A ridged power divider structure and waveguide antenna

Abstract

This invention relates to a waveguide antenna, comprising a waveguide channel, the waveguide channel including a waveguide input cavity, a waveguide power divider cavity, a T-ridge power divider, and multiple radiation slots. The waveguide power divider cavity extends from the distal end of the waveguide input cavity to both sides. The T-ridge power divider is placed within the waveguide input cavity and the waveguide power divider cavity and integrates impedance adjustment and power division. The multiple radiation slots communicate with the waveguide power divider cavity and are positioned above the waveguide power divider cavity.

Description

Technical Field

[0001] This invention relates to the field of waveguide devices and antenna technology, and more specifically to a ridged power divider structure and a waveguide antenna. Background Technology

[0002] Conventional millimeter-wave radar antennas typically employ a rectangular cavity waveguide structure, lacking external independent matching components and power dividers. The core functionality—electromagnetic wave transmission, power division, impedance matching, and radiation—is achieved through an internal cavity structure. This type of conventional millimeter-wave radar antenna uses a rectangular cavity as its basic structure, with a diaphragm structure (usually a rectangular block protrusion) embedded within the cavity's edge as its core internal structure. This diaphragm structure controls impedance matching within the cavity, while simultaneously regulating signal power division and current distribution, thereby completing energy distribution through the radiation slots. The overall structure consists of a waveguide input cavity, a waveguide power divider cavity, and radiation slots. The diaphragm structure is symmetrically arranged along the cavity's central plane, and the radiation slots are evenly distributed above the cavity, ultimately achieving electromagnetic wave radiation at a specific frequency band and fixed elevation angle.

[0003] However, conventional millimeter-wave radar antennas rely on diaphragm structures to control impedance matching. The impedance matching range is narrow and the bandwidth adaptation capability is insufficient, which cannot meet the multi-band detection requirements of millimeter-wave radar. Furthermore, the rectangular cavity of conventional millimeter-wave radar antennas can only suppress sidelobes at a fixed elevation angle by adjusting the current inside the cavity through the diaphragm structure. The sidelobe level increases when radiating at multiple angles. In addition, the conventional diaphragm structure has low utilization efficiency of the internal space of the cavity, and the cavity structure is not compact enough, making it difficult to achieve a high-density compact arrangement with an antenna spacing of one wavelength. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a ridged power divider structure and waveguide antenna. Without external independent matching or power divider components, and achieving power division and impedance matching solely within the cavity, it integrates impedance regulation and energy distribution through a T-shaped ridge power divider structure. This directly eliminates the need for the conventional rectangular cavity's internal diaphragm structure, avoiding additional structural elements and the manufacturing difficulties associated with the coexistence of diaphragms and power dividers. It significantly improves impedance matching bandwidth and low sidelobe performance while ensuring simple and feasible fabrication. Furthermore, the simplified structure significantly reduces the overall antenna size, breaking through the limitations of conventional waveguide antenna layouts. High-density arrangement within a single wavelength spacing is possible, something conventional designs cannot achieve. Optimized impedance matching and current regulation within the cavity enable wideband, multi-angle low sidelobe radiation, while simultaneously improving the efficiency of internal cavity space utilization, reducing manufacturing difficulty, and achieving a high-density, compact arrangement with an antenna spacing of one wavelength.

[0005] Therefore, one aspect of the present invention provides a waveguide antenna including a waveguide channel, the waveguide channel including a waveguide input cavity, a waveguide power divider cavity, a T-ridge power divider and a plurality of radiation slots, the waveguide power divider cavity extending from the far end of the waveguide input cavity to both sides, the T-ridge power divider cavity being disposed within the waveguide input cavity and the waveguide power divider cavity and integrating impedance adjustment and power division, the plurality of radiation slots communicating with the waveguide power divider cavity and disposed above the waveguide power divider cavity.

[0006] According to one aspect of the invention, the plurality of radiating slots are disposed above the waveguide power divider cavity at an offset from each other. The plurality of radiating slots are arranged in pairs symmetrically about the center plane of the H-plane of the waveguide input cavity. The first pair of radiating slots is offset toward the waveguide input cavity; the second pair of radiating slots is offset away from the waveguide input cavity; the third pair of radiating slots is offset toward the waveguide input cavity again; the fourth pair of radiating slots is offset away from the waveguide input cavity again, and so on.

[0007] According to one aspect of the invention, the further away from the center plane of the H-plane of the waveguide input cavity, the smaller the offset of each pair of radiation slots relative to the center plane of the H-plane of the waveguide power divider cavity.

[0008] According to one aspect of the invention, the near end of the waveguide input cavity forms a waveguide feed port as an electromagnetic wave input port, the waveguide power splitter cavity is arranged symmetrically perpendicular to the H-plane center plane of the waveguide input cavity, and is connected to the far end of the waveguide input cavity to form a T-shaped power splitter junction, the H-plane center plane of the waveguide power splitter cavity is perpendicular to the H-plane center plane of the waveguide input cavity.

[0009] According to one aspect of the present invention, the T-shaped ridge power divider includes a first power divider branch and a second power divider branch, the first power divider branch and the second power divider branch being symmetrically arranged along the H-plane center plane of the waveguide input cavity, and the second power divider branch being further symmetrically arranged along the H-plane center plane of the waveguide power divider cavity.

[0010] According to one aspect of the invention, the lateral spacing of the plurality of radiation slots is close to or the same, approximately equal to 1 / 2 of the waveguide wavelength of the waveguide power divider cavity.

[0011] According to one aspect of the present invention, the long and short side dimensions of the cross-section of the waveguide power divider cavity both meet the general requirements for the cutoff wavelength of the TE10 mode pair in the waveguide.

[0012] According to one aspect of the invention, the long side width of the waveguide input cavity is greater than the long side width of the waveguide power divider cavity, and the E-plane heights of the two are the same.

[0013] According to one aspect of the invention, the length of the waveguide power divider cavity is approximately equal to half of its corresponding waveguide wavelength multiplied by the number of the radiation slots in its projection area.

[0014] According to one aspect of the invention, the length of the second branch of the T-shaped ridge power divider is slightly less than or equal to the length of the waveguide power divider cavity. Attached Figure Description

[0015] The accompanying drawings, which illustrate different embodiments of the present invention, are described below. It should be understood that the drawings are not necessarily drawn to scale, and in all the drawings, the same reference numerals denote the same or similar parts or structures.

[0016] Figure 1 This is a three-dimensional view of the waveguide antenna according to the present invention; Figure 2 yes Figure 1 A three-dimensional view of the waveguide channel in a waveguide antenna; Figure 3 yes Figure 2 Top view of the waveguide channel; Figure 4 yes Figure 2 A top view of the waveguide channel, which specifically shows the configuration of multiple waveguide slots; Figure 5 An example arrangement of the waveguide antenna according to the present invention is shown; Figure 6 A graph showing the S11 parameters of the waveguide antenna according to the present invention as a function of frequency is shown. Figure 7 The radiation gain distribution of the waveguide antenna according to the present invention at different angles is shown. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions of embodiments are intended only to aid in understanding the present invention and do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] The embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that the positional relationships between the various components in the present invention are described with reference to the horizontal and vertical directions shown in the accompanying drawings.

[0019] Reference Figure 1 and Figure 2 , Figure 1 A perspective view of a waveguide antenna 1 according to the present invention is shown, as shown in the figure, the waveguide antenna 1 includes a waveguide channel 2. Figure 2 yes Figure 1The figure shows a three-dimensional view of the waveguide channel 2 in the waveguide antenna 1. The waveguide channel 2 includes a waveguide input cavity 21, a waveguide power divider cavity 22, a T-shaped ridge power divider 23, and multiple radiation slots 25. As shown, the near end of the waveguide input cavity 21 is open to form a waveguide feed port 212 as an electromagnetic wave input port. The waveguide power divider cavity 22 extends vertically to both sides from the far end of the waveguide input cavity 21, thus forming a T-shaped cavity structure together. The T-shaped ridge power divider 23 is disposed within the T-shaped cavity structure formed by the waveguide input cavity 21 and the waveguide power divider cavity 22. The T-shaped ridge power divider 23 includes a first power divider branch 231 and a second power divider branch 232. The second power divider branch 232 extends vertically to both sides from the far end of the first power divider branch 231 to form the T-shaped ridge power divider. When the T-shaped power divider 23 is disposed within the waveguide input cavity 21 and the waveguide power divider cavity 22, the extension direction of the first power divider branch 231 is consistent with the extension direction of the waveguide input cavity 21, and the extension direction of the second power divider branch 232 is consistent with the extension direction of the waveguide power divider cavity 22. Multiple radiation slots 25 are connected to the waveguide power divider cavity 22 and are disposed offset from each other above the waveguide power divider cavity 22 to radiate signals outward.

[0020] This invention integrates impedance adjustment and power distribution into a T-shaped ridge power divider structure, directly eliminating the need for the diaphragm structure inside a conventional rectangular cavity. This avoids the difficulties in fabrication caused by the coexistence of the diaphragm and power divider components, significantly improving impedance matching bandwidth and low sidelobe performance while ensuring simple and feasible fabrication. At the same time, the overall size of the antenna is greatly reduced, enabling high-density arrangement within a single wavelength interval, a layout that conventional waveguide antennas cannot achieve due to size and structural limitations.

[0021] This invention introduces a T-shaped ridge power divider 23 to optimize the power distribution and impedance matching within the cavity, reducing antenna size and improving compactness. This allows for a high-density, compact arrangement with an antenna spacing of one wavelength, while simultaneously reducing manufacturing complexity and production costs. Furthermore, by replacing the conventional diaphragm structure with the T-shaped ridge power divider 23, sidelobe suppression can be achieved over a wide elevation angle range, thereby enabling low sidelobe radiation at multiple angles. In addition, by forming a T-shaped cavity structure together with the waveguide input cavity 21 and the waveguide power divider cavity 22, and arranging the T-shaped ridge power divider 23 within this T-shaped cavity structure, the internal space utilization efficiency of the cavity is improved, and the manufacturing difficulty is reduced.

[0022] Reference Figure 3 and Figure 4 , Figure 3 It shows Figure 2 A top view of the waveguide channel. For ease of explanation later, we will use the center plane of the H-plane of the waveguide input cavity 21 as the first center plane 211, and the center plane of the H-plane of the waveguide power divider cavity 22 as the second center plane 221. The first center plane 211 and the second center plane 221 are perpendicular to each other. Figure 3As shown, when the T-shaped ridge power divider 23 is set in the waveguide input cavity 21 and the waveguide power divider cavity 22, the first power divider branch 231 and the second power divider branch 232 of the T-shaped ridge power divider 23 are symmetrically arranged along the first central plane 211, and the second power divider branch 232 is further symmetrically arranged along the second central plane 221. Figure 4 The specific illustration shows the configuration of multiple waveguide slots 25, which are arranged symmetrically in pairs about a first central plane 211. Figure 4 As can be seen, starting from both sides of the first central plane 211, the first pair of radiation slots 25A are offset towards the waveguide input cavity 21, meaning that most of them are located in the waveguide. Figure 4 Below the second center plane 221; the second pair of radiation slots 25B are offset away from the waveguide input cavity 21, that is, mostly located below the second center plane 221. Figure 4 Above the second central plane 221, although Figure 4 Only two pairs of radiating slots 25 are shown, but more pairs can be provided. For example, at a position further away from the first central plane 211, a third pair of radiating slots (not shown) can be offset closer to the waveguide input cavity, and a fourth pair of radiating slots (not shown) can be offset further away from the waveguide input cavity, and so on. Furthermore, the further away from the first central plane 211 of the waveguide input cavity 21, the smaller the offset of each pair of radiating slots 25 relative to the second central plane 221 of the waveguide power divider cavity 22. Specifically, as... Figure 4 As shown, starting from both sides of the first central plane 211, the second pair of radial slots 25B has a smaller offset relative to the second central plane 221 compared to the first pair of radial slots 25A. Figure 4 As can be seen, the lower side of the second pair of radial slots 25B has a smaller offset relative to the second central plane 221 than the upper side of the first pair of radial slots 25B, meaning it is closer to the second central plane 221. In other words, the central plane 251 of the second pair of radial slots 25 is closer to the second central plane 221 than the central plane 251 of the first pair of radial slots 25. Although Figure 4 Not shown, but as previously described, more pairs of radiating slots can be provided, such as a third pair and a fourth pair of radiating slots located further away from the first central plane 211. The third pair of radiating slots has a smaller offset relative to the second central plane 221 than the second pair of radiating slots 25B, and the fourth pair of radiating slots has a smaller offset relative to the second central plane 221 than the third pair of radiating slots, and so on.

[0023] This offset setting of the radiating slot 25 results in a larger offset near the center line, leading to higher radiation intensity, while the offset of slots further away from the center line decreases, gradually reducing radiation intensity. This effectively suppresses sidelobe levels in the radiation pattern, avoids signal interference and energy waste, improves the directivity and gain of the main lobe, and allows for smooth energy distribution along the array, reducing local energy abrupt changes, lowering the reflection coefficient, achieving better impedance matching over a wider frequency band, and improving antenna efficiency and stability.

[0024] According to one embodiment, the lateral spacing of the plurality of radiation slots 25 is close to or the same, approximately equal to half the waveguide wavelength of the waveguide power divider cavity 22.

[0025] According to one embodiment, the long and short side dimensions of the waveguide power divider cavity 22 both meet the general requirements for the cutoff wavelength of the waveguide TE10 mode pair.

[0026] According to one embodiment, the long side width of the waveguide input cavity 21 is greater than the long side width of the waveguide power divider cavity 22, and the E-plane heights of the two are the same.

[0027] According to one embodiment, the length of the waveguide power divider cavity 22 is approximately equal to half of its corresponding waveguide wavelength multiplied by the number of radiation slots 25 in its projection area.

[0028] According to one embodiment, the length of the second branch of the T-shaped ridge power divider 23 is slightly less than or equal to the length of the waveguide power divider cavity 22.

[0029] Figure 5 shows an example arrangement of waveguide antennas according to the present invention, wherein two waveguide antennas 1 are arranged back-to-back side-by-side with waveguide power divider cavities 22, and the distance between the second center planes of the two waveguide power divider cavities 22 is one free space wavelength. This shows that the antenna structure is compact and can be arranged with an antenna spacing of one free space wavelength, and its specific arrangement is not limited to this.

[0030] Figure 6 A graph showing the S11 parameter of the waveguide antenna according to the present invention as a function of frequency is shown. The waveguide antenna of the present invention exhibits a return loss S11 of less than -25dB in the 76-81GHz frequency band, demonstrating excellent standing wave characteristics and impedance matching robustness.

[0031] Figure 7 The diagram shows the radiation gain distribution of the waveguide antenna according to the present invention at different angles. The waveguide antenna of the present invention has a sidelobe level of less than -21dB, with significant sidelobe suppression effect, achieving a synergistic improvement in wideband low VSWR and high anti-interference directional radiation.

[0032] The advantages of the waveguide antenna of the present invention are as follows: 1. Effectively expands the effective operating bandwidth of the antenna to meet the multi-band detection requirements of millimeter-wave radar and significantly reduces signal reflection; 2. Achieve low sidelobe horizontal radiation under multi-angle radiation in the antenna elevation direction; 3. Improve the efficiency of internal space utilization in the cavity, achieve a high-density and compact arrangement with an antenna spacing of one wavelength, replace the diaphragm structure with a T-shaped ridge integrated power divider, avoid the additional structure, avoid the processing difficulties caused by the coexistence of the diaphragm and the power divider, simplify the cavity processing procedure, improve production efficiency and product yield, and reduce production costs; 4. Reduce the antenna's sensitivity to manufacturing errors in structural dimensions, optimize production processes, improve design iteration efficiency, and quickly adapt to the technical requirements of different millimeter-wave radar antenna application scenarios; 5. The power divider and impedance matching are integrated within the cavity, eliminating the need for any external components, maintaining the simplicity of cavity assembly, and improving the overall reliability of the product.

[0033] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, 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 limiting the scope of protection of this invention.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments.

[0035] For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A waveguide antenna, comprising a waveguide channel, the waveguide channel including a waveguide input cavity, a waveguide power divider cavity, a T-ridge power divider, and a plurality of radiation slots, the waveguide power divider cavity extending from the distal end of the waveguide input cavity to both sides, the T-ridge power divider cavity being disposed within the waveguide input cavity and the waveguide power divider cavity and integrating impedance adjustment and power division, the plurality of radiation slots communicating with the waveguide power divider cavity and disposed above the waveguide power divider cavity.

2. The waveguide antenna as described in claim 1, wherein, The plurality of radiating slots are offset from each other above the waveguide power divider cavity. The plurality of radiating slots are arranged in pairs symmetrically with respect to the center plane of the H-plane of the waveguide input cavity. The first pair of radiating slots is offset toward the waveguide input cavity; the second pair of radiating slots is offset away from the waveguide input cavity; the third pair of radiating slots is offset toward the waveguide input cavity again; the fourth pair of radiating slots is offset away from the waveguide input cavity again, and so on.

3. The waveguide antenna as described in claim 2, wherein, The further away from the center plane of the H-plane of the waveguide input cavity, the smaller the offset of each pair of radiation slots relative to the center plane of the H-plane of the waveguide power divider cavity.

4. The waveguide antenna as described in claim 1, wherein, The near end of the waveguide input cavity forms a waveguide feed port as an electromagnetic wave input port. The waveguide power splitter cavity is arranged symmetrically with respect to the center plane of the H-plane of the waveguide input cavity and is connected to the far end of the waveguide input cavity to form a T-shaped power splitter junction. The center plane of the H-plane of the waveguide power splitter cavity is perpendicular to the center plane of the H-plane of the waveguide input cavity.

5. The waveguide antenna as described in claim 1, wherein, The T-shaped ridge power divider includes a first power divider branch and a second power divider branch. The first power divider branch and the second power divider branch are symmetrically arranged along the center plane of the H-plane of the waveguide input cavity, and the second power divider branch is further symmetrically arranged along the center plane of the H-plane of the waveguide power divider cavity.

6. The waveguide antenna as claimed in claim 1, wherein, The lateral spacing of the plurality of radiation slots is close to or the same, approximately equal to 1 / 2 of the waveguide wavelength of the waveguide power divider cavity.

7. The waveguide antenna as claimed in claim 1, wherein, The long and short side dimensions of the waveguide power divider cavity both meet the general requirements for the cutoff wavelength of the TE10 waveguide mode pair.

8. The waveguide antenna as claimed in claim 1, wherein, The long side width of the waveguide input cavity is greater than the long side width of the waveguide power divider cavity, and the E-plane heights of the two are the same.

9. The waveguide antenna as claimed in claim 1, wherein, The length of the waveguide power divider cavity is approximately equal to half of its corresponding waveguide wavelength multiplied by the number of radiation slots in its projection area.

10. The waveguide antenna as claimed in claim 1, wherein, The length of the second branch of the T-shaped ridge power divider is slightly less than or equal to the length of the waveguide power divider cavity.

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