A square waveguide transition
By designing a hollow, symmetrical, frustum-shaped square waveguide transition device, the problems of excessive length and high processing cost of existing square waveguide transition devices are solved. This achieves excellent electrical performance and low-cost processing over a wide frequency band, making it suitable for multi-band microwave waveguide devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- THE 54TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORPORATION
- Filing Date
- 2023-03-31
- Publication Date
- 2026-06-02
AI Technical Summary
Existing square waveguide transitions suffer from excessive overall device length and high manufacturing costs when connecting square waveguide devices of different sizes, especially in low-frequency and large-size applications.
Design a square waveguide transition device consisting of an input round flange, an output round flange, and a square transition waveguide. It adopts a hollow symmetrical frustum structure and connects aluminum plates by brazing to achieve a 45° angle transition between the small square waveguide port and the large square waveguide port, simplifying the manufacturing process.
It achieves excellent electrical performance over a wide frequency band while significantly reducing device length and manufacturing costs, making it suitable for microwave waveguide devices in high, medium, and low frequency bands.
Smart Images
Figure CN116404383B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of microwave waveguide device technology, specifically relating to a square waveguide transition device, wherein the included angle between the side lengths of the two square waveguide ports is 45°. Background Technology
[0002] With the rapid development of reflector antenna technology, the requirements for electrical performance indicators such as high frequency, wide bandwidth, low loss, and high power in antenna feed systems are becoming increasingly stringent. Simultaneously, due to limitations in antenna mounting structures and manufacturing costs, the miniaturization, lightweighting, and low-cost design of feed waveguide devices have become practical problems that microwave designers need to solve. Thanks to the low loss, high power capacity, and high reliability of metallic waveguides, standard waveguides and waveguide components are widely used in the design and implementation of antenna feed systems. Transitions between waveguides and waveguide components of different apertures are achieved through waveguide transitions, such as the most common circular-square waveguide transitions, circular-rectangular waveguide transitions, and circular-circular waveguide transitions. In antenna feed systems, square waveguides, due to their broadband characteristics, are commonly used in the design of broadband waveguide devices, such as square waveguide orthogonal mode couplers and square waveguide corrugated phase shifters. For square waveguide orthogonal mode couplers operating in the same frequency band, the square waveguide size is typically smaller than that of a square waveguide corrugated phase shifter. When designing a circularly polarized feed to connect these two types of devices, the angle between the side length of the square waveguide port of the square waveguide orthogonal mode coupler and the side length of the square waveguide port of the square waveguide corrugated phase shifter is 45°. The traditional method for transitioning between these two square waveguides is to design two circular waveguides with identical ports, one large and one small square waveguide port, transitioning first from the smaller square waveguide to the circular waveguide, and then from the circular waveguide to the larger square waveguide. In situations where feed length is limited, this transition method is difficult to achieve the design goals due to the excessive overall length of the device. Furthermore, the industry currently mostly uses wire cutting of cylindrical aluminum ingots for circular-square transitions, which requires high-precision processing equipment and incurs high material and processing costs, especially for low-frequency, large-size circular-square transitions such as L and S waveguides, where the processing time and financial costs are even higher. Summary of the Invention
[0003] The purpose of this invention is to address the shortcomings of existing square waveguide transition design technologies by providing a high-performance square waveguide transition. It not only possesses a wide operating bandwidth and excellent electrical performance, but more importantly, it has a simple structure, short longitudinal length, is easy to manufacture, and is inexpensive, making it applicable to microwave waveguide devices across high, medium, and low frequency bands.
[0004] The objective of this invention is achieved through the following technical solution:
[0005] A square waveguide transition device is composed of an input circular flange 1, an output circular flange 2 and a square transition waveguide 3. The square transition waveguide 3 is a hollow symmetrical frustum structure formed by alternating arrangement of four large isosceles triangular plates 31 and four small isosceles triangular plates 32.
[0006] The bases of the four large isosceles triangular plates are on the same plane and connected to the output circular flange; the bases of the four small isosceles triangular plates are on the same plane and connected to the input circular flange; the waists of the large isosceles triangular plates are in close contact with the small isosceles triangular plates.
[0007] Furthermore, the input end of the square transition waveguide 3 is a small square waveguide port corresponding to the base of the small isosceles triangle plate, and the output end is a large square waveguide port corresponding to the base of the large isosceles triangle plate. The planes of the small square waveguide port and the large square waveguide port are parallel to each other, and the angle between their side lengths is 45°.
[0008] Furthermore, the included angle between the adjacent large isosceles triangular plate 31 and small isosceles triangular plate 32 in the inner cavity of the square transition waveguide 3 is 133.22°.
[0009] Furthermore, the input round flange 1 is a circular female flange, and the inner cavity of the input round flange 1 is a square waveguide 11; the flange connection surface of the input round flange 1 is machined with a stop groove 12 and eight circumferentially distributed first mounting holes 13; the back side of the flange connection surface of the input round flange 1 is a welding plane.
[0010] Furthermore, the output round flange 2 is a circular male flange, and the inner cavity of the output round flange 2 is a square waveguide 21; the flange connection surface of the output round flange 2 is machined with a stop platform 22 and eight circumferentially distributed second mounting holes 23; the back side of the flange connection surface of the output round flange 2 is a welding plane.
[0011] Furthermore, the small square waveguide port at the input end of the square transition waveguide 3 is connected to the square waveguide 11 on the welding plane of the input round flange 1, and the large square waveguide port at the output end of the square transition waveguide 3 is connected to the square waveguide 21 on the welding plane of the output round flange 2.
[0012] Furthermore, the input circular flange 1, the output circular flange 2, the large isosceles triangle plate 31, and the small isosceles triangle plate 32 are all made of aluminum plates.
[0013] Furthermore, the square transition waveguide 3 is connected to the input circular flange 1 and the output circular flange 2 by brazing; the large isosceles triangular plate 31 and the small isosceles triangular plate 32 are connected by brazing.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] The square waveguide transition device provided by this invention achieves excellent electrical performance over a wide frequency range while significantly reducing the device length by incorporating a hollow, symmetrical, frustum-shaped square transition waveguide 3. The square waveguide transition device can be assembled by brazing standard-shaped aluminum plates, making the entire device easy to manufacture, low in cost, and widely applicable in engineering projects. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of the present invention.
[0017] Figure 2 This is a structural diagram of the input circular flange 1 of the present invention.
[0018] Figure 3 This is a rear view of the input round flange 1 of the present invention.
[0019] Figure 4 This is a structural diagram of the output circular flange 2 of the present invention.
[0020] Figure 5 This is a rear view of the output circular flange 2 of the present invention.
[0021] Figure 6 This is a structural diagram of the square transition waveguide 3 of the present invention, showing the direction of the large square waveguide port.
[0022] Figure 7 This is a structural diagram of the square transition waveguide 3 of the present invention, showing the direction of the small square waveguide port.
[0023] Figure 8 This is a front view of the square transition waveguide 3 of the present invention, with the large waveguide port orientation.
[0024] Figure 9 This is a structural diagram of the large isosceles triangle plate 31 of the present invention.
[0025] Figure 10 This is a structural diagram of the small isosceles triangular plate 32 of the present invention.
[0026] Figure 11 These are the standing wave simulation results of this invention. Detailed Implementation
[0027] Reference Figures 1 to 10This embodiment discloses a square waveguide transition device, comprising an input circular flange 1, an output circular flange 2, and a square transition waveguide 3. It operates in the Ku band, with a working frequency of 10.7 GHz to 14.5 GHz, and a longitudinal length of 49 mm. The input circular flange 1 is a circular female flange with an outer diameter of 48 mm and a thickness of 7 mm. The inner cavity of the input circular flange 1 is a square waveguide 11 with a side length of 18 mm. The flange connection surface of the input circular flange 1 is machined with a stop groove 12 and eight circumferentially distributed mounting holes 13. The stop groove 12 has an inner diameter of 27.1 mm, an outer diameter of 33.5 mm, and a groove depth of 2.7 mm. The mounting holes 13 have a diameter of 4.2 mm and a hole spacing diameter of 39 mm. The back side of the flange connection surface of the input circular flange 1 is a welding plane. The output circular flange 2 is a circular male flange with an outer diameter of 65 mm and a thickness of 6 mm. The inner cavity of the output circular flange 2 is a square waveguide 21 with a side length of 23 mm. The flange connection surface of the output circular flange 2 is machined with a stop 22 and eight circumferentially distributed mounting holes 23. The inner diameter of the stop 22 is 34mm, the outer diameter is 40mm, and the height is 1mm. The mounting holes 23 have a diameter of 4.2mm and a spacing diameter of 51mm. The back of the flange connection surface of the output circular flange 2 is a welding surface. The square transition waveguide 3 has a diamond-like shape and is composed of four large isosceles triangular plates 31 and four small isosceles triangular plates 32. The base 311 of the large isosceles triangular plate 31 has a length of 23mm, the waist sides 312 and 313 have a length of 36.86mm, and the thickness is 3mm. The base 321 of the small isosceles triangular plate 32 has a length of 18mm, the waist sides 322 and 323 have a length of 36.86mm, and the thickness is 3mm. A large isosceles triangle plate 31 has its side 312 and a small isosceles triangle plate 32's side 322 connected by aligning their vertices. Another small isosceles triangle plate 32's side 323 is connected to the first large isosceles triangle plate 31's side 313 by aligning their vertices. These four large and four small isosceles triangle plates 32 are then combined in this alternating large and small arrangement to form a hollow, diamond-shaped, symmetrical square transition waveguide 3. The input end of the square transition waveguide 3 is a small square waveguide port with its base 321 as its side, and the output end is a large square waveguide port with its base 311 as its side. The small and large square waveguide ports are parallel to each other, 41 mm apart, and their sides form a 45-degree angle. The included angle between the faces of a pair of adjacent large isosceles triangular plates 31 and small isosceles triangular plates 32 within the cavity of the square transition waveguide 3 is 133.22°. Finally, the small square waveguide port at the input end of the square transition waveguide 3 is coincidentally connected to the square waveguide 11 on the welding plane of the input circular flange 1, and the large square waveguide port at the output end of the square transition waveguide 3 is coincidentally connected to the square waveguide 21 on the welding plane of the output circular flange 2.
[0028] The square waveguide transition device described herein includes an input circular flange 1, an output circular flange 2, a large isosceles triangular plate 31, and a small isosceles triangular plate 32, all of which are aluminum plates.
[0029] In the aforementioned square waveguide transition device, the square transition waveguide 3 is connected to the input circular flange 1 and the output circular flange 2 by brazing. The large isosceles triangular plate 31 and the small isosceles triangular plate 32 are connected by brazing.
[0030] This invention utilizes the unique structure of the square transition waveguide 3 to design a square waveguide transition device operating in the Ku band (10.7GHz~14.5GHz) of a reflector antenna. It achieves a transition from an 18mm×18mm square waveguide to a 23mm×23mm square waveguide with a 45° angle rotation, exhibiting a VSWR better than 1.05 across the entire frequency band. The newly designed square waveguide transition device has an overall longitudinal length of 49mm. Compared to the traditional circular-square transition scheme, which involves transitioning from a small-aperture square waveguide to a large-aperture square waveguide with a 45° angle rotation, the overall device length is reduced by 50%. (Refer to...) Figure 11 This demonstrates the good broadband VSWR performance of this embodiment.
[0031] The key component of this invention, the square transition waveguide 3, can be fabricated by alternately welding four large isosceles triangular plates 31 and four small isosceles triangular plates 32. During fabrication, it is only necessary to process the corresponding aluminum plates according to the specific dimensions described in this invention, and then alternately weld them. During welding, it is essential to ensure that the positioning and angle of each aluminum plate meet the dimensional requirements.
[0032] This invention allows for the fabrication of the entire device using aluminum plate brazing, which is simpler and less costly compared to the wire cutting process for round-square transitions. The benefits are particularly pronounced when applied to large-size waveguide devices in the low-frequency bands such as L and S.
[0033] The square waveguide dimensions of 18mm×18mm, 23mm×23mm and longitudinal length of 49mm of the present invention can be updated to other dimensions according to actual requirements. The device design can meet the required structural dimensions and electrical performance requirements.
[0034] Those skilled in the art will understand that the above specific embodiments are for the convenience of readers to understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific embodiments. Various modifications or scalings made by those skilled in the art based on the teachings of the disclosed technology of the present invention without departing from the essence of the present invention are still within the scope of protection of the present invention.
Claims
1. A square waveguide transition device, comprising an input circular flange (1), an output circular flange (2), and a square transition waveguide (3), characterized in that, The square transition waveguide (3) is a hollow symmetrical frustum structure formed by alternating arrangement of 4 large isosceles triangular plates (31) and 4 small isosceles triangular plates (32); The bases of the four large isosceles triangular plates are on the same plane and are connected to the output circular flange; the bases of the four small isosceles triangular plates are on the same plane and are connected to the input circular flange; the waists of the large isosceles triangular plates are in close contact with the small isosceles triangular plates. The input end of the square transition waveguide (3) is the small square waveguide port corresponding to the base of the small isosceles triangle plate, and the output end is the large square waveguide port corresponding to the base of the large isosceles triangle plate. The planes of the small square waveguide port and the large square waveguide port are parallel to each other, and the angle between their side lengths is 45°.
2. A square waveguide transition according to claim 1, characterized in that, The included angle between the adjacent large isosceles triangular plate (31) and small isosceles triangular plate (32) in the cavity of the square transition waveguide (3) is 133.22°.
3. A square waveguide transition device according to claim 1, characterized in that, The input round flange (1) is a circular female flange, and the inner cavity of the input round flange (1) is an input square waveguide (11); the flange connection surface of the input round flange (1) is machined with a stop groove (12) and eight circumferentially distributed first mounting holes (13); the back side of the flange connection surface of the input round flange (1) is a welding plane.
4. A square waveguide transition device according to claim 1, characterized in that, The output round flange (2) is a circular male flange, and the inner cavity of the output round flange (2) is an output square waveguide (21); the flange connection surface of the output round flange (2) is machined with a stop plate (22) and eight circumferentially distributed second mounting holes (23); the back of the flange connection surface of the output round flange (2) is a welding plane.
5. A square waveguide transition according to claim 2, characterized in that, The small square waveguide port at the input end of the square transition waveguide (3) is connected to the input square waveguide (11) on the welding plane of the input round flange (1), and the large square waveguide port at the output end of the square transition waveguide (3) is connected to the output square waveguide (21) on the welding plane of the output round flange (2).
6. A square waveguide transition according to claim 1, characterized in that, The input round flange (1), output round flange (2), large isosceles triangular plate (31) and small isosceles triangular plate (32) are all aluminum plates.
7. A square waveguide transition device according to claim 1, characterized in that, The square transition waveguide (3) is connected to the input round flange (1) and the output round flange (2) by brazing; the large isosceles triangular plate (31) and the small isosceles triangular plate (32) are connected by brazing.