Waveguide element and method for producing a waveguide element, and also radiofrequency arrangement and radar system

Abstract

The invention relates to a waveguide element, in particular a hollow waveguide for transmission of electromagnetic waves. The waveguide element has a cavity surrounded by an electrically conductive material. The cavity is designed so as to afford for electromagnetic waves an effective width which is larger than the actual dimension of the cavity.

Description

[0001] Description

[0002] title

[0003] Waveguide element and method for producing a waveguide element, as well as high-frequency arrangement and radar system

[0004] Technical area

[0005] The present invention relates to a waveguide element and a method for manufacturing a waveguide element. The present invention further relates to a high-frequency arrangement and radar system comprising such a waveguide element.

[0006] background

[0007] Waveguide elements such as hollow conductors are used for transmitting high-frequency signals. Such hollow conductors can have different geometries, such as rectangular, circular, or elliptical cross-sections. The minimum width of the hollow conductor should generally be slightly larger than half the wavelength of the electrical wave that can propagate in the hollow conductor. The hollow conductor's geometry thus results in a lower limit frequency, known as the cutoff frequency.

[0008] For example, the document EP 3903376 A1 describes a waveguide arrangement for conducting electromagnetic waves.

[0009] Disclosure of the invention

[0010] The present invention provides a waveguide element, a method for manufacturing a waveguide element, and a high-frequency arrangement and radar system having the features of the independent claims. Further advantageous embodiments are the subject of the dependent claims.

[0011] Accordingly, the following is provided: A waveguide element for guiding an electromagnetic wave. The waveguide element is formed from an electrically conductive material surrounding a cavity. This cavity is intended to guide the electromagnetic wave. The cavity has a cross-section that is essentially perpendicular to a propagation direction of the electromagnetic wave. However, the cavity can also, in principle, have a wave-compatible curvature. This cavity has an alternating regular structure along a virtual line in the direction of the cross-section.

[0012] Furthermore, it is planned:

[0013] A high-frequency arrangement comprising a waveguide element according to the invention and a high-frequency circuit. The high-frequency circuit is coupled to the waveguide element.

[0014] Learner is intended:

[0015] A radar system with a transmitting and / or receiving unit and a waveguide element according to the invention which is coupled to the transmitting and / or receiving unit.

[0016] Finally, it is planned:

[0017] A method for producing a waveguide element. The method comprises a step for providing a body and a step for introducing a continuous cavity into the body. The cavity can be introduced by drilling, milling, or another mechanical processing method. The body can preferably be a metallic, i.e., electrically conductive body. Alternatively, a non-electrically conductive body can be used, which, after the cavity has been introduced, is provided with an electrically conductive coating in the edge region. The cavity has a cross-section perpendicular to a propagation direction of the electromagnetic wave. This cross-section has an alternating regular structure along a virtual line in the direction of the cross-section. Advantages of the Invention

[0018] Waveguide elements such as hollow conductors intended for the transmission of high-frequency signals generally require a minimum width slightly larger than half the wavelength of the electromagnetic wave intended to propagate within the waveguide element. Thus, the dimensions, particularly the width, of such a waveguide element determine a lower limit frequency (cut-off frequency). Conversely, the minimum dimensions of the respective waveguide element are determined by the minimum frequency intended to be transmitted via the waveguide element.

[0019] Based on this finding, it is an idea of ​​the present invention to create a waveguide element in the form of a hollow guide or a dielectrically filled and metallically edged waveguide, which has improved properties with regard to the relationship between dimensions and lower cut-off frequency.

[0020] This requirement can be achieved according to the invention by providing a special design for the interior of such a waveguide element. In particular, the cavity of such a waveguide element can be formed in the form of a geometric structure resulting from an alternating regular structure along a virtual line in a cross-section of the waveguide element. As will be explained in more detail below, this regular structure can be formed in a variety of ways.

[0021] In particular, geometric structures can be formed for the interior of the waveguide element, which can also be realized particularly easily using mechanical methods such as drilling or milling. Thus, the waveguide element according to the invention can also be manufactured particularly easily.

[0022] The edge of the cavity has an electrically conductive structure. For example, the waveguide element can be formed from an electrically conductive material into which the cavity is introduced. Alternatively, it is also possible to provide only the edge region between the body and the cavity with an electrically conductive material. The edge region can either be formed entirely from an electrically conductive material. For example, the edge region can be coated with an electrically conductive material. Alternatively, other, not necessarily full-surface electrically conductive structures are also possible, such as grid-like structures for the edge region. The electrically conductive edge region should have a thickness that is sufficient for the reflection of the electromagnetic waves.

[0023] As will be explained in more detail below, the cavity may be filled with air, a gas or another suitable, preferably solid dielectric.

[0024] According to one embodiment, the cross-section of the cavity has a periodic, regular structure. Periodic structures are understood to be any suitable structures that repeat multiple times along the virtual line in the cross-section of the waveguide element.

[0025] According to one embodiment, the cross-section comprises several overlapping circles or polygons. Circles can be created particularly easily, for example, by drilling or milling with an appropriate diameter. Polygons can be quadrilaterals, especially rectangles or squares. However, polygons, especially regular polygons with more than four corners, are also possible. Since the individual geometric elements overlap, this creates a coherent cavity.

[0026] According to one embodiment, the overlapping circles or polygons are of the same size. This allows the structure according to the invention for the waveguide element to be manufactured particularly easily and without tool changes. Alternatively, structures with circles or polygons of different sizes are also possible.

[0027] According to one embodiment, the cross-section of the cavity has a structure composed of several overlapping, alternating structures. For example, the geometry of the cross-section can also be formed from two structures that are axially symmetric with respect to the virtual line.

[0028] According to one embodiment, the cavity is filled with a gaseous or solid dielectric. Air, for example, can also be provided as the gaseous dielectric. Furthermore, depending on the application, a dielectric with a higher dielectric constant can also be provided.

[0029] According to one embodiment, the waveguide element comprises a metallic body. The cavity can be created in this metallic body by drilling, milling, or another mechanical processing method. In this way, the waveguide structure according to the invention can be realized particularly easily using mechanical manufacturing processes.

[0030] Alternatively, the waveguide can also be formed from a body that is not entirely made of a metallic or electrically conductive material. In this case, the desired structure for the cavity can also be created by drilling, milling, or another mechanical processing method. The edge of the cavity can then be coated with an electrically conductive material. Any suitable method for coating the edge region within the cavity is possible.

[0031] In an alternative embodiment, the waveguide element can be realized by means of an extrusion process or the like.

[0032] The above embodiments and further developments can be combined with one another as desired, where appropriate. Further embodiments, further developments, and implementations of the invention also include combinations of features of the invention not explicitly mentioned above or described below with respect to the exemplary embodiments. In particular, those skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the invention.

[0033] Short description of the drawings

[0034] Further features and advantages of the invention are explained below with reference to the figures.

[0035] Fig. 1: a schematic representation of a cross section through a waveguide element according to an embodiment; Fig. 2: a schematic representation of a cross section through a

[0036] Waveguide element according to another embodiment;

[0037] Fig. 3: a schematic representation of a cross section through a

[0038] Waveguide element according to another embodiment;

[0039] Fig. 4: a schematic representation of a cross section through a

[0040] Waveguide element according to yet another embodiment;

[0041] Fig. 5: a schematic representation of a cross section through a

[0042] Waveguide element according to another embodiment;

[0043] Fig. 6: a schematic representation of a cross section through a

[0044] Waveguide element according to another embodiment;

[0045] Fig. 7: a schematic representation of a cross section through a

[0046] Waveguide element according to yet another embodiment; and

[0047] Fig. 8: a flow chart of a method for manufacturing a

[0048] Waveguide element according to one embodiment.

[0049] Description of embodiments

[0050] Figure 1 shows a schematic representation of a cross-section through a waveguide element 1 according to one embodiment. The waveguide element 1 is formed by a cavity 10 enclosed by an electrically conductive material 20, for example a metal. The cavity 10 can, for example, be filled with a solid or gaseous dielectric. In particular, such a dielectric can also be air. The waveguide element 1 extends in a direction perpendicular to the plane of the drawing with an at least approximately constant cross-section. Thus, an electromagnetic wave can propagate in the cavity 10 of the waveguide element 1. Such a waveguide element 1 can, for example, be used for any product in high-frequency technology, in particular in applications in which a waveguide is to be used for the transmission of electromagnetic waves.For example, such a waveguide element can be used for a radar system, such as a vehicle radar. Here, the waveguide element 1 can be used in particular for signal coupling and transmission from a radar circuit, such as an ASIC or similar, into or through a circuit board.

[0051] As can be seen in Figure 1, the cross-section of the waveguide element 1 for the cavity 10 has a structure that has an alternating regular pattern along a virtual line 12. In Figure 1, this regular pattern is formed, for example, by several circular elements 11 whose centers are alternately located below or above the virtual line 12.

[0052] Such a structure of the cavity 10 makes it possible to achieve an effective width w eff for an electromagnetic wave in this waveguide element 1 that is significantly greater than a width B of the cavity 10 along the virtual line 12. Accordingly, such an increased effective width w eff also allows the lower cut-off frequency of the waveguide element 1 to be increased. In particular, such a configuration of the waveguide element 1 results in a lower cut-off frequency that is significantly higher than a waveguide element with a rectangular cross-section of width B.

[0053] In the embodiment illustrated in Figure 1, the cavity 10 is formed, for example, from four circular elements 11, all of which have the same diameter. However, as will be explained in more detail below, the present invention is not limited to embodiments with four circles or other geometric elements. Rather, the cavity 10 can also be realized by other suitable structures that allow for an increased effective width w eff with respect to the width B.

[0054] For a cavity 10 having a cross-section composed of several overlapping circular elements, the cavity 10 can be formed, for example, by drilling into a (solid) metal body. However, other mechanical processing methods, such as milling or similar, are also possible. In principle, it is also possible to realize the waveguide element 1, for example, using another manufacturing process, such as extrusion or similar.

[0055] Figure 2 shows a schematic representation of a cross-section through a waveguide element 1 according to another embodiment. The waveguide element 1 according to Figure 2 differs from the previously illustrated embodiment in particular in that the cavity 10 is formed by only three geometric elements, in particular circles. Furthermore, all explanations already provided in Figure 1 apply to this embodiment.

[0056] Figure 3 shows a schematic representation of a cross-section through a waveguide element 1 according to another embodiment. As shown in Figure 3, the cavity 10 of the waveguide element 1 can also be formed by more than just three or four lined-up, overlapping geometric elements 11.

[0057] Figure 4 shows a schematic representation of a cross-section through a waveguide element 1 according to yet another embodiment. The cavity 10 of the waveguide element 1 according to Figure 4 differs from the previously described embodiments in particular in that the individual geometric elements 11 have partially different sizes.

[0058] Figure 5 shows a schematic representation of a cross-section through a waveguide element 1 according to another embodiment. The cavity 10 of the waveguide element 1 according to Figure 5 differs from the previously described embodiments in that, instead of circular elements 11, rectangular elements 11 are provided here to form the cavity 10. The individual rectangular elements 11 are arranged in a zigzag-shaped structure, alternating along the virtual line 12.

[0059] Figure 6 shows a schematic representation of a cross-section through a waveguide element 1 according to another embodiment. The cavity 10 of the waveguide element 11 is realized as a wave-shaped structure, similar to a sinusoidal function. This structure also has a regular alternating shape with respect to the virtual line 12.

[0060] Finally, Figure 7 shows a schematic representation of a cross-section through a waveguide element 1 according to yet another embodiment. The cavity 10 in this embodiment can, for example, be formed from a combination of two symmetrical structures according to Figure 2. For better illustration, the individual structures are hatched differently. The geometric elements 11a of the first structure are axially symmetric with respect to the geometric elements 11b of the second structure. This also makes it possible to achieve an increased effective length w eff relative to the width B.

[0061] Figure 8 shows a flowchart underlying a method for producing a waveguide element 1 according to one embodiment. The method can, in principle, comprise any steps that may be required to realize one of the previously described waveguide elements 1.

[0062] In step S1, a body is first provided. This can be, for example, a solid metallic body or a body made of an electrically conductive material with the outer dimensions of the desired waveguide element 1.

[0063] In step S2, a continuous cavity 10 is created in the body. This creation can be achieved, for example, by drilling, milling, or another mechanical processing method. If the body is made of a material that is not electrically conductive, the edge regions of the cavity can be provided with an electrically conductive material in a further step.

[0064] In addition, the waveguide can also be realized by an extrusion process or similar, whereby a waveguide structure with the desired cavity is formed from the material (for example in the form of a body).

[0065] The resulting cavity 10 in the body has a cross-section perpendicular to an intended propagation direction of an electromagnetic wave, which has an alternating regular structure along a virtual axis 12. In particular, the cavity 10 can have one of the structures previously described in connection with Figures 1 to 7. If necessary, the cavity can also be filled with a desired dielectric.

[0066] In summary, the present invention relates to a waveguide element, in particular a hollow guide for transmitting electromagnetic waves. The waveguide element has a cavity surrounded by an electrically conductive material. The cavity is designed such that an effective width for electromagnetic waves is greater than the actual dimensions of the cavity.

Claims

Claims 1. Waveguide element (1) for guiding an electromagnetic wave, comprising: a cavity (10) surrounded by an electrically conductive material (20), wherein the cavity (10) has a cross-section perpendicular to a propagation direction of the electromagnetic wave, which has an alternating regular structure along a virtual line (12) in a plane of the cross-section.

2. Waveguide element (1) according to claim 1, wherein the cross section of the cavity (10) has a periodic regular structure.

3. Waveguide element (1) according to claim 1 or 2, wherein the cross section comprises a plurality of overlapping circles (11) or polygons.

4. Waveguide element (1) according to claim 3, wherein the overlapping circles (11) or polygons have the same size.

5. Waveguide element (1) according to one of claims 1 to 4, wherein the cross-section of the cavity (10) has a structure of several overlapping alternating structures (11a, 11b).

6. Waveguide element (1) according to one of claims 1 to 5, wherein the cavity (10) is filled with a gaseous or solid dielectric.

7. Waveguide element (1), wherein the waveguide element comprises a metallic body into which the cavity (10) has been introduced by means of drilling, milling or another mechanical processing method.

8. A high-frequency arrangement comprising: a waveguide element (1) according to any one of claims 1 to 7; and a high-frequency circuit coupled to the waveguide element (1).

9. Radar system, comprising: a transmitting and / or receiving unit, and a waveguide element (1) according to one of claims 1 to 7.

10. A method for producing a waveguide element (1), comprising the steps: Providing (S 1) a body, in particular a metallic body; Introducing (S 2) a continuous cavity (20) into the body by means of drilling, milling or another mechanical processing method, wherein the cavity (10) has a cross-section perpendicular to a propagation direction of the electromagnetic wave, which has an alternating regular structure along a virtual line (12) in a plane of the cross-section, and wherein the cavity (10) has an electrically conductive edge.

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