An e-h plane waveguide transition structure

Abstract

This invention relates to an E-H plane waveguide conversion structure, comprising a housing and a first rectangular waveguide, a second rectangular waveguide, and a waveguide conversion device disposed within the housing. The first and second rectangular waveguides are horizontally placed, with the wider side of the first rectangular waveguide parallel to a reference horizontal plane and the wider side of the second rectangular waveguide perpendicular to the reference horizontal plane. The first rectangular waveguide is positioned to the left of the second rectangular waveguide, and the waveguide conversion device is disposed between the first and second rectangular waveguides. Electromagnetic waves are fed into the first rectangular waveguide, and the polarization direction of the electromagnetic waves is changed by 90° through the waveguide conversion device before propagation in the second rectangular waveguide, thereby achieving the conversion from the E-plane to the H-plane. This invention achieves mutual conversion between the E-plane and H-plane waveguides through the rational design of the structure, position, and dimensional relationship between the waveguide conversion device and the rectangular waveguides, and features a simple structure, small size, low insertion loss, and unchanged transmission direction.

Description

Technical Field

[0001] This invention relates to millimeter-wave radar technology in the field of autonomous driving, specifically to antenna and waveguide conversion technology for millimeter-wave radar, and particularly to an EH-plane waveguide conversion structure. Background Technology

[0002] In millimeter-wave radar applications, waveguide antennas are becoming increasingly common. As the performance of millimeter-wave radar continues to improve, the number of antennas also increases. However, the space available for installing millimeter-wave radar in automobiles is very limited, which imposes strict constraints on the size of the radar. From a cost perspective, millimeter-wave radar RF chips using LOP packaging are typically small in size, resulting in narrow spacing between adjacent waveguide ports on the RF chip. To lead each waveguide port of the RF chip out through waveguide traces and connect it to the antenna, H-plane waveguides (i.e., the narrow side of the waveguide is placed horizontally) are required at the narrowly spaced waveguide ports on the RF chip. This results in the simultaneous existence of E-plane and H-plane waveguide traces. Since waveguide antennas either use the same waveguide type or the same waveguide port for feeding, an EH-plane waveguide conversion structure is needed to convert all E-plane and H-plane waveguide traces to the same waveguide trace to achieve feeding of the waveguide antenna.

[0003] Existing EH-plane waveguide conversion structures have several shortcomings. One approach uses a 90° twisted waveguide for conversion, but this structure is complex, difficult to implement in millimeter-wave radar waveguide antenna wiring, and has a large size, making integration inconvenient. Another approach, while achieving EH-plane waveguide conversion, deflects the signal transmission direction by 90°. For scenarios requiring consistent signal transmission direction during EH-plane waveguide conversion, this structure is unsuitable due to its large space requirement. Therefore, there is an urgent need for an EH-plane waveguide conversion structure that is simple in structure, small in size, has low insertion loss, and can maintain consistent transmission direction. Summary of the Invention

[0004] The present invention aims to solve the problems of existing waveguide conversion structures, such as complex structure, large size which is not convenient for integration, and large space occupation caused by the deflection of signal transmission direction during the conversion process. It provides an EH plane waveguide conversion structure that is simple in structure, small in size, has low insertion loss and does not change the transmission direction.

[0005] To address the problems existing in the prior art, an EH-plane waveguide conversion structure is disclosed, including a housing and a first rectangular waveguide, a second rectangular waveguide, and a waveguide conversion device disposed within the housing. The first and second rectangular waveguides are horizontally placed, with the wider side of the first rectangular waveguide parallel to a reference horizontal plane and the wider side of the second rectangular waveguide perpendicular to the reference horizontal plane. The first rectangular waveguide is disposed to the left of the second rectangular waveguide, and the waveguide conversion device is disposed between the first and second rectangular waveguides. Electromagnetic waves entering the waveguide conversion structure are fed from the first rectangular waveguide, and the polarization direction of the electromagnetic waves is changed by 90° by the waveguide conversion device, and then transmitted in the second rectangular waveguide to achieve the conversion from the E-plane to the H-plane. The propagation direction of the electromagnetic waves is the same as the propagation direction in the first rectangular waveguide.

[0006] Furthermore, the left side wall of the first rectangular waveguide penetrates the left side of the housing, and the right side wall of the second rectangular waveguide penetrates the right side of the housing.

[0007] Furthermore, the top wall of the first rectangular waveguide and the top wall of the second rectangular waveguide are located in the same plane, and the rear sidewall of the first rectangular waveguide and the rear sidewall of the second rectangular waveguide are located in the same plane.

[0008] Furthermore, the cross-sections of the first rectangular waveguide and the second rectangular waveguide are rectangular, and the dimensions of the cross-sections are configured to support single-mode electromagnetic wave transmission within a predetermined operating frequency band.

[0009] Furthermore, the transmission frequency band of the electromagnetic wave is determined based on the cross-sectional dimensions of the first rectangular waveguide and / or the second rectangular waveguide.

[0010] Furthermore, the waveguide conversion device is a rectangular cavity, with the left side of the waveguide conversion device connected to the right side of the first rectangular waveguide, and the right side of the waveguide conversion device connected to the left side of the second rectangular waveguide.

[0011] Furthermore, the top wall three of the waveguide conversion device and the top wall two of the second rectangular waveguide are located in the same plane, and the bottom side wall two of the waveguide conversion device and the bottom side wall one of the second rectangular waveguide are located in the same plane.

[0012] Furthermore, the narrow side dimension of the waveguide conversion device is the same as the wide side dimension of the second rectangular waveguide, the narrow side dimension of the waveguide conversion device is larger than the narrow side dimension of the first rectangular waveguide, the wide side dimension of the waveguide conversion device is larger than the wide side dimension of the first rectangular waveguide, and the length of the waveguide conversion device is smaller than the narrow side dimension of the first rectangular waveguide.

[0013] Furthermore, the waveguide conversion device is movable and adjustable along the wide side direction of the waveguide conversion device. When the waveguide conversion device moves along the wide side direction of the waveguide conversion device, the offset distance of the waveguide conversion device is less than the distance between the rear sidewall of the waveguide conversion device and the rear sidewall of the first rectangular waveguide.

[0014] Furthermore, the EH surface waveguide conversion structure is an integrated structure manufactured by metallization process after CNC machining or injection molding.

[0015] The beneficial effects of the present invention include, but are not limited to: (1) The present invention can realize the mutual conversion between E-plane waveguides and H-plane waveguides by reasonably designing the waveguide conversion device and the structural, positional and dimensional relationships between rectangular waveguides, with a wide bandwidth and low insertion loss; (2) The EH-plane waveguide conversion structure designed in the present invention has a simple structure and small size, which is convenient for manufacturing and system integration; (3) The EH-plane waveguide conversion structure designed in the present invention can realize the mutual conversion between E-plane waveguides and H-plane waveguides while maintaining the transmission direction unchanged, which greatly saves waveguide routing space for specific application scenarios; (4) By using the side of the rectangular waveguide The wall penetrates the shell, forming a clear connection port, which facilitates installation and debugging, and makes electromagnetic waves enter and leave the waveguide conversion structure more smoothly, reducing signal reflection and loss at the connection point, thereby improving the quality and efficiency of signal transmission; (5) By setting the top wall of the rectangular waveguide and the top wall of the waveguide conversion device, as well as the rear side wall of the first rectangular waveguide and the rear side wall of the second rectangular waveguide, the bottom side wall of the waveguide conversion device and the bottom side wall of the second rectangular waveguide respectively in the same plane, the reflection and scattering of electromagnetic waves during transmission are reduced, thereby optimizing the signal transmission path and improving the efficiency and quality of signal transmission. Furthermore, this regular structural design makes the structure simple, the size small, and easy to process, manufacture and system integration; (6) By rationally designing the size of the waveguide cross section, only one mode of electromagnetic wave can propagate in the waveguide within a specific working frequency range, which can avoid mode interference and energy dispersion caused by multimode transmission, thereby improving the transmission efficiency and signal quality of electromagnetic waves, reducing the interaction between different modes, making the transmission of electromagnetic waves more stable, and reducing the influence of signal distortion and noise; (7) By rationally designing the size of the waveguide cross section, the requirements of electromagnetic waves in the required transmission frequency band are met, thereby meeting the requirements of different fields and different application scenarios for electromagnetic wave frequency bands. The rational selection of transmission frequency bands improves the bandwidth of the waveguide and reduces insertion loss; (8) The waveguide conversion device forms a continuous transmission channel by docking with the first rectangular waveguide and the second rectangular waveguide, reducing the reflection and loss of electromagnetic waves in the transmission process and improving the smoothness of signal transmission. Furthermore, it provides a stable and efficient environment for the polarization direction conversion of electromagnetic waves, which is conducive to improving the conversion efficiency and performance of the waveguide conversion device; (9) By adjusting the position of the waveguide conversion device, the transmission path and polarization direction conversion of electromagnetic waves can be optimized according to the actual situation, thereby improving the conversion effect and performance of the waveguide conversion device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a perspective view of the EH-plane waveguide conversion structure according to an embodiment of the present invention; Figure 2 This is a top view of the EH-plane waveguide conversion structure according to an embodiment of the present invention; Figure 3 This is a side view of the EH-plane waveguide conversion structure according to an embodiment of the present invention; Figure 4 This is a graph showing the insertion loss (S21) curve of the EH-plane waveguide conversion structure according to an embodiment of the present invention. In the figure: 1-First rectangular waveguide, 11-Top wall one, 12-Rear side wall one, 2-Second rectangular waveguide, 21-Top wall two, 22-Rear side wall two, 23-Bottom side wall one, 3-Waveguide conversion device, 31-Top wall three, 32-Rear side wall three, 33-Bottom side wall two, 4-Shell. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. In the description of the invention, it should be understood that the terms "upper," "inner," "lower," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein.

[0020] Reference Figures 1-4 In one feasible embodiment, the EH-plane waveguide conversion structure designed in this invention includes a housing 4 and a first rectangular waveguide 1, a second rectangular waveguide 2, and a waveguide conversion device 3 disposed within the housing 4. The first rectangular waveguide 1 and the second rectangular waveguide 2 are both placed horizontally. The wide side of the first rectangular waveguide 1 is parallel to the reference horizontal plane, and the wide side of the second rectangular waveguide 2 is perpendicular to the reference horizontal plane. The first rectangular waveguide 1 is disposed to the left of the second rectangular waveguide 2, and the waveguide conversion device 3 is disposed between the first rectangular waveguide 1 and the second rectangular waveguide 2. The electromagnetic wave entering the waveguide conversion structure is fed in from the left side of the first rectangular waveguide 1, and the polarization direction of the electromagnetic wave is changed by 90° through the waveguide conversion device 3, and then transmitted in the second rectangular waveguide 2. Specifically, when the electromagnetic wave is fed in from the left side of the first rectangular waveguide 1, its polarization direction is perpendicular to the wide side direction of the first rectangular waveguide 1. Since the wide side direction of the first rectangular waveguide 1 is parallel to the reference horizontal plane, its polarization direction is perpendicular to the reference horizontal plane. After entering the waveguide conversion device, the space transition of the waveguide conversion device cavity causes the polarization direction of the electromagnetic wave to naturally twist by 90° with the change of the waveguide structure, ultimately adapting to the narrow side direction of the second rectangular waveguide 2, that is, the direction parallel to the reference horizontal plane. This ultimately achieves the conversion from the E-plane to the H-plane, and the propagation direction of the electromagnetic wave is the same as the propagation direction of the first rectangular waveguide 1. It can be understood that, with reference... Figure 1The rectangular waveguide mentioned here has its wide side along the X-axis and its narrow side along the Y-axis. The EH-plane waveguide conversion structure of this invention can realize mutual conversion between E-plane and H-plane waveguides, with a wide bandwidth and low insertion loss; and while realizing mutual conversion between E-plane and H-plane waveguides, it also keeps the transmission direction unchanged, which greatly saves waveguide trace space for specific application scenarios.

[0021] Furthermore, continue to refer to Figures 1-4 The left side wall of the first rectangular waveguide 1 penetrates the left side of the housing 4, and the right side wall of the second rectangular waveguide 2 penetrates the right side of the housing 4. By having the side walls of the waveguides penetrate the housing, a clear connection port is formed, which facilitates installation and debugging, and makes electromagnetic waves enter and leave the waveguide conversion structure more smoothly, reducing signal reflection and loss at the connection point, thereby improving the quality and efficiency of signal transmission.

[0022] Furthermore, the top wall 11 of the first rectangular waveguide 1 and the top wall 21 of the second rectangular waveguide 2 are located in the same plane, and the rear side wall 12 of the first rectangular waveguide 1 and the rear side wall 22 of the second rectangular waveguide 2 are located in the same plane. The top wall 31 of the waveguide conversion device 3 and the top wall 21 of the second rectangular waveguide 2 are located in the same plane, and the bottom side wall 33 of the waveguide conversion device 3 and the bottom side wall 23 of the second rectangular waveguide 2 are located in the same plane. By setting the top wall 11 of the first rectangular waveguide 1, the top wall 21 of the second rectangular waveguide 2, and the top wall 31 of the waveguide conversion device 3, as well as the rear side wall 12 of the first rectangular waveguide 1 and the rear side wall 22 of the second rectangular waveguide 2, and the bottom side wall 33 of the waveguide conversion device 3 and the bottom side wall 23 of the second rectangular waveguide 2 in the same plane, the reflection and scattering of electromagnetic waves during transmission are reduced, thereby optimizing the signal transmission path and improving the efficiency and quality of signal transmission. Furthermore, this regular structural design makes the structure simple, the size small, and facilitates processing, manufacturing, and system integration.

[0023] Furthermore, the first rectangular waveguide 1 and the second rectangular waveguide 2 have rectangular cross-sections, and their cross-sectional dimensions are configured to support single-mode electromagnetic wave transmission within a predetermined operating frequency band. After their dimensions are rationally designed according to actual needs, only one mode of electromagnetic wave can propagate in the waveguide within a specific operating frequency range. It is understood that single-mode transmission can avoid mode interference and energy dispersion caused by multi-mode transmission, thereby improving the transmission efficiency and signal quality of electromagnetic waves, and reducing the interaction between different modes, making the transmission of electromagnetic waves more stable and reducing the impact of signal distortion and noise. In addition, the rational design of the waveguide's cross-sectional dimensions according to actual needs can also meet the requirements of the required transmission frequency band of electromagnetic waves, thus satisfying the requirements of different fields and application scenarios for electromagnetic wave frequency bands, expanding the application range of waveguide conversion structures, and the rational selection of transmission frequency bands helps to improve the bandwidth of the waveguide and reduce insertion loss. It is understood that, referring to... Figure 1 The cross-sectional dimensions mentioned here refer to the cross-sectional dimensions of a cross section parallel to the XY plane.

[0024] Furthermore, the waveguide conversion device 3 is a rectangular cavity. The left side of the waveguide conversion device 3 is connected to the right side of the first rectangular waveguide 1, and the right side of the waveguide conversion device 3 is connected to the left side of the second rectangular waveguide 2. Through its connection with the first rectangular waveguide 1 and the second rectangular waveguide 2, the waveguide conversion device 3 forms a continuous transmission channel, reducing electromagnetic wave reflection and loss during transmission and improving signal transmission smoothness. It also provides a stable and efficient environment for electromagnetic wave polarization direction conversion, which is beneficial for improving the conversion efficiency and performance of the waveguide conversion device.

[0025] Furthermore, the narrow side dimension of waveguide conversion device 3 is the same as the wide side dimension of the second rectangular waveguide 2, the narrow side dimension of waveguide conversion device 3 is larger than the narrow side dimension of the first rectangular waveguide 1, the wide side dimension of waveguide conversion device 3 is larger than the wide side dimension of the first rectangular waveguide 1, and the length of waveguide conversion device 3 is smaller than the narrow side dimension of the first rectangular waveguide 1. By rationally designing the dimensions of waveguide conversion device 3 to match the dimensions of the first rectangular waveguide 1 and the second rectangular waveguide 2, the polarization direction conversion of electromagnetic waves can be effectively realized, improving the conversion effect, optimizing the transmission path of electromagnetic waves in the waveguide conversion device, reducing signal reflection and loss, and improving the efficiency and quality of signal transmission. It is understood that, referring to... Figure 1 The wide side dimension of the rectangular waveguide and waveguide conversion device mentioned here refers to the dimension along the X-axis, the narrow side dimension refers to the dimension along the Y-axis, and the length refers to the dimension along the electromagnetic wave propagation direction (Z-axis).

[0026] Furthermore, the center of the wide side of the waveguide conversion device 3 can be aligned with or not aligned with the center of the wide side of the first rectangular waveguide 1 in the wide side direction. That is, the waveguide conversion device 3 can be moved and adjusted along the wide side direction. However, when the waveguide conversion device 3 moves along the wide side direction, the offset distance of the waveguide conversion device 3 is less than the distance between the rear sidewall of the waveguide conversion device 3 and the rear sidewall of the first rectangular waveguide 1. In other words, the rear sidewall of the waveguide conversion device 3 must not be offset inside the rear sidewall of the first rectangular waveguide 1. By movably adjusting the position of the waveguide conversion device 3, the transmission path and polarization direction conversion of electromagnetic waves can be optimized according to the actual situation, thereby improving the conversion effect and performance of the waveguide conversion device.

[0027] Furthermore, the waveguide conversion structure is an integrated structure manufactured through CNC machining or metallization after injection molding. This integrated design makes the waveguide conversion structure more robust, reducing malfunctions and performance degradation caused by component connection issues.

[0028] Preferably, in this embodiment, the first rectangular waveguide 1 has a wide side dimension of 2.54 mm and a narrow side dimension of 1.6 mm, the waveguide conversion device 3 has a wide side dimension of 3.14 mm, a narrow side dimension of 2.5 mm, and a length of 0.7 mm, and the second rectangular waveguide 2 has a wide side dimension of 2.5 mm and a narrow side dimension of 1.0 mm.

[0029] Figure 4 The figure shows the simulated insertion loss (S21) curve of the EH-plane waveguide conversion structure designed in this embodiment. As can be seen from the figure, the insertion loss of the waveguide conversion structure is less than 0.2 dB within the 74.44 GHz to 80.66 GHz frequency band. This indicates that the waveguide conversion structure has extremely low signal attenuation in this frequency band, enabling efficient transmission of electromagnetic wave signals and achieving higher signal quality and strength. Furthermore, the insertion loss of less than 0.2 dB means that there is minimal energy loss during signal transmission, thereby improving the overall system transmission efficiency and making it suitable for scenarios requiring high-quality signal transmission. The dimensions set in this embodiment allow the waveguide conversion structure to maintain good performance within a relatively wide frequency band of 74.44 GHz to 80.66 GHz, meeting the signal transmission requirements within a certain frequency range and exhibiting good bandwidth adaptability.

[0030] This invention achieves mutual conversion between E-plane and H-plane waveguides through the rational design of the waveguide conversion device and the structural, positional, and dimensional relationships between the rectangular waveguides. It offers a wide bandwidth and low insertion loss, while also simplifying the structure, reducing size, and facilitating manufacturing and system integration. Furthermore, it maintains the transmission direction while enabling mutual conversion between E-plane and H-plane waveguides, significantly saving waveguide routing space for specific applications. This invention provides a simple, compact, low-insertion-loss, and direction-invariant EH-plane waveguide conversion structure.

[0031] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. An E-H plane waveguide transition structure, characterized by, The waveguide conversion structure includes: a housing (4) and a first rectangular waveguide (1), a second rectangular waveguide (2), and a waveguide conversion device (3) disposed within the housing (4). The first rectangular waveguide (1) and the second rectangular waveguide (2) are placed horizontally. The wide side of the first rectangular waveguide (1) is parallel to a reference horizontal plane, and the wide side of the second rectangular waveguide (2) is perpendicular to the reference horizontal plane. The first rectangular waveguide (1) is disposed to the left of the second rectangular waveguide (2). The waveguide conversion device (3) is disposed between the first rectangular waveguide (1) and the second rectangular waveguide (2). Electromagnetic waves entering the waveguide conversion structure are fed from the first rectangular waveguide (1), and the polarization direction of the electromagnetic waves is changed by 90° by the waveguide conversion device (3), and then transmitted in the second rectangular waveguide (2). To achieve the conversion from the E plane to the H plane, the propagation direction of the electromagnetic wave is the same as the propagation direction in the first rectangular waveguide (1). The top wall 1 (11) of the first rectangular waveguide (1) and the top wall 2 (21) of the second rectangular waveguide (2) are located in the same plane. The rear side wall 1 (12) of the first rectangular waveguide (1) and the rear side wall 2 (22) of the second rectangular waveguide (2) are in the same plane. The waveguide conversion device (3) is a rectangular cavity. The waveguide conversion device (3) is movable and adjustable along the wide side direction of the waveguide conversion device (3). When the waveguide conversion device (3) moves along the wide side direction of the waveguide conversion device (3), the offset distance of the waveguide conversion device (3) is less than the distance between the rear side wall (32) of the waveguide conversion device and the rear side wall 1 (12) of the first rectangular waveguide.

2. The EH-plane waveguide conversion structure according to claim 1, characterized in that, The left side wall of the first rectangular waveguide (1) penetrates the left side of the housing (4), and the right side wall of the second rectangular waveguide (2) penetrates the right side of the housing (4).

3. The EH-plane waveguide conversion structure according to claim 2, characterized in that, The first rectangular waveguide (1) and the second rectangular waveguide (2) have rectangular cross-sections, and the dimensions of the cross-sections are configured to support single-mode electromagnetic wave transmission within a predetermined operating frequency band.

4. The EH-plane waveguide conversion structure according to claim 3, characterized in that, The transmission frequency band of the electromagnetic wave is determined based on the cross-sectional dimensions of the first rectangular waveguide (1) and / or the second rectangular waveguide (2).

5. The EH-plane waveguide conversion structure according to claim 1 or 2, characterized in that, The left side of the waveguide conversion device (3) is connected to the right side of the first rectangular waveguide (1), and the right side of the waveguide conversion device (3) is connected to the left side of the second rectangular waveguide (2).

6. The EH-plane waveguide conversion structure according to claim 1, characterized in that, The top wall three (31) of the waveguide conversion device (3) and the top wall two (21) of the second rectangular waveguide (2) are located in the same plane, and the bottom side wall two (33) of the waveguide conversion device (3) and the bottom side wall one (23) of the second rectangular waveguide (2) are located in the same plane.

7. The EH-plane waveguide conversion structure according to claim 1, characterized in that, The narrow side dimension of the waveguide conversion device (3) is the same as the wide side dimension of the second rectangular waveguide (2). The narrow side dimension of the waveguide conversion device (3) is greater than the narrow side dimension of the first rectangular waveguide (1). The wide side dimension of the waveguide conversion device (3) is greater than the wide side dimension of the first rectangular waveguide (1). The length of the waveguide conversion device (3) is less than the narrow side dimension of the first rectangular waveguide (1).

8. The EH-plane waveguide conversion structure according to claim 1, characterized in that, The waveguide conversion structure is an integrated structure manufactured by metallization process after CNC machining or injection molding.

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