Waveguide antenna, waveguide antenna array and radar antenna

Abstract

The present application relates to a waveguide antenna, a waveguide antenna and a radar antenna, comprising: a metal body, the top surface of which extends in the horizontal direction; the power divider network is arranged in the metal body and comprises a plurality of power divider branches, each power divider branch is bent and extends along the horizontal direction, and a first polarization direction is formed at the tail end of each power divider branch; the antenna units extend from the interior of the metal body to the top surface of the metal body along a normal direction perpendicular to the horizontal direction, and the antenna units are connected to the tail ends of the power divider branches in a one-to-one correspondence manner through the polarization direction switching units; wherein the polarization direction switching unit configures the polarization direction emitted from the antenna units as a second polarization direction perpendicular to the first polarization direction, and the plurality of antenna units are arranged at intervals along the first polarization direction.

Description

Technical Field

[0001] The present application relates to the technical field of communication equipment, and in particular to a waveguide antenna, a waveguide antenna array, and a radar antenna. Background Art

[0002] As the design technology for electronic components in the millimeter-wave frequency band matures, millimeter-wave radio equipment is gaining market traction. Using classic microwave design techniques, designing low-cost, miniaturized, and high-performance microwave components has become an urgent technical challenge. Waveguide antennas, a common antenna type, are widely used in communications and radar due to their robust structure, low insertion loss, and medium-to-high gain. Because they utilize waveguide transmission lines, which offer very low line loss, these antennas are typically combined into arrays to achieve wide bandwidth, high gain, and low sidelobe requirements in demanding applications. However, as array sizes increase, despite the use of profile reduction methods such as 3D stacking, the size of waveguide antenna arrays, especially in the cross-sectional direction, remains large, limiting their practicality. With the rise of SOC chips and MIMO technology, the design of low-profile, compact waveguide antennas has become a pressing challenge.

[0003] Currently, waveguide slot antennas are commonly used to address the high profile of waveguide antennas. These antennas place the narrow side of a rectangular waveguide in the cross-sectional direction. Specific narrow slots are then machined into the wide side of the waveguide, and the number of slots is controlled to tailor the radiation characteristics for different applications. However, these antenna arrays are typically designed only for horizontal polarization. Another approach involves evenly distributing horn-shaped openings along the waveguide transmission line to create a waveguide horn array antenna, but this approach only allows for vertical polarization. Summary of the Invention

[0004] Embodiments of the present application provide a waveguide antenna, a waveguide antenna array, and a radar antenna, which realize electromagnetic wave radiation in arbitrary linear polarization forms through the direction and polarization direction conversion unit of the antenna unit, while reducing the cross-sectional size to realize a low-profile waveguide antenna.

[0005] In one embodiment of the present application, a waveguide antenna is provided, comprising: a metal body, wherein a top surface of the metal body extends in a horizontal direction; A power divider network, the power divider network being disposed in the metal body and comprising a plurality of power divider branches, each power divider branch being bent and extended along the horizontal direction, and an end of each power divider branch forming a first polarization direction; An antenna unit, wherein the antenna unit extends from the metal body along a normal direction perpendicular to the horizontal direction to the top surface of the metal body, and the antenna unit is connected to the end of the power divider branch in a one-to-one correspondence via a polarization direction switching unit; The polarization direction switching unit configures the polarization direction emitted from the antenna unit to a second polarization direction perpendicular to the first polarization direction, and the plurality of antenna units are arranged at intervals along the first polarization direction.

[0006] In one embodiment, the method includes: a plurality of first choke slots, the first choke slots being recessed inwardly from the top surface of the metal body and spaced apart from the power divider network in the normal direction; Each of the first choke slots extends along the first polarization direction, and the length of the first choke slot covers all antenna units.

[0007] In one embodiment, the antenna unit comprises: an antenna port, the antenna port being connected to the polarization direction switching unit and extending along the normal direction; The antenna opening gradually expands outward from the antenna port to the top surface of the metal body, so as to form an opening with a size greater than or equal to that of the antenna port from the top surface of the metal body.

[0008] In one embodiment, the antenna port has a rectangular cross-section, The antenna opening is configured such that: The long side of the opening extends along the first polarization direction; or A long side of the opening extends along the second polarization direction.

[0009] In one embodiment, the power divider network comprises: a first power divider branch having a connection port connected to a waveguide transmission line; At least one second power divider branch, the second power divider branch is connected to the first power divider branch, and is arranged on one side or both sides of the first power divider branch in the first polarization direction.

[0010] In one embodiment, the power divider branch comprises: a first impedance matching structure, wherein the first impedance matching structure is bent along the horizontal direction; and / or A second impedance matching structure is provided, wherein the second impedance matching structure is protruding or recessed along the normal direction, and the power divider branch is connected to the polarization direction switching unit via the second impedance matching structure.

[0011] In one embodiment, a waveguide flange is included, wherein the waveguide flange is connected to a connection port of the power divider network via a waveguide transmission line, and the waveguide flange includes: a waveguide housing having a bottom surface for docking with the circuit board and a side surface for docking with the connection port; a waveguide connection cavity, the waveguide connection cavity being opened in the waveguide housing and having a waveguide output port extending through the side surface and a waveguide input port extending through the bottom surface, the waveguide input port extending along the first polarization direction or the second polarization direction; a second choke slot, the second choke slot being recessed inward from the bottom surface and surrounding the waveguide input port; A short-circuit branch is attached to both sides of the waveguide input port in the extension direction of the waveguide input port, and the short-circuit branch protrudes from the second choke slot to the bottom surface or is flush with the bottom surface.

[0012] In one embodiment, the waveguide flange is in contact with the circuit board; or The waveguide flange forms a non-contact connection with the circuit board with a spacing less than or equal to a first threshold, and the first threshold is 0.2 mm.

[0013] In one embodiment, the length of the second choke slot is 1.5 times the wavelength; and / or The length of the short-circuit branch is 1 / 4 wavelength.

[0014] The present application also provides a waveguide antenna array, comprising a plurality of waveguide antennas as described above, wherein the plurality of waveguide antennas are arranged in an array or in a radial arrangement; a waveguide transmission line connected to a connection port of the power divider network; A waveguide flange, the waveguide flange being connected to the waveguide transmission line, the waveguide flange comprising: a waveguide housing having a bottom surface for docking with the circuit board and a side surface for docking with the connection port; a waveguide connection cavity, the waveguide connection cavity being opened in the waveguide housing and having a waveguide output port extending through the side surface and a waveguide input port extending through the bottom surface, the waveguide input port extending along the first polarization direction or the second polarization direction; a second choke slot, the second choke slot being recessed inward from the bottom surface and surrounding the waveguide input port; Short-circuit branches, the short-circuit branches being attached to both sides of the waveguide input port in the extension direction of the waveguide input port, and the short-circuit branches protruding from the second choke slot out of the bottom surface or being flush with the bottom surface; Wherein, a plurality of the waveguide flanges are arranged in an array, the number of the waveguide flanges corresponds one-to-one to the number of the waveguide antennas, and the extension directions of the waveguide input ports of two adjacent waveguide flanges are perpendicular to each other.

[0015] The present application also provides a radar antenna, comprising: A waveguide antenna array as described above; a circuit board, the circuit board being in contact with the waveguide flange; or The waveguide flange forms a non-contact connection with the circuit board with a distance therebetween being less than or equal to a first threshold.

[0016] The present application also provides a waveguide flange, comprising: A waveguide housing, the waveguide housing having a bottom surface connected to the circuit board and a side surface connected to the bottom surface; a waveguide connection cavity, the waveguide connection cavity being opened in the waveguide housing and having a waveguide output port extending through the side surface and a waveguide input port extending through the bottom surface, the waveguide input port extending along the first polarization direction or the second polarization direction; a second choke slot, the second choke slot being recessed inward from the bottom surface and surrounding the waveguide input port; The short-circuit branches are attached to both sides of the waveguide input port in the extension direction of the waveguide input port.

[0017] In one embodiment, the short-circuit branch protrudes from the second choke slot out of the bottom surface or is flush with the bottom surface.

[0018] In one embodiment, the waveguide flange is in contact with the circuit board; or The waveguide flange forms a non-contact connection with the circuit board with a spacing less than or equal to a first threshold, and the first threshold is 0.2 mm.

[0019] In one embodiment, the waveguide housing comprises an upper waveguide housing and a lower waveguide housing; The waveguide connection cavity includes an upper waveguide connection cavity and a lower waveguide connection cavity that are spliced ​​together. The upper waveguide connection cavity is recessed inward from the lower surface of the upper waveguide shell, and the lower waveguide connection cavity is recessed inward from the upper surface of the lower waveguide shell.

[0020] In one embodiment, a circumference of the second choke slot is 1.5 times the wavelength.

[0021] The present application also provides a waveguide antenna array, comprising: a waveguide flange, wherein the waveguide flange comprises: A waveguide housing, the waveguide housing having a bottom surface connected to the circuit board and a side surface connected to the bottom surface; a waveguide connection cavity, the waveguide connection cavity being opened in the waveguide housing and having a waveguide output port extending through the side surface and a waveguide input port extending through the bottom surface, the waveguide input port extending along the first polarization direction or the second polarization direction; a second choke slot, the second choke slot being recessed inward from the bottom surface and surrounding the waveguide input port; The short-circuit branches are attached to both sides of the waveguide input port in the extension direction of the waveguide input port.

[0022] In one embodiment, the short-circuit branch protrudes from the second choke slot out of the bottom surface or is flush with the bottom surface.

[0023] In one embodiment, the waveguide flange is in contact with the circuit board; or The waveguide flange forms a non-contact connection with the circuit board with a spacing less than or equal to a first threshold, and the first threshold is 0.2 mm.

[0024] In one embodiment, the waveguide housing comprises an upper waveguide housing and a lower waveguide housing; The waveguide connection cavity includes an upper waveguide connection cavity and a lower waveguide connection cavity that are spliced ​​together. The upper waveguide connection cavity is recessed inward from the lower surface of the upper waveguide shell, and the lower waveguide connection cavity is recessed inward from the upper surface of the lower waveguide shell.

[0025] In one embodiment, a waveguide antenna is included, the waveguide antenna comprising: a metal body, wherein a top surface of the metal body extends in a horizontal direction; A power divider network, the power divider network being disposed in the metal body and comprising a plurality of power divider branches, each power divider branch being bent and extended along the horizontal direction, and an end of each power divider branch forming a first polarization direction; An antenna unit, wherein the antenna unit extends from the metal body along a normal direction perpendicular to the horizontal direction to the top surface of the metal body, and the antenna unit is connected to the end of the power divider branch in a one-to-one correspondence via a polarization direction switching unit; The polarization direction switching unit configures the polarization direction emitted from the antenna unit to a second polarization direction perpendicular to the first polarization direction, and the plurality of antenna units are arranged at intervals along the first polarization direction.

[0026] In one embodiment, the waveguide antenna comprises: a plurality of first choke slots, the first choke slots being recessed inwardly from the top surface of the metal body and spaced apart from the power divider network in the normal direction; Each of the first choke slots extends along the first polarization direction, and the length of the first choke slot covers all antenna units.

[0027] In one embodiment, the antenna unit comprises: an antenna port, the antenna port being connected to the polarization direction switching unit and extending along the normal direction; The antenna opening gradually expands outward from the antenna port to the top surface of the metal body, so as to form an opening with a size greater than or equal to that of the antenna port from the top surface of the metal body.

[0028] In one embodiment, the antenna port has a rectangular cross-section, The antenna opening is configured such that: The long side of the opening extends along the first polarization direction; or A long side of the opening extends along the second polarization direction.

[0029] In one embodiment, the power divider network comprises: a first power divider branch having a connection port connected to a waveguide transmission line; at least one second power divider branch, the second power divider branch being connected to the first power divider branch and being arranged on one side or both sides of the first power divider branch in the first polarization direction; The side surface of the waveguide flange is butted against the connection port.

[0030] In one embodiment, the power divider branch comprises: a first impedance matching structure, wherein the first impedance matching structure is bent along the horizontal direction; and / or A second impedance matching structure is provided, wherein the second impedance matching structure is protruding or recessed along the normal direction, and the power divider branch is connected to the polarization direction switching unit via the second impedance matching structure.

[0031] In related technologies, in order to achieve a low-profile design, the antenna form is limited and arbitrary conversion of the polarization direction of the antenna cannot be achieved, because it is usually necessary to achieve it by first converting it to the normal direction and then to the horizontal direction. This requires space in both the horizontal direction and the normal direction, and therefore cannot meet the low-profile requirements.

[0032] In this example, the power divider network 20 extends in the horizontal direction, and each power divider branch 201 bends and extends in the horizontal direction. In order to realize the setting of any polarization direction by the power divider network 20 that bends in the horizontal direction, in this example, the antenna unit 30 is connected to the end of the power divider branch 201 via the polarization direction switching unit 40 one by one. Each power divider branch 201 does not need to generate a bending component in the normal direction, thereby greatly reducing the height of the waveguide antenna in the normal direction, thereby achieving the low profile requirement while meeting the polarization direction conversion. The antenna unit 30 extending along the normal direction can directly realize the steering of the propagation direction of the electromagnetic wave, so that the electromagnetic wave input from the power divider network 20 is directly emitted from the top surface of the metal body 10 along the normal direction via the antenna unit 30.

[0033] Furthermore, in order to realize the setting of arbitrary polarization direction by the power divider network 20 bent in the horizontal direction, in this example, the antenna unit 30 is connected to the end of the power divider branch 201 one by one via the polarization direction switching unit 40 to convert the first polarization direction at the end of the power divider branch 201 into a vertical second polarization direction.

[0034] It can be seen that the embodiments of the present application provide a waveguide antenna, a waveguide antenna array and a radar antenna, which realize electromagnetic wave radiation in arbitrary linear polarization forms through the direction and polarization direction conversion unit of the antenna unit, while reducing the cross-sectional size to realize a low-profile waveguide antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following drawings are merely provided to illustrate and explain the present application, and do not limit the scope of the present application.

[0036] Figure 1a This is a schematic diagram of the external structure of the waveguide antenna of this application.

[0037] Figure 1b This is a partial cross-sectional schematic diagram of the waveguide antenna of the present application.

[0038] Figure 1c This is a partial top view of the waveguide antenna of the present application.

[0039] Figure 2 This is a schematic structural diagram of the waveguide antenna array of this application.

[0040] Figure 3a and Figure 3b This is a schematic structural diagram of the waveguide antenna array of this application.

[0041] Figure 4a and Figure 4bThis is a schematic structural diagram of the antenna unit of the waveguide antenna of the present application.

[0042] Figure 5 This is a schematic diagram of the partial structure of the waveguide antenna of this application.

[0043] Figure 6 This is a partial top view of the waveguide antenna of the present application.

[0044] Figures 7a to 7d This is a schematic structural diagram of the waveguide flange of the waveguide antenna of the present application.

[0045] Figure 8 Schematic diagram of the structure of a waveguide flange used for a waveguide antenna array.

[0046] Figure 9 This is a schematic structural diagram of the waveguide antenna array of this application.

[0047] Figure 10 This is a schematic structural diagram of the waveguide antenna array of this application.

[0048] Figure 11 This is a schematic structural diagram of the radar antenna of this application. DETAILED DESCRIPTION

[0049] In order to have a clearer understanding of the technical features, purposes and effects of the invention, specific embodiments of the present invention are now described with reference to the accompanying drawings, in which the same reference numerals represent the same parts.

[0050] In this document, “illustrative” means “serving as an example, instance or illustration”, and any diagram or implementation described in this document as “illustrative” should not be interpreted as a more preferred or more advantageous technical solution.

[0051] To simplify the drawings, only the parts relevant to the present invention are schematically shown in each figure and do not represent the actual structure of the product. In addition, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically depicted or labeled.

[0052] In this document, “upper”, “lower”, “front”, “back”, “left”, “right”, etc. are only used to indicate the relative position relationship between related parts, rather than to limit the absolute positions of these related parts.

[0053] In this article, "first", "second", etc. are only used to distinguish each other, and do not indicate the importance and order, or the prerequisite for each other's existence.

[0054] In this document, "equal" and "same" are not strictly limited in the mathematical and / or geometric sense, but also include errors that can be understood by those skilled in the art and are allowed in manufacturing or use. Unless otherwise specified, the numerical ranges herein include not only the entire range within its two endpoints, but also several sub-ranges contained therein.

[0055] Embodiments of the present application provide a waveguide antenna, a waveguide antenna array, and a radar antenna, which realize electromagnetic wave radiation in arbitrary linear polarization forms through the direction and polarization direction conversion unit of the antenna unit, while reducing the cross-sectional size to realize a low-profile waveguide antenna.

[0056] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0057] like Figures 1a to 1c As shown, this embodiment provides a waveguide antenna, including: The metal body 10 has a normal direction perpendicular to its top surface and a horizontal direction parallel to its top surface; The power divider network 20 is provided in the metal body 10 and includes a plurality of power divider branches 201. Each power divider branch 201 bends and extends along a horizontal direction, and the end of each power divider branch 201 forms a first polarization direction. The antenna unit 30 extends from the metal body 10 along the normal direction to the top surface of the metal body 10. The antenna unit 30 is connected to the end of the power divider branch 201 via the polarization direction switching unit 40 in a one-to-one correspondence; The polarization switching unit 40 configures the polarization direction emitted from the antenna unit 30 to be a second polarization direction perpendicular to the first polarization direction, and the plurality of antenna units 30 are arranged at intervals along the first polarization direction.

[0058] The operating principle of a waveguide power splitter network is based on the electromagnetic wave propagation characteristics of a waveguide structure. A waveguide is a hollow tube enclosed by a metal shell that confines electromagnetic waves within the tube. A waveguide power splitter typically consists of multiple branch waveguides and a main waveguide. By properly designing the waveguide branch structure and dimensions, input power can be evenly distributed to multiple output ports, or multiple input signals can be combined into a single output.

[0059] In this example, the power divider network 20 extends in the horizontal direction, and each power divider branch 201 bends and extends in the horizontal direction. In order to realize the setting of any polarization direction by the power divider network 20 that bends in the horizontal direction, in this example, the antenna unit 30 is connected to the end of the power divider branch 201 via the polarization direction switching unit 40 one by one. Each power divider branch 201 does not need to generate a bending component in the normal direction, thereby greatly reducing the height of the waveguide antenna in the normal direction, thereby achieving the low profile requirement while meeting the polarization direction conversion. The antenna unit 30 extending along the normal direction can directly realize the steering of the propagation direction of the electromagnetic wave, so that the electromagnetic wave input from the power divider network 20 is directly emitted from the top surface of the metal body 10 along the normal direction via the antenna unit 30.

[0060] Furthermore, in order to realize the setting of arbitrary polarization direction by the power divider network 20 bent in the horizontal direction, in this example, the antenna unit 30 is connected to the end of the power divider branch 201 one by one via the polarization direction switching unit 40 to convert the first polarization direction at the end of the power divider branch 201 into a vertical second polarization direction.

[0061] The first polarization direction and the second polarization direction are two directions perpendicular to each other in the horizontal plane. The polarization direction depends on the long side direction of the power divider branch. For example, the extension direction of the end of the power divider branch is Figure 4b The horizontal direction in the figure, the first polarization direction at the end of the power divider branch is the vertical direction perpendicular to its long side, such as Figure 4b The direction of the arrow at the power divider branch 201 is shown. When the polarization direction of the electromagnetic wave emitted by the antenna unit 30 is required to be horizontal, this example converts the first polarization direction into the second polarization direction through a polarization direction switching unit 40 with a 90° bend in a horizontal plane. The polarization direction switching unit 40 can, for example, be bent twice at 45° to achieve a 90° bend. The polarization direction of the antenna is as follows: Figure 4b The direction of the arrow is always perpendicular to the long side. Figure 4b The intermediate polarization switching unit 40 directly converts polarization within the horizontal plane, eliminating the need for conversion to the normal direction and then to the horizontal direction. Each power divider branch 201 eliminates the need for a normal bending component, significantly reducing the normal height of the waveguide antenna and significantly contributing to a lower profile. By varying the bending angle (e.g., 0° or 45°), linearly polarized radiation characteristics in other directions can be achieved.

[0062] The first and second polarization directions are vertical and horizontal polarization directions within the horizontal plane. Horizontal polarization refers to a polarization state in which the vibration direction of the electric field vector is parallel to the horizontal plane. Horizontally polarized antennas typically have a wide horizontal coverage range and are suitable for terrestrial broadcasting and certain communication systems. Horizontally polarized antennas have high gain in the horizontal direction and are suitable for horizontal signal propagation. Vertical polarization refers to a polarization state in which the vibration direction of the electric field vector is perpendicular to the horizontal plane. Vertically polarized antennas typically have high gain and are suitable for communication systems requiring high directivity.

[0063] In this example, it is not specifically stipulated which polarization direction the first polarization direction and the second polarization direction refer to, but the polarization direction can be arbitrarily converted through the polarization direction switching unit 40 .

[0064] In a specific example, Figures 2 to 3b As shown, the metal body includes an upper metal body 11 and a lower metal body 12 that are stacked, and the upper metal body 11 is located above the lower metal body 12. The power divider network 20 includes an upper power divider network 21 and a lower power divider network 22 of the same shape, wherein the upper power divider network 21 is recessed from the lower surface of the upper metal body 11 to the upper metal body 11, and the lower power divider network 22 is recessed from the upper surface of the lower metal body 12 to the lower metal body 12. The power divider network 10 includes a plurality of power divider branches 201, each of which bends and extends in a plane perpendicular to the stacking direction.

[0065] Antenna unit 30 extends from the interior of lower metal body 12 along the stacking direction (normal direction) to the upper surface of upper metal body 11, forming an opening. Electromagnetic wave energy input from power divider network 20 is emitted from the upper surface of upper metal body 11 along the normal direction through antenna unit 30.

[0066] Among them, include: a plurality of first choke slots 50 , the first choke slots 50 being recessed inward from the top surface of the metal body 10 and spaced apart from the power divider network 20 in a normal direction; Each first choke slot 50 extends along the first polarization direction and forms a spacing of an integer multiple of 1 / 2 wavelength with the antenna unit 30 in the second polarization direction. The length of the first choke slot 50 covers all antenna units 30.

[0067] This embodiment is composed of two layers of materials, the lower half of which is the lower half of the waveguide power splitting network, and the upper half of which is the waveguide power splitting network and the horizontally polarized antenna. The upper half has an electromagnetic wave suppression structure composed of a first choke slot.

[0068] Choke slots are used to suppress electromagnetic waves. Their depth is approximately one-quarter the wavelength of the resonant frequency in air. By fine-tuning the choke slot depth, the current distribution near the antenna can be fine-tuned. Here, the depth is set to 0.28 times the wavelength of air. During the design process, it was found that the number of choke slots also affects the antenna's radiation pattern. After three repeated choke slots, the radiation pattern remains unchanged. To ensure the antenna's radiation pattern is as stable as possible, an example configuration with three choke slots on each side of the antenna element is shown here.

[0069] In a specific example, the antenna unit 30 includes: Antenna port 31, which is connected to the polarization direction switching unit 40 and extends along the normal direction; The antenna opening 32 gradually extends outward from the antenna port 31 to the top surface of the metal body 10 to form an opening with a size greater than or equal to that of the antenna port 31 from the top surface of the metal body 10 .

[0070] Antenna opening 32 is formed into a gradually increasing trumpet-shaped shape. The opening formed on the top surface of metal body 10 by the enlargement of antenna opening 32 is not necessarily a proportional enlargement of the cross-section of antenna port 31. Rather, it can be adjusted. The gradually expanding trumpet-shaped opening is designed to prevent reflections of electromagnetic waves during the transition from conduction mode to radiation mode.

[0071] The dimensions of the antenna opening 32 in the polarization direction can correspondingly affect the antenna's gain in that direction. By adjusting the aspect ratio of the antenna opening 32 and the direction of its long side, the waveguide antenna's radiated energy in different polarization directions can be adjusted. A larger dimension of the antenna opening 32 in a particular polarization direction results in greater gain and more concentrated energy in that polarization direction.

[0072] Furthermore, in addition to considering radiated energy, the layout space also needs to be considered. Because the power divider branches 201 need to be spaced apart and the overall size must be limited to a preset range, the size of the antenna opening 32 in any polarization direction cannot be infinitely expanded or reduced. When the size in any polarization direction increases to an extreme value, the gain can be increased by adjusting the size ratio with the other polarization direction.

[0073] In one embodiment, the antenna port 31 has a rectangular cross section, and the antenna opening 32 is configured as follows via an opening angle 33 that forms an acute angle with the normal direction: like Figure 1c The long sides of the openings shown extend along the first polarization direction; or Figure 6 The long sides of the openings shown extend along the second polarization direction.

[0074] Antenna port 31 has a rectangular cross-section. Accordingly, antenna opening 32 is also enclosed by four planes that form acute angles with the normal direction. A pair of non-adjacent opposing planes can be configured to have the same opening angle 33. When the opening angle 33 of a pair of opposing planes increases, the opening size of the other adjacent pair of planes will also increase accordingly.

[0075] For example, Figure 1c The long side of the opening shown extends along the first polarization direction, so the size of the opening in the first polarization direction is larger than the size in the second polarization direction, and the beam width of the waveguide antenna in the first polarization direction is the narrowest. Figure 6 The long side of the opening shown extends along the second polarization direction, so the size of the opening in the second polarization direction is larger than that in the first polarization direction, and the beam width of the waveguide antenna in the second polarization direction is the narrowest.

[0076] In this example, if Figure 1c As shown, the power divider network 20 comprises: A first power divider branch 201a, wherein the first power divider branch 201 has a connection port A connected to the waveguide transmission line 41; At least one second power divider branch 201b is provided. The second power divider branch 201b is connected to the first power divider branch 201a and is arranged on one side or both sides of the first power divider branch 201a in the first polarization direction.

[0077] The first power divider branch 201a forms the input port of the entire waveguide antenna, and has a connection port A connected to the waveguide transmission line 41. The electromagnetic wave energy is input into the first power divider branch 201a from the connection port A, and is sequentially distributed to one or more second power divider branches 201b through a one-to-many branch design. Among them, the second power divider branches 201b can be located on one side of the first power divider branch 201a to form a serial structure connected in sequence, or distributed on both sides of the first power divider branch 201a. This center-feed method achieves its antenna pattern pointing normal at different frequencies by adjusting the length and spacing.

[0078] Among them, combined Figure 1c and Figure 4a As shown, the power divider branch 201 includes: A first impedance matching structure 202, the first impedance matching structure 202 is bent along the horizontal direction; and / or The second impedance matching structure 203 is protruding or recessed along the normal direction. The power divider branch 201 is connected to the polarization direction switching unit 40 via the second impedance matching structure 203 .

[0079] By modifying the size of the antenna opening and the dimensions of the impedance matching structure within the 90° bend, antenna structures with varying apertures can be realized. The stepped or recessed impedance matching structure allows electromagnetic waves to be transmitted losslessly to the antenna unit's opening structure and radiated into free space.

[0080] In one embodiment, a waveguide flange 60 is included, and the waveguide flange 60 is connected to the connection port A of the power divider network 20 via the waveguide transmission line 41. The waveguide flange 60 includes: A waveguide housing 61 having a bottom surface for docking with the circuit board and a side surface for docking with the connection port A; A waveguide connection cavity 62 is provided in the waveguide housing 61 and has a waveguide output port 63 extending through the side surface and a waveguide input port 64 extending through the bottom surface. The waveguide input port 64 extends along the first polarization direction or the second polarization direction. a second choke slot 65 , which is recessed inward from the bottom surface and surrounds the waveguide input port 64 ; The short-circuit branches 66 are attached to both sides of the waveguide input port 64 in the extension direction of the waveguide input port 64 , and protrude from the bottom surface of the second choke slot 65 or are flush with the bottom surface.

[0081] Typically, the spacing between the choke slot and the waveguide input port 64 needs to be greater than or equal to 1 / 4 wavelength, which fails to meet the requirements of miniaturization and compact structure. In this example, a short-circuit branch 66 is arranged around the waveguide input port 64. Unlike traditional choke structures, the short-circuit branch 66 has a semi-open structure. Because the electromagnetic intensity of the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part. Furthermore, the inwardly recessed second choke slot 65 surrounds the waveguide input port 64 and the short-circuit branch 66. The second choke slot 65 achieves an elongated spacing through a U-shaped bending structure, thereby ensuring the spacing requirement with a surrounding (closely fitting) structure. Furthermore, the short-circuit branch 66 protrudes from the bottom surface of the waveguide housing 61, and the protruding structure can achieve a greater contact force. Optionally, the short-circuit branch 66 can also be flush with the bottom surface of the waveguide housing 61.

[0082] The waveguide flange can realize the contact or contactless interconnection between the waveguide antenna and the circuit board through the transmission line. The waveguide port on the circuit board (can be rectangular waveguide, single ridge waveguide or double ridge waveguide) Figure 7d and Figure 9A schematic diagram of the assembly of a waveguide transmission line and a double-ridge waveguide is provided. The structure is divided into two parts: the upper part is the waveguide transition structure proposed in the present invention, and the lower part is a traditional waveguide structure (the example shown in the figure is a double-ridge waveguide circuit board). In the figure, the waveguide connection cavity 62 is used to transmit energy to the waveguide transmission line 41. The short-circuit branch 66 is used to shield electromagnetic waves and provide support, with a length of approximately 1 / 4 of the resonant wavelength (λ). The second choke slot 65 surrounds the waveguide input port 64, with a total length of approximately 1.5 wavelengths (λ). Between the waveguide input port 64 and the short-circuit branch 66, there is a section of the second choke slot 65 that performs impedance matching. Unlike traditional choke structures, the short-circuit branch 66 is a semi-open structure. Because the electromagnetic intensity in the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part.

[0083] The gap between the waveguide flange and the circuit board can be controlled within the range of 0 to 0.2 mm. When the gap is 0, the connection method is contact connection, and when the gap is less than 0.2 mm, the connection method is non-contact connection.

[0084] This embodiment further provides a waveguide antenna array, including: Multiple waveguide antennas, multiple waveguide antennas arranged in an array or radially arranged; a waveguide transmission line 41 connected to a connection port A of the power divider network 20; The waveguide flange 60 is connected to the waveguide transmission line 41 and includes: A waveguide housing 61 having a bottom surface for docking with the circuit board and a side surface for docking with the connection port A; A waveguide connection cavity 62 is provided in the waveguide housing 61 and has a waveguide output port 63 extending through the side surface and a waveguide input port 64 extending through the bottom surface. The waveguide input port 64 extends along the first polarization direction or the second polarization direction. a second choke slot 65 , which is recessed inward from the bottom surface and surrounds the waveguide input port 64 ; Short-circuit branches 66 , which are attached to both sides of the waveguide input port 64 in the extension direction of the waveguide input port 64 and protrude from the bottom surface of the second choke slot 65 or are flush with the bottom surface; A plurality of waveguide flanges 60 are arranged in an array, the number of the waveguide flanges 60 corresponds to the number of the waveguide antennas, and the extension directions of the waveguide input ports 64 of two adjacent waveguide flanges 60 are perpendicular to each other.

[0085] In this example, eight waveguide antennas are arranged in a radar antenna array, for example, in an array pattern, such as a radial arrangement. The eight waveguide antennas can be arranged in a relatively compact manner, reducing the spacing between the waveguide antennas. The connection ports of each waveguide antenna are concentrated at the center of the radar antenna array by inwardly converging waveguide transmission lines. They are connected to the waveguide flange 60 at this location.

[0086] Among them, the waveguide flanges 60 are arranged in a combined form. As shown in the figure, multiple waveguide flanges 60 are arranged in an array. The number of waveguide flanges 60 corresponds one-to-one to the number of waveguide antennas, and the extension directions of the waveguide input ports 64 of two adjacent waveguide flanges 60 are perpendicular to each other.

[0087] This embodiment further provides a radar antenna, including: Waveguide antenna array as shown above; The circuit board 70 is in contact with the waveguide flange 60; or The waveguide flange 60 and the circuit board 70 form a non-contact connection with a distance less than or equal to a first threshold, and the first threshold is 0.2 mm.

[0088] The waveguide flange realizes the contact or contactless interconnection between the waveguide antenna and the circuit board through the transmission line. The waveguide port on the circuit board (can be rectangular waveguide, single ridge waveguide or double ridge waveguide) Figure 7d The assembly diagram of the waveguide transmission line and the double-ridge waveguide is given, combined with Figures 7a to 7c As shown, the structure is divided into two parts, the upper part is the waveguide transfer structure proposed by the present invention, and the lower part is the traditional waveguide structure (the example given in the figure is a double-ridge waveguide circuit board). In the figure, the waveguide connection cavity 62 is used to transmit energy to the waveguide transmission line 41, and the short-circuit branch 66 is used to shield electromagnetic waves and play a supporting role. The length is about 1 / 4 of the resonant wavelength (λ). The second choke slot 65 surrounds the waveguide input port 64, and the total length is about 1.5 times the wavelength (λ). Between the waveguide input port 64 and the short-circuit branch 66, there is a second choke slot 65 that plays an impedance matching role. The short-circuit branch 66 is different from the traditional choke structure and is a semi-open structure. Since the electromagnetic intensity of the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part.

[0089] In related technologies, in order to achieve a low-profile design, the antenna form is limited and arbitrary conversion of the polarization direction of the antenna cannot be achieved, because it is usually necessary to achieve it by first converting it to the normal direction and then to the horizontal direction. This requires space in both the horizontal direction and the normal direction, and therefore cannot meet the low-profile requirements.

[0090] In this example, the power divider network extends in the horizontal direction, and each power divider branch bends and extends in the horizontal direction. In order to achieve the setting of any polarization direction through the power divider network that bends in the horizontal direction, in this example, the antenna unit is connected to the end of the power divider branch one by one via the polarization direction switching unit. Each power divider branch does not need to generate a bending component in the normal direction, thereby greatly reducing the height of the waveguide antenna in the normal direction, thereby meeting the low-profile requirement while meeting the polarization direction conversion. The propagation direction of the electromagnetic wave can be directly turned by the antenna unit extending in the normal direction, so that the electromagnetic wave input from the power divider network is directly emitted from the top surface of the metal body along the normal direction via the antenna unit.

[0091] Furthermore, in order to achieve the setting of any polarization direction through a power divider network bent in the horizontal direction, in this example, the antenna units are connected one-to-one to the ends of the power divider branches via polarization direction switching units to convert the first polarization direction at the ends of the power divider branches into a vertical second polarization direction.

[0092] It can be seen that the embodiments of the present application provide a waveguide antenna, a waveguide antenna array and a radar antenna, which realize electromagnetic wave radiation in arbitrary linear polarization forms through the direction and polarization direction conversion unit of the antenna unit, while reducing the cross-sectional size to realize a low-profile waveguide antenna.

[0093] Figures 7a to 7d This is a schematic diagram of the structure of the waveguide flange of this application. Figures 7a to 7d As shown, one embodiment of the present application provides a waveguide flange, and the waveguide flange 60 includes: A waveguide housing 61 having a bottom surface connected to the circuit board and a side surface connected to the bottom surface; A waveguide connection cavity 62 is provided in the waveguide housing 61 and has a waveguide output port 63 extending through the side surface and a waveguide input port 64 extending through the bottom surface. The waveguide input port 64 extends along the first polarization direction or the second polarization direction. a second choke slot 65 , which is recessed inward from the bottom surface and surrounds the waveguide input port 64 ; The short-circuit branches 66 are attached to both sides of the waveguide input port 64 in the extension direction of the waveguide input port 64 , and protrude from the bottom surface of the second choke slot 65 or are flush with the bottom surface.

[0094] Typically, the spacing between the choke slot and the waveguide input port 64 needs to be greater than or equal to 1 / 4 wavelength, which fails to meet the requirements of miniaturization and compact structure. In this example, a short-circuit branch 66 is arranged around the waveguide input port 64. Unlike traditional choke structures, the short-circuit branch 66 has a semi-open structure. Because the electromagnetic intensity of the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part. Furthermore, the inwardly recessed second choke slot 65 surrounds the waveguide input port 64 and the short-circuit branch 66. The second choke slot 65 achieves an elongated spacing through a U-shaped bending structure, thereby ensuring the spacing requirement with a surrounding (closely fitting) structure. Furthermore, the short-circuit branch 66 protrudes from the bottom surface of the waveguide housing 61, and the protruding structure can achieve a greater contact force. Optionally, the short-circuit branch 66 can also be flush with the bottom surface of the waveguide housing 61.

[0095] The waveguide flange can realize the contact or contactless interconnection between the waveguide antenna and the circuit board through the transmission line. The waveguide port on the circuit board (can be rectangular waveguide, single ridge waveguide or double ridge waveguide) Figure 7d and Figure 9 A schematic diagram of the assembly of a waveguide transmission line and a double-ridge waveguide is provided. The structure is divided into two parts: the upper part is the waveguide transition structure proposed in the present invention, and the lower part is a traditional waveguide structure (the example shown in the figure is a double-ridge waveguide circuit board). In the figure, the waveguide connection cavity 62 is used to transmit energy to the waveguide transmission line 41. The short-circuit branch 66 is used to shield electromagnetic waves and provide support, with a length of approximately 1 / 4 of the resonant wavelength (λ). The second choke slot 65 surrounds the waveguide input port 64, with a total length of approximately 1.5 wavelengths (λ). Between the waveguide input port 64 and the short-circuit branch 66, there is a section of the second choke slot 65 that performs impedance matching. Unlike traditional choke structures, the short-circuit branch 66 is a semi-open structure. Because the electromagnetic intensity in the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part.

[0096] The gap between the waveguide flange and the circuit board can be controlled within the range of 0 to 0.2 mm. When the gap is 0, the connection method is contact connection, and when the gap is less than 0.2 mm, the connection method is non-contact connection.

[0097] like Figure 7a As shown, the waveguide housing 61 includes an upper waveguide housing and a lower waveguide housing; The waveguide connection cavity 62 includes an upper waveguide connection cavity and a lower waveguide connection cavity that are spliced ​​together. The upper waveguide connection cavity is recessed inward from the lower surface of the upper waveguide shell, and the lower waveguide connection cavity is recessed inward from the upper surface of the lower waveguide shell.

[0098] Combine Figures 7a to 9As shown, one embodiment of the present application also discloses a waveguide antenna array, including Figures 7a to 7d The waveguide flange 60 shown includes: A waveguide housing 61 having a bottom surface connected to the circuit board and a side surface connected to the bottom surface; A waveguide connection cavity 62 is provided in the waveguide housing 61 and has a waveguide output port 63 extending through the side surface and a waveguide input port 64 extending through the bottom surface. The waveguide input port 64 extends along the first polarization direction or the second polarization direction. a second choke slot 65 , which is recessed inward from the bottom surface and surrounds the waveguide input port 64 ; The short-circuit branches 66 are attached to both sides of the waveguide input port 64 in the extension direction of the waveguide input port 64 , and protrude from the bottom surface of the second choke slot 65 or are flush with the bottom surface.

[0099] Typically, the spacing between the choke slot and the waveguide input port 64 needs to be greater than or equal to 1 / 4 wavelength, which fails to meet the requirements of miniaturization and compact structure. In this example, a short-circuit branch 66 is arranged around the waveguide input port 64. Unlike traditional choke structures, the short-circuit branch 66 has a semi-open structure. Because the electromagnetic intensity of the open part is very weak, combined with the choke structure, the short-circuit branch does not need to be a fully enclosed structure, thereby reducing the size of the open part. Furthermore, the inwardly recessed second choke slot 65 surrounds the waveguide input port 64 and the short-circuit branch 66. The second choke slot 65 achieves an elongated spacing through a U-shaped bending structure, thereby ensuring the spacing requirement with a surrounding (closely fitting) structure. Furthermore, the short-circuit branch 66 protrudes from the bottom surface of the waveguide housing 61, and the protruding structure can achieve a greater contact force. Optionally, the short-circuit branch 66 can also be flush with the bottom surface of the waveguide housing 61.

[0100] Combine Figure 8 and Figure 9 As shown, the waveguide antenna array of the present application includes multiple Figures 1a to 6 The waveguide antenna shown is arranged in an array or radially arranged. a waveguide transmission line 41 connected to a connection port A of the power divider network 20; The waveguide flange 60 is connected to the waveguide transmission line 41 and includes: A waveguide housing 61 having a bottom surface for docking with the circuit board and a side surface for docking with the connection port A; A waveguide connection cavity 62 is provided in the waveguide housing 61 and has a waveguide output port 63 extending through the side surface and a waveguide input port 64 extending through the bottom surface. The waveguide input port 64 extends along the first polarization direction or the second polarization direction. a second choke slot 65 , which is recessed inward from the bottom surface and surrounds the waveguide input port 64 ; Short-circuit branches 66 , which are attached to both sides of the waveguide input port 64 in the extension direction of the waveguide input port 64 and protrude from the bottom surface of the second choke slot 65 or are flush with the bottom surface; A plurality of waveguide flanges 60 are arranged in an array, the number of the waveguide flanges 60 corresponds to the number of the waveguide antennas, and the extension directions of the waveguide input ports 64 of two adjacent waveguide flanges 60 are perpendicular to each other.

[0101] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A waveguide antenna, characterized in that: include: A metal body (10), wherein the top surface of the metal body (10) extends in a horizontal direction; A power distributor network (20), the power distributor network (20) being opened in the metal body (10) and comprising a plurality of power distributor branches (201), each power distributor branch (201) being bent and extended along the horizontal direction, and an end of each power distributor branch (201) forming a first polarization direction; An antenna unit (30), the antenna unit (30) extending from the inside of the metal body (10) along a normal direction perpendicular to the horizontal direction to the top surface of the metal body (10), the antenna unit (30) being connected to the end of the power distributor branch (201) in a one-to-one correspondence via a polarization direction switching unit (40); The polarization direction switching unit (40) configures the polarization direction emitted from the antenna unit (30) to be a second polarization direction perpendicular to the first polarization direction, and a plurality of the antenna units (30) are arranged at intervals along the first polarization direction.

2. The waveguide antenna according to claim 1, wherein include: a plurality of first choke slots (50), wherein the first choke slots (50) are recessed inward from the top surface of the metal body (10) and are spaced apart from the power distributor network (20) in the normal direction; Each of the first choke slots (50) extends along the first polarization direction, the length of the first choke slot (50) covers all antenna units (30), and a plurality of the first choke slots (50) are spaced apart in the second polarization direction.

3. The waveguide antenna according to claim 1, wherein: The antenna unit (30) comprises: An antenna port (31), the antenna port (31) being connected to the polarization direction switching unit (40) and extending along the normal direction; An antenna opening (32), the antenna opening (32) gradually extending outward from the antenna port (31) to the top surface of the metal body (10), so as to form an opening with a size greater than or equal to that of the antenna port (31) from the top surface of the metal body (10).

4. The waveguide antenna according to claim 3, wherein: The antenna port (31) has a rectangular cross section, The antenna opening (32) is configured such that, via an opening angle (33) forming an acute angle with the normal direction, the opening is: The long side of the opening extends along the first polarization direction; or A long side of the opening extends along the second polarization direction.

5. The waveguide antenna according to claim 1, wherein: The power divider network (20) comprises: A first power distributor branch (201a), the first power distributor branch (201) having a connection port (A) connected to a waveguide transmission line (41); At least one second power divider branch (201b), the second power divider branch (201b) being connected to the first power divider branch (201a) and arranged on one side or both sides of the first power divider branch (201a) in the first polarization direction.

6. The waveguide antenna according to claim 1, wherein: The power distributor branch (201) comprises: a first impedance matching structure (202), the first impedance matching structure (202) being bent along the horizontal direction; and / or A second impedance matching structure (203), wherein the second impedance matching structure (203) is convex or concave along the normal direction, and the power divider branch (201) is connected to the polarization direction switching unit (40) via the second impedance matching structure (203).

7. The waveguide antenna according to claim 1, wherein: The invention comprises a waveguide flange (60), wherein the waveguide flange (60) is connected to a connection port (A) of the power divider network (20) via a waveguide transmission line (41), and the waveguide flange (60) comprises: A waveguide housing (61), the waveguide housing (61) having a bottom surface docked with the circuit board, and a side surface docked with the connection port (A); a waveguide connection cavity (62), the waveguide connection cavity (62) being opened in the waveguide housing (61) and having a waveguide output port (63) penetrating to the side surface, and a waveguide input port (64) penetrating to the bottom surface, the waveguide input port (64) extending along the first polarization direction or the second polarization direction; a second choke slot (65), the second choke slot (65) being recessed inward from the bottom surface and surrounding the waveguide input port (64); A short-circuit branch (66), wherein the short-circuit branch (66) is attached to both sides of the waveguide input port (64) in the extension direction of the waveguide input port (64), and the short-circuit branch (66) protrudes from the bottom surface from the second choke slot (65) or is flush with the bottom surface.

8. The waveguide antenna according to claim 7, wherein: The waveguide flange (60) is in contact with the circuit board; or The waveguide flange (60) forms a non-contact connection with the circuit board with a spacing less than or equal to a first threshold, and the first threshold is 0.2 mm.

9. The waveguide antenna according to claim 7, wherein: The length of the second choke slot (65) is 1.5 times the wavelength; and / or The length of the short-circuit branch (66) is 1 / 4 wavelength.

10. A waveguide antenna array, characterized in that: The method comprises a plurality of waveguide antennas according to any one of claims 1 to 6, wherein the plurality of waveguide antennas are arranged in an array or in a radial arrangement; a waveguide transmission line (41), the waveguide transmission line (41) being connected to a connection port (A) of the power distributor network (20); A waveguide flange (60), the waveguide flange (60) being connected to the waveguide transmission line (41), the waveguide flange (60) comprising: A waveguide housing (61), the waveguide housing (61) having a bottom surface docked with the circuit board, and a side surface docked with the connection port (A); a waveguide connection cavity (62), the waveguide connection cavity (62) being opened in the waveguide housing (61) and having a waveguide output port (63) penetrating to the side surface, and a waveguide input port (64) penetrating to the bottom surface, the waveguide input port (64) extending along the first polarization direction or the second polarization direction; a second choke slot (65), the second choke slot (65) being recessed inward from the bottom surface and surrounding the waveguide input port (64); Short-circuit branches (66), the short-circuit branches (66) being attached to both sides of the waveguide input port (64) in the extension direction of the waveguide input port (64), and the short-circuit branches (66) protruding from the second choke slot (65) to the bottom surface or being flush with the bottom surface; The plurality of waveguide flanges (60) are arranged in an array, the number of the waveguide flanges (60) corresponds one-to-one to the number of the waveguide antennas, and the extension directions of the waveguide input ports (64) of two adjacent waveguide flanges (60) are perpendicular to each other.

11. A radar antenna, characterized in that: include: The waveguide antenna array according to claim 10; A circuit board (70), the circuit board (70) being in contact with and connected to the waveguide flange (60); or The waveguide flange (60) and the circuit board (70) form a non-contact connection with a spacing less than or equal to a first threshold.

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