Radio frequency device and radio frequency equipment

Abstract

The embodiment of the utility model relates to the technical field of semiconductors, and discloses a radio frequency device and radio frequency equipment, and the radio frequency device comprises a PCB, the first surface of which is provided with at least one first waveguide hole; the waveguide structure is mounted on the first surface; second waveguide holes are formed in the positions, corresponding to the first waveguide holes, of the surface, connected with the PCB, of the waveguide structure. Isolation structures are arranged at the positions, corresponding to the first waveguide holes, in the PCB, and the isolation structures are isolation spaces arranged around the first waveguide holes; the isolation space is of a structure in which a metal part is removed, the isolation space is provided with a first boundary surface and a second boundary surface which are opposite, the first boundary surface is located on the first surface and is not provided with the metal part, and the second boundary surface is located in the PCB and is provided with the metal part. According to the scheme, when the external waveguide antenna and the PCB are bonded and fixed, signals can be effectively prevented from leaking from a bonding gap, and meanwhile, the external waveguide antenna is not limited by a processing technology.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor technology, and in particular to a radio frequency device and a radio frequency equipment. Background Art

[0002] With the development of autonomous driving technology, the performance of millimeter-wave radar needs to be further improved. Compared with the board-level antenna designed on the printed circuit boards (PCB), the external waveguide antenna can further reduce the feeder loss and improve the performance of the millimeter-wave radar module. When the external waveguide antenna is installed and fixed to the PCB board, due to processing size errors and other reasons, the external waveguide cannot be completely fitted with the PCB surface, and there will be a gap at the junction of the two parts, which will cause the isolation between the RF signal transmission channels to be seriously deteriorated. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a radio frequency device and a radio frequency equipment, which can effectively prevent the signal from leaking from the gap when the external waveguide antenna is bonded and fixed to the PCB board, and is not limited by the processing technology.

[0004] In order to solve the above technical problems, an embodiment of the present application provides a radio frequency device, including:

[0005] A PCB board, wherein at least one first waveguide hole is arranged on a first surface thereof;

[0006] A waveguide structure is arranged on the first surface; a second waveguide hole is arranged on the surface of the waveguide structure connected to the PCB board at positions corresponding to each of the first waveguide holes, and the first waveguide hole is connected to the second waveguide hole to form a radio frequency signal transmission channel;

[0007] An isolation structure is provided in the PCB board at a position corresponding to the first waveguide hole. The isolation structure is an isolation space arranged around the first waveguide hole. The isolation space is used to prevent the radio frequency signal from being transmitted laterally along the end surface where the PCB board and the waveguide structure are connected.

[0008] The isolation space is a structure in which the metal part is removed from the inside. The isolation space has a first boundary surface and a second boundary surface relative to each other. The first boundary surface is located on the first surface and has no metal part, and the second boundary surface is located inside the PCB board and has a metal part.

[0009] The radio frequency device provided by the embodiment of the present application has a waveguide structure installed on the first surface of the PCB board; a first waveguide hole is set on the first surface of the PCB board; a second waveguide hole is set on the surface where the waveguide structure is connected to the PCB board, corresponding to the first waveguide hole, and the first waveguide hole and the second waveguide hole are connected to form a radio frequency signal transmission channel; an isolation structure is set in the PCB board at a position corresponding to the first waveguide hole, and the isolation structure is an isolation space arranged around the first waveguide hole to prevent the radio frequency signal from being transmitted laterally along the end face where the PCB board and the waveguide structure are connected; the isolation space is a structure where the metal part is removed from the inside, and the isolation space has a first boundary surface and a second boundary surface relative to each other, the first boundary surface is located on the first surface and has no metal part, and the second boundary surface is located in the PCB board and has a metal part. This scheme prevents the radio frequency signal from being transmitted laterally along the end face where the PCB board and the waveguide structure are connected by setting an isolation structure, thereby achieving the effect of improving the isolation between the radio frequency signal transmission channels.

[0010] In one embodiment, the distance from the second boundary surface to the first boundary surface is equal to an integer multiple of a quarter wavelength of the radio frequency signal transmitted in the isolation structure.

[0011] In one embodiment, the medium in the isolation structure is air or a dielectric layer of a PCB board.

[0012] In one embodiment, the isolation structure is formed by removing each metal layer in the isolation space from the PCB board.

[0013] In one embodiment, a plurality of metal vias are arranged in the PCB board around each of the first waveguide holes.

[0014] In one embodiment, at least one metal via among the plurality of metal vias passes through the isolation structure at the location thereof.

[0015] In one embodiment, the metal portion disposed on the second boundary surface is a third metal layer in the PCB board away from the first surface.

[0016] In one embodiment, the PCB board includes at least six metal layers.

[0017] On the other hand, an embodiment of the present application provides a radio frequency device, including: the radio frequency device as described above, wherein a waveguide antenna is provided at one end of the second waveguide hole away from the first surface; a chip package body, mounted on the second surface of the PCB board, the second surface is opposite to the first surface, and a radiation part is provided on the end surface of the chip package body connected to the second surface corresponding to each of the first waveguide holes, for sending and receiving radio frequency signals.

[0018] In one embodiment, a plurality of solder balls are disposed around each of the radiation portions on the end surface of the chip package body butting against the second surface, and a cavity surrounded by the plurality of solder balls is connected to the first waveguide hole to form a radio frequency signal transmission channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0020] Figure 1 It is a schematic diagram of the assembly of a chip package, a PCB board and a waveguide structure in the prior art;

[0021] Figure 2 yes Figure 1 Schematic diagram of the gap waveguide at the interface between the PCB board and the waveguide structure;

[0022] Figure 3 is a schematic diagram of a radio frequency device provided in an embodiment of the present application;

[0023] Figure 4 is a schematic diagram of another radio frequency device provided in an embodiment of the present application;

[0024] Figure 5 is a top view of the connection between the PCB board and the waveguide structure in the radio frequency device provided in the embodiment of the present application;

[0025] Figure 6 A top view of the metal layer of the PCB board in the radio frequency device provided in the embodiment of the present application Figure 1 ;

[0026] Figure 7 A top view of the metal layer of the PCB board in the radio frequency device provided in the embodiment of the present application Figure 2 ;

[0027] Figure 8 It is a comparison diagram of isolation before and after the isolation structure is set in the embodiment of the present application. DETAILED DESCRIPTION

[0028] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined and referenced with each other without contradiction.

[0029] like Figure 1 As shown, in the prior art, a radiation part 02 is provided on one side surface of the chip package 01, and the radio frequency signal emitted by the radiation part 02 reaches the antenna 06 through the radio frequency signal transmission channel formed by the signal cavity surrounded by the solder ball 03, the waveguide hole on the PCB board 04 and the waveguide hole on the waveguide structure 05, and radiates outward. When the waveguide hole on the PCB board 04 is connected with the waveguide hole on the waveguide structure 05, the signal will leak here due to the existence of the gap G, thereby causing the isolation between the radio frequency signal transmission channels to be seriously deteriorated.

[0030] At present, when there is a gap at the junction of two parts, a gap waveguide can be used to prevent signal leakage. The gap waveguide forms an electromagnetic band gap (EBG) without physical contact under certain conditions through a periodic electromagnetic structure, and uses the electromagnetic bandgap characteristics of EBG to build a waveguide or shielding structure. However, the gap waveguide that prevents signal leakage at the waveguide channel where the PCB board and the waveguide structure are connected is usually realized by mechanical processing. When there are multiple waveguide channels arranged and the distance between the waveguide channels is small, it is easily limited by the processing technology. Figure 2 As shown, when the distance between the two waveguide channels T1 and T2 is small, due to the limitations of the minimum machinable wall thickness and the minimum distance between the two waveguide channels, one or more bed of nails blocks B cannot be placed between the two waveguide channels, thereby failing to form a good electromagnetic band gap (EBG) structure to prevent signal leakage.

[0031] One embodiment of the present application relates to a radio frequency device, which can effectively prevent the signal from leaking from the gap when the external waveguide antenna is attached to the PCB board, and is not limited by the processing technology. Figure 3 As shown, the radio frequency device includes: a PCB board 11 and a waveguide structure 21.

[0032] The PCB board 11 has at least one first waveguide hole 12 disposed on its first surface S1.

[0033] The PCB board 11 may be, but is not limited to, Figure 3 The six-layer metal layer (L1-L6) structure shown in the figure. The first surface S1 is a side of the PCB board 11 used for connecting the waveguide structure 21. The first surface S1 is provided with a first waveguide hole 12. A plurality of first waveguide holes 12 can be provided. Each first waveguide hole 12 usually passes through the first surface S1 and the second surface S2 of the PCB board 11 that is opposite to the first surface S1.

[0034] The waveguide structure 21 is arranged on the first surface S1; on the surface S3 where the waveguide structure 21 is connected to the PCB board 11, second waveguide holes 22 are arranged corresponding to each first waveguide hole 12, and the first waveguide holes 12 and the second waveguide holes 22 are connected to form a radio frequency signal transmission channel.

[0035] When the first surface S1 of the PCB board 11 is connected to the surface S3 of the waveguide structure 21, there will be a gap between the two surfaces. The sizes of the waveguide openings of the first waveguide hole 12 and the second waveguide hole 22 at the connection point are consistent, which is more convenient for connection. The second waveguide hole 22 usually passes through the surface S3 and the surface S4 of the waveguide structure 21 that is opposite to the surface S3, and the path of the penetration can be a straight path or a broken line path.

[0036] An isolation structure 13 is provided in the PCB board 11 at a position corresponding to the first waveguide hole 12. The isolation structure 13 is an isolation space arranged around the first waveguide hole 12. The isolation space is used to prevent the RF signal from being transmitted laterally along the end surface where the PCB board 11 and the waveguide structure 21 are connected.

[0037] The isolation space is a structure without metal parts inside. The isolation space has a first boundary surface C1 and a second boundary surface C2 opposite to each other. The first boundary surface C1 is located on the first surface S1 and has no metal parts. The second boundary surface C2 is located inside the PCB board 11 and has metal parts.

[0038] by Figure 3Taking the first waveguide hole 12 on the left side as an example, an isolation space is arranged around the first waveguide hole 12, and the isolation space forms an isolation structure 13 corresponding to the first waveguide hole 12. The interior of the isolation space can be hollow (the medium is air) or a non-metallic medium. The purpose of removing the metal part in the isolation space is to enable unimpeded transmission of the RF signal, especially to prevent the RF signal from leaking from the gap between the PCB board and the waveguide structure. The first boundary surface C1 is set on the first surface S1 (the two surfaces overlap) without a metal part, so as to ensure that the radio frequency signal can enter the isolation space of the isolation structure 13 through the first boundary surface C1 (specifically, near the edge of the first waveguide hole 12) after flowing out from the gap at the joint of the first waveguide hole 12 and the second waveguide hole 22; the second boundary surface C2 is set in the PCB board 11 and has a metal part, so that when the radio frequency signal is transmitted to the second boundary surface C2, a short circuit is formed at the second boundary surface C2. In this way, by appropriately adjusting the distance h between the first boundary surface C1 and the second boundary surface C2, when the radio frequency signal flows back from the second boundary surface C2 to the first boundary surface C1, it is approximately in an open circuit state at the first boundary surface C1 (specifically, away from the edge of the first waveguide hole 12), thereby preventing the radio frequency signal from being transmitted laterally along the end surface where the PCB board 11 and the waveguide structure 21 are joined, and finally achieving the effect of isolating different radio frequency signal transmission channels from each other.

[0039] Regarding the setting of the distance h between the first boundary surface C1 and the second boundary surface C2, this embodiment does not limit this. In principle, the RF signal can be in an open circuit state to a certain extent at the first boundary surface C1, which can prevent the RF signal from being transmitted laterally along the end surface where the PCB board and the waveguide structure are connected.

[0040] In this embodiment, the number, shape and material of the other boundary surfaces in the isolation structure 13 except the first boundary surface C1 and the second boundary surface C2 are not limited. For example, the other boundary surfaces can be closed loop surfaces surrounded by four planes that are perpendicular to the first boundary surface C1 and the second boundary surface C2, and the isolation structure 13 formed thereby is a hexahedral structure. These other boundary surfaces can be configured to have, not have or partially have a metal portion.

[0041] In some embodiments, the distance h from the second boundary surface C2 to the first boundary surface C1 is equal to an integer multiple of 1 / 4 wavelength of the RF signal transmitted in the isolation structure 13, that is, h≈n*0.25λg, where n is an integer greater than 0, and λg is the medium wavelength when the RF signal is transmitted in the medium.

[0042] like Figure 3In the embodiment, since there is a metal part on the second boundary surface C2, a short circuit is formed at the second boundary surface C2 when the radio frequency signal is transmitted to the second boundary surface C2. When the distance h from the second boundary surface C2 to the first boundary surface C1 of the isolation structure 13 is set to an integer multiple of 1 / 4 waveguide wavelength of the radio frequency signal transmitted in the isolation space, according to the principle of 1 / 4 wavelength impedance inversion, the first boundary surface C1 of the PCB board 11 (specifically, the edge away from the first waveguide hole 12) will form an open circuit. When the first surface S1 of the PCB board 11 is open, a high impedance surface is formed, thereby blocking the radio frequency signal from leaking from the gap between the PCB board 11 and the waveguide structure 21. In some embodiments, the medium in the isolation structure 13 can be air, that is, the isolation space of the isolation structure 13 is a hollow structure; or the medium in the isolation structure 13 can also be the dielectric layer of the PCB board 11, that is, it is ensured that the isolation space does not contain a metal part.

[0043] Among them, the metal part on the second boundary surface C2 in the isolation structure 13 can be the metal layer structure originally used as a layer board in the PCB board 11, and other areas of the metal layer structure other than the second boundary surface C2 can be normally arranged with layer board circuits and other structures, or can be an additional metal layer structure that is only set as the second boundary surface C2.

[0044] In some embodiments, the isolation structure 13 is formed by removing each metal layer in the isolation space from the PCB board.

[0045] For the corresponding Figure 3 The top view of each metal layer in the PCB board 11 with the isolation structure 13 is shown in FIG. 1 , taking the PCB board 11 including six metal layers as an example, the top view of the metal layers L1 to L3 is shown in FIG. Figure 4 As shown, the top view of the L4~L6 metal layers is as follows Figure 5 shown. Figure 4 In the figure, the metal layers L1 to L3 are full metal layers, and the middle portion not covered by the metal layer is the first waveguide hole 12 formed after the metal layer is dug out. Figure 5 In the example, the metal parts of the L4 to L6 metal layers are dug out around the first waveguide hole 12 of the PCB board 11. Although the L4 to L6 metal layers are dug out in the example, in the application, only the L6 layer, or the L5 to L6 layer, or the L3 to L6 layer, etc. can be dug out, and it is only necessary to ensure that the dielectric height from the first boundary surface C1 at the bottom of the PCB board 11 to the full metal layer is h.

[0046] In some embodiments, Figure 3 and Figure 6 As shown, Figure 6 for Figure 3 FIG. 1 is a top view of the connection between the PCB board 11 in which the isolation structure 13 is arranged and the external waveguide structure 21 . In the PCB board 11 , a plurality of metal vias 14 are arranged around each first waveguide hole 12 .

[0047] Specifically, on the basis of setting the isolation structure 13, multiple metal vias 14 can be set around each first waveguide hole 12 in the PCB board 11 as a unit of the electromagnetic band gap (EBG) structure. When multiple metal vias 14 are arranged periodically, an electromagnetic band gap structure can be formed, which can further prevent the leakage of radio frequency signals. Figure 3 In the PCB board 11 with six metal layers, the isolation structure is composed of a medium with a height of h, an L3 full metal layer, L4 to L6 layers without the metal layer part, and a metal via 14. When there is a gap at the connection between the PCB board 11 and the external waveguide structure 21, it can more effectively prevent signal leakage and improve the isolation between waveguide channels.

[0048] In some embodiments, at least one of the plurality of metal vias 14 passes through the isolation structure 13 at the location where the metal via 14 is located. Figure 3 In the figure, the metal via 14 located in the middle has its end close to the first surface S1 penetrating the isolation structure 13 .

[0049] In some embodiments, the metal portion disposed on the second boundary surface C2 is the third metal layer in the PCB board that is away from the first surface S1. Figure 3 In the embodiment, after removing the metal layers L4 to L6 surrounding the first waveguide hole 12, L3 as a full metal layer becomes the second boundary surface C2 in the isolation space of the isolation structure 13. Using the metal layer L3 as the second boundary surface C2 makes it easier to achieve the requirement that h is an integer multiple of 1 / 4 of the medium wavelength.

[0050] On this basis, the PCB board 11 includes at least six metal layers. When the PCB board 11 with six or more metal layers forms the isolation structure 13, the structural support at the full metal layer is better, and the mutual interference of the RF signal when transmitting on the first surface S1 and the second surface S2 of the PCB board 11 is also smaller.

[0051] Another embodiment of the present application relates to a radio frequency device, such as Figure 3 As shown, the RF device, in addition to the RF device, further includes a waveguide antenna 23 disposed at one end of the second waveguide hole 22 away from the first surface S1; a chip package 31 is mounted on the second surface S2 of the PCB board 11, the second surface S2 is arranged opposite to the first surface S1, and a radiation portion 33 is disposed at each first waveguide hole 12 on the end surface where the chip package 31 is connected to the second surface S2, for receiving and sending RF signals.

[0052] The radiation portion 33 may be specifically a metal patch.

[0053] In some embodiments, Figure 3 As shown, a plurality of solder balls 32 are arranged around each radiating portion 33 on the end surface where the chip package 31 is connected to the second surface S2 , and a cavity surrounded by the plurality of solder balls 32 is connected to the first waveguide hole 12 to form a radio frequency signal transmission channel.

[0054] Thus, the cavity surrounded by the plurality of solder balls 32 , the first waveguide hole 12 , and the second waveguide hole 22 are connected to form a radio frequency signal transmission channel from the radiation portion 33 to the waveguide antenna 23 .

[0055] like Figure 7 As shown, when the PCB board 11 without adding the isolation structure 13 is connected to the external waveguide structure 21, except for the first waveguide hole 12 through which the radio frequency signal flows in the PCB board 11, the metal layers L1 to L6 of the PCB board 11 are all full metal layers. The radio frequency signal is first transmitted from the chip package 31 to the first waveguide hole 12 of the PCB board 11 through the cavity surrounded by the solder balls 32, and then transmitted from the first waveguide hole 12 of the PCB board 11 to the second waveguide hole 22 of the external waveguide structure 21, and then radiated through the waveguide antenna 23. When there is a gap between the PCB board 11 and the external waveguide structure 21, the radio frequency signal flows from the gap to the surrounding waveguide channels (the arrow points to the flow direction), thereby causing the isolation between the waveguide channels to deteriorate and the signal leakage to be serious.

[0056] In contrast, Figure 3 to Figure 5 As shown, when the PCB board 11 with the isolation structure 13 added is connected to the external waveguide structure 21, part of the metal structure of the L4 to L6 metal layers around the first waveguide hole 12 of the PCB board 11 is dug out to form the isolation structure 13. When the height of the medium in the isolation space of the isolation structure 13 is an integer multiple of 1 / 4 waveguide wavelength, since L3 is a full metal layer, it is equivalent to a short circuit. According to the principle of 1 / 4 wavelength impedance inversion, the first boundary surface C1 at the bottom of the PCB board 11 (specifically, the edge away from the first waveguide hole 12) forms an open circuit. When the bottom of the PCB board 11 is open, a high impedance surface is formed, thereby blocking the signal from leaking from the gap between the bottom of the PCB board 11 and the external waveguide structure 21.

[0057] In addition, Figure 3 and Figure 7 In the embodiment, metal vias 14 are provided in the PCB board 11 as units of the EBG structure. When the metal vias 14 are arranged periodically, an electromagnetic bandgap structure can be formed to further prevent signal leakage. Figure 8 Show that under the same structural conditions, before adding the isolation structure 13 ( Figure 7 ) and after the isolation structure 13 ( Figure 3 ) after the isolation between the two waveguide channels is compared. Figure 8It can be seen that after adding the isolation structure, the isolation between waveguide channels is increased from 20dB to 50dB, and the isolation is significantly improved.

[0058] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A radio frequency device, characterized in that: include: A PCB board, wherein at least one first waveguide hole is arranged on a first surface thereof; A waveguide structure, disposed on the first surface; On the surface of the waveguide structure connected to the PCB board, second waveguide holes are provided at positions corresponding to the first waveguide holes, and the first waveguide holes are connected to the second waveguide holes to form a radio frequency signal transmission channel; An isolation structure is provided in the PCB board at a position corresponding to the first waveguide hole, and the isolation structure is an isolation space arranged around the first waveguide hole, and the isolation space is used to prevent the radio frequency signal from being transmitted laterally along the end surface where the PCB board and the waveguide structure are connected; The isolation space is a structure in which the metal part is removed from the inside. The isolation space has a first boundary surface and a second boundary surface relative to each other. The first boundary surface is located on the first surface and has no metal part, and the second boundary surface is located inside the PCB board and has a metal part.

2. The radio frequency device according to claim 1, characterized in that: The distance from the second boundary surface to the first boundary surface is equal to an integral multiple of a quarter wavelength of the radio frequency signal transmitted in the isolation structure.

3. The radio frequency device according to claim 1, characterized in that: The medium in the isolation structure is air or a dielectric layer of a PCB board.

4. The radio frequency device according to claim 1, characterized in that: The isolation structure is formed by removing each metal layer in the isolation space from the PCB board.

5. The radio frequency device according to any one of claims 1 to 4, characterized in that: A plurality of metal vias are arranged in the PCB board around each of the first waveguide holes.

6. The radio frequency device according to claim 5, characterized in that: Among the plurality of metal vias, there is at least one metal via that passes through the isolation structure at its location.

7. The radio frequency device according to any one of claims 1 to 4, characterized in that: The metal portion disposed on the second boundary surface is the third metal layer in the PCB board away from the first surface.

8. The radio frequency device according to claim 7, characterized in that: The PCB board includes at least six metal layers.

9. A radio frequency device, characterized in that: include: The radio frequency device according to any one of claims 1 to 8, wherein a waveguide antenna is provided at one end of the second waveguide hole away from the first surface; The chip package is mounted on the second surface of the PCB board. The second surface is arranged opposite to the first surface. On the end surface where the chip package is connected to the second surface, a radiation part is arranged corresponding to each of the first waveguide holes for sending and receiving radio frequency signals.

10. The radio frequency device according to claim 9, characterized in that: A plurality of solder balls are arranged around each of the radiation parts on the end surface of the chip package body butting against the second surface, and a cavity surrounded by the plurality of solder balls is connected to the first waveguide hole to form a radio frequency signal transmission channel.

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