Phased Array Antenna Based on Folded Butler Matrix

Abstract

The present invention provides a phased array antenna based on a folded Butler matrix. The phased array antenna includes: two folded Butler matrices based on asymmetric dielectric integrated transmission lines, a triple-dipole antenna array, and a conversion structure from an asymmetric dielectric integrated coaxial transmission line to a waveguide; wherein, the folded Butler matrix is connected to the conversion structure, and the triple-dipole antenna array is respectively located on different layers of one of the folded Butler matrices. An embodiment of the present invention provides a folded Butler matrix. Its folded structure can save the size of the crossed first directional coupler and second directional coupler, and stack the traditional Butler matrices up and down, effectively realizing miniaturization and scalability; moreover, the loaded asymmetric defected ground directional coupler of the asymmetric dielectric integrated transmission line proposed by the present invention realizes a broadband effect; finally, the phased array antenna with the folded Butler matrix proposed by the present invention realizes high integration and beam scanning effect.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and in particular, to a phased array antenna based on a folded Butler matrix. Background Art

[0002] With the popularization of 5G technology, millimeter-wave multi-beam antennas can achieve wide beam coverage and high-gain beams, and are thus considered an ideal choice for future millimeter-wave wireless communication systems. The scanning function of multi-beam antennas is related to the feeding network. The Butler matrix, Blass matrix, and Nolen matrix are several methods that have received much attention in passive beam feeding networks. The Blass matrix causes additional insertion loss due to the theoretically required loading of loads, which makes the overall efficiency of millimeter-wave transmission, which is extremely sensitive to losses, even worse. The Nolen matrix reduces losses by using a large number of transmission lines to reduce the use of phase shifters and couplers, but is limited by its different path lengths and narrow bandwidth.

[0003] Compared with the above two methods, the Butler matrix has a simple structure and avoids losses during the energy transmission process. In addition, the fixed-length current transmission path makes it easier for the beamforming network to achieve stable phase differences and amplitude differences.

[0004] Traditional Butler matrices require multiple 90-degree couplers, hybrid junctions, and phase shifters. As the order of the Butler matrix increases, the phase accuracy becomes higher, but the volume of the Butler matrix increases exponentially, which is not conducive to the integration of large-scale phased array antenna systems.

[0005] Therefore, in order to achieve high integration of phased array antennas, there is an urgent need for a phased array antenna with a miniaturized Butler matrix. Summary of the Invention

[0006] The present invention provides a phased array antenna based on a folded Butler matrix, and its main purpose is to provide a phased array antenna with a miniaturized Butler matrix.

[0007] An embodiment of the present invention provides a phased array antenna based on a folded Butler matrix, including two folded Butler matrices based on asymmetric dielectric integrated transmission lines, a triple-dipole antenna array, and a conversion structure from an asymmetric dielectric integrated coaxial transmission line to a waveguide;

[0008] Wherein, the folded Butler matrix is connected to the conversion structure, and the triple-dipole antenna array is respectively located in different layers of one of the folded Butler matrices.

[0009] Further, the folded Butler matrix includes an upper-layer asymmetric dielectric integrated transmission line, a lower-layer asymmetric dielectric integrated transmission line, a loaded asymmetric defected ground first directional coupler of the upper-layer asymmetric dielectric integrated transmission line, a loaded asymmetric defected ground second directional coupler of the lower-layer asymmetric dielectric integrated transmission line, a first phase shifter of the upper-layer asymmetric dielectric integrated transmission line, a second phase shifter of the lower-layer asymmetric dielectric integrated transmission line, and an interlayer connection structure.

[0010] Further, the upper-layer asymmetric dielectric integrated transmission line includes a first dielectric plate, a second dielectric plate, a first signal line, a first metal floor, a second metal floor, and a first grounding via. The thicknesses of the first dielectric plate and the second dielectric plate are different. The first dielectric plate is located above the second dielectric plate. The first signal line is located between the first dielectric plate and the second dielectric plate. The first metal floor is located on the top layer of the first dielectric plate. The second metal floor is located on the bottom layer of the second dielectric plate. The first grounding via passes through the first dielectric plate and the second dielectric plate and connects the first dielectric plate and the second dielectric plate to form an asymmetric dielectric integrated coaxial transmission line.

[0011] The lower-layer asymmetric dielectric integrated transmission line includes a third dielectric plate, a fourth dielectric plate, a second signal line, a third metal floor, a fourth metal floor, and a second grounding via. The thicknesses of the third dielectric plate and the fourth dielectric plate are different. The third dielectric plate is located above the fourth dielectric plate. The second signal line is located between the third dielectric plate and the fourth dielectric plate. The third metal floor is located on the top layer of the third dielectric plate. The fourth metal floor is located on the bottom layer of the fourth dielectric plate. The second grounding via passes through the third dielectric plate and the fourth dielectric plate and connects the third dielectric plate and the fourth dielectric plate to form an asymmetric dielectric integrated coaxial transmission line.

[0012] Among them, the first dielectric plate and the fourth dielectric plate have the same thickness, and the second dielectric plate and the third dielectric plate have different thicknesses.

[0013] Further, there are 2 conversion structures. One of the conversion structures is located at the first metal floor and is connected to the first directional coupler.

[0014] The other conversion structure is located at the fourth metal floor and is connected to the second directional coupler.

[0015] Further, the asymmetric defected ground of the first directional coupler includes 3 first metal slots with inconsistent sizes and a rectangular shape. The asymmetric defected ground of the first directional coupler is located on the first metal floor, and the asymmetric defected ground of the second directional coupler is located on the fourth metal floor.

[0016] Further, the first phase shifter is 45°, and is used to connect the first directional coupler, and the second phase shifter is 45°, and is used to connect the second directional coupler.

[0017] Further, the interlayer connection structure includes 1 interlayer connection line, a second metal groove, and a matching patch. The matching patch is located in the second metal groove, and the matching patch is connected to the interlayer connection line.

[0018] Further, the interlayer connection line also passes through the second dielectric plate and is connected to the matching patch of the interlayer connection structure located at the second metal floor, and the interlayer connection line also passes through the third dielectric plate and is connected to the matching patch of the interlayer connection structure located at the third metal floor.

[0019] Further, the second metal groove is located on the second metal floor and the third metal floor.

[0020] Further, the three-dipole antenna arrays are respectively located on the first metal floor, the second metal floor, and the layer where the first signal line is located. Each dipole arm of the dipole antenna array includes two branches with different lengths. The two branches are in an F shape. The direction of the dipole located in the layer where the first signal line is located is opposite to the direction of the dipole located in the first metal floor layer, and the direction of the dipole located in the layer where the first signal line is located is opposite to the direction of the dipole located in the second metal floor layer.

[0021] A phased array antenna based on a folded Butler matrix proposed in an embodiment of the present invention proposes a folded Butler matrix. Its folded structure can save the size of the crossed first directional coupler and second directional coupler, and stack the traditional Butler matrix up and down, effectively realizing miniaturization and scalability. Moreover, the asymmetric dielectric integrated transmission line loaded with an asymmetric defected ground directional coupler proposed in the present invention realizes a broadband effect. Finally, the phased array antenna with the folded Butler matrix proposed in the present invention realizes high integration and beam scanning effects. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the implementation principle of the folded Butler matrix provided by the embodiment of the present invention.

[0023] Figure 2 It is a schematic structural diagram of a phased array antenna based on a folded Butler matrix provided by the embodiment of the present invention.

[0024] Figure 3 It is a schematic diagram of the phase difference of the folded Butler matrix of the asymmetric dielectric integrated transmission line provided by the embodiment of the present invention.

[0025] Figure 4 Schematic diagram of S parameters of the phased array antenna based on the folded Butler matrix according to the embodiment of the present invention.

[0026] Figure 5 Schematic diagram of beam scanning gain of the phased array antenna based on the folded Butler matrix according to the embodiment of the present invention.

[0027] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0028] The following details the implementation manners of the present application. The examples of the implementation manners are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The implementation manners described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as a limitation to the present application.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0030] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0031] In the embodiments of the present application, "at least one" means one or more; "a plurality" means two or more. In the description of the present application, terms such as "first", "second", "third", etc. are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0032] The reference to "an embodiment" or "some embodiments" described in this specification means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, the terms "including", "comprising", "having", and their variants in this specification all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0033] Figure 1 This is the schematic diagram of the implementation principle of the folded Butler matrix provided by the embodiments of the present invention. As Figure 1 shown, the folded Butler matrix can be composed of four 90° couplers and two 45° phase shifters. Two 90° couplers and one 45° phase shifter are respectively located in the upper layer and the lower layer. The upper-layer 90° coupler and the lower-layer 90° coupler are connected through an interlayer structure. Figure 1 In the folded Butler matrix, #1, #2, #3, #4 are output ports, #5, #6, #7, #8 are input ports, 101 represents the upper layer, 102 represents the lower layer, Phaseshifter represents the phase shifter, coupler represents the coupler, and x, y, z represent the earth coordinate system.

[0034] Figure 2 This is the schematic structural diagram of a phased array antenna based on a folded Butler matrix provided by the embodiments of the present invention. As Figure 2 shown, a phased array antenna based on a folded Butler matrix in the embodiments of the present invention includes a folded Butler matrix based on an asymmetric dielectric integrated transmission line, a triple-dipole antenna array, and a conversion structure from the asymmetric dielectric integrated transmission line to a waveguide. These two folded Butler matrices are respectively represented by 209 and 212, the triple-dipole antenna array is represented by 211, and the conversion structure is represented by 207.

[0035] The folded Butler matrix of the asymmetric dielectric integrated transmission line consists of two loaded asymmetric defected ground directional couplers of the asymmetric dielectric integrated transmission line, two 45° phase shifters of the asymmetric dielectric integrated transmission line, and two interlayer connection structures of the asymmetric dielectric integrated transmission line. The directional coupler is denoted by 208, the phase shifter is denoted by 210, and the interlayer connection structure is denoted by 213.

[0036] Among them, the folded Butler matrix includes an upper-layer asymmetric dielectric integrated transmission line, a lower-layer asymmetric dielectric integrated transmission line, a first loaded asymmetric defected ground directional coupler of the upper-layer asymmetric dielectric integrated transmission line, a second loaded asymmetric defected ground directional coupler of the lower-layer asymmetric dielectric integrated transmission line, a first phase shifter of the upper-layer asymmetric dielectric integrated transmission line, a second phase shifter of the lower-layer asymmetric dielectric integrated transmission line, and an interlayer connection structure.

[0037] The directional coupler includes a first directional coupler and a second directional coupler. The first directional coupler corresponds to the loaded asymmetric defected ground of the upper-layer asymmetric dielectric integrated transmission line, and the second directional coupler corresponds to the loaded asymmetric defected ground of the lower-layer asymmetric dielectric integrated transmission line. The phase shifter includes a first phase shifter and a second phase shifter. The first phase shifter corresponds to the upper-layer asymmetric dielectric integrated transmission line, and the second phase shifter corresponds to the lower-layer asymmetric dielectric integrated transmission line.

[0038] It should be noted that Figure 2 both the first directional coupler and the second directional coupler are denoted by 208, and both the first phase shifter and the second phase shifter are denoted by 210, without distinction in the figure.

[0039] As an example, the upper-layer asymmetric dielectric integrated transmission line includes a first dielectric plate, a second dielectric plate, a first signal line, a first metal ground plane, a second metal ground plane, and a first grounding via. The thicknesses of the first dielectric plate and the second dielectric plate are different. The first dielectric plate is located above the second dielectric plate. The first signal line is located between the first dielectric plate and the second dielectric plate. The first metal ground plane is located on the top layer of the first dielectric plate. The second metal ground plane is located on the bottom layer of the second dielectric plate. The first grounding via passes through the first dielectric plate and the second dielectric plate and connects the first dielectric plate and the second dielectric plate to form an asymmetric dielectric integrated coaxial transmission line;

[0040] The lower-layer asymmetric dielectric integrated transmission line includes a third dielectric plate, a fourth dielectric plate, a second signal line, a third metal floor, a fourth metal floor, and a second grounding via. The thicknesses of the third dielectric plate and the fourth dielectric plate are different. The third dielectric plate is located above the fourth dielectric plate. The second signal line is located between the third dielectric plate and the fourth dielectric plate. The third metal floor is located on the top layer of the third dielectric plate. The fourth metal floor is located on the bottom layer of the fourth dielectric plate. The second grounding via passes through the third dielectric plate and the fourth dielectric plate and connects the third dielectric plate and the fourth dielectric plate to form an asymmetric dielectric integrated coaxial transmission line;

[0041] Among them, the first dielectric plate and the fourth dielectric plate have the same thickness, and the second dielectric plate and the third dielectric plate have different thicknesses.

[0042] In the embodiment of the present invention, the thicknesses of the first dielectric plate and the fourth dielectric plate are both 0.787 mm, and the thicknesses of the second dielectric plate and the third dielectric plate are both 0.127 mm. Refer to Figure 2 , the first dielectric plate is represented by 1, the second dielectric plate is represented by 2, the first signal line is represented by 202, the first metal floor is represented by 201, and the second metal floor is represented by 203; the third dielectric plate is represented by 3, the fourth dielectric plate is represented by 4, the second signal line is represented by 205, the third metal floor is represented by 204, and the fourth metal floor is represented by 206.

[0043] It should be noted that, refer to Figure 2 and, taking Figure 1 the geodetic coordinate system shown in as a reference, the positive direction of the Z-axis represents upward or above, and the negative direction of the Z-axis represents downward or below. The top layer refers to the upper surface, and the bottom layer refers to the lower surface. The first dielectric plate being located above the second dielectric plate means that the first dielectric plate is located above the second dielectric plate; the first metal floor being located on the top layer of the first dielectric plate means that the first metal floor is located on the upper surface of the first dielectric plate, and the second metal floor being located on the bottom layer of the second dielectric plate means that the second metal floor is located on the lower surface of the second dielectric plate.

[0044] The third dielectric plate being located above the fourth dielectric plate means that the third dielectric plate is located above the fourth dielectric plate, the third metal floor being located on the top layer of the third dielectric plate means that the third metal floor is located on the upper surface of the third dielectric plate, and the fourth metal floor being located on the bottom layer of the fourth dielectric plate means that the fourth metal floor is located on the lower surface of the fourth dielectric plate.

[0045] As an example, there are 2 conversion structures. One of the conversion structures is located at the first metal floor and is connected to the first directional coupler;

[0046] Another one of the conversion structures is located at the fourth metal floor and is connected to the second directional coupler.

[0047] In the embodiment of the present invention, referring to Figure 2 , the conversion structure is denoted by 207. The conversion structure 207 from the asymmetric dielectric integrated transmission line to the waveguide is used for connecting the asymmetric dielectric integrated transmission line to the waveguide. Two conversion structures from the asymmetric dielectric integrated transmission line to the waveguide are respectively located at the upper metal floor of the first dielectric board and the lower metal floor of the fourth dielectric board, that is, one conversion structure is located at the first metal floor and the other conversion structure is located at the fourth metal floor.

[0048] The conversion structure from the upper-layer asymmetric dielectric integrated transmission line to the waveguide is connected to the loaded asymmetric defected ground directional coupler of the upper-layer asymmetric dielectric integrated transmission line, that is, connected to the first directional coupler. The conversion structure from the lower-layer asymmetric dielectric integrated transmission line to the waveguide is connected to the loaded asymmetric defected ground directional coupler of the lower-layer asymmetric dielectric integrated transmission line, that is, connected to the second directional coupler.

[0049] As an example, the asymmetric defected ground of the first directional coupler includes three first metal slots with inconsistent sizes and a rectangular shape. The asymmetric defected ground of the first directional coupler is located on the first metal floor, and the asymmetric defected ground of the second directional coupler is located on the fourth metal floor.

[0050] Referring to Figure 2 , the first metal slot is denoted by 8.

[0051] As an example, the first phase shifter is 45°, which is used to connect the first directional coupler, and the second phase shifter is 45°, which is used to connect the second directional coupler.

[0052] In the embodiment of the present invention, the 45° phase shifter (i.e., the first phase shifter) of the upper-layer asymmetric dielectric integrated transmission line is connected to the loaded asymmetric defected ground directional coupler (i.e., the first directional coupler) of the two upper-layer asymmetric dielectric integrated transmission lines, and the 45° phase shifter (i.e., the second phase shifter) of the lower-layer asymmetric dielectric integrated transmission line is connected to the loaded asymmetric defected ground directional coupler (i.e., the second directional coupler) of the two asymmetric dielectric integrated transmission lines.

[0053] As an example, the interlayer connection structure includes one interlayer connection line, a second metal slot, and a matching patch. The matching patch is located in the second metal slot, and the matching patch is connected to the interlayer connection line.

[0054] In the embodiment of the present invention, referring to Figure 2, the interlayer connection line is denoted by 6, the second metal groove is denoted by 7, and the matching patch is denoted by 5. By adjusting the length and width of the matching patch, the phase consistency of each output port between the upper and lower layers is compensated.

[0055] Among them, the interlayer connection line also passes through the second dielectric plate and is connected downward to the matching patch of the interlayer connection structure located at the second metal floor. The interlayer connection line also passes through the third dielectric plate and is connected upward to the matching patch of the interlayer connection structure located at the third metal floor.

[0056] In the embodiment of the present invention, the interlayer connection line of the first signal line passes through the second dielectric plate and is connected downward to the matching patch of the interlayer connection structure located at the second metal floor. The interlayer connection line of the second signal line passes through the third dielectric plate and is connected upward to the matching patch of the interlayer connection structure located at the third metal floor.

[0057] Among them, the second metal groove is located on the second metal floor and the third metal floor.

[0058] In the embodiment of the present invention, the second metal grooves are respectively located on the second metal floor and the third metal floor. Therefore, the interlayer connection structures of the second dielectric plate and the third dielectric plate are in contact on the second metal floor and the third metal floor.

[0059] As an example, the three-dipole antenna arrays are respectively located on the first metal floor, the second metal floor, and the layer where the first signal line is located. Each dipole arm of the dipole antenna array includes two branches with different lengths. The two branches are in an F shape. The direction of the dipole located in the layer where the first signal line is located is opposite to the direction of the dipole located in the first metal floor layer, and the direction of the dipole located in the layer where the first signal line is located is opposite to the direction of the dipole located in the second metal floor layer.

[0060] In the embodiment of the present invention, the three-dipole antenna arrays are respectively located on the first metal floor, the second metal floor, and the layer where the first signal line is located. Each dipole arm includes two branches with different lengths and is in an "F" shape. The F direction of the dipole in the layer where the first signal line is located is opposite to the F directions in the first metal floor layer and the second metal floor layer.

[0061] Compared with the prior art, the folded Butler matrix phased array antenna proposed by the present invention effectively reduces the transition structure, and reduces the size of the Butler matrix and the complexity of the feeding network.

[0062] Figure 3 It is a schematic diagram of the phase difference of the folded Butler matrix of the asymmetric dielectric integrated transmission line according to the embodiment of the present invention, as Figure 3As shown in the figure, the abscissa in the figure represents frequency with the unit of GHz, and the ordinate represents the phase difference with the unit of degree. P = 1 represents port #1, P = 2 represents port #2, P = 3 represents port #3, and P = 4 represents port #4. It is obtained by exciting each input port #1 to #4 of the folded Butler matrix of the asymmetric dielectric integrated transmission line. The phase differences of each output port 5 to 8 of the folded Butler matrix of the asymmetric dielectric integrated transmission line are distributed within ±45° and ±135°, and the fluctuation range of the phase error is within ±9°.

[0063] Figure 4 Schematic diagram of S parameters of the phased array antenna based on the folded Butler matrix according to the embodiment of the present invention, as Figure 4 shown. In the figure, the abscissa represents frequency with the unit of GHz, and the ordinate represents S parameter with the unit of degree. In the working frequency band of 52.3 GHz to 67.5 GHz, S 11 , S 22 , S 33 and S 44 are all less than -10 dB, and the relative bandwidth of -10 dB is 25.3%.

[0064] Figure 5 Schematic diagram of beam scanning gain of the phased array antenna based on the folded Butler matrix according to the embodiment of the present invention, as Figure 5 shown. In the figure, the abscissa represents phase with the unit of degree, and the ordinate represents gain with the unit of dBi. At the center frequency of 60 GHz, by exciting the input ports #1 to #4 of the phased array antenna based on the folded Butler matrix, the corresponding four beam pointing directions are -10°, 29°, 9° and -30° in sequence, and the corresponding gains are 13.3 dBi, 11.2 dBi, 13 dBi and 12.1 dBi.

[0065] A phased array antenna based on a folded Butler matrix proposed in the embodiment of the present invention proposes a folded Butler matrix. Its folded structure can save the size of the crossed first directional coupler and second directional coupler, and stack the traditional Butler matrix up and down, effectively realizing miniaturization and scalability. And, the loaded asymmetric defected ground directional coupler of the asymmetric dielectric integrated transmission line proposed by the present invention realizes a broadband effect. Finally, the phased array antenna with the folded Butler matrix proposed by the present invention realizes high integration and beam scanning effect.

[0066] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

[0067] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A phased array antenna based on a folded Butler matrix, characterized in that: It includes two folded Butler matrices based on asymmetric dielectric integrated transmission lines, a three-dipole antenna array, and a conversion structure from an asymmetric dielectric integrated coaxial transmission line to a waveguide; Wherein, the folded Butler matrix is ​​connected to the conversion structure, and the three-dipole antenna arrays are respectively located at different layers of one of the folded Butler matrices; The folded Butler matrix comprises an upper asymmetric dielectric integrated transmission line, a lower asymmetric dielectric integrated transmission line, a first directional coupler loaded with an asymmetric defect of the upper asymmetric dielectric integrated transmission line, a second directional coupler loaded with an asymmetric defect of the lower asymmetric dielectric integrated transmission line, a first phase shifter of the upper asymmetric dielectric integrated transmission line, a second phase shifter of the lower asymmetric dielectric integrated transmission line, and an interlayer connection structure; The upper asymmetric dielectric integrated transmission line includes a first dielectric plate, a second dielectric plate, a first signal line, a first metal floor, a second metal floor and a first grounding via, the first dielectric plate and the second dielectric plate have different thicknesses, the first dielectric plate is located above the second dielectric plate, the first signal line is located between the first dielectric plate and the second dielectric plate, the first metal floor is located on the top layer of the first dielectric plate, the second metal floor is located on the bottom layer of the second dielectric plate, the first grounding via passes through the first dielectric plate and the second dielectric plate, and connects the first dielectric plate and the second dielectric plate to form an asymmetric dielectric integrated coaxial transmission line; The lower layer asymmetric dielectric integrated transmission line includes a third dielectric plate, a fourth dielectric plate and a second signal line, a third metal floor, a fourth metal floor and a second grounding via, the third dielectric plate and the fourth dielectric plate have different thicknesses, the third dielectric plate is located above the fourth dielectric plate, the second signal line is located between the third dielectric plate and the fourth dielectric plate, the third metal floor is located on the top layer of the third dielectric plate, the fourth metal floor is located on the bottom layer of the fourth dielectric plate, and the second grounding via passes through the third dielectric plate and the fourth dielectric plate and connects the third dielectric plate and the fourth dielectric plate to form an asymmetric dielectric integrated coaxial transmission line.

2. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: The first dielectric plate and the fourth dielectric plate have the same thickness, and the second dielectric plate and the third dielectric plate have different thicknesses.

3. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: There are two conversion structures, one of which is located at the first metal floor and connected to the first directional coupler; Another conversion structure is located at the fourth metal floor and connected to the second directional coupler.

4. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: The asymmetric defect of the first directional coupler includes three first metal grooves of inconsistent sizes and rectangular shapes. The asymmetric defect of the first directional coupler is located on the first metal floor, and the asymmetric defect of the second directional coupler is located on the fourth metal floor.

5. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: The first phase shifter is 45° and is used to connect the first directional coupler, and the second phase shifter is 45° and is used to connect the second directional coupler.

6. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: The interlayer connection structure includes an interlayer connection line, a second metal groove, and a matching patch. The matching patch is located in the second metal groove, and the matching patch is connected to the interlayer connection line.

7. The phased array antenna based on the folded Butler matrix according to claim 6, characterized in that: The interlayer connection line also passes through the second dielectric plate and is connected to the matching patch of the interlayer connection structure located at the second metal floor. The interlayer connection line also passes through the third dielectric plate and is connected to the matching patch of the interlayer connection structure located at the third metal floor.

8. The phased array antenna based on the folded Butler matrix according to claim 6, characterized in that: The second metal groove is also located on the second metal floor and the third metal floor.

9. The phased array antenna based on the folded Butler matrix according to claim 1, characterized in that: The three dipole antenna arrays are respectively located at the layers where the first metal floor, the second metal floor and the first signal line are located. The dipole arm of each dipole antenna array includes two branches of different lengths, and the two branches are F-shaped. The direction of the dipole located at the layer where the first signal line is located is opposite to the direction of the dipole located at the first metal floor layer, and the direction of the dipole located at the layer where the first signal line is located is opposite to the direction of the dipole located at the second metal floor layer.

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