waveguide

Abstract

The present invention relates to a waveguide (1) consisting of two waveguide parts (11, 12). Each waveguide part (11, 12) has a waveguide body (111, 121) and at least one waveguide channel (10) portion (110, 120), the portions (110, 120) being arranged so that, when the two waveguide parts (11, 12) are joined, they form at least one waveguide channel (10). The opposing surfaces (112, 122) of the two waveguide parts are formed parallel to each other. Recesses (2, 23-26) are formed in the sidewalls (114, 124) of the waveguide channel (10). The width (b) and height (h) of the recesses (2, 23-26) are substantially smaller than half the wavelength of the signal for which the at least one waveguide channel (10) is designed.

Description

Technical Field

[0001] The present invention relates to a waveguide composed of two waveguide components to be joined. Each waveguide component has at least a portion of one waveguide channel (i.e., a portion of one waveguide channel or portions of multiple waveguide channels), particularly the upper or lower half of at least one waveguide channel. The waveguide components are joined, for example, by welding, adhesion, screwing, etc. After the waveguide components are joined, they form at least one waveguide channel. The opposing surfaces of the two waveguide components are formed parallel to each other.

[0002] Furthermore, the present invention relates to a system including a waveguide and a further waveguide or a circuit board. The waveguide has a waveguide channel, and the waveguide channel is connected to a further waveguide or a circuit board at its output. The connection is realized, for example, by welding, adhesion, or screwing. The surface of the waveguide at the exit of the waveguide channel, which is connected to each other, and the surface of the further waveguide or the surface of the circuit board are formed parallel to each other.

Background Art

[0003] For example, a waveguide is produced by forming two waveguide components and then joining them. Each waveguide component has a waveguide body, and at least a portion of one waveguide channel is processed on the waveguide body by a method known per se, such as milling or injection molding. Then, the two waveguide components are joined at their waveguide bodies to produce a strong connection. During joining, the portions of at least one waveguide channel are aligned vertically and combined into at least one waveguide channel. The joining is performed by methods such as screwing, adhesion, press-fitting, welding, etc.

[0004] At junctions, leakage of electromagnetic waves transmitted within the waveguide can occur. This is due to the interruption of the current path at the surface by incomplete galvanic contact. From Montgomery et al.'s "Principles of Microwave Circuits," Stevenage: IET, 1987, it is known that waveguides can be divided in regions where little current flows, or ideally, no current flows at all. In a rectangular waveguide, for example, this region is located in the center of the longer side with respect to the fundamental mode. When the waveguide is divided in this region, symmetry is largely maintained, and leakage does not occur even if there is incomplete galvanic contact between the two waveguide components, for example, by bonding or press-fitting.

[0005] However, even this cannot completely prevent leakage. Even if the waveguide design is perfectly symmetrical (which is usually not the case due to curvature and components such as transistors), small defects and manufacturing tolerances will result in a slightly asymmetric waveguide, which will cause at least a small amount of energy leakage between waveguide components. However, if the asymmetry is small, the leakage will also be small, so when the asymmetry is small enough, leakage can be ignored depending on the application.

[0006] Typically, a gap remains between waveguide bodies. The aligned surfaces of the waveguide bodies extend parallel to each other and can be considered as the parallel plates of a parallel-plate capacitor. Even a very small amount of leakage can cause excitation of parallel-plate modes between the parallel surfaces of the waveguide bodies of the waveguide component. As long as the energy is sufficiently small, the leakage can be ignored. However, the excitation can cause resonance within the gap between the two waveguide bodies of the waveguide component or between adjacent waveguide channels. Resonance can significantly increase the energy of the parallel-plate modes, which leads to a decrease in the modes propagating within the waveguide. As a result, leakage increases and the performance of the waveguide (or waveguide antenna using the waveguide) deteriorates. The occurrence of resonance depends on the frequency used, as well as the geometric boundary conditions of the waveguide and the gap between the waveguide components. This can render the waveguide design unusable or necessitate welding during joining.

[0007] Electromagnetic leakage can also occur when a waveguide is connected to another waveguide or circuit board. Here, the waveguide does not necessarily have to consist of two waveguide components as described above. Typically, a gap remains between the waveguide bodies. The surfaces of the waveguide and the surfaces of the other waveguide or circuit board extend parallel to each other at the connection point and can be considered as the parallel plates of a parallel plate capacitor. Even very small leakage can cause excitation of parallel plate modes between the parallel surfaces. As long as the energy amount is sufficiently small, the leakage can be ignored. However, excitation can cause resonance within the gap between the waveguide and the other waveguide or circuit board. Resonance can significantly increase the energy amount of the parallel plate modes, which leads to a decrease in the modes propagating within the waveguide. As a result, leakage increases and the performance of the waveguide (or waveguide antenna using a waveguide) is degraded. The occurrence of resonance depends on the frequency used, as well as the geometric boundary conditions of the waveguide and the gap between the waveguide and the other waveguide or circuit board. This may render waveguide designs unusable or necessitate welding during joining. [Overview of the Initiative]

[0008] The waveguide according to the present invention has a recess formed in the side wall of the waveguide channel. The recess is preferably formed perpendicular to the side wall and forms a cavity in the side wall. The recess can have various shapes, such as rectangular, circular, or conical. The width and height of the recess in the side wall are substantially smaller than half a wavelength of the signal in free space for which at least one waveguide channel is designed (<<λ0 / 2). The wavelength of the signal in free space corresponds to the wavelength of the parallel plate mode. For example, the width and height of the recess are each about one-quarter of the wavelength of the signal in free space (<λ0 / 2). The position and depth of the recess can be selected basically freely, as long as the condition that the width and height are substantially smaller than half a wavelength of the signal in free space is met. Due to the dimensions of the recess, the propagation mode in the waveguide channel is not affected by the recess, does not interact with the recess, and therefore does not reach the cutoff frequency with respect to the recess, so the output of the propagation mode is unchanged.

[0009] According to one embodiment, the recess is provided in a waveguide consisting of two joined waveguide components and is positioned at the joint. Parallel plate modes are generated within the gap created by the incomplete joining between the two waveguide bodies of the waveguide components.

[0010] In a further embodiment, a recess is provided in a system including a waveguide and a further waveguide or circuit board connected to the waveguide. The waveguide in this system may generally be any type of waveguide, i.e., the waveguide described above consisting of two waveguide components, or a waveguide consisting of a partial piece, having at least one waveguide channel. The further waveguide or circuit board is connected to the waveguide on the outer surface of the waveguide where the output of the waveguide channel is located. The opening is called the output of the waveguide channel, and through the opening, a signal is decoupled from or coupled to the waveguide. Thus, the input of the waveguide channel is also considered an output. Explicitly, the opening of a portion of the waveguide channel that is closed when joined to form a waveguide channel cannot be considered an outlet. Parallel plate modes occur in the gap at the connection between the waveguide body of the waveguide and the coupling point of the waveguide body or circuit board of the further waveguide.

[0011] The recesses can also be considered as stubs. As a result, the propagation characteristics of parallel plate modes on the surface of the waveguide body are altered, thereby shifting the resonant frequency or attenuating the resonance. By positioning and numbering the recesses, the resonant frequency of the waveguide body can be controlled and eliminated within the relevant frequency band. As a result, energy leakage from the waveguide is reduced.

[0012] Preferably, the recess is provided on the surface of the waveguide body where joining or connection is achieved and parallel plate modes are generated. When joining waveguide components, the relevant surface of the waveguide body faces the other waveguide component and is the surface on which at least one waveguide channel portion is machined. When connecting to a further waveguide or circuit board, the relevant surface is the surface having the waveguide channel exit. Thus, the propagation characteristics of the parallel plate modes can be effectively altered. Furthermore, the surface is easily accessible for external machining.

[0013] When a waveguide consists of two waveguide components, preferably, recesses are formed on the surface of each of the two waveguide components. The position and shape of these recesses are matched. When the waveguide components are joined, the recesses of the two waveguide components face each other, and these form a common recess in at least one waveguide channel. This makes it easy to provide the recesses during the manufacturing of the waveguide components. Furthermore, in this case, the recesses are arranged symmetrically within the waveguide channel.

[0014] Multiple recesses can be formed in the side wall, and these recesses are arranged adjacently, preferably at the same height. This allows for the selective and particularly effective suppression of the parallel plate mode.

[0015] The recessed portion is particularly advantageous in the waveguide channel configuration described below, but can be applied in any form. In one embodiment, a waveguide consisting of two waveguide components has a bent or curved waveguide channel surrounding a region in the gap between the two waveguide components where a resonant cavity may occur. Resonance occurs when one dimension of the resonant cavity corresponds to approximately half (or a multiple thereof) of the free-space wavelength of the signal propagating through the waveguide channel (l ≈ λ0 / 2). The recess is preferably located in this region of the waveguide body of the first waveguide component, surrounded by the bent or curved waveguide channel. This destroys the resonant cavity and significantly reduces the parallel plate modes in the gap between the waveguide bodies. Here, generally, any shape of waveguide surrounding such a region where a resonant cavity may occur may be relevant. In particular, a U-shaped waveguide channel with two legs extending parallel to each other, a V-shaped waveguide channel with legs at an angle to each other, or an L-shaped waveguide channel may be relevant.

[0016] In a further form, a waveguide consisting of two waveguide components has two parallel waveguide channels. In the region of the waveguide body between the two parallel waveguide channels, a resonant cavity may develop in the gap between the two waveguide components. Furthermore, unwanted energy coupling may occur between the two waveguide channels. Resonance occurs when the distance between the two parallel waveguide channels corresponds to approximately half (or a multiple thereof) of the free-space wavelength of the signal propagating through the waveguide channels (l ≈ λ0 / 2). Multiple recesses placed adjacent to each other are particularly advantageous in this design. This destroys the resonant cavity and significantly reduces the parallel plate modes in the gap between the waveguide bodies. Furthermore, this prevents energy coupling between the waveguide channels across the gap.

[0017] A recess is particularly advantageous when the waveguide has a choke at the connection point with a further waveguide or circuit board. Chokes are used to reduce leakage, especially when the connection is not realized by welding. However, such chokes function optimally only in cases of perfect symmetry. If there is a misalignment between the waveguide and the connection point with the further waveguide or circuit board, the symmetry is broken, and resonance occurs on the surface of the waveguide body between the waveguide channel and the choke. Preferably, a hollow is formed in the side wall of the waveguide channel located in the direction of the choke. Preferably, the hollow penetrates the side wall and connects the choke to the waveguide channel. This destroys the resonance between the waveguide channel and the choke.

[0018] Exemplary embodiments of the present invention are shown in the drawings and described in more detail below. [Brief explanation of the drawing]

[0019] [Figure 1] This is a cross-sectional view of a waveguide joined from two waveguide components, each having a waveguide channel. [Figure 2] This is a cross-sectional view of a recess in a waveguide according to one embodiment of the present invention. [Figure 3]This is a top perspective view of a waveguide component of an exemplary embodiment of a waveguide according to the present invention, comprising a waveguide channel of the first embodiment. [Figure 4] This is a top perspective view of a waveguide component of an exemplary embodiment of a waveguide according to the present invention, which includes a waveguide channel of a second form. [Figure 5] This is a front perspective view of a further exemplary embodiment of a waveguide according to the present invention, having a choke at the exit of the waveguide channel. [Modes for carrying out the invention]

[0020] Figure 1 shows a waveguide 1 consisting of two waveguide components 11 and 12. The first waveguide component 11 has a waveguide body 111, in which a hollowed-out portion 110 is formed. In this example, the hollowed-out portion 110 has a rectangular cross-section and extends in a third direction through the waveguide body 111. Similarly, the second waveguide component 12 has a waveguide body 121, in which a hollowed-out portion 120 is formed. In this example, the hollowed-out portion 120 has the same shape as the hollowed-out portion 110 of the first waveguide component 11. The waveguide bodies 111 and 121 have opposing surfaces 112 and 122 on the outside of the hollowed-out portions, and the surfaces 112 and 122 extend parallel to each other. To assemble waveguide 1, two waveguide components 11 and 12 are joined at their surfaces 112 and 122. In addition to welding, adhesive or screw fastening can also be used for joining. The joining brings together two hollowed-out sections 110 and 120 to form a waveguide channel 10, which is a rectangular hollow tube, allowing electromagnetic signals (not shown) to be transmitted within the waveguide channel 10. That is, the hollowed-out sections 110 and 120 are part of the waveguide channel 10, and can be easily formed on the waveguide body 111 and 121 in a separate state, for example by milling or injection molding, and then joined to form the waveguide channel 10. By appropriately forming the hollowed-out sections 110 and 120, waveguide channels of different shapes and even multiple waveguide channels can be formed within the same waveguide 1. See Figures 3 and 4 for details. During joining, a gap 13 may occur between surfaces 112 and 122, and this gap 13 is shown larger in the drawing than it actually is. Since the two surfaces 112 and 122 are parallel to each other, parallel plate modes may form within the gap 13. This results in leakage of electromagnetic energy of the signal transmitted in the waveguide channel 10 (indicated by arrow 131), thereby reducing the energy of the signal in the waveguide channel 10.

[0021] In further diagrams, identical components are characterized by the same reference symbols; please refer to the above descriptions for their explanations. FIG. 2 shows a cross-section of the waveguide 1 according to the present invention configured as shown in FIG. 1. The waveguide 1 according to the present invention has recesses 2 that extend vertically from the waveguide channel 10 into the waveguide bodies 111, 121 and are formed symmetrically with respect to the gap 13. The first waveguide component 11 has a rectangular recess 21 on its surface 112 at the side wall 114 of the waveguide channel 10, that is, the cutout 110 which is a part of the waveguide channel 10. The second waveguide component 12 has a rectangular recess 22 on its surface 122 at the side wall 124 of the waveguide channel 10, that is, the cutout 120 which is the other part of the waveguide channel 10. The recess 22 corresponds to the recess 21 of the first waveguide component 12 and is arranged at the same position. By joining the waveguide components 11, 12, the two recesses 21 and 22 are combined to form a common recess 2 having a rectangular parallelepiped shape here. In other embodiments (not shown here), the recess 2 can take another shape, for example, a cylindrical shape. The recess 2 has a height h, which is much smaller than the wavelength of the signal in free space (h << λ0), and here, for example, is one-fourth of the wavelength of the signal in free space (h = λ0 / 4). Further, the recess has a width d (not shown in FIG. 2 as it extends perpendicular to the plane of the paper; see FIGS. 3 and 4), and this width is also substantially smaller than the wavelength of the signal in free space (d << λ0), and here, for example, is also one-fourth of the wavelength of the signal in free space (b = λ0 / 4).

[0022] FIGS. 3 and 4 each show exemplary embodiments of the waveguide 1 according to the present invention having different forms of the waveguide channel 10. FIGS. 3 and 4 each show a perspective view of the first waveguide component 11 as seen from above. The second waveguide component 12 is not shown for clarity but is configured similarly to the first waveguide component 11.

[0023] In Figure 3, the waveguide channel 10 is formed in a U-shape, having a base portion 101 and two parallel leg portions 102 and 103. The base portion 101 and the leg portions 102 and 103 surround the region of the waveguide body 111 from three sides. When the length l of this region of the waveguide body 111 between the leg portions 102 and 103, i.e., the distance between the leg portions 102 and 103, is close to half a wavelength of the signal in free space (l ≈ λ0 / 2), a resonant cavity may form in the gap 13 between the parallel waveguide bodies 111 and 121 within the surrounded region, and this resonant cavity amplifies the leakage of electromagnetic energy. In other exemplary embodiments (not shown), the waveguide channel may be formed in a V-shape or L-shape, similarly surrounding a region, within which a resonant cavity may form. According to the present invention, a plurality of recesses (four in this case) 23-26 are provided in the side wall 114 of one leg 102 of the waveguide channel 10 in the direction of the enclosed region. As shown with reference to Figure 2, these recesses 23-25 ​​together with the recesses (not shown) of the second waveguide component 12 form a common recess. The recesses 23-26 each have the same width b and the same height h, and are each substantially smaller than half a wavelength of the signal in free space, here for example, one-quarter of the signal wavelength, and are located at the same distance d, where the distance d corresponds here for example to approximately half a wavelength of the signal (d ≈ λ0 / 2). The recesses 23-26 alter the geometric boundary conditions, thereby suppressing parallel plate modes and resulting in no leakage or only slight leakage.

[0024] Figure 4 shows two waveguide channels 10 and 100 extending parallel to each other. The waveguide channels surround the region of the waveguide body 111 from two opposing sides. When the length l of this region of the waveguide body 111 between waveguide channels 10 and 100, i.e., the distance between waveguide channels 10 and 100, is close to half a wavelength of the signal in one of the waveguide channels 10 or 100 (l ≈ λ0 / 2), a resonant cavity may form in the gap 13 between the parallel waveguide bodies 111 and 121 within the surrounded region, and this resonant cavity amplifies the leakage of electromagnetic energy. According to the present invention, a plurality (in this case, four) of recesses 23-26 are provided in the side wall 114 of one leg 102 of waveguide channel 10, facing toward the other waveguide channel 100 and the surrounded region. As shown in Figure 2, these recesses 23-26, together with the recesses of the second waveguide component 12 (not shown), form a common recess. Each of the recesses 23-26 has the same width b and the same height h, and they are each substantially smaller than half a wavelength of the signal in free space, here for example, one-quarter of the signal wavelength, and are located at the same distance d, where the distance d corresponds here for example to approximately half a wavelength of the signal (d ≈ λ0 / 2). The recesses 23-26 alter the geometric boundary conditions, thereby suppressing parallel plate modes and resulting in little to no leakage.

[0025] Figure 5 shows a front view of waveguide 3. Waveguide 3 may be the waveguide 1 described above, consisting of two waveguide components. Generally, waveguide 3 can also be made in a different form, for example, a partial piece. Waveguide 3 has a waveguide body 31 and a waveguide channel 30 configured as a rectangular hollow tube within the waveguide body 31. The outlet of waveguide channel 30 is on the front surface 32 of waveguide body 31. Waveguide 3 is connected to a further waveguide (not shown) or circuit board (not shown) via this surface 32, and thus a signal is coupled to or decoupled from a coupling point in the further waveguide or circuit board via the output of waveguide channel 30. A choke 4 surrounding waveguide channel 30 is provided at the outlet of waveguide channel 30. According to the present invention, two recesses 27 and 28 are provided on the side wall 34 of waveguide channel 30 on the surface 32, facing each other and arranged parallel to each other. In this example, recesses 27 and 28 are formed on the long sides of the rectangular waveguide channel 30, respectively. In other embodiments (not shown), a different number and arrangement of recesses may be provided, for example, two recesses may be provided on each long side, and two recesses on each short side. Here, the recesses 27 and 28 penetrate the side walls 34 and thus connect the waveguide channel 30 and the choke 4. This blocks resonance that would form between the waveguide channel 30 and the choke 4 in the gap between the surface 32 of the waveguide body 32 of the waveguide 3 and other waveguides or circuit boards, resulting in no leakage or only minimal leakage.

Claims

1. A waveguide (1) comprising a first waveguide component (11) and a second waveguide component (12), The first waveguide component (11) comprises a first waveguide body (111) and a first portion (110) of at least one waveguide channel (10) formed in the first waveguide body (111), The second waveguide component (12) comprises a second waveguide body (121) and a second portion (120) of the at least one waveguide channel (10) formed in the second waveguide body (121), The first waveguide body (111) and the second waveguide body (121) form a waveguide body (111, 121), In a waveguide (1) in which the first waveguide component (11) and the second waveguide component (12) are joined together, the first portion (110) and the second portion (120) are arranged to form at least one waveguide channel (10), and the opposing surfaces (112, 122) of the first waveguide component (11) and the second waveguide component (12) are formed in parallel, Recesses (2, 23-26) are formed in the side walls (114, 124) of at least one waveguide channel (10), and the width (b) and height (h) of the recesses (2, 23-26) are substantially smaller than half a wavelength of the signal for which the at least one waveguide channel (10) is designed. The at least one waveguide channel (10) has two waveguide channels extending parallel to each other, the two waveguide channels extending parallel to each other are positioned to surround the region of the first waveguide body (111) where the recesses (2, 23-26) are located, and in the waveguide (1) having the two waveguide channels extending parallel to each other, the recesses (2, 23-26) are formed on the side wall (114) of one waveguide channel toward the other waveguide channel. A waveguide (1) characterized in that the distance between the two waveguide channels extending parallel to each other is approximately the same as half the wavelength of the signal.

2. The at least one waveguide channel (10) is formed in a U-shape overall, the two waveguide channels extending parallel to each other are the two legs (102, 103) of the U-shape, the at least one waveguide channel (10) further has a waveguide channel that forms the bottom (101) of the U-shape, and the at least one U-shaped waveguide channel (10) is formed to surround the region of the first waveguide body (111) from three sides. Waveguide (1) according to claim 1, wherein the distance between the two leg portions (102, 103) is approximately the same as half the wavelength of the signal.

3. Waveguide (1) according to claim 1, characterized in that the recessed areas (2, 23-26) are formed perpendicular to the side walls (114, 124) and in the side walls (114, 124).

4. The waveguide (1) according to claim 1, characterized in that the recessed areas (2, 23-26) are formed on the surface (112, 122) of the waveguide body (111, 121).

5. The waveguide (1) according to Claim 4, characterized in that recesses (21, 22) are formed on the surfaces (112, 122) of the first waveguide component (11) and the second waveguide component (12), the positions of the recesses (21, 22) correspond to each other, and when the first waveguide component (11) and the second waveguide component (12) are joined to each other, the recesses (21, 22) face each other to form a common recess (2).

6. The waveguide (1) according to claim 1, characterized in that the first waveguide component (11) and the second waveguide component (12) have a plurality of recesses (23 to 26) arranged adjacent to each other.

7. A system comprising a waveguide body (31), a waveguide (3) having at least one waveguide channel (30) formed in the waveguide body (31), and a further waveguide or circuit board, wherein the at least one waveguide channel (30) is connected at an output to the further waveguide or the circuit board, wherein recesses (27, 28) are formed in the side wall (34) of the at least one waveguide channel (30), and the width (b) and height (h) of the recesses (27, 28) are smaller than half a wavelength of the signal for which the at least one waveguide channel (30) is designed. In a system in which the waveguide (3) has a choke (4), the recesses (27, 28) are formed in the side wall (34) of the waveguide channel (30) toward the choke (4).

8. The system according to claim 7, characterized in that the recessed areas (27, 28) are formed perpendicular to the side wall (34) in the side wall (34).

9. The system according to claim 7, characterized in that the recessed areas (27, 28) are formed on the surface (32) of the waveguide body (31).

10. The system according to claim 7, characterized in that the waveguide (3) has a plurality of recesses (27, 28).

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