A waveguide radar substrate

Abstract

The invention relates to the technical field of waveguide radar substrates, and discloses a waveguide radar substrate, comprising two plates, two metal coatings, and a polytetrafluoroethylene sheet; the two plates are bonded to each other, the polytetrafluoroethylene sheet is clamped between two first metal layers, the two second metal layers are abutted against each other, and the two third metal layers and the polytetrafluoroethylene sheet together form a waveguide cavity; the waveguide radar substrate also includes a through hole that penetrates the two plates, the two first metal layers, and the polytetrafluoroethylene sheet; in actual use, the gas contained in the waveguide cavity of the radar substrate manufactured by the method of the invention can be connected to the outside through the sheet made of expanded polytetrafluoroethylene, such as the through hole, so that the waveguide cavity can effectively avoid pressure damage caused by thermal expansion and contraction, and external water vapor or pollutants can also be blocked by the sheet outside the waveguide cavity, thereby maintaining the stability of the waveguide cavity, so as to be suitable for application fields with high electrical performance requirements and harsh environmental conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of waveguide radar substrates, and in particular to a waveguide radar substrate. Background Art

[0002] The radar substrate is a key component in the radar system, carrying the radar antenna and other electronic components, and has an important impact on the performance and stability of the radar.

[0003] Existing radar substrates have cavities formed inside them. The cavities can firstly suppress the propagation of surface waves generated during the operation of the radar, reduce signal interference and improve the performance of the radar; in addition, they can help to broaden the impedance bandwidth of the radar antenna, enable the radar system to operate in a wider frequency range, and improve the adaptability and flexibility of the radar system; finally, they can also optimize the electric field distribution in the radar substrate, confine the electric field to a specific area, reduce electric field leakage and interference, and improve the stability and accuracy of the radar system.

[0004] The cavity in the radar substrate is designed to be closed to avoid being affected by external moisture or pollutants. However, the gas contained in the closed cavity is isolated from the outside world, making the gas in the cavity susceptible to thermal expansion and contraction, causing pressure damage to the cavity, thereby affecting the performance of the radar substrate. Summary of the invention

[0005] In view of the shortcomings of the background technology, the present invention provides a waveguide radar substrate. The technical problem to be solved is that the cavity in the existing radar substrate is designed to be closed, and the gas in the cavity is easily affected by thermal expansion and contraction to cause pressure damage to the cavity.

[0006] In order to solve the above technical problems, in the first aspect, the present invention provides the following technical solutions: a waveguide radar substrate, comprising:

[0007] Two plates, each comprising a processing surface and a groove concavely arranged on the processing surface, wherein the processing surface of each plate is provided with a first processing area and a second processing area on both sides of the groove in the width direction, respectively, and the vertical distance between the second processing area and the groove bottom of the groove is greater than the vertical distance between the first processing area and the groove bottom of the groove;

[0008] Two metal coatings are formed on the two plates respectively, and each metal coating comprises a first metal layer, a second metal layer and a third metal layer respectively: the first metal layer is located on a first processing area of ​​the corresponding plate, the second metal layer is located on a second processing area of ​​the corresponding plate, and the third metal layer is located on a wall surface of the groove of the corresponding plate; the first metal layer and the second metal layer are connected to both sides of the third metal layer;

[0009] A polytetrafluoroethylene sheet is used for waterproofing and breathability; wherein the two plates are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet is clamped between the two first metal layers, the two second metal layers are abutted against each other, and the two third metal layers and the polytetrafluoroethylene sheet together form a closed waveguide cavity;

[0010] The waveguide radar substrate further includes a through hole that penetrates the two plates, the two first metal layers and the polytetrafluoroethylene sheet along the thickness direction, and the waveguide cavity is connected to the through hole through the polytetrafluoroethylene sheet.

[0011] In a certain embodiment of the first aspect, conductive layers are respectively formed on the hole walls of the through holes on both sides of the polytetrafluoroethylene sheet.

[0012] In a certain embodiment of the first aspect, each of the plates comprises an insulating layer having the groove formed therein, and an inner conductive layer formed on the inner surface of the insulating layer, wherein the inner conductive layer is located on the second processing area;

[0013] The first metal layer is located on the inner surface of the insulating layer, and the second metal layer is located on the inner conductive layer.

[0014] In a certain embodiment of the first aspect, the polytetrafluoroethylene sheet includes an inner edge defining a partial through hole and an outer edge surrounding the outside of the through hole, and a portion of the outer edge protrudes out of the adjacent third metal layer.

[0015] In a certain embodiment of the first aspect, the polytetrafluoroethylene sheet is circular in shape, the local protrusion distance of the outer edge is between 0.5% and 3% of the outer diameter of the sheet, and the local part has a central angle of 20° to 35° compared to the center of the sheet; the center of the sheet is inside the through hole or outside the through hole.

[0016] In certain embodiments of the first aspect, the dielectric constant of the polytetrafluoroethylene sheet is between 1.3 and 1.4.

[0017] In a certain embodiment of the first aspect, the thickness of the polytetrafluoroethylene sheet is between 18% and 30% of the height of the waveguide cavity along the thickness direction, and at least 25% of the through hole is formed on the polytetrafluoroethylene sheet.

[0018] In a second aspect, the present invention provides another waveguide radar substrate, comprising

[0019] A first plate, comprising a processing surface and a groove concavely arranged on the processing surface, wherein the processing surface of the first plate is provided with a first processing area and a second processing area on both sides of the groove in a width direction, respectively, and a vertical distance between the second processing area and the bottom of the groove is greater than a vertical distance between the first processing area and the bottom of the groove;

[0020] The first metal plating layer is formed on the two plates, including a first metal layer, a second metal layer and a third metal layer: the first metal layer is located in a first processing area of ​​the first plate, the second metal layer is located in a second processing area of ​​the first plate, and the third metal layer is located on the wall surface of the groove of the first plate; the first metal layer and the second metal layer are connected to both sides of the third metal layer

[0021] a second plate and a second metal coating, wherein the second metal coating is located on the second plate;

[0022] A polytetrafluoroethylene sheet is used for waterproofing and breathability; wherein the first sheet and the second sheet are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet is clamped between the first metal layer and the second metal coating, the second metal layer abuts against the second metal coating, and the third metal layer, a portion of the second metal coating corresponding to the third metal layer and the polytetrafluoroethylene sheet together form a closed waveguide cavity;

[0023] The waveguide radar substrate further includes a through hole that penetrates the first plate, the second plate, the first metal layer, the second metal plating layer and the polytetrafluoroethylene sheet along the thickness direction, and the waveguide cavity is connected to the through hole through the polytetrafluoroethylene sheet.

[0024] In a certain embodiment of the second aspect, conductive layers are respectively formed on the hole walls of the through holes on both sides of the polytetrafluoroethylene sheet.

[0025] In a certain embodiment of the second aspect, the dielectric constant of the polytetrafluoroethylene sheet is between 1.3 and 1.4, and at least 25% of the through holes are formed on the polytetrafluoroethylene sheet.

[0026] Compared with the prior art, the present invention has the following beneficial effects: the gas contained in the waveguide cavity of the radar substrate of the present invention can be connected to the outside through the polytetrafluoroethylene sheet, such as the through hole, so that the waveguide cavity can effectively avoid pressure damage caused by thermal expansion and contraction, and external moisture or pollutants can also be blocked outside the waveguide cavity by the polytetrafluoroethylene sheet, thereby maintaining the stability of the waveguide cavity, so as to be suitable for application fields with high electrical performance requirements and harsh environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the structure of the groove on the plate in the first embodiment;

[0028] Figure 2 It is a schematic diagram of the structure of the metal layer on the plate in Example 1;

[0029] Figure 3 This is a schematic diagram of the structure before two plates are combined in Example 1;

[0030] Figure 4 This is a schematic diagram of the structure after two plates are combined in Example 1;

[0031] Figure 5 It is a schematic diagram of the structure of the through hole in the present invention in Example 1;

[0032] Figure 6 for Figure 5 The schematic top view of the plate and metal coating located above is omitted;

[0033] Figure 7 for Figure 6 A schematic diagram of a variation of ;

[0034] Figure 8 It is a schematic diagram of the conductive layer of the present invention in Example 1;

[0035] Fig. 9 Schematic diagram of the waveguide radar substrate in the second embodiment.

[0036] Wherein: 1: plate; 1a: first plate; 10: processing surface; 11: first processing area; 12: second processing area; 13: groove; 14: insulating layer; 15: inner conductive layer; 1b: second plate;

[0037] 2: metal plating; 2a: first metal plating; 21: first metal layer; 22: second metal layer; 23: third metal layer; 2b: second metal plating

[0038] 3: sheet body; 31: center of circle; 32: inner edge; 33: outer edge; 331: part

[0039] 4: Conductive layer;

[0040] 5: Through hole;

[0041] 100: waveguide radar substrate;

[0042] W: width direction; T: thickness direction; C: waveguide cavity; D: outer diameter; D331: protrusion distance;

[0043] σ331: center angle; T3: thickness; Hc: height. DETAILED DESCRIPTION

[0044] The following is an explanation of the implementation method of the waveguide radar substrate manufacturing method disclosed in the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0045] It should be understood that, although the terms first, second, third, etc. may be used herein to describe various components or features, these components or features should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one feature from another feature. In addition, the terms or used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0046] Embodiment 1

[0047] In order to effectively prevent the waveguide cavity of the waveguide radar substrate from being damaged by pressure due to thermal expansion and contraction, Figure 6-9 As shown, this embodiment provides a waveguide radar substrate, including: two plates 1 joined to each other along a thickness direction T, two metal coatings 2 respectively formed on the two plates 1, a polytetrafluoroethylene sheet 3 sandwiched between the two metal coatings 2, and a conductive layer 4 formed on the two plates 1 and the two metal coatings 2.

[0048] It should be noted that the waveguide radar substrate 100 in this embodiment is described as being configured with a conductive layer 4 and a polytetrafluoroethylene sheet 3, but the specific number of polytetrafluoroethylene sheets 3 may also be increased according to actual needs, and the conductive layer 4 may also be omitted, and the present invention is not limited thereto.

[0049] The other two plates 1 are only partially described in this embodiment, and the two plates 1 are substantially mirror-symmetrically arranged, but the present invention is not limited thereto. For example, in other embodiments not shown in the present invention, the structures of the two plates 1 may also be slightly different according to actual needs.

[0050] The structures of the two plates 1 are described as follows:

[0051] like Figure 1As shown, in this embodiment, the two plates 1 each include a processing surface 10 and a groove 13 recessed on the processing surface 10, and the processing surface 10 of each plate 1 is provided with a first processing area 11 and a second processing area 12 on both sides of the width direction of the groove 13, respectively, and the vertical distance between the second processing area 12 and the bottom of the groove 13 is greater than the vertical distance between the first processing area 11 and the bottom of the groove 13.

[0052] In more detail, each plate 1 includes an insulating layer 14 and an inner conductive layer 15 formed on the inner surface of the insulating layer 14. The insulating layer 14 is formed with a groove 13, and the insulating layer 14 can also be provided with a conductive layer inside or on the outer surface thereof according to actual needs. Furthermore, the inner conductive layer 15 is located in the second processing area 12 but not in the first processing area 11, so that the second processing area 12 is higher than the first processing area 11.

[0053] The structures of the two metal plating layers 2 are described as follows:

[0054] like Figure 2 As shown, in this embodiment, two metal coatings 2 are respectively formed on two plates 1, and each metal coating 2 includes a first metal layer 21, a second metal layer 22 and a third metal layer 23: the first metal layer 21 is located in the first processing area 11 of the corresponding plate 1, the second metal layer 22 is located in the second processing area 12 of the corresponding plate 1, for example, located on the inner conductive layer, and the third metal layer 23 is located on the wall surface of the groove 13 of the corresponding plate 1; the first metal layer 21 and the second metal layer 22 are connected on both sides of the third metal layer 23.

[0055] The structure of the polytetrafluoroethylene sheet 3 is described as follows:

[0056] like Figure 3 and 4 As shown, in this embodiment, the polytetrafluoroethylene sheet 3 is an expanded polytetrafluoroethylene sheet for waterproof and breathable use. In addition, the dielectric constant of the polytetrafluoroethylene sheet 3 is between 1.3 and 1.4; and the polytetrafluoroethylene sheet 3 is a circular sheet in this embodiment and has a center 31, but the present invention is not limited to this.

[0057] The other two plates 1 are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet 3 is clamped between the two first metal layers 21, the two second metal layers 22 abut against each other, and the two third metal layers 23 and the polytetrafluoroethylene sheet 3 together form a closed waveguide cavity C.

[0058] In addition, in this embodiment, the polytetrafluoroethylene sheet 3 has a thickness T3 along the thickness direction T, which is between 18% and 30% of a height Hc of the waveguide cavity C in the thickness direction T. Exemplarily, T3=0.2Hc, or T3=0.24Hc, or T3=0.28Hc.

[0059] The structure of the conductive layer 4 in this embodiment is described as follows:

[0060] First, Figure 5 As shown, in this embodiment, the waveguide radar substrate 100 further includes a through hole 5 penetrating the two plates 1, the two first metal layers 21 and the polytetrafluoroethylene sheet 3 along the thickness direction, and the waveguide cavity C is connected to the through hole 5 through the polytetrafluoroethylene sheet 3.

[0061] Then as Fig. 9 As shown, conductive layers 4 are formed on the hole wall of the through hole 5 on both sides of the polytetrafluoroethylene sheet 3. The conductive layer 4 is not formed on the inner edge 32 of the expanded polytetrafluoroethylene sheet 3, so that the conductive layer 4 is separated by the expanded polytetrafluoroethylene sheet 3 to form two sections separated from each other.

[0062] According to the above content, the gas contained in the waveguide cavity C of the waveguide radar substrate 100 of the present invention can be connected to the outside through the polytetrafluoroethylene sheet 3, such as the through hole 5, so that the waveguide cavity C can effectively avoid pressure damage caused by thermal expansion and contraction, and external moisture or pollutants can also be blocked outside the waveguide cavity C by the polytetrafluoroethylene sheet, thereby maintaining the stability of the waveguide cavity C, so as to be suitable for application fields with high electrical performance requirements and harsh environmental conditions.

[0063] It should be additionally explained that, in order for the polytetrafluoroethylene sheet 3 to provide a better technical effect for the waveguide cavity C, the polytetrafluoroethylene sheet 3 preferably has at least part of the following conditions, but the present invention is not limited thereto.

[0064] In this embodiment, at least 25% of the through hole 5 is formed on the polytetrafluoroethylene sheet 3; for example: Figure 7 As shown, the through hole 5 can be formed entirely in the polytetrafluoroethylene sheet 3, and the center 31 of the polytetrafluoroethylene sheet 3 is located within the through hole 5; or Figure 8 As shown, the through hole 5 may also be partially (eg, at least 25%) formed in the polytetrafluoroethylene sheet 3 , and the center 31 of the polytetrafluoroethylene sheet 3 is located outside the through hole 5 .

[0065] In addition, in this embodiment, Figure 7As shown, the polytetrafluoroethylene sheet 3 includes an inner edge 32 defining a partial through hole 5 and an outer edge 33 surrounding the outside of the through hole 5, and a portion 331 of the outer edge 33 protrudes out of the adjacent third metal layer 23. In other words, a portion 331 of the outer edge 33 of the polytetrafluoroethylene sheet 3 is located within the waveguide cavity C.

[0066] Furthermore, the polytetrafluoroethylene sheet 3 has an outer diameter D, and a portion 331 of the outer edge 33 of the polytetrafluoroethylene sheet 3 has a protrusion distance D331 along the width direction W, which is between 0.5% and 3% of the outer diameter D. The portion 331 of the outer edge 33 of the polytetrafluoroethylene sheet 3 has a center angle σ331 between 20 degrees and 35 degrees relative to the center 31.

[0067] Embodiment 2

[0068] This embodiment provides another waveguide radar substrate 100. Since this embodiment is similar to the above-mentioned embodiment 1, the similarities between the two embodiments will not be described in detail, and the differences between this embodiment and the above-mentioned embodiment 1 are roughly described as follows:

[0069] like Fig. 9 As shown, the waveguide radar substrate 100 in this example includes a first plate 1a and a second plate 1b bonded to each other along a thickness direction T, a first metal coating layer 2a formed on the first plate 1a, a second metal coating layer 2b formed on the second plate 1b, and an expanded polytetrafluoroethylene sheet 3 sandwiched between the first metal layer 21 and the second metal coating layer 2b, but the present invention is not limited thereto.

[0070] The structure and connection relationship of the first plate 1a and the first metal coating 2a in this embodiment are roughly equivalent to any plate and corresponding metal coating in Example 1, so the following content only roughly describes the first plate 1a and the first metal coating 2a, and their specific structure and connection relationship can be referred to in Example 1.

[0071] Furthermore, the first plate 1a includes a processing surface 10 and a groove 13 recessed on the processing surface 10. The processing surface 10 of the first plate 1a is provided with a first processing area 11 and a second processing area 12 on both sides of the width direction of the groove 13, and the vertical distance between the second processing area 12 and the bottom of the groove 13 is greater than the vertical distance between the first processing area 11 and the bottom of the groove 13.

[0072] In this embodiment, the first metal coating 2 is formed on two plates 1, including a first metal layer 21, a second metal layer 22 and a third metal layer 23: the first metal layer 21 is located in the first processing area 11 of the first plate 1a, the second metal layer 22 is located in the second processing area 12 of the first plate 1a, and the third metal layer 23 is located on the wall surface of the groove 13 of the first plate 1a; the first metal layer 21 and the second metal layer 22 are connected to both sides of the third metal layer 23

[0073] A second plate 1b and a second metal coating 2b, wherein the second metal coating 2b is located on the second plate 1b;

[0074] The polytetrafluoroethylene sheet 3 is used for waterproof and breathable, wherein the first sheet 1a and the second sheet 1b are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet 3 is clamped between the first metal layer 21 and the second metal coating 2b, the second metal layer 22 is in contact with the second metal coating 2b, and the third metal layer 23, the part of the second metal coating 2b corresponding to the third metal layer 23 and the polytetrafluoroethylene sheet 3 together form a closed waveguide cavity C;

[0075] The waveguide radar substrate 100 further includes a through hole 5 penetrating the first plate 1a, the second plate 1b, the first metal layer 21, the second metal coating 2b and the polytetrafluoroethylene sheet 3 in the thickness direction, and the waveguide cavity is connected to the through hole 5 through the sheet 3.

[0076] It should be noted that the features of the polytetrafluoroethylene sheet 3 and the relative relationship between the through hole 5 in this embodiment are roughly the same as those in the first embodiment, and are not described in detail here. Furthermore, the through hole 5 of the waveguide radar substrate 100 can also be equipped with a conductive layer as described in the first embodiment according to actual needs.

[0077] In addition, in this embodiment, the dielectric constant of the polytetrafluoroethylene sheet 3 is between 1.3 and 1.4, and at least 25% of the through holes 5 are formed on the polytetrafluoroethylene sheet 3 .

[0078] The above is based on the present invention as an inspiration. Through the above description, relevant staff can make various changes and modifications without departing from the technical idea of ​​this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A waveguide radar substrate, characterized in that: include: Two plates (1), each comprising a processing surface (10) and a groove (13) recessed on the processing surface (10), wherein the processing surface (10) of each plate (1) is provided with a first processing area (11) and a second processing area (12) on both sides of the groove (13) in the width direction, respectively, and the vertical distance between the second processing area (12) and the bottom of the groove (13) is greater than the vertical distance between the first processing area (11) and the bottom of the groove (13); Two metal coatings (2) are respectively formed on the two plates (1), and each metal coating (2) comprises a first metal layer (21), a second metal layer (22) and a third metal layer (23): the first metal layer (21) is located on a first processing area (11) of the corresponding plate (1), the second metal layer (22) is located on a second processing area (12) of the corresponding plate (1), and the third metal layer (23) is located on a wall surface of a groove (13) of the corresponding plate (1); the first metal layer (21) and the second metal layer (22) are connected to both sides of the third metal layer (23); A polytetrafluoroethylene sheet (3) for waterproofing and breathability; wherein the two plates (1) are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet (3) is clamped between the two first metal layers (21), the two second metal layers (22) are in contact with each other, and the two third metal layers (23) and the polytetrafluoroethylene sheet (3) together form a closed waveguide cavity; The waveguide radar substrate further comprises a through hole (5) penetrating the two plates (1), the two first metal layers (21) and the polytetrafluoroethylene sheet (3) along the thickness direction, and the waveguide cavity is connected to the through hole (5) via the polytetrafluoroethylene sheet (3).

2. A waveguide radar substrate according to claim 1, characterized in that: Conductive layers (4) are formed on the hole walls of the through holes (5) on both sides of the polytetrafluoroethylene sheet (3).

3. A waveguide radar substrate according to claim 1, characterized in that: Each of the plates (1) comprises an insulating layer (14) formed with the groove (13), and an inner conductive layer (15) formed on the inner surface of the insulating layer (14), wherein the inner conductive layer (15) is located on the second processing area (12); The first metal layer (21) is located on the inner surface of the insulating layer (14), and the second metal layer (22) is located on the inner conductive layer (15).

4. The waveguide radar substrate according to claim 1, characterized in that: The polytetrafluoroethylene sheet (3) comprises an inner edge (32) defining a partial through hole (5) and an outer edge (33) surrounding the outside of the through hole (5), wherein a portion (331) of the outer edge (33) protrudes out of an adjacent third metal layer (23).

5. A waveguide radar substrate according to claim 4, characterized in that: The polytetrafluoroethylene sheet (3) is circular in shape, the protrusion distance of a portion (331) of the outer edge (33) is between 0.5% and 3% of the outer diameter of the sheet (3), and the portion (331) has a central angle of 20° to 35° compared to the center (31) of the sheet (3); the center (31) of the sheet (3) is inside the through hole (5) or outside the through hole (5).

6. A waveguide radar substrate according to claim 1, 4 or 5, characterized in that: The dielectric constant of the polytetrafluoroethylene sheet (3) is between 1.3 and 1.

4.

7. The waveguide radar substrate according to claim 1, characterized in that: The thickness of the polytetrafluoroethylene sheet (3) is between 18% and 30% of the height of the waveguide cavity along the thickness direction, and at least 25% of the area of ​​the through hole (5) is formed on the polytetrafluoroethylene sheet (3).

8. A waveguide radar substrate, characterized in that: include: A first plate (1a) comprises a processing surface (10) and a groove (13) concavely arranged on the processing surface (10), wherein a first processing area (11) and a second processing area (12) are respectively arranged on the processing surface (10) of the first plate (1a) on both sides of the groove (13) in a width direction, and a vertical distance between the second processing area (12) and the bottom of the groove (13) is greater than a vertical distance between the first processing area (11) and the bottom of the groove (13); A first metal coating (2) is formed on the two plates (1), comprising a first metal layer (21), a second metal layer (22) and a third metal layer (23): the first metal layer (21) is located on a first processing area (11) of the first plate (1a), the second metal layer (22) is located on a second processing area (12) of the first plate (1a), and the third metal layer (23) is located on a wall surface of a groove (13) of the first plate (1a); the first metal layer (21) and the second metal layer (22) are connected to both sides of the third metal layer (23); A second plate (1b) and a second metal coating (2b), wherein the second metal coating (2b) is located on the second plate (1b); A polytetrafluoroethylene sheet (3) for waterproofing and breathability; wherein a first sheet (1a) and a second sheet (1b) are joined to each other along a thickness direction perpendicular to the width direction, and the polytetrafluoroethylene sheet (3) is clamped between the first metal layer (21) and the second metal coating (2b), the second metal layer (22) abuts against the second metal coating (2b), and the third metal layer (23), a portion of the second metal coating corresponding to the third metal layer (23), and the polytetrafluoroethylene sheet (3) together form a closed waveguide cavity; The waveguide radar substrate further comprises a through hole (5) which penetrates the first plate (1a), the second plate (1b), the first metal layer (21), the second metal coating (2b) and the polytetrafluoroethylene sheet (3) along the thickness direction, and the waveguide cavity is connected to the through hole (5) via the polytetrafluoroethylene sheet (3).

9. A waveguide radar substrate according to claim 8, characterized in that: Conductive layers (4) are formed on the hole walls of the through holes (5) on both sides of the polytetrafluoroethylene sheet (3).

10. A waveguide radar substrate according to claim 9, characterized in that: The dielectric constant of the polytetrafluoroethylene sheet (3) is between 1.3 and 1.4, and at least 25% of the area of ​​the through hole (5) is formed on the polytetrafluoroethylene sheet (3).

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