A cascaded antenna device and radar

Abstract

The utility model discloses a kind of cascaded antenna device and radar.The cascaded antenna device includes waveguide feed layer, waveguide wiring layer and slit radiating layer;Waveguide feed layer includes at least two interface regions, several waveguide interfaces are provided in each interface region, and waveguide interface penetrates waveguide feed layer;Waveguide feed layer is provided with at least two waveguide chips on the side away from waveguide wiring layer, and one waveguide chip corresponds to one interface region, and at least two waveguide chips are cascaded by power divider;Slit radiating layer includes several radiation slits, and each radiation slit penetrates slit radiating layer;Waveguide interface and radiation slit one-to-one correspond;Several propagation paths are formed on waveguide wiring layer, and one propagation path is used to connect one waveguide interface and its corresponding radiation slit.The cascaded antenna device provided in the scheme is simple in process, low in cost, flexible in layout, and has the advantages of multi-channel, large aperture, high radiation efficiency, etc., to provide the basis for improving environmental perception effect.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a cascaded antenna device and radar. Background Technology

[0002] With the continuous development of autonomous driving technology, users are placing higher demands on the perception system's ability to perceive the surrounding environment. As an important component of the perception system, the performance of centralized radar systems directly affects the accuracy and stability of environmental perception.

[0003] Centralized radar systems typically consist of millimeter-wave radar and a centralized processing architecture. Compared to traditional 3D millimeter-wave radar, 4D millimeter-wave radar has more antenna channels, enabling it to provide high-quality point clouds. These high-quality point clouds allow 4D millimeter-wave radar to overcome limitations in areas such as stationary target recognition, lateral movement detection, height recognition, distinguishing nearby objects, and detecting hidden vehicles, greatly expanding the application scope of millimeter-wave radar.

[0004] However, existing 4D millimeter-wave radars are relatively expensive to manufacture and typically only have one waveguide chip, limiting the number of antenna channels and making it difficult to provide the data required for a centralized processing architecture. Utility Model Content

[0005] This invention provides a cascaded antenna device and radar, which is simple in process, low in cost, and flexible in layout. It also has the advantages of multiple channels, large aperture, and high radiation efficiency, providing a foundation for improving environmental perception.

[0006] According to one aspect of this utility model, a cascaded antenna device is provided, comprising a waveguide feed layer, a waveguide trace layer, and a slot radiating layer stacked together, wherein the waveguide trace layer is located between the waveguide feed layer and the slot radiating layer; wherein, the waveguide feed layer includes at least two interface regions, each interface region having a plurality of waveguide interfaces, the waveguide interfaces penetrating the waveguide feed layer; at least two waveguide chips are disposed on the side of the waveguide feed layer away from the waveguide trace layer, one waveguide chip corresponding to one interface region, and the at least two waveguide chips are cascaded through a power divider; the slot radiating layer includes a plurality of radiating slots, each radiating slot penetrating the slot radiating layer; the waveguide interfaces correspond one-to-one with the radiating slots; a plurality of propagation paths are formed on the waveguide trace layer, one propagation path being used to connect a waveguide interface and its corresponding radiating slot.

[0007] Optionally, the waveguide routing layer includes M+N first vias, M second vias, and M third vias, where M and N are both positive integers; the side of the waveguide routing layer near the waveguide feed layer has N first routing slots and M second routing slots; the side of the waveguide routing layer near the slot radiation layer has M third routing slots and M+N fourth routing slots; the propagation path includes N first paths and M second paths; when the electromagnetic signal is transmitted from the waveguide interface to the radiation slot along the first path, the electromagnetic signal passes through the first routing slot, the first via, and the fourth routing slot in sequence; when the electromagnetic signal is transmitted from the waveguide interface to the radiation slot along the second path, the electromagnetic signal passes through the second via, the third routing slot, the third via, the second routing slot, the first via, and the fourth routing slot in sequence.

[0008] Optionally, the waveguide trace layer is provided with a pin periodic structure and a reinforcing rib structure on the side surface near the waveguide feed layer and the side surface near the slot radiation layer. The pin periodic structure surrounds the first trace groove, the second trace groove, the third trace groove and the fourth trace groove. The reinforcing rib structure is used to improve the strength of the waveguide trace layer.

[0009] Optionally, matching structures are provided at both ends of the first, second, and third wiring channels; the matching structures include at least two stepped structures along the extension direction of the wiring channels; the matching structures are used to guide the conversion between vertical and horizontal transmission of electromagnetic signals.

[0010] Optionally, the waveguide chip is electrically connected to the power divider via traces, and the trace length between each waveguide chip and the power divider is equal.

[0011] Optionally, a rectangular groove is provided on the surface of the radiating layer away from the waveguide trace layer; the rectangular groove is located on opposite sides of the radiating slit.

[0012] Optionally, the waveguide feed layer, the waveguide trace layer, and the slot radiation layer are connected by fasteners; after the connection is completed, there is a first gap between the waveguide feed layer and the waveguide trace layer, and a second gap between the waveguide trace layer and the slot radiation layer.

[0013] Optionally, the waveguide feed layer is an FR4 dielectric substrate layer; the waveguide trace layer and the slot radiation layer are plastic substrate layers with a metal coating on the surface.

[0014] Optionally, the dimensions of the cascaded antenna device are 91mm*70mm*5.8mm; the length of the waveguide interface is 2.74mm and the width is 0.8mm.

[0015] According to another aspect of the present invention, a radar is provided, comprising a cascaded antenna device according to any of the above embodiments.

[0016] The technical solution of this utility model embodiment, through the design of the structure of the cascaded antenna device, includes a waveguide feed layer, a waveguide trace layer, and a slot radiation layer stacked together. The waveguide feed layer includes at least two interface regions, each with several waveguide interfaces that penetrate the waveguide feed layer. At least two waveguide chips are disposed on the side of the waveguide feed layer away from the waveguide trace layer, with one waveguide chip corresponding to one interface region. The at least two waveguide chips are cascaded through a power divider. The slot radiation layer includes several radiation slots, each penetrating the slot radiation layer. Each waveguide interface corresponds to one radiation slot. Several propagation paths are formed on the waveguide trace layer, with each propagation path connecting a waveguide interface and its corresponding radiation slot. Firstly, because at least two waveguide chips are disposed on the side of the waveguide feed layer away from the waveguide trace layer, and these at least two waveguide chips are cascaded through a power divider, the channel expansion of the cascaded antenna device is achieved, improving the radiation efficiency and aperture of the cascaded antenna device. Secondly, the waveguide trace layer forms several propagation paths, each connecting a waveguide interface and its corresponding radiating slot. This confines the electromagnetic signal within the air cavity for transmission, rather than within a metallic conductor, significantly reducing conductor loss and signal energy attenuation. This low-loss characteristic is beneficial for realizing large-scale array antennas and sparse antenna arrays, improving antenna gain and directivity. Thirdly, the gap waveguide structure, composed of the waveguide feed layer, waveguide trace layer, and slot radiating layer, eliminates the limitations imposed by component obstruction, allowing for more flexible optimization of the antenna's physical layout to achieve optimal radiation modes and directivity. Furthermore, the elimination of soldering allows for a certain degree of mechanical tolerance, greatly reducing manufacturing and assembly difficulty and cost.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an exploded view of a cascaded antenna device provided in an embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of a waveguide feed layer provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of a waveguide routing layer provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of a slit radiation layer provided in an embodiment of this utility model;

[0023] Figure 5 This is a channel distribution diagram of a waveguide chip provided in an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the return loss of the cascaded antenna device provided in this embodiment of the present invention;

[0025] Figure 7 This is a two-dimensional radiation pattern of the cascaded antenna device provided in this embodiment of the utility model. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] It should be noted that the terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] Furthermore, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] Example 1

[0031] Figure 1 This is an exploded view of a cascaded antenna device provided in an embodiment of this utility model. Figure 2 This is a schematic diagram of a waveguide feed layer provided in an embodiment of the present invention, wherein, Figure 2 (a) is a top view of the side of the waveguide feed layer away from the waveguide trace layer. Figure 2 (b) is a top view of the side of the waveguide feed layer near the waveguide trace layer. Figure 3 This is a schematic diagram of a waveguide routing layer provided in an embodiment of the present invention, wherein, Figure 3 (a) is a top view of the waveguide trace layer near the slot radiation layer. Figure 3 (b) is a top view of the waveguide trace layer near the waveguide feed layer. Figure 4 This is a schematic diagram of the structure of a slit radiation layer provided in an embodiment of the present invention, wherein, Figure 4 (a) is a top view of the side of the slot radiation layer away from the waveguide trace layer. Figure 4 (b) is a top view of the side of the slot radiation layer near the waveguide trace layer.

[0032] refer to Figures 1-4 As shown, the cascaded antenna device includes a waveguide feed layer 10, a waveguide trace layer 20, and a slot radiating layer 30 stacked together. The waveguide trace layer 20 is located between the waveguide feed layer 10 and the slot radiating layer 30. The waveguide feed layer 10, the waveguide trace layer 20, and the slot radiating layer 30 all have a certain thickness, which allows them to withstand certain mechanical stresses and ensure the stability and reliability of the cascaded antenna device under various environments.

[0033] In one embodiment, the waveguide feed layer 10, the waveguide trace layer 20, and the slot radiation layer 30 are connected by fasteners. Optionally, screws can be used as fasteners. For example, threaded holes can be provided on the waveguide feed layer 10, the waveguide trace layer 20, and the slot radiation layer 30, so that screws can be used to fix the waveguide feed layer 10, the waveguide trace layer 20, and the slot radiation layer 30 through the threaded holes.

[0034] After the fixed connection is completed, there is a first gap between the waveguide feed layer 10 and the waveguide trace layer 20, and a second gap between the waveguide trace layer 20 and the slot radiating layer 30. This forms a slotted waveguide structure, which exhibits lower transmission loss in the millimeter-wave band compared to microstrip lines in traditional radar. Furthermore, due to the presence of the first and second gaps, a certain degree of mechanical tolerance is allowed between the waveguide feed layer 10 and the waveguide trace layer 20, and between the waveguide trace layer 20 and the slot radiating layer 30. Strict alignment to micrometer-level precision is not required, nor is welding necessary, significantly reducing manufacturing and assembly difficulty and cost. The first and second gaps also facilitate heat dissipation, thereby improving the reliability and lifespan of the cascaded antenna device. In addition, the slotted waveguide structure eliminates the limitations of component obstruction, allowing for more flexible optimization of the antenna's physical layout to achieve optimal radiation modes and directivity, solving the problem of limited antenna layout space.

[0035] M2 screws can be used to ensure stable connections between layers without taking up too much space, which is beneficial for the overall miniaturization of the cascaded antenna device, but it is not a limitation. Alternatively, the screws may not be exposed on the surface of each layer to improve the aesthetics of the device.

[0036] Optionally, to improve fixing accuracy, the waveguide feed layer 10 near the waveguide trace layer 20 and the waveguide trace layer 20 near the waveguide feed layer 10 can be provided with matching positioning structures, such as protrusions and recesses. The protrusions and recesses cooperate with each other to ensure that the waveguide feed layer 10 and the waveguide trace layer 20 will not be misaligned during fixing. Similarly, the waveguide trace layer 20 near the slot radiation layer 30 and the slot radiation layer 30 near the waveguide trace layer 20 can also be provided with matching positioning structures, such as protrusions and recesses. The protrusions and recesses cooperate with each other to ensure that the waveguide trace layer 20 and the slot radiation layer 30 will not be misaligned during fixing.

[0037] The waveguide feed layer 10 includes at least two interface regions 11, for example... Figure 2 The diagram is illustrated using a waveguide feed layer 10 comprising two interface regions 11 as an example. Each interface region 11 contains several waveguide interfaces 12, which penetrate the waveguide feed layer 10.

[0038] At least two waveguide chips 13 are disposed on the side of the waveguide feed layer 10 away from the waveguide trace layer 20. Each waveguide chip 13 corresponds to an interface region 11, and the at least two waveguide chips 13 are cascaded through a power divider 14. One channel of the waveguide chip 13 corresponds to a waveguide interface 12 within the interface region 11.

[0039] Optionally, waveguide chips 13 are electrically connected to power divider 14 via traces, with each trace between waveguide chip 13 and power divider 14 having an equal length. This ensures that all waveguide chips 13 are in phase and share the same local oscillator.

[0040] In this invention, the number of interface regions 11 and waveguide chips 13 in the waveguide feed layer 10 can be set according to actual needs. The more interface regions 11 there are, the more waveguide chips 13 there are, resulting in more receiving and transmitting channels for the cascaded antenna device; conversely, the fewer interface regions 11 there are, the fewer waveguide chips 13 there are, resulting in fewer receiving and transmitting channels for the cascaded antenna device. This design allows for the expansion of antenna channels, thereby improving the radiation efficiency of the cascaded antenna device. For example, the number of waveguide chips 13 can be 2, 3, 4, etc., and the specific value can be set according to actual needs; this embodiment of the invention does not impose specific limitations on this. Compared to a single waveguide chip, at least two waveguide chips have more channels, enabling a larger aperture and superior performance.

[0041] Optionally, waveguide chip 13 can be a 4-transmit 4-receive waveguide chip, which has one local oscillator (LO) signal output port and two LO signal input ports. Figure 5 This is a channel distribution diagram of a waveguide chip provided in an embodiment of this utility model. For example... Figure 5 As shown, the waveguide chip includes four receiving channels (denoted as RX1, RX2, RX3, and RX4, respectively) and four transmitting channels (denoted as TX1, TX2, TX3, and TX4, respectively).

[0042] Optionally, the waveguide chip 13 supports an operating bandwidth of 76GHz-81GHz. This band falls within an atmospheric window that is relatively less affected by water vapor and oxygen absorption, resulting in less attenuation of electromagnetic signals during propagation through the air, which is beneficial for long-range detection. Furthermore, in autonomous driving and ADAS systems, using the 76GHz-81GHz band for radar provides higher resolution and a shorter wavelength, which is advantageous for constructing miniaturized antenna arrays and achieving high-precision target detection.

[0043] The slit radiation layer 30 includes a plurality of radiation slits 31, each radiation slit 31 penetrating the slit radiation layer 30; the waveguide interface 12 corresponds one-to-one with the radiation slit 31. In this invention, the one-to-one correspondence between the waveguide interface 12 and the radiation slit 31 means that there is a signal transmission correspondence between one waveguide interface 12 and one radiation slit 31, rather than spatial overlap.

[0044] Optionally, a rectangular groove 32 is provided on the surface of the radiating layer 30 away from the waveguide trace layer 20; the rectangular groove 32 is located on opposite sides of the radiating slit 31.

[0045] Specifically, such as Figure 4 As shown, the rectangular groove 32 is located on the upper and lower sides of the radiation slot 31. The rectangular groove 32 can disrupt the continuity of surface waves. By introducing an additional phase delay, the surface waves generated at different positions are out of phase, thereby achieving surface wave phase cancellation. This reduces the negative impact of surface waves on the far-field radiation pattern of the antenna, improves the main lobe gain of the antenna and suppresses side lobes, and optimizes the overall radiation performance of the antenna.

[0046] The rectangular groove 32 does not penetrate the slotted radiating layer 30, meaning the depth of the rectangular groove 32 is less than the thickness of the slotted radiating layer 30. On the one hand, this prevents electromagnetic signal energy from dissipating in unintended radiation directions, maintaining the antenna's high efficiency and directional radiation capability; on the other hand, it maintains the mechanical strength of the slotted radiating layer 30, ensuring the stability of the overall structure.

[0047] It should be noted that the number and size of the rectangular grooves 32 can be set according to actual needs, and this utility model embodiment does not impose specific limitations on this.

[0048] Several propagation paths are formed on the waveguide trace layer 20. One propagation path is used to connect a waveguide interface 12 and its corresponding radiation slot 31.

[0049] In one embodiment, reference continues Figure 3 The waveguide routing layer 20 includes M+N first vias a, M second vias b, and M third vias c. M and N are both positive integers, and the value of M+N equals the total number of waveguide interfaces 12 and the total number of radiation slots 31. The waveguide routing layer 20 has N first routing slots 21 and M second routing slots 22 on the side near the waveguide feed layer 10; and M third routing slots 23 and M+N fourth routing slots 24 on the side near the slot radiation layer 30.

[0050] For example, Figure 3The diagram is drawn using M=8 and N=8 as an example. To clearly show the positional relationship of the first through hole a, the second through hole b, the third through hole c, the first wiring slot 21, the second wiring slot 22, the third wiring slot 23, and the fourth wiring slot 24, Figure 3 (a) marks all the third wiring slots 23, and all other unmarked wiring slots are fourth wiring slots 24. One first through hole a corresponds to one fourth wiring slot 24. The two ends of one third wiring slot 23 correspond to one second through hole b and one third through hole c, respectively. Figure 3 (b) marks all the first routing slots 21, and all the remaining unmarked routing slots are second routing slots 22. One end of a first routing slot 21 corresponds to a first via a, and the other end corresponds to a waveguide interface 12 of the waveguide feed layer 10. The two ends of a second routing slot 22 correspond to a first via a and a third via c, respectively.

[0051] The propagation paths formed on the waveguide trace layer 20 include N first paths and M second paths.

[0052] Specifically, when the electromagnetic signal is transmitted from the waveguide interface 12 to the radiation slot 21 along the first path, the electromagnetic signal passes through the first trace 21, the first via a, and the fourth trace 24 in sequence. That is, the electromagnetic signal is first transmitted along the side of the waveguide trace layer 20 near the waveguide feed layer 10 (i.e., the first trace 21), passes through the first via a through the waveguide trace layer 20, and then is transmitted along the side of the waveguide trace layer 20 near the slot radiation layer 30 (i.e., the fourth trace 24).

[0053] When the electromagnetic signal is transmitted from the waveguide interface 12 to the radiating slot 31 along the second path, the electromagnetic signal passes sequentially through the second via b, the third trace 23, the third via c, the second trace 22, the first via a, and the fourth trace 24. That is, the electromagnetic signal first passes through the waveguide trace layer 20 through the second via b, then propagates along the side of the waveguide trace layer 20 near the slot radiating layer 30 (i.e., the third trace 23), then passes through the third via c through the waveguide trace layer 20, then propagates along the side of the waveguide trace layer 20 near the waveguide feed layer 10 (i.e., the second trace 22), and finally passes through the first via a through the waveguide trace layer 20, propagating along the side of the waveguide trace layer 20 near the slot radiating layer 30 (i.e., the fourth trace 24).

[0054] Similarly, when the electromagnetic signal is transmitted from the radiating slot 31 to the waveguide interface 12 along the first path, the electromagnetic signal passes through the fourth wiring slot 24, the first through hole a, and the first wiring slot 21 in sequence; when the electromagnetic signal is transmitted from the radiating slot 31 to the waveguide interface 12 along the second path, the electromagnetic signal passes through the fourth wiring slot 24, the first through hole a, the second wiring slot 22, the third through hole c, the third wiring slot 23, and the second through hole b in sequence.

[0055] In this way, electromagnetic signals can be confined within an air cavity for transmission, rather than within a metallic conductor, thereby significantly reducing conductor loss and signal energy attenuation. This low-loss characteristic is beneficial for realizing large-scale array antennas and sparse antenna arrays, improving antenna gain and directivity. Moreover, the first and second paths fully utilize the two surface spaces of the waveguide trace layer 20, avoiding mutual interference between different electromagnetic signals while achieving a more compact antenna layout, thus saving space.

[0056] Further options are available for reference. Figure 3 The waveguide trace layer 20 is provided with a pin periodic structure 41 and a reinforcing rib structure 42 on the side surface near the waveguide feed layer 10 and the side surface of the waveguide trace layer 20 near the slot radiation layer 30.

[0057] The pin periodic structure 41 surrounds the first wiring groove 21, the second wiring groove 22, the third wiring groove 23, and the fourth wiring groove 24. Specifically, the pin periodic structure 41 may include multiple protruding pins arranged in a certain period to suppress the transmission of electromagnetic signals in certain frequency bands. The frequency band of electromagnetic signal transmission can be controlled by changing the shape and size of the pin periodic structure 41, but this embodiment of the present invention does not specifically limit this.

[0058] Typically, the height of the pin periodic structure 41 does not exceed the surface of the waveguide trace layer 20.

[0059] The reinforcing rib structure 42 is used to enhance the strength of the waveguide trace layer 20.

[0060] Optionally, the reinforcing rib structure 42 can be arranged around the threaded hole mentioned above, which can help disperse the concentrated stress generated by screw fastening, which is beneficial to reduce material cracks or hole displacement that may occur during processing, and improve processing accuracy and product quality.

[0061] In one embodiment, reference continues Figure 3 Matching structures 43 are provided at both ends of the first wiring slot 21, the second wiring slot 22, and the third wiring slot 23. The matching structures 43 are used to guide the conversion between vertical and horizontal transmission of electromagnetic signals.

[0062] Optionally, the matching structure 43 may include at least two step structures along the extension direction of the wiring channel. For example, the matching structure 43 may include 2-step structures, 3-step structures, 4-step structures, 5-step structures, etc.

[0063] Along the extension direction of the cable tray, at least two stepped structures are arranged in sequence.

[0064] Furthermore, the height of at least two step structures can satisfy one of the following: the height of at least two step structures is equal; the height of at least two step structures gradually decreases; the height of at least two step structures gradually increases; the height of at least two step structures first gradually decreases and then gradually increases; the height of at least two step structures first gradually increases and then gradually decreases.

[0065] The width of at least two step structures can satisfy one of the following: the width of at least two step structures is equal; the width of at least two step structures gradually decreases; the width of at least two step structures gradually increases; the width of at least two step structures first gradually decreases and then gradually increases; the width of at least two step structures first gradually increases and then gradually decreases.

[0066] This configuration helps to extend the operating bandwidth of the cascaded antenna device, enabling it to maintain good impedance matching over a wider frequency range, thereby improving the antenna's bandwidth performance.

[0067] It should be noted that the structure and quantity of the matching structure 43 described above are only one example of the present invention, but are not limited thereto.

[0068] In one embodiment, the waveguide feed layer 10 is an FR4 dielectric substrate. FR4 is a printed circuit board (PCB) substrate with good electrical insulation and mechanical strength, while being relatively inexpensive and suitable for mass production.

[0069] The surface of the waveguide feed layer 10 near the waveguide trace layer 20 and the inner wall of the waveguide interface 12 are covered with a metal layer, enabling it to guide and radiate electromagnetic signals. The metal layer can be made of materials such as copper or gold, which helps to reduce the loss of electromagnetic signals during transmission.

[0070] Optionally, the waveguide feed layer 10 has a thickness of 1.6 mm, the FR4 material has a thickness of 0.127 mm, a dielectric constant of 3.9, and a loss tangent of 0.025.

[0071] Both the waveguide trace layer 20 and the slot radiating layer 30 are plastic sheets with metal-coated surfaces. Utilizing the low-loss characteristics of plastic and the high conductivity of metal, the cascaded antenna device can form a metal cavity that both protects the internal signals and effectively guides them, thus confining electromagnetic signals to a predetermined path, avoiding signal scattering and loss, and improving transmission efficiency. Moreover, plastic sheets are less expensive than high-frequency substrates.

[0072] Optionally, the waveguide routing layer 20 and the slot radiation layer 30 can be fabricated using injection molding and surface metallization processes. Specifically, the plastic structures of the waveguide routing layer 20 and the slot radiation layer 30 are first formed by injection molding or 3D printing using plastic particles. Then, a metal layer is fabricated on the surface of the plastic structures of the waveguide routing layer 20 and the slot radiation layer 30 to enable them to guide and radiate electromagnetic signals. This manufacturing method is simple in process, low in cost, and can significantly improve production efficiency, making it suitable for mass production.

[0073] It is understandable that the waveguide trace layer 20 and the slot radiation layer 30 can also be made of metal plates (such as copper plates or aluminum plates). Metal plates can provide high mechanical strength and rigidity, which helps to maintain the integrity and stability of the structure when subjected to external pressure or vibration.

[0074] In one embodiment, the cascaded antenna device has dimensions of 91mm*70mm*5.8mm, which enables a miniaturized design of the cascaded antenna device.

[0075] The waveguide interface 12 has a length of 2.74 mm and a width of 0.8 mm. The dimensions of the waveguide interface 12 are matched to the wavelength of the electromagnetic signal to ensure that electromagnetic signals of a specific frequency (e.g., the 76 GHz-81 GHz band) can pass through effectively without causing excessive attenuation or distortion, but it is not limited to this.

[0076] Taking a cascaded antenna device consisting of two waveguide chips as an example, Figure 6 This is a schematic diagram of the return loss of the cascaded antenna device provided in this embodiment of the present invention, where the horizontal axis represents frequency in GHz and the vertical axis represents return loss in dB. Figure 6 As shown, within the 76GHz-81GHz frequency band, the return loss of all 16 antenna ports of the cascaded antenna device is less than -10dB, which can meet the application requirements of vehicle-mounted millimeter-wave radar.

[0077] Figure 7 This is a two-dimensional radiation pattern of the cascaded antenna device provided in this embodiment of the utility model, where the horizontal axis represents the azimuth angle in degrees (deg); and the vertical axis represents the gain in dB. Figure 7As shown, the transmitting / receiving antennas have a gain greater than 5dB within a ±75° range, making them suitable for angle and range measurement over large angles. The main lobe-to-side lobe ratio is greater than 20dB, and the antennas have a wide main lobe radiation pattern, which can meet the field of view requirements of vehicle-mounted millimeter-wave radar.

[0078] The technical solution of this utility model embodiment, through the design of the structure of the cascaded antenna device, includes a waveguide feed layer, a waveguide trace layer, and a slot radiation layer stacked together. The waveguide feed layer includes at least two interface regions, each with several waveguide interfaces that penetrate the waveguide feed layer. At least two waveguide chips are disposed on the side of the waveguide feed layer away from the waveguide trace layer, with one waveguide chip corresponding to one interface region. The at least two waveguide chips are cascaded through a power divider. The slot radiation layer includes several radiation slots, each penetrating the slot radiation layer. Each waveguide interface corresponds to one radiation slot. Several propagation paths are formed on the waveguide trace layer, with each propagation path connecting a waveguide interface and its corresponding radiation slot. Firstly, because at least two waveguide chips are disposed on the side of the waveguide feed layer away from the waveguide trace layer, and these at least two waveguide chips are cascaded through a power divider, the channel expansion of the cascaded antenna device is achieved, improving the radiation efficiency and aperture of the cascaded antenna device. Secondly, the waveguide trace layer forms several propagation paths, each connecting a waveguide interface and its corresponding radiating slot. This confines the electromagnetic signal within the air cavity for transmission, rather than within a metallic conductor, significantly reducing conductor loss and signal energy attenuation. This low-loss characteristic is beneficial for realizing large-scale array antennas and sparse antenna arrays, improving antenna gain and directivity. Thirdly, the gap waveguide structure, composed of the waveguide feed layer, waveguide trace layer, and slot radiating layer, eliminates the limitations imposed by component obstruction, allowing for more flexible optimization of the antenna's physical layout to achieve optimal radiation modes and directivity. Furthermore, the elimination of soldering allows for a certain degree of mechanical tolerance, greatly reducing manufacturing and assembly difficulty and cost.

[0079] Example 2

[0080] This utility model also provides a radar, which includes a cascaded antenna device according to any embodiment of this utility model.

[0081] In one embodiment, the receiving antennas can be arranged at a specific distance on the horizontal plane at the upper and lower ends of the array, and the transmitting antennas can be arranged in both the horizontal and elevation directions of the receiving antennas, so that the radar can detect the phase azimuth information of the horizontal radiation pattern. The 4D millimeter-wave radar uses multiple-input multiple-output (MIMO) technology to place transmitting antennas at different heights in the elevation direction to realize a virtual aperture array in the vertical direction.

[0082] Optionally, the radar provided in this embodiment of the present invention can be a 4D millimeter-wave radar, which can generate high-precision point cloud data to construct a detailed image of the surrounding environment, including information such as the distance, speed, direction and height of the target, and can classify the target and predict its behavior, thereby providing key decision-making basis for applications such as advanced driver assistance systems (ADAS) and autonomous driving.

[0083] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A cascaded antenna device, characterized in that, It includes a waveguide feed layer, a waveguide routing layer, and a slot radiating layer stacked together, wherein the waveguide routing layer is located between the waveguide feed layer and the slot radiating layer; wherein... The waveguide feed layer includes at least two interface regions, and each interface region is provided with a plurality of waveguide interfaces, which penetrate the waveguide feed layer; at least two waveguide chips are provided on the side of the waveguide feed layer away from the waveguide trace layer, one waveguide chip corresponds to one interface region, and the at least two waveguide chips are cascaded through a power divider. The slotted radiation layer includes a plurality of radiation slots, each of which penetrates the slotted radiation layer; the waveguide interface corresponds one-to-one with the radiation slot; Several propagation paths are formed on the waveguide trace layer, and each propagation path is used to connect a waveguide interface and its corresponding radiation slot.

2. The cascaded antenna device according to claim 1, characterized in that, The waveguide routing layer includes M+N first vias, M second vias, and M third vias, where M and N are both positive integers; The waveguide routing layer has N first routing slots and M second routing slots on the side near the waveguide feed layer; the waveguide routing layer has M third routing slots and M+N fourth routing slots on the side near the slot radiation layer. The propagation path includes N first paths and M second paths; When an electromagnetic signal is transmitted from the waveguide interface to the radiation slot along the first path, the electromagnetic signal passes through the first wiring slot, the first through hole and the fourth wiring slot in sequence. When the electromagnetic signal is transmitted from the waveguide interface to the radiation slot along the second path, the electromagnetic signal passes sequentially through the second through hole, the third wiring slot, the third through hole, the second wiring slot, the first through hole, and the fourth wiring slot.

3. The cascaded antenna device according to claim 2, characterized in that, The waveguide trace layer is provided with a periodic pin structure and a reinforcing rib structure on the side surface near the waveguide feed layer and the side surface of the waveguide trace layer near the slot radiation layer. The pin periodic structure surrounds the first wiring groove, the second wiring groove, the third wiring groove, and the fourth wiring groove; The reinforcing rib structure is used to enhance the strength of the waveguide trace layer.

4. The cascaded antenna device according to claim 2, characterized in that, The first wiring groove, the second wiring groove, and the third wiring groove are all provided with matching structures at both ends; Along the extension direction of the wiring groove, the matching structure includes at least two stepped structures; The matching structure is used to guide the conversion between vertical and horizontal transmission of electromagnetic signals.

5. The cascaded antenna device according to claim 1, characterized in that, The waveguide chip is electrically connected to the power divider via traces, and the trace length between each waveguide chip and the power divider is equal.

6. The cascaded antenna device according to claim 1, characterized in that, A rectangular groove is provided on the surface of the slot radiation layer away from the waveguide trace layer. The rectangular grooves are located on opposite sides of the radial slit.

7. The cascaded antenna device according to any one of claims 1-6, characterized in that, The waveguide feed layer, the waveguide trace layer, and the slot radiation layer are connected by fasteners. After the connection is completed, there is a first gap between the waveguide feed layer and the waveguide trace layer, and a second gap between the waveguide trace layer and the slot radiation layer.

8. The cascaded antenna device according to any one of claims 1-6, characterized in that, The waveguide feed layer is an FR4 dielectric substrate layer; The waveguide trace layer and the slot radiation layer are plastic sheet layers with a metal coating on their surface.

9. The cascaded antenna device according to any one of claims 1-6, characterized in that, The dimensions of the cascaded antenna device are 91mm*70mm*5.8mm; The waveguide interface is 2.74 mm long and 0.8 mm wide.

10. A radar, characterized in that, Includes the cascaded antenna device as described in any one of claims 1-9.

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