Extremely compact bent waveguide
By using an extremely compact bent waveguide structure, the problems of low space utilization and compromised electrical performance of traditional waveguides in the high-frequency band are solved, achieving high echo suppression, broadband matching and low-loss signal transmission, which is suitable for high-density parallel feed structure applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-03-03
AI Technical Summary
In the design of parallel-fed hollow waveguide networks in the millimeter-wave band, traditional waveguide bend structures suffer from low space utilization, limited integration, and compromised electrical performance, especially in the high-frequency E-band, leading to increased standing wave ratio, increased insertion loss, and mode distortion.
The system employs an extremely compact bent waveguide structure, including an input rectangular waveguide and an output rectangular waveguide. Through the design of a chamfered transition region and a stepped matching region, it achieves direct signal transition and impedance gradient, eliminates abrupt changes in the electric field, and ensures stable signal transmission and low loss.
It achieves extremely high echo suppression and broadband matching performance at high frequencies, while significantly reducing space occupation, meeting the requirements of high-density parallel feed structures, and possessing excellent mechanical manufacturability.
Smart Images
Figure CN121602002A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of millimeter wave and microwave transmission technology, and in particular to an extremely compact bent waveguide. Background Technology
[0002] In the design of millimeter-wave parallel-fed hollow waveguide networks, the spatial orientation of the waveguide typically adopts a traditional three-stage bend pattern: "X-axis rectangular waveguide → Y-axis 90° turn → Z-axis 90° turn". While this structure can maintain the stability of the dominant mode (TE10) transmission, it has the following shortcomings in high-frequency bands (especially E-band 71–86 GHz): 1. Low space utilization: The bending path is relatively long, and each corner requires a large rounded chamfer to control reflection, which expands the overall structure volume and seriously occupies the internal layout space of the feeder network.
[0003] 2. Limited integration: In multi-channel parallel feed structures, the spacing between waveguides is limited. Traditional solutions can easily lead to excessively thin local metal walls, resulting in processing and strength risks.
[0004] 3. Electrical performance is significantly affected by bending: When the distance between bends is large, the E / H plane coupling effect accumulates, leading to increased standing wave ratio and insertion loss, especially at high frequencies where mode distortion occurs.
[0005] Therefore, there is an urgent need for a novel waveguide bend structure that can significantly shorten the spatial path while maintaining low reflection and low insertion loss, thereby enabling a high-density layout of E-band parallel feed networks. Summary of the Invention
[0006] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes an extremely compact bent waveguide.
[0007] One embodiment of the present invention provides a technical solution to solve its technical problem: an extremely compact bent waveguide, comprising an input rectangular waveguide and an output rectangular waveguide; The input rectangular waveguide is arranged along the X-axis; The output rectangular waveguide is arranged along the Z-axis and connected to the input rectangular waveguide; The output rectangular waveguide has a bottom surface, a top surface, a first wide surface, a second wide surface, a first long surface, and a second long surface, with the first long surface connected to the input rectangular waveguide; The bottom of the output rectangular waveguide is provided with a chamfered transition region and a stepped matching region. The chamfered transition region is connected to the bottom surface, the first wide surface and the second long surface. The stepped matching region is arranged in a stepped shape along the second wide surface to the first wide surface. The signal is input through the input rectangular waveguide and output through the top surface of the output rectangular waveguide.
[0008] As one of the preferred embodiments of the present invention, the angle between the chamfered transition zone and the first wide surface is set to α, where 35° < α < 45°.
[0009] In one preferred embodiment of the present invention, the stepped matching area includes fine-tuning steps and main steps arranged in a stepped manner along the second width surface to the first width surface. The depth of the fine-tuning steps is set to d1, and the depth of the main steps is set to d2. <d2。
[0010] As one of the preferred embodiments of the present invention, the depth d1 of the fine-tuning step is set to 1%–6% of the long side a of the output rectangular waveguide.
[0011] As one of the preferred embodiments of the present invention, the depth d2 of the main step is set to 15%–30% of the long side a of the output rectangular waveguide.
[0012] As one of the preferred embodiments of the present invention, the long side a of the output rectangular waveguide is set to 2.54 mm, the depth d1 of the fine-tuning step is set to 0.07 mm, and the depth d2 of the main step is set to 0.527 mm.
[0013] In one preferred embodiment of the present invention, the cross-section of the input rectangular waveguide is equal to the cross-section of the output rectangular waveguide.
[0014] The beneficial effects of this invention are as follows: An extremely compact bent waveguide includes an input rectangular waveguide and an output rectangular waveguide; the input rectangular waveguide is arranged along the X-axis; the output rectangular waveguide is arranged along the Z-axis and is connected to the input rectangular waveguide; the output rectangular waveguide has a bottom surface, a top surface, a first wide surface, a second wide surface, a first long surface, and a second long surface, the first long surface being connected to the input rectangular waveguide; a chamfered transition region and a stepped matching region are provided at the bottom of the output rectangular waveguide, the chamfered transition region being connected to the bottom surface, the first wide surface, and the second long surface, and the stepped matching region being arranged in a stepped manner along the second wide surface to the first wide surface; the signal is input from the input rectangular waveguide and then output from the top surface of the output rectangular waveguide; the above structure enables extremely high echo suppression and broadband matching performance at millimeter-wave high frequencies, while also possessing excellent mechanical manufacturability and significantly reduced space occupation, meeting the requirements of high-density parallel feed structures. Attached Figure Description
[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a first simulation diagram of a first embodiment of an extremely compact bent waveguide; Figure 2 This is a second simulation diagram of a first embodiment of an extremely compact bent waveguide; Figure 3 This is a third simulation diagram of a first embodiment of an extremely compact bent waveguide; Figure 4 This is a fourth simulation diagram of a first embodiment of an extremely compact bent waveguide; Figure 5 A comparison diagram of an ultra-compact bent waveguide and an existing bent waveguide; Figure 6 A simulation diagram of a second embodiment of an extremely compact bent waveguide; Figure 7 The reflection coefficient S of a first embodiment of an extremely compact bent waveguide in the E-band (71–86 GHz) frequency band. 11 Line graph; Figure 8 The reflection coefficient S of an ultra-compact bent waveguide in the E-band (71–86 GHz) is shown in the first embodiment of the ultra-compact bent waveguide. 21 Line graph. Detailed Implementation
[0016] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.
[0017] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0018] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are 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 this invention.
[0019] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integrally formed connection; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.
[0020] Reference Figures 1-8 An extremely compact bent waveguide includes an input rectangular waveguide 10 and an output rectangular waveguide 20; The input rectangular waveguide 10 is arranged along the X-axis; The output rectangular waveguide 20 is arranged along the Z-axis and is connected to the input rectangular waveguide 10; The output rectangular waveguide 20 has a bottom surface 21, a top surface 22, a first wide surface 23, a second wide surface 24, a first long surface 25, and a second long surface 26. The first long surface 25 is connected to the input rectangular waveguide 10. The bottom of the output rectangular waveguide 20 is provided with a chamfered transition region 30 and a stepped matching region 40. The chamfered transition region 30 is connected to the bottom surface 21, the first wide surface 23 and the second long surface 26. The stepped matching region 40 is arranged in a stepped shape along the second wide surface 24 toward the first wide surface 23. The signal is input through the input rectangular waveguide 10 and output through the top surface 22 of the output rectangular waveguide 20.
[0021] Reference Figures 1-4 This invention relates to the field of millimeter wave and microwave transmission technology, specifically to an extremely compact bent waveguide that addresses the technical pain points of traditional bent waveguides in E-band (71–86 GHz) parallel-fed hollow waveguide networks, such as large size, low integration, and compromised electrical performance. The following detailed description is provided in conjunction with specific embodiments, working principles, and relative positions of components.
[0022] The ultra-compact bent waveguide of this invention mainly consists of an input rectangular waveguide 10, an output rectangular waveguide 20, a chamfered transition region 30, and a stepped matching region 40, wherein: The spatial relative positions of the input rectangular waveguide 10 and the output rectangular waveguide 20 are as follows: The input rectangular waveguide 10 extends along the X-axis, with its axis coinciding with the X-axis, serving as the first straight waveguide for signal input; the output rectangular waveguide 20 extends along the Z-axis, with its axis coinciding with the Z-axis, serving as the second straight waveguide for signal output; the input rectangular waveguide 10 and the output rectangular waveguide 20 are spatially perpendicular, and their axes (X-axis and Z-axis) are perpendicular to each other in three-dimensional space and do not intersect. Physical connection and signal transmission are achieved through the first long surface 25 of the output rectangular waveguide 20, forming a direct turning path from X-axis input to Z-axis output, eliminating the intermediate transition section in the Y-axis direction in traditional structures; the cross-sectional dimensions of the input rectangular waveguide 10 and the output rectangular waveguide 20 are completely identical, ensuring no reflection loss caused by abrupt changes in cross-section during signal transmission; (refer to...) Figures 1-4 The dashed arrow indicates the direction of signal propagation.
[0023] Relative position of the chamfered transition region 30: The chamfered transition region 30 is located at the bottom of the output rectangular waveguide 20, specifically at the intersection corner of the bottom surface 21, the first wide surface 23 and the second long surface 26, which is a transition structure connecting the output end of the input rectangular waveguide 10 and the input end of the output rectangular waveguide 20; Refer to Figure 2 and Figure 4 , preferably, the inclined surface 31 of the chamfered transition region 30 is seamlessly connected to the bottom surface 21, the first wide surface 23 and the second long surface 26 at the same time. The included angle α between the inclined surface 31 and the first wide surface 23 satisfies 35° < α < 45°, covering the path turning angle of the signal incoming from the input rectangular waveguide 10, and realizing the smooth transition of the electric field.
[0024] Relative position of the stepped matching region 40: The stepped matching region 40 is also arranged at the bottom of the output rectangular waveguide 20, located on one side of the chamfered transition region 30, and extends in a stepped shape along the second wide surface 24 of the output rectangular waveguide 20 towards the first wide surface 23; Refer to Figures 1-4 , the stepped matching region 40 includes fine-tuning steps 41 and main steps 42 arranged in a stepped shape along the second wide surface 24 towards the first wide surface 23. The depth of the fine-tuning step 41 is set as d1, and the depth of the main step 42 is set as d2, where d1 < d2; Further, both the fine-tuning step 41 and the main step 42 are parallel to the extension direction X-axis of the input rectangular waveguide 10, and the end faces of the steps are parallel to the top surface 22 of the output rectangular waveguide 20. The depth directions of the two steps are perpendicular to the second wide surface 24, forming an impedance gradient structure along the signal transmission path; Preferably, the depth d1 of the fine-tuning step 41 is set to 1% - 6% of the long side a of the output rectangular waveguide 20, and the depth d2 of the main step 42 is set to 15% - 30% of the long side a of the output rectangular waveguide 20.
[0025] The core design logic of the present invention is to achieve the compact and low-loss transmission of high-frequency signals through path simplification + structure optimization. The specific working principle is as follows: The signal directly enters from the input rectangular waveguide 10 on the X-axis, directly turns to the output rectangular waveguide 20 on the Z-axis along the turning area, omitting the intermediate Y-axis transition section, and greatly compressing the volume in terms of spatial layout; The chamfered transition region 30 at the bottom of the output rectangular waveguide 20 eliminates the sudden change of the electric field at the corner through the inclined surface 31, reduces the E / H plane coupling effect, and suppresses TE 20 / TE 01 and other high-order mode excitations, ensuring the transmission purity of the main mode TE 10 .
[0026] The two steps of the stepped matching region 40 work in cooperation. The fine-tuning step d1 adjusts the reflection phase through perturbation to smooth the change of the electric field slope; The main step d2 completes the core impedance conversion, and the two cooperate to achieve the impedance continuous transition within the broadband, and finally achieve extremely high return loss (|S 11|<–35dB) and ultra-low insertion loss (<0.002dB).
[0027] Structure and process compatibility: All dimensions are designed to be compatible with CNC precision milling process to ensure that the metal wall thickness is ≥0.3mm. The compact structure balances mechanical strength and processing feasibility, avoiding the risk of thin-walled fracture or deformation.
[0028] Reference Figures 1-4 In the standard E-band frequency band adaptation scheme: 1) The cross-sections of the input rectangular waveguide 10 and the output rectangular waveguide 20 are the same, with the long side a = 2.54 mm (fitting the standard size of the E-band frequency band); 2) The angle α between the chamfered transition region 30 and the first wide surface 23 is preferably set to 40°; 3) The stepped matching region 40 includes a fine-tuning step 41 and a main step 42: the depth of the fine-tuning step d1 = 0.07 mm, which is about 2.76% of the long side a, and the depth of the main step d2 = 0.527 mm, which is about 20.75% of the long side a. The two steps are arranged in a stepped manner along the second wide surface 24 toward the first wide surface 23.
[0029] Reference Figures 7-8 Simulation results using CSTMicrowaveStudio demonstrate the following performance across the entire E-band (71–86 GHz): Reflection coefficient S 11 ≤-35dB, up to -48dB, with significant echo suppression effect; Insertion loss S 21 ≤0.0014dB, signal energy loss is negligible; Mode purity: No obvious higher-order mode distortion; Frequency band adaptation: When adapting to other high-frequency bands such as D-band and W-band, the depth of fine-tuning step d1 and main step d2 can be adjusted by 1%–6% of the long side a and 15%–30% of the long side a. The angle α between the chamfered transition area 30 slope 31 and the first wide surface 23 is optimized within the range of 35°–45°.
[0030] Reference Figures 1-5 This is a comparison diagram of the ultra-compact bent waveguide provided by the present invention and an existing bent waveguide. The input rectangular waveguide 10 of the ultra-compact bent waveguide coincides with the input rectangular waveguide of the existing bent waveguide. Figure 5The dashed box A includes the Y-axis turning segment 50, the Z-axis output rectangular waveguide 60, the first circular arc matching segment 70 connecting the input rectangular waveguide of the existing curved waveguide and the turning segment 50, and the second circular arc matching segment 80 connecting the turning segment of the existing curved waveguide and the output rectangular waveguide 60. As shown in the figure, the ultra-compact curved waveguide provided by the present invention significantly reduces the space occupied. Specifically, the volume of the ultra-compact curved waveguide provided by the present invention is approximately 28.42 mm³, while the volume of the existing curved waveguide is approximately 149.28 mm³. The present invention reduces the volume by approximately 520%, demonstrating a significant advantage in compactness.
[0031] Reference Figures 1-6 This invention provides an arrangement of multiple extremely compact bent waveguides in a parallel-fed hollow waveguide network, enabling higher density feed integration.
[0032] As can be seen from the above embodiments, the present invention achieves a combination of advantages in high echo suppression, broadband matching, compact size, and easy processing in the millimeter-wave high-frequency band through path simplification, composite design of chamfered transition region 30 and stepped matching region 40, and precise relative position layout of components. It fully meets the application requirements of high-density parallel feed structure and can be widely used in E-band millimeter-wave communication, phased array antenna feed, vehicle radar and modular waveguide system for test instruments.
[0033] The advantages of this invention are: the above structure can achieve extremely high echo suppression and broadband matching performance at millimeter-wave high frequencies, while also having excellent mechanical manufacturability and significantly reduced space occupation, meeting the requirements of high-density parallel feed structure.
[0034] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.
Claims
1. An extremely compact bent waveguide, characterized in that: It includes an input rectangular waveguide (10) and an output rectangular waveguide (20); The input rectangular waveguide (10) is arranged along the X-axis; The output rectangular waveguide (20) is arranged along the Z-axis and is connected to the input rectangular waveguide (10); The output rectangular waveguide (20) has a bottom surface (21), a top surface (22), a first wide surface (23), a second wide surface (24), a first long surface (25), and a second long surface (26), wherein the first long surface (25) is connected to the input rectangular waveguide (10); The bottom of the output rectangular waveguide (20) is provided with a chamfered transition region (30) and a stepped matching region (40). The chamfered transition region (30) is connected to the bottom surface (21), the first wide surface (23) and the second long surface (26). The stepped matching region (40) is arranged in a stepped manner along the second wide surface (24) toward the first wide surface (23). The signal is input through the input rectangular waveguide (10) and output through the top surface (22) of the output rectangular waveguide (20).
2. The ultra-compact bent waveguide according to claim 1, characterized in that: The angle between the chamfered transition area (30) and the first wide surface (23) is set to α, where 35° < α < 45°.
3. The ultra-compact bent waveguide according to claim 1, characterized in that: The stepped matching area (40) includes a fine-tuning step (41) and a main step (42) arranged in a stepped manner along the second width surface (24) toward the first width surface (23). The depth of the fine-tuning step (41) is set to d1, and the depth of the main step (42) is set to d2. <d2。 4. The ultra-compact bent waveguide according to claim 3, characterized in that: The depth d1 of the fine-tuning step (41) is set to 1%–6% of the long side a of the output rectangular waveguide (20).
5. The ultra-compact bent waveguide according to claim 3, characterized in that: The depth d2 of the main step (42) is set to 15%–30% of the long side a of the output rectangular waveguide (20).
6. The ultra-compact bent waveguide according to claim 3, characterized in that: The long side a of the output rectangular waveguide (20) is set to 2.54 mm, the depth d1 of the fine-tuning step (41) is set to 0.07 mm, and the depth d2 of the main step (42) is set to 0.527 mm.
7. The ultra-compact bent waveguide according to claim 1, characterized in that: The cross-section of the input rectangular waveguide (10) is equal to the cross-section of the output rectangular waveguide (20).