequency signals to the cross-shaped slots (the first cross-shaped slot 58, the second cross-shaped slot 59, the third cross-shaped slot 60, and the fourth cross-shaped slot 61), respectively, and then excite the broadband dual-polarized antenna array above. The structure of the cross-shaped slots in two dimensions is not exactly the same. This is to obtain the best impedance matching at high and low frequencies.

[0027] See also Figure 8 The first metal patch 62, the second metal patch 63, the third metal patch 64, the fourth metal patch 65, the fifth metal patch 66, the sixth metal patch 67, the seventh metal patch 68, and the eighth metal patch 69, which are respectively located on the third dielectric substrate 6 and the fourth dielectric substrate 7, constitute the radiation part of the broadband dual-polarization antenna array, wherein the metal patches on the lower layer are exactly the same, which are square metal patches with a side length of 2.9 mm, and the metal patches on the upper layer are also exactly the same, which are square metal patches with a side length of 2.8 mm. Finally, the various parts are connected together through the dielectric substrate to form the proposed dual-frequency multi-beam antenna array.

[0028] Continue to see Figure 1The material of the four dielectric substrates is Taconic TLY-5, the thickness of the first dielectric substrate 2 and the second dielectric substrate 4 is 0.127 mm, and the thickness of the third dielectric substrate 6 and the fourth dielectric substrate 8 is 0.508 mm.

[0029] Continue to see Figure 1 The material of the five metal layers is copper with a thickness of 0.018mm.

[0030] Continue to see Figure 3 The diameter of all metal through holes 18 used to suppress leakage is 0.4 mm, and the interval between adjacent metal through holes 18 is 0.7 mm.

[0031] See also Fig. 9 , is a schematic diagram of the reflection coefficient and isolation of each input port of the present application. It can be seen that the reflection coefficient and isolation of each input port are both less than -10dB.

[0032] See also Fig.10 and Fig.11 , is the normalized radiation pattern simulated when the dual-frequency multi-beam antenna array of the present invention works at 24 GHz and 30 GHZ. It can be seen that four stable radiation beams are obtained at these two frequencies, thereby verifying the feasibility of the dual-frequency multi-beam antenna array.

[0033] See also Fig.12 , which is a gain diagram of each input port simulated when the dual-frequency multi-beam antenna array of the present invention works at 24 GHz and 30 GHz. It can be seen that the gain of each input port at these two frequencies is greater than 8 dBi.

[0034] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0035] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A dual-frequency multi-beam antenna array based on a dual-mode Butler matrix design, characterized in that: The invention comprises a first metal layer (1), a first dielectric substrate (2), a second metal layer (3), a second dielectric substrate (4), a third metal layer (5), a third dielectric substrate (6), a fourth metal layer (7), a fourth dielectric substrate (8) and a fifth metal layer (9) which are stacked in sequence from bottom to top; the overlapping area of ​​the first metal layer (1), the first dielectric substrate (2), the second metal layer (3), the second dielectric substrate (4) and the third metal layer (5) in the vertical direction is divided into a first area, a second area and a third area in sequence along their own length direction; a port mode separator (10) is provided in the first area, a dual-mode Butler matrix (11) is provided in the second area, and the first metal layer (10) is provided in the second area. A dual-frequency feeder (12) is provided in the three areas, the dual-mode Butler matrix (11) is electrically connected to the port mode separator (10) and the dual-frequency feeder (12) respectively, the third dielectric substrate (6), the fourth metal layer (7), the fourth dielectric substrate (8) and the fifth metal layer (9) constitute a broadband dual-polarization antenna array, the external input signal is received through the port mode separator (10) to stimulate the dual-frequency band and high-frequency band of the dual-mode Butler matrix to output dual-frequency signals, and the dual-frequency signal is fed to the broadband dual-polarization antenna array through the dual-frequency feeder (12) to stimulate the broadband dual-polarization antenna array to radiate electromagnetic waves to form multiple beams with different directions.

2. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The port mode separator (10) is provided with eight input ports, namely input port #1, input port #2, input port #3, input port #4, input port #5, input port #6, input port #7, and input port #8. The input port #1, the input port #3, the input port #6, and the input port #8 are used to receive the input signal to excite the low frequency band of the dual-frequency Butler matrix, and the input port #2, the input port #4, the input port #5, and the input port #7 are used to receive the input signal to excite the high frequency band of the dual-mode Butler matrix.

3. The dual-frequency multi-beam antenna array according to claim 2, characterized in that: The port mode separator (10) comprises at least one mode separator, and the mode separator comprises: a first signal line (17) disposed at the top of the first metal layer (1), the input end of the first signal line (17) being respectively connected to the input port #1, the input port #3, the input port #6 and the input port #8, and the first dielectric substrate (2) being provided with at least one metal through hole (18) for the first signal line (17) to pass through; a second signal line (19), arranged at the top of the second metal layer (3), the input end of the second signal line (19) being connected to the output end of the first signal line (17); a first curved path (20), arranged at the top of the second metal layer (3), one end of the first curved path (20) being electrically connected to the output end of the second signal line (19), and the other end of the first curved path (20) being electrically connected to the dual-mode Butler matrix (11); a third signal line (21), arranged at the top of the first metal layer (1), the input end of the third signal line (21) being respectively connected to the input port #2, the input port #4, the input port #5 and the input port #7; A straight transmission path (22) is provided at the top of the first metal layer (1), one end of the straight transmission path (22) is electrically connected to the output end of the third signal line (21), and the other end of the straight transmission path (22) is electrically connected to the dual-mode Butler matrix (11); The first signal line (17), the second signal line (19) and the first curved path (20) form a low-frequency transmission path to feed the dual-mode Butler matrix (11), and the third signal line (21) and the straight transmission path (22) form a high-frequency transmission path to feed the dual-mode Butler matrix (11).

4. The dual-frequency multi-beam antenna array according to claim 3, characterized in that: The diameter of the metal through hole (18) is 0.4 mm.

5. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The dual-mode Butler matrix (11) comprises four dual-mode couplers, two dual-mode cross junctions and four dual-mode phase shifters, wherein the four dual-mode couplers are respectively a first dual-mode coupler (24), a second dual-mode coupler (25), a third dual-mode coupler (26) and a fourth dual-mode coupler (27), the two dual-mode cross junctions are respectively a first dual-mode cross junction (28) and a second dual-mode cross junction (29), and the four dual-mode phase shifters are respectively a first dual-mode phase shifter (30), a second dual-mode phase shifter (31 ), a third dual-mode phase shifter (32) and a fourth dual-mode phase shifter (33), the input end of the first dual-mode coupler (24) is connected to the output end of the port mode separator (10), the output end of the first dual-mode coupler (24) is respectively connected to the input end of the first dual-mode phase shifter (30) and the input end of the first dual-mode cross junction (28), the input end of the second dual-mode coupler (25) is connected to the output end of the port mode separator (10), the output end of the second dual-mode coupler (25) is respectively connected to the input end of the first dual-mode cross junction (28) and the input end of the second dual-mode phase shifter (31), the input end of the third dual-mode coupler (26) is respectively connected to the output end of the first dual-mode phase shifter (30) and the output end of the first dual-mode cross junction (28), the output end of the third dual-mode coupler (26) is respectively connected to the input end of the third dual-mode phase shifter (32) and the input end of the second dual-mode cross junction (29), the fourth dual-mode coupler ( The input end of the fourth dual-mode coupler (27) is respectively connected to the output end of the first dual-mode cross junction (28) and the output end of the second dual-mode phase shifter (31); the output end of the fourth dual-mode coupler (27) is respectively connected to the input end of the second dual-mode cross junction (29) and the input end of the fourth dual-mode phase shifter (33); the output end of the fourth dual-mode phase shifter (33), the output end of the second dual-mode cross junction (29) and the output end of the fourth dual-mode phase shifter (33) are connected to the dual-frequency feed line (12).

6. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The dual-frequency feed line (12) comprises a fourth signal line (42), a fifth signal line (43), a sixth signal line (44), a seventh signal line (45), a first forked signal line (50), a second forked signal line (51), a third forked signal line (52), a fourth forked signal line (53) arranged on the first metal layer (1) and an eighth signal line (46), a ninth signal line (47), a tenth signal line (48), an eleventh signal line (49), a fifth forked signal line (54), a sixth forked signal line (55), a seventh forked signal line (56), an eighth forked signal line (57), a The signal line (57) and a first cross-shaped slit (58), a second cross-shaped slit (59), a third cross-shaped slit (60), and a fourth cross-shaped slit (61) are provided on the third metal layer (5); the fourth signal line (42) is electrically connected to the first forked signal line (50); the fifth signal line (43) is electrically connected to the second forked signal line (51); the sixth signal line (44) is electrically connected to the third forked signal line (52); the seventh signal line (45) is electrically connected to the fourth forked signal line (53); the eighth signal line (46) is electrically connected to the fifth forked signal line (51); The fourth signal line (42), the fifth signal line (43), the sixth signal line (44), the seventh signal line (45), the eighth signal line (46), the ninth signal line (47), the tenth signal line (48) and the eleventh signal line (49) are electrically connected to the eighth fork-shaped signal line (57), and the dual-mode Butler matrix is ​​received through the fourth signal line (42), the fifth signal line (43), the sixth signal line (44), the seventh signal line (45), the eighth signal line (46), the ninth signal line (47), the tenth signal line (48) and the eleventh signal line (49). (11) outputs a dual-frequency signal, and feeds the dual-frequency signal to the first cross-shaped slot (58), the second cross-shaped slot (59), the third cross-shaped slot (60) and the fourth cross-shaped slot (61) through the first forked signal line (50), the second forked signal line (51), the third forked signal line (52), the fourth forked signal line (53), the fifth forked signal line (54), the sixth forked signal line (55), the seventh forked signal line (56) and the eighth forked signal line (57) to excite the broadband dual-polarization antenna array.

7. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The fourth metal layer (7) and the fifth metal layer (9) both comprise a plurality of metal patches, wherein the metal patches included in the fourth metal layer (7) are sequentially arranged between the third dielectric substrate (6) and the fourth dielectric substrate (8) along the width direction of the overlapping region, and the metal patches included in the fifth metal layer (9) are sequentially arranged on the top of the fourth dielectric substrate (8) along the width direction of the overlapping region.

8. The dual-frequency multi-beam antenna array according to claim 7, characterized in that: Each of the metal patches included in the fourth metal layer (7) is a square metal patch with a side length of 2.9 mm, and each of the metal patches included in the fifth metal layer (9) is a square metal patch with a side length of 2.8 mm.

9. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The thickness of the first dielectric substrate (2) and the second dielectric substrate (4) is 0.127 mm, and the thickness of the third dielectric substrate (6) and the fourth dielectric substrate (8) is 0.508 mm.

10. The dual-frequency multi-beam antenna array according to claim 1, characterized in that: The first metal layer (1), the second metal layer (3), the third metal layer (5), the fourth metal layer (7) and the fifth metal layer (9) are made of copper and have a thickness of 0.018 mm.

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