Antenna module, radar system and terminal device

Abstract

The embodiment of the invention relates to the technical field of wireless communication, and discloses an antenna module, a radar system and terminal equipment. The antenna comprises a PCB, a chip and an antenna body, the antenna body and the chip are located on the two opposite sides of the PCB respectively, and the antenna body and the chip are connected through a signal transmission path penetrating through the PCB; wherein the signal transmission path comprises a first signal transmission section located in the PCB, a metal layer, corresponding to the first signal transmission section, of the PCB is removed, and a plurality of metal structures are arranged around the first signal transmission section to form a waveguide channel for signal transmission. According to the antenna module provided by the embodiment of the invention, the radiation generated by the chip and the feeder line is structurally prevented from influencing the radiation of the antenna, the transmission efficiency and the transmission performance of the antenna module are not influenced by the thickness of the PCB, the full-band low-loss transmission can be realized, and the performance of a radar system is effectively improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of wireless communication technology, and in particular to an antenna module, a radar system, and a terminal device. Background Art

[0002] In the currently commonly used and mature PCB (Printed Circuit Board) grade millimeter wave radar antenna, the chip and antenna are both arranged on the same side of the PCB board (such as Figure 1 Such a design facilitates the connection between the chip and the PCB board, and also facilitates the connection between the chip and the antenna.

[0003] However, the chip and feed line also generate radiation, which will interfere with the radiation of the antenna itself, thereby reducing the performance of the radar system. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide an antenna module, a radar system and a terminal device, which structurally avoid the radiation generated by the chip and the feeder affecting the radiation of the antenna itself. The transmission efficiency and transmission performance are not affected by the thickness of the PCB board, and can achieve low-loss transmission in the entire frequency band, thereby effectively improving the performance of the radar system.

[0005] To solve the above technical problems, an embodiment of the present application provides an antenna module, which includes a PCB board, a chip and an antenna, wherein the antenna and the chip are respectively located on opposite sides of the PCB board, and the antenna and the chip are connected via a signal transmission path passing through the PCB board; wherein the signal transmission path includes a first signal transmission segment located inside the PCB board, the metal layer of the PCB board corresponding to the first signal transmission segment is removed, and a plurality of metal structures are arranged around the first signal transmission segment to form a waveguide channel for signal transmission.

[0006] An embodiment of the present application further provides a radar system, including a transmitter, a receiver and a transceiver antenna, wherein the transceiver antenna includes the antenna module as described above.

[0007] An embodiment of the present application also provides a terminal device, comprising the radar system as described above.

[0008] The antenna module, radar system and terminal device provided by the embodiment of the present application, the antenna module includes a PCB board, a chip and an antenna, the antenna and the chip are respectively located on opposite sides of the PCB board, and the antenna and the chip are connected through a signal transmission path passing through the PCB board, wherein the signal transmission path includes a first signal transmission section located in the PCB board, the metal layer of the PCB board corresponding to the first signal transmission section is removed, and a plurality of metal structures are arranged around the first signal transmission section to form a waveguide channel for signal transmission. Considering that most of the PCB-level millimeter-wave radar antennas in the industry adopt a front feeding method, that is, the chip and the antenna are arranged on the same side of the PCB board, under such a setting, the radiation generated by the chip and the feeder will interfere with the radiation of the antenna itself, thereby reducing the performance of the radar system, and the embodiment of the present application sets the signal transmission path so that the chip and the antenna are separated on both sides of the PCB board, thereby structurally avoiding the radiation generated by the chip and the feeder from affecting the radiation of the antenna itself, and its transmission efficiency and transmission performance are not affected by the thickness of the PCB board, and can achieve low-loss transmission in the full frequency band, effectively improving the performance of the radar system. At the same time, the first signal transmission section is more stable than the direct via structure, and can be applied to PCB boards with thicker thickness and more layers without destroying the functional integrity of the PCB board.

[0009] In some optional embodiments, the signal transmission path also includes a second signal transmission segment located on the PCB board near the side where the chip is located, and the chip transmits signals with the first signal transmission segment through the second signal transmission segment, and the second signal transmission segment is a coplanar waveguide transmission structure. The coplanar waveguide transmission structure is highly integrated, and the use of the coplanar waveguide transmission structure can further reduce the volume of the antenna module. At the same time, the coplanar waveguide structure has low loss, fast transmission speed, and high sensitivity, which greatly improves the quality and efficiency of signal transmission in the antenna module.

[0010] In some optional embodiments, the number of metal layers of the PCB board is N, where N is an integer greater than 4, and the chip is located on the outside of the Nth metal layer of the PCB board; the second signal transmission segment includes a chip feeder and a first opening extending along a first direction opened at a first position of the Nth metal layer, a first end of the chip feeder is connected to the chip, and a second end of the chip feeder is accommodated in the first opening, and the first position at least partially overlaps with the projection position of the first signal transmission segment on the Nth metal layer.

[0011] In some optional embodiments, the signal transmission path further includes a first coupling structure, the second signal transmission segment is connected to the first signal transmission segment through the first coupling structure, the first coupling structure includes a first narrow slit and a second narrow slit extending along a second direction at a second position of the N-1 metal layer of the PCB board, the first narrow slit and the second narrow slit are spaced along the first direction, the second direction is perpendicular to the first direction, and the second position is the projection position of the first signal transmission segment on the N-1 metal layer. Considering that the impedance of the chip feeder is different from the impedance of the first signal transmission segment, if the RF signal is directly coupled into the first signal transmission segment through the groove, it is bound to cause the loss of the RF signal. Therefore, the first coupling structure is set in the N-1 metal layer, which is not completely hollowed out, and only two narrow slits are opened. The RF signal is coupled into the first signal transmission segment through the groove and the narrow slit, which can ensure the good quality of the RF signal.

[0012] In some optional embodiments, a dielectric substrate is filled between adjacent metal layers in the PCB board, and the length of the first narrow slit and the second narrow slit is 1 / 2λg; wherein λg is the dielectric wavelength of the signal passing through the dielectric substrate. Such a setting can well match the impedance of the second signal transmission section with the first signal transmission section, thereby better improving the signal transmission quality.

[0013] In some optional embodiments, the signal transmission path further includes a third signal transmission segment located on the PCB board near the side where the antenna is located, and the antenna transmits signals with the first signal transmission segment through the third signal transmission segment, and the third signal transmission segment is a coplanar waveguide transmission structure. The coplanar waveguide transmission structure is also used on one side of the antenna, which further improves the quality and efficiency of signal transmission in the antenna module.

[0014] In some optional embodiments, the number of metal layers of the PCB board is N, where N is an integer greater than 4, and the antenna is located on one side of the first metal layer of the PCB board; the third signal transmission segment includes an antenna feeder and a second opening extending along a third direction opened at a third position of the first metal layer, a first end of the antenna feeder is connected to the antenna, and a second end of the antenna feeder is accommodated in the second opening, and the third position at least partially overlaps with the projection position of the first signal transmission segment on the first metal layer.

[0015] In some optional embodiments, the signal transmission path further includes a second coupling structure, the third signal transmission segment is connected to the first signal transmission segment through the second coupling structure, the second coupling structure includes a third narrow slit and a fourth narrow slit extending along the second direction opened at a fourth position of the second metal layer of the PCB board, the third narrow slit and the fourth narrow slit are arranged at intervals along the first direction, the second direction is perpendicular to the first direction, and the fourth position is the projection position of the first signal transmission segment on the second metal layer. Considering that the impedance of the antenna feeder is different from the impedance of the first signal transmission segment, if the RF signal is directly coupled into the antenna through the groove, it is bound to cause the loss of the RF signal. Therefore, a second coupling structure is set in the second metal layer, which is not completely hollowed out, and only two narrow slits are opened. The RF signal is coupled into the antenna through the groove and the narrow slit, which can ensure the good quality of the RF signal.

[0016] In some optional embodiments, a dielectric substrate is filled between adjacent metal layers in the PCB board, and the length of the third narrow slit and the fourth narrow slit is 1 / 2λg, where λg is the dielectric wavelength of the signal passing through the dielectric substrate. Such a setting can well match the impedance of the third signal transmission section with the first signal transmission section, thereby better improving the signal transmission quality.

[0017] In some optional embodiments, the number of metal layers of the PCB is N, where N is an integer greater than 4, the antenna is located on the first metal layer of the PCB, the projection of the first signal transmission segment on the first metal layer at least covers a portion of the antenna, and the antenna is connected to the first signal transmission segment. By setting the antenna on the first metal layer of the PCB, that is, a patch antenna, the antenna feeder can be omitted, thereby preventing the radiation of the antenna feeder from affecting the radiation of the antenna itself.

[0018] In some optional embodiments, the signal transmission path further includes a third coupling structure, the antenna is connected to the first signal transmission segment via the third coupling structure, the third coupling structure includes a fifth narrow slit extending along a fourth direction and opened at a fifth position of the second metal layer of the PCB board, the fourth direction is perpendicular to the first direction, and the fifth position is the projection position of the first signal transmission segment on the second metal layer. For the patch antenna, only one narrow slit is needed to meet the impedance matching during the coupling process, thereby better improving the signal transmission quality.

[0019] In some optional embodiments, the antenna is a patch array antenna, and the patch array antenna includes a plurality of antenna units connected in series, and the projection of the first signal transmission segment on the first metal layer covers at least the middle antenna unit of the patch array antenna. Considering that most of the patch array antennas used in the industry are front-fed and series-fed, that is, fed from one end of the array antenna, this will cause the maximum radiation direction of the antenna to deviate from the 0 degree direction as the frequency changes, affecting the antenna performance and the radar system performance, and the setting of the signal transmission path realizes back-feeding and middle-feeding, that is, feeding from the middle antenna unit of the patch array antenna, which effectively suppresses the radiation direction of the antenna itself from shifting with the frequency.

[0020] In some optional embodiments, the first signal transmission section forms an opening on the side opposite to the side where the chip is located on the PCB board, and the end of the opening is used as the antenna to radiate signals. The first signal transmission section digs through the metal layer on the side where the antenna is located to form an opening, and an aperture surface antenna can be formed at the end of the opening, which radiates outward in the form of aperture surface radiation, has a wider bandwidth, a simple structure, and a higher gain.

[0021] In some optional embodiments, at least one of the length and the width of the first signal transmission segment on the side of the PCB board where the chip is located is 1 / 2λg, where λg is the dielectric wavelength of the signal passing through the dielectric substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by the pictures in the corresponding drawings, and these exemplary descriptions do not constitute limitations on the embodiments.

[0023] Figure 1 It is a schematic diagram of a front-fed PCB-level millimeter-wave radar antenna;

[0024] Figure 2 is a schematic diagram of an antenna module provided in an embodiment of the present application;

[0025] Figure 3 is a schematic diagram of the position of a metal structure provided in an embodiment of the present application;

[0026] Figure 4 is a transverse cross-sectional view of a PCB board where a first signal transmission section is located according to an embodiment of the present application;

[0027] Figure 5 is a schematic diagram of the Nth metal layer of a PCB board provided in an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of the N-1th metal layer of the PCB board provided in an embodiment of the present application;

[0029] Figure 7 This is a schematic diagram of the first metal layer of the PCB board provided in the embodiment of the present application. Figure 1 ;

[0030] Figure 8 This is a schematic diagram of the second metal layer of the PCB board provided in the embodiment of the present application. Figure 1 ;

[0031] Fig. 9 This is a schematic diagram of the first metal layer of the PCB board provided in the embodiment of the present application. Figure 2 ;

[0032] Fig.10 This is a schematic diagram of the second metal layer of the PCB board provided in the embodiment of the present application. Figure 2 ;

[0033] Fig.11 This is a schematic diagram of the first metal layer of the PCB board provided in the embodiment of the present application. Figure 3 ;

[0034] Fig.12 is a longitudinal cross-section of an antenna module provided in an embodiment of the present application Figure 1 ;

[0035] Fig.13 is a schematic diagram of the return loss of the antenna module of the control group provided in the embodiment of the present application;

[0036] Fig.14 is a schematic diagram of insertion loss of an antenna module of a control group provided in an embodiment of the present application;

[0037] Fig.15 The embodiments of the present application provide Fig.12 Schematic diagram of return loss of the antenna module shown;

[0038] Fig.16 The embodiments of the present application provide Fig.12 Insertion loss diagram of the antenna module shown;

[0039] Fig.17 is a longitudinal cross-section of an antenna module provided in an embodiment of the present application Figure 2 ;

[0040] Fig.18 The embodiments of the present application provide Fig.17 The directional pattern of the antenna module shown;

[0041] Fig.19 is a longitudinal cross-section of an antenna module provided in an embodiment of the present application Figure 3 ;

[0042] Fig. 20 The embodiments of the present application provide Fig.19 Schematic diagram of return loss of the antenna module shown. DETAILED DESCRIPTION

[0043] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments 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 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 under the premise of no contradiction.

[0044] The PCB-level millimeter-wave radar antenna commonly used in the industry has the chip and antenna set on the same side of the PCB board. This setting is convenient for the feeder connection between the chip and the PCB, and also convenient for the feeder connection between the chip and the antenna. This setting can be called front feeding. However, this setting has defects. First, because the chip and the antenna are set on the same side of the PCB board, the radiation of the chip and the feeder will interfere with the radiation of the antenna itself, resulting in a decrease in the performance of the radar system such as the angle resolution accuracy. Secondly, the electromagnetic compatibility (EMC) shielding problem of the chip is difficult to solve.

[0045] There are also technical solutions in the prior art for arranging the antenna and the chip on both sides of the PCB board. Such solutions usually use metallized vias passing through the PCB board to achieve the connection between the chip and the antenna. For example, a quasi-coaxial structure formed by a metallized through-hole is used to arrange the chip and the antenna on opposite sides of the PCB board to achieve back-side feeding. However, the above solution has certain limitations. For the currently commonly used 77 GHz millimeter-wave radar antenna, the thickness of the PCB board generally reaches about 1.6 mm, and the length of the metallized through-hole passing through the PCB board also reaches about 1.6 mm. This thickness is too large for the 77 GHz frequency band, resulting in a large radiation loss of the structure and a low transmission efficiency. Therefore, the 77 GHz millimeter-wave radar antenna usually does not choose to place the antenna and the chip on both sides of the PCB board and connect them through metallized vias. The technical solution is more likely to be arranged on the same side of the PCB board.

[0046] In view of the above problems, an embodiment of the present application provides an antenna module, which can avoid the problem of mutual interference between the antenna and the chip, and solve the problems of large signal transmission loss and low transmission efficiency. The implementation details of the antenna module provided in this embodiment are described in detail below. The following content is only for the convenience of understanding the implementation details provided, and is not necessary for implementing this solution.

[0047] The antenna module provided in this embodiment is as follows: Figure 2 As shown, it includes a PCB board 11, a chip 12 and an antenna 13. The antenna 13 and the chip 12 are respectively located on two opposite sides of the PCB board 11. The antenna 13 and the chip 12 are connected via a signal transmission path 14 that passes through the PCB board 11.

[0048] Among them, the signal transmission path 14 includes a first signal transmission segment located in the PCB board 11, the metal layer of the PCB board 11 corresponding to the first signal transmission segment is removed, and a plurality of metal structures are arranged around the first signal transmission segment to form a waveguide channel for signal transmission.

[0049] In the specific implementation, considering that most of the PCB-level millimeter-wave radar antennas in the industry adopt the front feeding method, that is, the chip and the antenna are set on the same side of the PCB board, under this setting, the radiation generated by the chip and the feeder will interfere with the radiation of the antenna itself, thereby reducing the performance of the radar system. The embodiment of the present application sets the signal transmission path so that the chip and the antenna are separated on both sides of the PCB board, which structurally avoids the radiation generated by the chip and the feeder from affecting the radiation of the antenna itself. At the same time, the waveguide channel structure is not limited by the thickness of the PCB board compared to the direct through-hole structure. For thicker PCB boards, high-quality back feeding can be achieved, which effectively reduces the transmission loss and can achieve full-band low-loss transmission from 76GHz to 81GHz. In addition, only the metal layer is removed from the part where the first signal transmission section is located, and the dielectric substrate is retained, which can ensure the strength and integrity of the PCB board.

[0050] In some embodiments, the location of the metal structure can be as follows Figure 3 As shown, the metal structure can be connected to the two outermost metal layers of the PCB board, but no metal structure is set at the corresponding positions of the chip position, antenna position, chip feeder position, and antenna feeder position ( Figure 2 The chip position and antenna position are not shown, but it can be understood that the chip and antenna are set at the other end of the feeder, and the metal structure will not be set at the chip position and antenna position), that is, the metal structure should be set to avoid the position of the chip, antenna, and feeder.

[0051] In some embodiments, the metal structure may not be connected to the two outermost metal layers of the PCB board, as long as it is arranged around the first signal transmission section (waveguide channel).

[0052] In some embodiments, the transverse cross-sectional view of the PCB board 11 where the first signal transmission section is located can be as follows: Figure 4 As shown, the metal layer of the PCB board 11 corresponding to the first signal transmission section 141 is removed, and since the dielectric substrate is filled between two adjacent metal layers, the dielectric substrate of the PCB board 11 corresponding to the first signal transmission section 141 is still retained. Several metal structures arranged around the first signal transmission section 141 are Figure 4 As shown in the figure, the first signal transmission section 141 forms a cavity in the PCB board 11, and cooperates with the plurality of metal through holes 15 to form a waveguide channel for signal transmission.

[0053] In some embodiments, the signal transmission path 14 also includes a second signal transmission segment located on the PCB board 11 near the side where the chip 12 is located, and the chip 12 realizes signal transmission with the first signal transmission segment through the second signal transmission segment, and the second signal transmission segment is a coplanar waveguide transmission structure. The coplanar waveguide transmission structure is highly integrated, and the use of the coplanar waveguide transmission structure can further reduce the volume of the antenna module. At the same time, the coplanar waveguide structure has low loss, fast transmission speed, and high sensitivity, which greatly improves the quality and efficiency of signal transmission in the antenna module.

[0054] In some embodiments, the number of metal layers of the PCB board 11 is N, where N is an integer greater than 4, and the chip 12 is located outside the Nth metal layer of the PCB board 11. The Nth metal layer of the PCB board 11 can be as follows: Figure 5 The second signal transmission section 142 includes a chip feeder 1421 and a first opening 1422 opened at a first position of the Nth metal layer and extending along a first direction, a first end of the chip feeder 1421 is connected to the chip 12, and a second end of the chip feeder 1421 is accommodated in the first opening 1422, wherein the first position at least partially overlaps with the projection position of the first signal transmission section 141 on the Nth metal layer.

[0055] In some examples, the first opening 1422 may extend out from the projection position of the first signal transmission segment on the Nth metal layer, as long as the first opening and the projection position of the first signal transmission segment on the Nth metal layer at least partially overlap.

[0056] In some embodiments, the N-1th metal layer of the PCB board 11 can be as follows Figure 6As shown, the signal transmission path 14 also includes a first coupling structure 143, and the second signal transmission segment 142 is connected to the first signal transmission segment 141 through the first coupling structure 143. The first coupling structure 143 includes a first narrow slit 1431 and a second narrow slit 1432 extending along the second direction at the second position of the N-1 metal layer of the PCB board 11, and the first narrow slit 1431 and the second narrow slit 1432 are arranged at intervals along the first direction. Among them, the second direction is perpendicular to the first direction, and the second position is the projection position of the first signal transmission segment on the N-1 metal layer. Considering that the impedance of the chip feeder is different from the impedance of the first signal transmission segment, if the RF signal is directly coupled into the first signal transmission segment through the groove, it is bound to cause the loss of the RF signal. Therefore, the first coupling structure is set in the N-1 metal layer, which is not completely hollowed out, and only two narrow slits are opened. The RF signal is coupled into the first signal transmission segment through the groove and the narrow slit, which can ensure the good quality of the RF signal.

[0057] In other embodiments, the projection position of the first signal transmission segment on the N-1 metal layer may completely cover the first narrow slit and the second narrow slit, or may partially cover the first narrow slit and the second narrow slit, that is, the length of the first narrow slit and the second narrow slit may exceed the length (or width) of the projection of the first signal transmission segment on the N-1 metal layer.

[0058] In some embodiments, a dielectric substrate is filled between adjacent metal layers in the PCB board, and the length of the first narrow slit and the second narrow slit is preferably 1 / 2λg, where λg is the dielectric wavelength of the signal passing through the dielectric substrate. Such a setting can well match the impedance of the second signal transmission section with the first signal transmission section, thereby better improving the signal transmission quality. Of course, the length of the first narrow slit and the second narrow slit can also fluctuate around 1 / 2λg, which is not limited here; in addition, the width of the first narrow slit and the second narrow slit can be adjusted according to actual conditions to adjust the impedance matching.

[0059] The above description is that the coplanar waveguide transmission structure is used in conjunction with the slot coupling method to achieve signal transmission between the chip and the waveguide cavity. After the signal is output from the chip, it enters the first coupling structure through the chip feeder and the first opening of the second signal transmission section, and the first narrow slit and the second narrow slit of the first coupling structure couple the signal into the first signal transmission section. It is worth noting that the signal transmission method between the chip and the waveguide cavity is not limited to the above.

[0060] In some embodiments, the signal transmission path 14 also includes a third signal transmission segment located on the PCB board 11 near the side where the antenna 13 is located. The antenna 13 transmits signals with the first signal transmission segment through the third signal transmission segment, and the third signal transmission segment is a coplanar waveguide transmission structure. The coplanar waveguide transmission structure is also used on the antenna side, which further improves the quality and efficiency of signal transmission in the antenna module.

[0061] In some embodiments, the number of metal layers of the PCB board 11 is N, where N is an integer greater than 4. The antenna 13 is located on one side of the first metal layer of the PCB board 11. The first metal layer of the PCB board 11 can be as follows: Figure 7 The third signal transmission section 144 includes an antenna feeder 1441 and a second opening 1442 opened at a third position of the first metal layer and extending along a third direction, the first end of the antenna feeder 1441 is connected to the antenna 13, and the second end of the antenna feeder 1422 is accommodated in the second opening 1442, wherein the third position at least partially overlaps with the projection position of the first signal transmission section 141 on the first metal layer.

[0062] For example, the PCB board has 12 metal layers, and a dielectric substrate layer is filled between two adjacent metal layers, that is, there are 11 dielectric substrate layers in total. The chip is arranged on the outside of the 12th metal layer, and correspondingly, the antenna is arranged on one side of the first metal layer, that is, the antenna is formed on the first metal layer, and the first metal layer is not completely hollowed out, and only a second opening extending along the first direction is opened at the third position (the third position at least partially overlaps with the projection position of the first signal transmission segment on the first metal layer), the antenna is connected to one end of the antenna feeder, and the other end of the antenna feeder is accommodated in the second opening, and the antenna feeder and the second opening constitute the third signal transmission segment.

[0063] In some examples, the antenna may be an external antenna, that is, the antenna is disposed outside the first metal layer and welded on the first metal layer.

[0064] In some examples, the second opening may extend beyond the projection position of the first signal transmission segment on the first metal layer, as long as the first groove 1442 partially overlaps the projection position of the first signal transmission segment 141 on the first metal layer.

[0065] In some embodiments, the second metal layer of the PCB board 11 can be as follows Figure 8As shown, the signal transmission path 14 also includes a second coupling structure 145, and the third signal transmission segment 144 is connected to the first signal transmission segment 141 through the second coupling structure 145. The second coupling structure 145 includes a third narrow slit 1451 and a fourth narrow slit 1452 extending along the second direction and opened at the fourth position of the second metal layer of the PCB board 11, and the third narrow slit 1451 and the fourth narrow slit 1452 are arranged at intervals along the first direction. Among them, the second direction is perpendicular to the first direction, and the fourth position is the projection position of the first signal transmission segment 141 on the second metal layer. Considering that the impedance of the antenna feeder is different from the impedance of the first signal transmission segment, if the radio frequency signal is directly coupled into the antenna through the groove, it is bound to cause the loss of the radio frequency signal. Therefore, a second coupling structure is set in the second metal layer, which is not completely hollowed out, and only two narrow slits are opened. The radio frequency signal is coupled into the antenna through the groove and the narrow slit, which can ensure the good quality of the radio frequency signal.

[0066] For example, the PCB board has 12 metal layers, and a dielectric substrate layer is filled between two adjacent metal layers, that is, there are 11 dielectric substrate layers in total. The chip is arranged on the outside of the 12th metal layer, and correspondingly, the antenna is arranged on one side of the first metal layer. The first metal layer is not completely hollowed out, and only a second opening extending along the first direction is opened at the third position. The second metal layer is also not completely hollowed out, and only a third narrow slit and a fourth narrow slit extending along the second direction (perpendicular to the first direction) are opened at the fourth position (the projection position of the first signal transmission segment on the second metal layer), and the third narrow slit and the fourth narrow slit are arranged at intervals along the first direction. The third narrow slit and the fourth narrow slit constitute a second coupling structure.

[0067] In some embodiments, dielectric substrates are filled between adjacent metal layers in the PCB board, and the lengths of the third narrow slit and the fourth narrow slit are preferably 1 / 2λg, where λg is the dielectric wavelength of the signal passing through the dielectric substrate. Such a setting can well match the impedance of the third signal transmission segment and the first signal transmission segment, thereby better improving the signal transmission quality. Of course, the lengths of the third narrow slit and the fourth narrow slit can also fluctuate around 1 / 2λg, which is not limited here; in addition, the widths of the third narrow slit and the fourth narrow slit can be adjusted according to actual conditions to adjust the impedance matching.

[0068] The above description is that the coplanar waveguide transmission structure is used in conjunction with the slot coupling to realize the signal transmission between the waveguide cavity and the antenna. After the signal enters the waveguide cavity (the first signal transmission section), the third narrow slot and the fourth narrow slot of the second coupling structure couple the signal into the third signal transmission section, and then enter the antenna through the second opening of the third signal transmission section and the antenna feeder. It is worth noting that the signal transmission method from the waveguide cavity to the chip is not limited to the above.

[0069] It is worth noting that the form of the antenna is not limited to the form in the above embodiments. The antenna can be directly arranged above the waveguide cavity, or formed in the form of aperture surface radiation. The following introduces some transformation embodiments of the antenna side.

[0070] In some embodiments, the number of metal layers of the PCB board 11 is N, where N is an integer greater than 4. The first metal layer of the PCB board 11 can be as follows: Fig. 9 The antenna 13 is located on the first metal layer of the PCB board 11, the projection of the first signal transmission segment on the first metal layer at least covers a portion of the antenna 13, and the antenna 13 is connected to the first signal transmission segment. Fig. 9 The antenna 13 shown is completely covered by the projection of the first signal transmission section on the first metal layer. Placing the antenna on the first metal layer of the PCB board, that is, a patch antenna, can save the antenna feeder, thereby preventing the radiation of the antenna feeder from affecting the radiation of the antenna itself.

[0071] In some examples, the antenna is directly formed by metal lines drawn on the first metal layer of the PCB board, and the shape of the antenna is any one of the following: straight line, inverted F shape, zigzag shape, circular shape, creeping curve shape.

[0072] In some examples, the antenna is a patch antenna that is attached to the first metal layer.

[0073] In some embodiments, the second metal layer of the PCB board 11 can be as follows Fig.10 As shown, the signal transmission path 14 also includes a third coupling structure 146, and the antenna 13 transmits signals with the first signal transmission section 141 through the third coupling structure 146. The third coupling structure 146 includes a fifth narrow slit 1461 extending along a fourth direction and opened at a fifth position of the second metal layer of the PCB board 11, wherein the fourth direction is perpendicular to the first direction, and the fifth position is the projection position of the first signal transmission section 141 on the second metal layer. For the patch antenna, only one narrow slit is required to meet the impedance matching in the coupling process, thereby better improving the signal transmission quality.

[0074] In some embodiments, the first metal layer of the PCB board 11 can be as follows Fig.11As shown, the antenna 13 is a patch array antenna, which includes a plurality of antenna units connected in series, and the projection of the first signal transmission segment 141 on the first metal layer at least covers the middle antenna unit 131 of the patch array antenna. Considering that most of the patch array antennas used in the industry are front-fed and series-fed, that is, fed from one end of the array antenna, this will cause the maximum radiation direction of the antenna to deviate from the 0-degree direction as the frequency changes, affecting the antenna performance and the radar system performance, while the setting of the signal transmission path realizes back-feeding and middle-feeding, that is, feeding from the middle antenna unit of the patch array antenna, effectively suppressing the deviation of the radiation direction of the antenna itself as the frequency changes.

[0075] In some embodiments, the first signal transmission section forms an opening on the side opposite to the side where the chip is located on the PCB board, and the end of the opening is used as an antenna to radiate signals. The first signal transmission section forms an opening by digging through the metal layer on the side where the antenna is located, and an aperture surface antenna can be formed at the end of the opening, which radiates outward in the form of aperture surface radiation, has a wider bandwidth, a simple structure, and a higher gain.

[0076] In some embodiments, at least one of the length and width of the first signal transmission segment on the side of the PCB board where the chip is located is 1 / 2λg, thereby ensuring that the cavity (opening) can radiate as an aperture surface antenna, where λg is the dielectric wavelength of the signal passing through the dielectric substrate.

[0077] The following is a further description of the specific embodiments:

[0078] Embodiment 1:

[0079] In this embodiment, the number of metal layers of the PCB board is 12. Of course, the number of metal layers of the PCB board can be selected according to specific circumstances and is not limited here. The following is a further explanation taking the PCB board including 12 metal layers as an example.

[0080] like Fig.12As shown, the PCB board has 12 metal layers, and a dielectric substrate layer is filled between two adjacent metal layers, that is, there are 11 dielectric substrate layers in total. The chip is arranged on the outside of the 12th metal layer, and correspondingly, the antenna is arranged on the side of the 1st metal layer. The first signal transmission section 141 is arranged on the 3rd metal layer to the 10th metal layer, and the 3rd metal layer to the 10th metal layer where the first signal transmission section 141 is located are completely hollowed out, and a plurality of metal structures 15 are arranged around the first signal transmission section 141, and the plurality of metal structures 15 are connected to the 1st metal layer and the 12th metal layer from top to bottom. The 12th metal layer is not completely hollowed out, and only a first opening 1421 extending along the first direction is opened at the first position (the first position at least partially overlaps with the projection position of the first signal transmission section 141 on the 12th metal layer), the chip is connected to one end of the chip feeder, and the other end of the chip feeder is accommodated in the first opening 1421, and the chip feeder and the first opening 1421 constitute the second signal transmission section. The 11th metal layer is not completely hollowed out either, and only a first narrow slit 1431 and a second narrow slit 1432 extending along the second direction (perpendicular to the first direction) are provided at the second position (the projection position of the first signal transmission section 141 on the 11th metal layer), and are spaced apart along the first direction. The first narrow slit 1431 and the second narrow slit 1432 form a first coupling structure. The 1st metal layer is not completely hollowed out, and only a second opening 1441 extending along the third direction is provided at the third position (the third position at least partially overlaps with the projection position of the first signal transmission section 141 on the 1st metal layer), and the first end of the antenna feeder is connected to the antenna, and the second end of the antenna feeder is accommodated in the second opening 1441. The second metal layer is not completely hollowed out, and only a third narrow slit 1451 and a fourth narrow slit 1452 extending along the second direction (perpendicular to the first direction) and spaced apart along the first direction are opened at the fourth position (the projection position of the first signal transmission segment 141 on the second metal layer), and the third narrow slit 1451 and the fourth narrow slit 1452 form a second coupling structure.

[0081] The traditional back-feed antenna with via-hole structure is used as the control group antenna module. Fig.12 The antenna module shown and the control group antenna module are simulated under the same conditions. Fig.13 This is a schematic diagram of the return loss of the antenna module in the control group. Fig.14 This is a schematic diagram of the insertion loss of the antenna module in the control group. Fig.15 For Fig.12 The return loss diagram of the antenna module is shown in FIG. Fig.16 For Fig.12 The insertion loss diagram of the antenna module is shown in Figure 2. From the simulation results, it can be seen that the radiation effect of the antenna module in the control group is very obvious, the return loss is large, and the insertion loss for the 77GHz frequency band is as high as 4dB. Fig.12The bandwidth of the antenna module shown can fully cover the 76 GHz to 81 GHz required by the millimeter wave radar. When the high-frequency board 5515 is used on the surface of the PCB board and the low-frequency board FR4 is used on the remaining layers, the transmission loss for the 77 GHz frequency band is about 1 dB.

[0082] Embodiment 2:

[0083] In this embodiment, the number of metal layers of the PCB board is 12. Of course, the number of metal layers of the PCB board can be selected according to specific circumstances and is not limited here. The following is a further explanation taking the PCB board including 12 metal layers as an example.

[0084] like Fig.17 As shown, the PCB board has 12 metal layers, and a dielectric substrate layer is filled between two adjacent metal layers, that is, there are 11 dielectric substrate layers in total. The chip is arranged on the outside of the 12th metal layer, the antenna is a patch array antenna, and the projection of the first signal transmission segment 141 on the 1st metal layer at least covers the middlemost antenna unit of the patch array antenna. The first signal transmission segment 141 is arranged on the 3rd metal layer to the 10th metal layer, and the 3rd metal layer to the 10th metal layer where the first signal transmission segment 141 is located are completely hollowed out, and a plurality of metal structures 15 are arranged around the first signal transmission segment 141, and the plurality of metal structures 15 are connected to the 1st metal layer and the 12th metal layer from top to bottom. The 12th metal layer is not completely hollowed out, and only the first opening 1421 extending along the first direction is opened at the first position (the first position at least partially overlaps with the projection position of the first signal transmission section 141 on the 12th metal layer), the chip is connected to one end of the chip feeder, and the other end of the chip feeder is accommodated in the first opening 1421, and the chip feeder and the first opening 1421 constitute the second signal transmission section. The 11th metal layer is also not completely hollowed out, and only the first narrow slit 1431 and the second narrow slit 1432 extending along the second direction (perpendicular to the first direction) are opened at the second position (the projection position of the first signal transmission section 141 on the 11th metal layer), and the first narrow slit 1431 and the second narrow slit 1432 are arranged at intervals along the first direction, and constitute the first coupling structure. The 2nd metal layer is not completely hollowed out, and only the fifth narrow slit 1461 extending along the fourth direction (perpendicular to the first direction) is opened at the fifth position (the projection position of the first signal transmission section 141 on the 2nd metal layer), and the third narrow slit 1461 is the third coupling structure.

[0085] For example Fig.17 The antenna module shown is simulated. Fig.18 For Fig.17 From the directional diagram of the antenna module shown, it can be seen that the directional diagram stability and symmetry of the antenna module with the back-side feed structure are very high.

[0086] Embodiment 3:

[0087] In this embodiment, the number of metal layers of the PCB board is 12. Of course, the number of metal layers of the PCB board can be selected according to specific circumstances and is not limited here. The following is a further explanation taking the PCB board including 12 metal layers as an example.

[0088] like Fig.19 As shown, the PCB board has 12 metal layers, and a dielectric substrate layer is filled between two adjacent metal layers, that is, there are 11 dielectric substrate layers in total. The chip is arranged on the outside of the 12th metal layer, and the first signal transmission section 141 is arranged on the 1st metal layer to the 10th metal layer. The 1st metal layer to the 10th metal layer where the first signal transmission section 141 is located are completely hollowed out, that is, an opening is formed on the side opposite to the side where the chip is located, and the end of the opening is used as an antenna to radiate signals. A plurality of metal structures 15 are arranged around the first signal transmission section 141, and the plurality of metal structures 15 are connected to the 1st metal layer and the 12th metal layer from top to bottom. The 12th metal layer is not completely hollowed out, and only a first opening 1421 extending along the first direction is opened at the first position (the first position at least partially overlaps with the projection position of the first signal transmission section 141 on the 12th metal layer), the chip is connected to one end of the chip feeder, and the other end of the chip feeder is accommodated in the first opening 1421, and the chip feeder and the first opening 1421 constitute the second signal transmission section. The 11th metal layer is not completely hollowed out, but only has a first narrow slit 1431 and a second narrow slit 1432 extending along the second direction (perpendicular to the first direction) at the second position (the projection position of the first signal transmission segment 141 on the 11th metal layer), and are spaced apart along the first direction. The first narrow slit 1431 and the second narrow slit 1432 form a first coupling structure.

[0089] For example Fig.19 The antenna module shown is simulated. Fig. 20 For Fig.19 From the return loss diagram of the antenna module shown, it can be seen that the antenna module with an aperture-surface radiation structure has an operating frequency band of 75.5 GHz to 80.5 GHz, which is greater than the bandwidth of less than 2 GHz of a conventional microstrip patch antenna and has better application prospects.

[0090] Another embodiment of the present application relates to a radar system, including a transmitter, a receiver and a transceiver antenna, wherein the transceiver antenna includes the antenna module as described in the above embodiment.

[0091] Another embodiment of the present application relates to a terminal device, including the radar system as described in the above embodiment.

[0092] Those skilled in the art will appreciate that the above embodiments are specific embodiments 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. An antenna module, characterized in that: It includes a PCB board, a chip and an antenna, wherein the antenna and the chip are respectively located on two opposite sides of the PCB board, and the antenna and the chip are connected via a signal transmission path passing through the PCB board; Among them, the signal transmission path includes a first signal transmission segment located in the PCB board, the metal layer of the PCB board corresponding to the first signal transmission segment is removed, and a plurality of metal structures are arranged around the first signal transmission segment to form a waveguide channel for signal transmission.

2. The antenna module according to claim 1, characterized in that: The signal transmission path also includes a second signal transmission segment located on the PCB board on a side close to the chip, and the chip transmits signals with the first signal transmission segment through the second signal transmission segment, and the second signal transmission segment is a coplanar waveguide transmission structure.

3. The antenna module according to claim 2, characterized in that: The number of metal layers of the PCB is N, where N is an integer greater than 2, and the chip is located outside the Nth metal layer of the PCB; The second signal transmission segment includes a chip feeder and a first opening extending along a first direction at a first position of the Nth metal layer, the first end of the chip feeder is connected to the chip, the second end of the chip feeder is accommodated in the first opening, and the first position at least partially overlaps with the projection position of the first signal transmission segment on the Nth metal layer.

4. The antenna module according to claim 3, characterized in that: The signal transmission path also includes a first coupling structure, and the second signal transmission segment is connected to the first signal transmission segment through the first coupling structure. The first coupling structure includes a first narrow slit and a second narrow slit extending along a second direction at a second position of the N-1 metal layer of the PCB board, and the first narrow slit and the second narrow slit are arranged at intervals along the first direction, the second direction is perpendicular to the first direction, and the second position is the projection position of the first signal transmission segment on the N-1 metal layer.

5. The antenna module according to claim 4, characterized in that: A dielectric substrate is filled between adjacent metal layers in the PCB board, and the length of the first narrow slit and the second narrow slit is 1 / 2λg; wherein λg is the dielectric wavelength of the signal passing through the dielectric substrate.

6. The antenna module according to any one of claims 1 to 5, characterized in that: The signal transmission path also includes a third signal transmission segment located on the PCB board on a side close to the antenna, and the antenna transmits signals with the first signal transmission segment through the third signal transmission segment, and the third signal transmission segment is a coplanar waveguide transmission structure.

7. The antenna module according to claim 6, characterized in that: The number of metal layers of the PCB is N, where N is an integer greater than 4, and the antenna is located on one side of the first metal layer of the PCB; The third signal transmission segment includes an antenna feeder and a second opening extending along a third direction at a third position of the first metal layer, the first end of the antenna feeder is connected to the antenna, the second end of the antenna feeder is accommodated in the second opening, and the third position at least partially overlaps with the projection position of the first signal transmission segment on the first metal layer.

8. The antenna module according to claim 7, characterized in that: The signal transmission path also includes a second coupling structure, the third signal transmission segment is connected to the first signal transmission segment via the second coupling structure, the second coupling structure includes a third narrow slit and a fourth narrow slit extending along a second direction and opened at a fourth position of the second metal layer of the PCB board, the third narrow slit and the fourth narrow slit are spaced apart along the first direction, the second direction is perpendicular to the first direction, and the fourth position is a projection position of the first signal transmission segment on the second metal layer.

9. The antenna module according to claim 8, characterized in that: A dielectric substrate is filled between adjacent metal layers in the PCB board, and the length of the third narrow slit and the fourth narrow slit is 1 / 2λg; wherein λg is the dielectric wavelength of the signal passing through the dielectric substrate.

10. The antenna module according to any one of claims 1 to 5, characterized in that: The number of metal layers of the PCB board is N, where N is an integer greater than 4. The antenna is located on the first metal layer of the PCB board. The projection of the first signal transmission segment on the first metal layer at least covers a portion of the antenna. The antenna is connected to the first signal transmission segment.

11. The antenna module according to claim 10, characterized in that: The signal transmission path also includes a third coupling structure, and the antenna transmits signals with the first signal transmission segment through the third coupling structure. The third coupling structure includes a fifth narrow slit extending along a fourth direction and opened at a fifth position of the second metal layer of the PCB board, the fourth direction is perpendicular to the first direction, and the fifth position is a projection position of the first signal transmission segment on the second metal layer.

12. The antenna module according to claim 10, characterized in that: The antenna is a patch array antenna, which includes a plurality of antenna units connected in series, and the projection of the first signal transmission segment on the first metal layer at least covers the middlemost antenna unit of the patch array antenna.

13. The antenna module according to any one of claims 1 to 4, characterized in that: The first signal transmission section forms an opening on the side of the PCB board opposite to the side where the chip is located, and the end of the opening is used as the antenna to radiate signals.

14. The antenna module according to claim 13, characterized in that: At least one of the length and the width of the first signal transmission section on the side of the PCB board where the chip is located is 1 / 2λg, where λg is the dielectric wavelength of the signal passing through the dielectric substrate.

15. A radar system, characterized in that: It comprises a transmitter, a receiver and a transceiver antenna, wherein the transceiver antenna comprises the antenna module as claimed in any one of claims 1 to 14.

16. A terminal device, characterized in that: Comprising a radar system as claimed in claim 15.

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