Waveguide

Abstract

The invention relates to a waveguide (1) consisting of two waveguide parts (11, 12). Each waveguide member (11, 12) has a waveguide body (111, 121) and a portion (110, 120) of at least one waveguide channel (10), the waveguide body and the portion being arranged to form the at least one waveguide channel (10) when joining the two waveguide members (11, 12). Opposite surfaces (112, 122) of the two waveguide parts are formed in parallel. A cutout (2, 23-26) is formed in a side wall (114, 124) of the waveguide channel (10). The width (b) and height (h) of the cutout (2, 23-26) are significantly less than half the wavelength of the signal for which the at least one waveguide channel (10) is designed.

Description

Technical Field

[0001] The invention relates to a waveguide, which consists of two joined waveguide components. Each waveguide component has a part of at least one waveguide channel (i.e. a part of one waveguide channel or a part of a plurality of waveguide channels), in particular the upper half or the lower half of the at least one waveguide channel. The waveguide components are, for example, welded, glued, screwed, etc. After the waveguide components are joined, they form the at least one waveguide channel. The opposing surfaces of the two waveguide components are designed in parallel.

[0002] The invention also relates to a system consisting of a waveguide and another waveguide or a printed circuit board. The waveguide has a waveguide channel, which is connected to the other waveguide or the printed circuit board at its output end. The connection is achieved, for example, by welding, gluing or screwing. The surface of the waveguide at the output end of the waveguide channel and the surface of the other waveguide or the printed circuit board that are connected to each other are parallel. Background Art

[0003] The waveguide is produced, for example, by forming two waveguide components and then joining them. Each waveguide component has a waveguide body into which a portion of at least one waveguide channel is respectively machined by means of methods known per se, such as milling or injection molding. The two waveguide components are then joined at their waveguide bodies and thus form a firm connection. During the joining, the components of the at least one waveguide channel are aligned one above the other and combined to form at least one waveguide channel. The joining is achieved, for example, by screwing, gluing, press-fitting, welding or the like.

[0004] Leakage of the electromagnetic waves guided in the waveguide can occur at the joints. This is caused by the interruption of the current path on the surface due to imperfect plated contacts. It is known from the publication "Principles of Microwave Circuits" by Montgomery et al. (Stevenage: IET, 1987) that the waveguide is divided in an area where only a small amount of current flows or, ideally, no current flows. In a rectangular waveguide for the fundamental mode, this area is located, for example, in the middle of the longer side. If the waveguide is divided in this area, the symmetry is largely preserved and, ideally, no leakage occurs, even if there are imperfect plated contacts between the two waveguide components (for example due to bonding or press-fitting).

[0005] However, even this does not completely prevent leakage. Even if the design of the waveguide is perfectly symmetrical (which is usually not the case due to bends and components such as transistors), small defects and manufacturing tolerances lead to slightly asymmetrical waveguides, which lead to leakage of at least a small amount of energy between waveguide components. However, small asymmetries also lead to smaller leakages, so that if the asymmetry is small enough, the leakage can be ignored depending on the application.

[0006] Usually, there is a gap between the waveguides. The aligned surfaces of the waveguides run parallel to each other so that these surfaces can be regarded as the plates of a plate capacitor. Even the smallest leakage will produce the excitation of the parallel plate mode between the parallel surfaces of the waveguides of the waveguide components. As long as the amount of energy is small enough, the leakage can be ignored. However, due to the excitation, resonance can be generated in the gap between the two waveguides of the waveguide component or between adjacent waveguide channels. Through resonance, the energy amount of the parallel plate mode can be greatly increased, which leads to a reduction in the propagation mode in the waveguide. As a result, leakage increases and the performance of the waveguide (or waveguide antenna using the waveguide) is reduced. The occurrence of resonance depends on the frequency used and the geometric boundary conditions of the waveguide and the gap between the waveguide components. This will cause the design of the waveguide to be unusable or to be welded when joining.

[0007] The leakage of electromagnetic waves also occurs when connecting a waveguide to another waveguide or a printed circuit board. Here, the waveguide does not have to be composed of two waveguide components as described above. Usually, a gap is left between the waveguide bodies. The surface of the waveguide and the surface of another waveguide or a printed circuit board run parallel to each other at the connection, so that these surfaces can be regarded as plates of a plate capacitor. Even the smallest leakage will produce the excitation of the parallel plate mode between the parallel surfaces. As long as the amount of energy is small enough, the leakage can be ignored. However, due to the excitation, resonance can be generated in the gap between the waveguide and another waveguide or the printed circuit board. Through resonance, the energy amount of the parallel plate mode can be greatly increased, which leads to a reduction in the mode propagated in the waveguide. As a result, leakage increases and the performance of the waveguide (or a waveguide antenna using a waveguide) is reduced. The occurrence of resonance depends on the frequency used and the geometric boundary conditions of the waveguide and the gap between the waveguide and another waveguide or the printed circuit board. This will cause the design of the waveguide to be unavailable or to be soldered as a prerequisite when joining. Summary of the invention

[0008] The waveguide has a recessed portion, which is constructed in the side wall of the waveguide channel. The recessed portion is preferably constructed perpendicular to the side wall into the side wall and forms a cavity in the side wall. The recessed portion can have various shapes, such as rectangular, circular, conical, etc. The width and height of the recessed portion on the side wall are significantly less than half of the wavelength of the signal in free space for which the 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 recessed portion are respectively about one quarter of the wavelength of the signal in free space (<λ0 / 2). The position and depth of the recessed portion can be basically freely selected as long as the condition that the width and height are significantly less than half of the wavelength of the signal in free space is met. Due to the size of the recessed portion, the propagation mode in the waveguide channel is not affected by the recessed portion, and they will not interact with each other, so that the power of the propagation mode will not change because the limit frequency (Grenzfrequenz) of the recessed portion is not reached.

[0009] According to one aspect, the recess is provided in a waveguide consisting of two waveguide components and is positioned there at the joining point. A parallel plate mode is formed in the gap between the two waveguide bodies of the waveguide components which is produced due to the imperfect joining.

[0010] According to another aspect, the recessed portion is arranged in a system consisting of a waveguide and another waveguide or a printed circuit board, and the other waveguide or printed circuit board is connected to the waveguide. In general, the waveguide of the system can be any type of waveguide, that is, it can be the waveguide consisting of two waveguide components as mentioned above, or it can be a waveguide of integral construction, and has at least one waveguide channel. Another waveguide or a printed circuit board is connected to the waveguide on the outer side of the waveguide, and the output end of the waveguide channel is located on the outer side. The output end of the waveguide channel refers to the following opening: through this opening, the signal is coupled out of or coupled into the waveguide-therefore, the input end of the waveguide channel is also regarded as the output end here. Clearly, therefore, the opening of the component of the waveguide channel that is closed as a waveguide channel when joined should not be regarded as the output end. The parallel plate mode is formed at the gap in the connection between the waveguide conductor of the waveguide and the waveguide of another waveguide or the coupling part of the printed circuit board.

[0011] The cutouts can be considered as stubs. As a result, the propagation characteristics of the parallel plate mode on the surface of the waveguide are changed, so that the resonant frequency is shifted or the resonance is weakened. By the positioning and number of the cutouts, the resonant frequency of the waveguide can be controlled and eliminated in the relevant frequency band. As a result, the energy leakage from the waveguide is reduced.

[0012] Preferably, the cutout is arranged on the surface of the waveguide body, via which the joining or connection is achieved and on which the parallel plate mode is generated. When joining waveguide components, the relevant surface of the waveguide body is the surface that points toward the other waveguide component and into which the part of the at least one waveguide channel is machined. When connecting to another waveguide or a printed circuit board, the relevant surface is the surface with the output end of the waveguide channel. There, the propagation characteristics of the parallel plate mode can be effectively changed. In addition, this surface is easy to machine from the outside.

[0013] In the case of a waveguide consisting of two waveguide components, preferably, in each of the two waveguide components, a cutout is constructed on the corresponding surface. The positions and shapes of the cutouts correspond to each other. When the waveguide components are joined, the cutouts of the two waveguide components cooperate with each other so that a common cutout is formed in the at least one waveguide channel. As a result, the cutouts can be provided in a simple manner when the waveguide components are manufactured. In addition, the cutouts are arranged symmetrically in the waveguide channel in this case.

[0014] It is also possible to form a plurality of recesses in the side wall, which are arranged next to each other and preferably at the same height. Parallel plate modes can thereby be suppressed selectively and particularly effectively.

[0015] The recess acts particularly advantageously in the configuration of the waveguide channel described below, but can be used in any configuration.

[0016] In one configuration, a waveguide consisting of two waveguide components has a curved or bent waveguide channel that surrounds the following area in which a resonant cavity can be formed in the gap between the two waveguide components. Resonance is formed when one dimension of the resonant cavity corresponds approximately to half (or a multiple thereof) of the free space wavelength of the signal propagating through the waveguide channel (I≈λ0 / 2). The recessed portion is preferably arranged in the area of ​​the waveguide conductor of the first waveguide component that is surrounded by the curved or bent waveguide channel. The resonant cavity is thereby destroyed and the parallel plate mode in the gap between the waveguide conductors is significantly reduced. In general, any shape of the waveguide surrounding such an area in which a resonant cavity can be formed can be relevant. The following shapes are particularly relevant: a U-shaped waveguide channel in which the waveguide channels run parallel on two legs, a V-shaped waveguide channel or an L-shaped waveguide channel in which the legs are bent at an angle to each other.

[0017] In another configuration, the waveguide consisting of two waveguide components has two waveguide channels running in parallel. In the region of the waveguide body between the two parallel waveguide channels, a resonant cavity can be formed in the gap between the two waveguide components. In addition, undesirable energy coupling may occur between the two waveguide channels. When the spacing between the two parallel waveguide channels corresponds approximately to half (or a multiple thereof) of the free space wavelength of the signal propagating through the waveguide channel (I≈λ0 / 2), resonance will be formed. For this configuration, multiple side-by-side arranged gaps are particularly advantageous. As a result, the resonant cavity is destroyed, and the parallel plate mode in the gap between the waveguide bodies is significantly weakened. In addition, energy coupling between the waveguide channels via the gap is thereby prevented.

[0018] Furthermore, the recess is particularly advantageous if the waveguide has a choke at the connection to another waveguide or a printed circuit board. The choke is used to reduce leakage, in particular when the connection is not achieved by soldering. However, such a choke only works optimally in the case of perfect symmetry. Any misalignment of the coupling portion of the waveguide to another waveguide or a printed circuit board destroys the symmetry and causes resonances on the surface of the waveguide body between the waveguide channel and the choke. A groove is preferably formed in the side wall of the waveguide channel, which groove is located in the direction toward the choke. Preferably, the groove penetrates the side wall and connects the choke to the waveguide channel. As a result, the resonance between the waveguide channel and the choke is destroyed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description.

[0020] Figure 1 A cross-sectional view of a waveguide having a waveguide channel joined by two waveguide components is shown.

[0021] Figure 2 A cross-sectional view showing a deepening in a waveguide according to an embodiment of the present invention.

[0022] Figure 3 An isometric view of the upper side of a waveguide component showing an embodiment of a waveguide according to the present invention having a first configuration of waveguide channels.

[0023] Figure 4 An isometric view of the upper side of a waveguide component showing an embodiment of a waveguide according to the present invention having a second configuration of waveguide channels.

[0024] Figure 5 An isometric view of the front side of another embodiment of a waveguide according to the invention with a choke at the output end of the waveguide channel is shown. DETAILED DESCRIPTION

[0025] Figure 1A waveguide 1 is shown, which consists of two waveguide components 11, 12. The first waveguide component 11 has a waveguide conductor 111, in which a groove 110 is constructed, which in this embodiment has a rectangular cross-section and extends through the waveguide conductor 111 in a third direction. Similarly, the second waveguide component 12 has a waveguide conductor 121, in which a groove 120 is constructed, which in this embodiment has the same shape as the above-mentioned groove 110 of the first waveguide component 11. Outside the groove, the waveguides 111, 121 have surfaces 112 and 122 that are opposite to each other and run parallel to each other. In order to assemble the waveguide 1, the two waveguide components 11, 12 are joined at these surfaces 112 and 122. As a method for joining, bonding or screwing can also be used in addition to welding. Through joining, the two grooves 110 and 120 together form a waveguide channel 10 constructed as a rectangular hollow conductor, in which electromagnetic signals not shown here can be guided. That is, the grooves 110, 120 are parts of the waveguide channel 10, which can be easily formed in the waveguide bodies 111, 121 in a separated state, for example by milling or injection molding, and form the waveguide channel 10 in a joined state. By means of correspondingly formed grooves 110, 120, waveguide channels of different shapes and also multiple waveguide channels can be formed in the same waveguide 1. For this, see Figure 3 and Figure 4 When joined, a gap 13 is formed between the surfaces 112 and 122, which is shown disproportionately large in the current figure. Since the surfaces 112 and 122 are parallel to each other, a parallel plate mode can be formed in the gap 13. This causes leakage of electromagnetic energy of the signal guided in the waveguide channel 10 (shown by arrow 131), so that the energy of the signal in the waveguide channel 10 is reduced.

[0026] In other drawings, the same components are marked with the same reference numerals, and reference is made to the above description for their explanation.

[0027] Figure 2 FIG. 1 shows a portion of a waveguide 1 according to the present invention. Figure 1The waveguide 1 according to the present invention has a recess 2, which extends vertically from the waveguide channel 10 into the waveguide bodies 111, 121 and is symmetrically constructed with respect to the gap 13. The first waveguide component 11 has a rectangular recess 21 on its surface 112 in the side wall 114 (i.e., the groove 110, which represents a part of the waveguide channel 10) of the waveguide channel 10. The second waveguide component 12 has a rectangular recess 22 on its surface 122 in the side wall 124 (i.e., the groove 120, which represents another part of the waveguide channel 10) of the waveguide channel 10, which corresponds to the recess 21 in 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 together form a common recess 2, which has a rectangular parallelepiped shape here. In other embodiments not shown here, the recess 2 can also adopt other shapes, such as a cylindrical shape. The cutout 2 has a height h which is significantly smaller than the wavelength of the signal in free space (h<<λ0) and here is, for example, one quarter of the wavelength of the signal in free space (h=λ0 / 4). Furthermore, the cutout has a width d (which is Figure 2 is not shown because it extends into the page; see Figure 3 and Figure 4 ), which width is also significantly smaller than the wavelength of the signal in free space (d<<λ0) and here is, for example, also one quarter of the wavelength of the signal in free space (b=λ0 / 4).

[0028] exist Figure 3 and Figure 4 Detailed description of the invention shows exemplary embodiments of a waveguide 1 according to the invention with different configurations of a waveguide channel 10 . Figure 3 and Figure 4 In each case an isometric view from above onto the first waveguide component 11 is shown. For the sake of clarity, the second waveguide component 12 is not shown, but is constructed identically to the first waveguide component 11 .

[0029] exist Figure 3In the embodiment, the waveguide channel 10 is constructed in a U shape and has a base section 101 and two leg sections 102, 103 extending parallel to each other. The base section 101 and the leg sections 102, 103 surround a region of the waveguide 111 from three sides. If the length I of this region of the waveguide 111 between the leg sections 102, 103 (i.e., the spacing between the leg sections 102, 103) is close to half the wavelength of the signal in free space (I≈λ0 / 2), a resonant cavity will be formed in the gap 13 between the parallel waveguides 111 and 121 in this surrounded region, which resonant cavity enhances the leakage of electromagnetic energy. In other embodiments not shown, the waveguide channel can be constructed in a V shape or an L shape and also surround a region in which a resonant cavity can be formed. According to the present invention, in the side wall 114 of a leg section 102 of the waveguide channel 10, a plurality of recesses (here four) 23 to 26 are provided in the direction toward the surrounded region. As shown in reference Figure 2 As shown, these cutouts 23 to 25 form a common cutout together with the cutout of the second waveguide component 12 (not shown). The cutouts 23 to 26 each have the same width b and height h, which are each significantly smaller than half the wavelength of the signal in free space and are, for example, a quarter of the wavelength of the signal here, and are arranged at the same spacing d, which corresponds to, for example, approximately half the wavelength of the signal (d≈λ0 / 2). The cutouts 23 to 26 change the geometric boundary conditions so that the parallel plate mode is suppressed and no or only a small amount of leakage occurs.

[0030] exist Figure 4 In the figure, two waveguide channels 10 and 100 extending parallel to each other are shown. The waveguide channels surround a region of the waveguide body 111 from two opposite sides. If the length I of this region of the waveguide body 111 between the waveguide channels 10, 100 (i.e. the spacing between the waveguide channels 10, 100) is close to half the wavelength of the signal in one of the waveguide channels 10, 100 (I≈λ0 / 2), a resonance cavity can be formed in the gap 13 between the parallel waveguides 111 and 121 in this surrounding region, which resonance cavity enhances the leakage of electromagnetic energy. According to the present invention, in the side wall 114 of a leg section 102 of the waveguide channel 10, a plurality of recesses (here four) 23 to 26 are provided in the direction toward the other waveguide channel 100 and the surrounding region. As shown in reference Figure 2As shown, these cutouts 23 to 26 form a common cutout together with the cutout of the second waveguide component 12 (not shown). The cutouts 23 to 26 each have the same width b and height h, which are each significantly smaller than half the wavelength of the signal in free space and are, for example, a quarter of the wavelength of the signal here, and are arranged at the same spacing d, which corresponds to, for example, approximately half the wavelength of the signal here (d≈λ0 / 2). The cutouts 23 to 26 change the geometric boundary conditions so that the parallel plate mode is suppressed and no or only a small amount of leakage occurs.

[0031] exist Figure 5 In the figure, a front view of the waveguide 3 is shown. The waveguide 3 can be the above-mentioned waveguide 1 composed of two waveguide components. In general, the waveguide 3 can also be constructed in other ways, for example, in an integral manner. The waveguide 3 has a waveguide body 31 and a waveguide channel 30 constructed as a rectangular hollow conductor in the waveguide body. The output end of the waveguide channel 30 is located on a surface 32 of the waveguide body 31 pointing toward the front. The waveguide 3 is connected to another waveguide (not shown here) or to a printed circuit board (also not shown) via the surface 32, so that the signal is coupled into or coupled out of the coupling portion of another waveguide or circuit board via the output end of the waveguide channel 30. A choke 4 is arranged at the output end of the waveguide channel 30, which surrounds the waveguide channel 30. According to the present invention, in the side wall 34 of the waveguide channel 30, two recesses 27 and 28 are arranged on the surface 32, and the recesses are arranged opposite to each other and in parallel. In this embodiment, the cutouts 27, 28 are each formed on the long sides of the rectangular waveguide channel 30. In other embodiments not shown, a different number and arrangement of cutouts are provided, for example, two cutouts may be provided on each long side and two grooves may be provided on each short side. The cutouts 27, 28 penetrate the side wall 34 and thus connect the waveguide channel 30 to the choke 4. As a result, the resonance formed between the waveguide channel 30 and the choke 4 in the gap between the surface 32 of the wave conductor 32 of the waveguide 3 and another waveguide or circuit board is interrupted, and no leakage or only a small amount of leakage occurs.

Claims

1. A waveguide (1) comprising two waveguide components (11, 12), wherein: Each waveguide component (11, 12) has a waveguide conductor (111, 121) and a portion (110, 120) of at least one waveguide channel (10), the waveguide conductor and the portion being arranged to form the at least one waveguide channel (10) when the two waveguide components (11, 12) are joined, wherein the opposing surfaces (112, 122) of the two waveguide components are designed to be parallel, It is characterized in that a recess (2, 23-26) is formed in the side wall (114, 124) of the waveguide channel (10), wherein the width (b) and the height (h) of the recess (2, 23-26) are significantly smaller than half the wavelength of the following signal, for which the at least one waveguide channel (10) is designed.

2. The waveguide (1) according to claim 1, characterized in that The recesses (2, 23-26) are formed in the side walls (114, 124) perpendicularly thereto.

3. The waveguide (1) according to claim 1 or 2, characterized in that The recesses (2, 23-26) are formed on the surface (112, 122) of the waveguide (111, 121).

4. The waveguide (1) according to claim 3, characterized in that In each waveguide component (11, 12), a recess (21, 22) is constructed on a corresponding surface (112, 122), and the positions of the recesses (21, 22) correspond to each other, so that in the joined state of the waveguide (1), the recesses (21, 22) cooperate with each other to form a common recess (2).

5. Waveguide (1) according to any one of the preceding claims, characterized in that A waveguide component (11, 12) has a plurality of recesses (23-26) arranged side by side.

6. A waveguide (1) according to any one of the preceding claims, wherein: The waveguide has a curved or angled waveguide channel (101, 102, 103) surrounding a region, characterized in that the recess (2, 23-26) is formed in the region of the waveguide body (111, 121) surrounded by the curved or angled waveguide channel (101, 102, 103).

7. A waveguide (1) according to any one of the preceding claims, wherein: The waveguide (1) has two waveguide channels (10, 100) extending in parallel, characterized in that the recess (2, 23-26) is formed in a side wall (114) of one waveguide channel (10) in the direction toward the other waveguide channel (100).

8. A system comprising a waveguide (3) having at least one waveguide channel (30) and a further waveguide or a printed circuit board, wherein: The at least one waveguide channel (30) is connected to the other waveguide or to the printed circuit board at the output end, characterized in that cutouts (27, 28) are formed in the side walls (34) of the at least one waveguide channel (30), wherein the width (b) and height (h) of the cutouts (27, 28) are less than half the wavelength of the signal for which the at least one waveguide channel (30) is designed.

9. The system according to claim 8, characterized in that The recesses (27, 28) are formed perpendicularly to the side wall (34) in the side wall.

10. The system according to claim 8 or 9, characterized in that The recesses (27, 28) are formed on a surface (32) of the waveguide (31).

11. The system according to any one of claims 8 to 10, characterized in that The waveguide (1) has a plurality of recesses (27, 28).

12. A system according to any one of claims 8 to 11, wherein: The waveguide (1) has a choke (4), characterized in that the recesses (27, 28) are formed in the side wall (34) of the waveguide channel (30) facing the choke (4).

Images