Dielectric waveguide arrangement

Abstract

A dielectric waveguide arrangement for radar equipment, comprising a dielectric waveguide and a mount that at least partially encloses the dielectric waveguide, the front end of the mount having at least one recess or protuberance.

Description

[0001] Dielectric waveguide arrangement

[0002] Reference to related applications

[0003] This application claims priority from European patent application No. 23 181 523.4, filed on 26 June 2023, which is incorporated in its entirety by reference.

[0004] Technical area

[0005] The present disclosure relates to measuring devices for process automation in industrial or private environments. In particular, the present disclosure relates to a dielectric waveguide arrangement for a radar device, a radar device with such a dielectric waveguide arrangement, and a use thereof.

[0006] Technical background

[0007] Waveguides are suitable for transmitting radio-frequency (RF) waves, e.g., from an RF generator to an antenna. For at least some waveguides—e.g., above a certain waveguide length—it may be necessary to arrange one or more supports and / or other support devices on the waveguide, e.g., to support the waveguide. However, for at least some waveguides, e.g., some types of dielectric waveguides, these supports can lead to RF waves escaping from the waveguide and / or to spurious reflections in the RF signal. Summary

[0008] Against this background, it is an object of the present invention to provide a dielectric waveguide arrangement for a radar device which enables good signal quality.

[0009] This object is achieved by the features of the independent patent claims. Further developments of the invention emerge from the subclaims and the following description of embodiments.

[0010] A first aspect of the present disclosure relates to a dielectric, in particular asymmetric, waveguide arrangement, and in particular to a dielectric waveguide arrangement configured for use in a radar device. The radar device can be, in particular, a radar device for process automation in an industrial or private environment, in particular a level radar device. The dielectric waveguide arrangement has a dielectric waveguide configured to propagate high-frequency waves (radar waves). A holder is provided which at least partially encloses the dielectric waveguide in order to hold it. The holder is configured to be inserted with its end face into a receptacle in the base of an electronics can containing a radar module of the radar device. For example, the holder has a substantially cylindrical shape.On its front surface, the holder has at least one recess or protrusion to effect a rotational alignment of the holder, and thus of the waveguide, when the holder is inserted into the receptacle in the base.

[0011] The term "recess" or "protrusion" does not refer exclusively to holes and pins. Rather, it can also refer to other orientation elements incorporated into the mount, such as a milled edge.

[0012] The dielectric waveguide arrangement can thus be used with a defined orientation relative to the radar device's electronics, and in particular to the radar signal source, in order to couple the RF signal with a defined orientation. This is particularly advantageous if the dielectric waveguide is not a circular waveguide with a circular cross-section.

[0013] According to one embodiment of the present disclosure, the protuberance has the shape of a cylindrical pin.

[0014] According to a further embodiment, the recess is designed in the form of a bore.

[0015] According to a further embodiment, the holder is constructed from a first half-shell and a second half-shell, wherein the first half-shell has a design corresponding to the second half-shell.

[0016] According to a further embodiment, the first half-shell and / or the second half-shell has a receptacle for the dielectric waveguide. This can enable centering of the dielectric waveguide in the holder.

[0017] According to a further embodiment of the present disclosure, the holder is made of stainless steel, in particular of 316L stainless steel, or aluminum, and / or of a metallically coated plastic, in particular HDPE, of a foam, in particular of a rigid foam, for example Rohacell, or comprises such a material.

[0018] According to a further embodiment, the material of the holder has a lower DK value than the dielectric waveguide.

[0019] According to a further embodiment, the holder is connected to the dielectric waveguide by means of a positive, a non-positive and / or a material connection.

[0020] According to a further embodiment of the present disclosure, the dielectric waveguide has a non-rotationally symmetric, in particular a rectangular, cross-section.

[0021] According to a further embodiment, the dielectric waveguide comprises a first section with a substantially uniform cross-section and a second section with a larger cross-section than the first section. The second section can serve to facilitate the longitudinal positioning of the dielectric waveguide.

[0022] The dielectric waveguide can be designed as a plastic filament, with a cross-sectional area of, in principle, any desired shape, which in at least some embodiments can be rectangular or round. The dielectric waveguide can be suitable or configured to transmit a high-frequency signal, in particular with low loss. A dielectric waveguide can, for example, have a cross-sectional area between 0.25 mm 2 and 8 mm 2The cross-sectional area may depend on the frequency to be transmitted by the waveguide. In general, a dielectric waveguide with a relatively small cross-sectional area—which may correspond to the first section—may exhibit relatively lower signal attenuation than a waveguide with a relatively larger cross-sectional area. However, a waveguide with a larger cross-sectional area—which may correspond to the second section—may be less sensitive to external influences and objects (such as mounting brackets) located in the immediate vicinity of the waveguide.

[0023] Therefore, the dielectric waveguide described here can be designed as a first section with a substantially uniform cross-section over a predominant part of its length, and as a second section or widened section over at least some parts of its length, wherein the second section has a larger cross-section than the first section. The second section or widened section can be particularly suitable for arranging fastening elements (such as holders) on it, for example. This advantageously makes it possible to achieve a compromise between low signal attenuation, which in particular characterizes the first section(s), and low interference sensitivity, which is typical of the second section.Furthermore, this can minimize interference from the waveguide mounts and improve the radar system's ringing behavior (interference reflections in the antenna area and / or near the antenna). Furthermore, measurement reliability at close range can be increased.

[0024] The production of such dielectric waveguides with expansion can be achieved using various manufacturing processes. For example, production by injection molding, particularly plastic injection molding, has proven to be very efficient and / or cost-effective.

[0025] In some embodiments, the cross-sectional area of ​​the second section is larger than the cross-sectional area of ​​the first section by a factor of 3 to 80, in particular by a factor of 10 to 50, for example by a factor of 15 to 30, in particular by a factor of 3. This has proven to be a particularly efficient compromise between low signal attenuation and low interference when arranged with (e.g.) mounts.

[0026] In some embodiments, a transition between the first section and the second section is designed to be stepped, slanted, and / or rounded. The transition on the left and right sides of the second section can be designed identically. The design of the transition can depend on the selected manufacturing method.

[0027] In some embodiments, the dielectric waveguide has a cross-sectional area between 0.25 mm 2 and 8 mm 2 , especially between 0.3 mm2 and 3 mm 2 The diameter of the cross-section can depend, for example, on the frequency and / or the shape of the cross-section (e.g., rectangular) as well as on the plastic used.

[0028] In some embodiments, the dielectric waveguide has a plurality of second sections, and the second sections are spaced between 10 mm and 300 mm. The spacing between the dielectric waveguide flares can be equidistant from each other, but uneven spacing is also possible. The spacing between the flares can be significantly larger than the length of the flares. This can advantageously emphasize low signal attenuation.

[0029] In some embodiments, the cross-section of the first section and / or the second section is elliptical, in particular round, rectangular, in particular square, and / or polygonal, in particular an equilateral polygon. The design of the cross-section may depend on the selected measurement frequency, the plastic used, the selected manufacturing method, and / or the objects arranged thereon (e.g., fastening elements or mounts).

[0030] In some embodiments, the dielectric waveguide has a DK value (relative dielectric constant E r ) between 2 and 5 and / or loss factors tan(ö) between 0.00001 and 0.1.

[0031] In some embodiments, the dielectric waveguide consists of a plastic or comprises this material, in particular a material from a group comprising polyetheretherketone, PEEK, polytetrafluoroethylene, PTFE, perfluoroalkoxy, PFA, polyvinylidene fluoride, PVDF, and / or high-density polyethylene (HDPE). These plastics can, in particular, tolerate high process temperatures and / or be resistant to a variety of chemicals. Furthermore, from a high-frequency perspective, these plastics can have small DK values ​​(2 < E r 3.5) and loss factors (0.00001 < tan(ö) < 0.1).

[0032] Another aspect of the present disclosure relates to a radar device comprising a dielectric waveguide or a dielectric waveguide arrangement described above and below.

[0033] Another aspect of the present disclosure relates to the use of a radar device for level measurement, topology determination and / or limit level determination.

[0034] One aspect relates to a use of a dielectric waveguide as described above and / or below or a dielectric waveguide arrangement as described above and / or below for propagating radar waves, in particular for frequencies between 70 GHz and 500 GHz, for example between 100 GHz and 300 GHz.

[0035] The term "process automation in industrial environments" can be understood as a branch of technology that includes measures for operating machines and systems without human intervention. One goal of process automation is to automate the interaction of individual components of a plant in the chemical, food, pharmaceutical, petroleum, paper, cement, shipping, or mining industries. A variety of sensors can be used for this purpose, which are specifically adapted to the specific requirements of the process industry, such as mechanical stability, insensitivity to contamination, extreme temperatures, and extreme pressures. Measured values ​​from these sensors are usually transmitted to a control room, where process parameters such as fill level, limit level, flow rate, pressure, or density are monitored, and settings for the entire plant can be changed manually or automatically.

[0036] A sub-area of ​​process automation in the industrial environment concerns the logistics automation of plants and the logistics automation of supply chains. With the help of distance and angle sensors, processes inside or outside a building, or within a single logistics facility, are automated in the field of logistics automation. Typical applications for logistics automation systems include baggage and freight handling at airports, traffic monitoring (toll systems), retail, parcel distribution, and building security (access control). What the aforementioned examples have in common is that the respective application requires presence detection in combination with precise measurement of the size and location of an object.For this purpose, sensors based on optical measuring methods using lasers, LEDs, 2D cameras or 3D cameras that measure distances according to the time of flight (ToF) principle can be used.

[0037] Another sub-area of ​​process automation in the industrial environment concerns factory-to-production automation. Applications for this can be found in a wide variety of industries, such as automotive manufacturing, food production, the pharmaceutical industry, and packaging in general. The goal of factory automation is to automate the production of goods using machines, production lines, and / or robots, i.e., to run it without human intervention. The sensors used here and the specific requirements regarding measurement accuracy in detecting the position and size of an object are comparable to those in the previous example of logistics automation. The terms used in the claims should be construed to give them the broadest possible reasonable interpretation in accordance with the above description.For example, the use of the article "a" or "the" when introducing an element should not be interpreted as excluding a plurality of elements. Similarly, the mention of "or" should be interpreted as including a plurality of elements, so that the mention of "A or B" does not exclude "A and B" unless it is clear from the context or preceding description that only one of A and B is meant. Further, the phrase "at least one of A, B, and C" should be understood as one or more elements from a group of elements consisting of A, B, and C, and should not be interpreted as requiring at least one of each of the listed elements A, B, and C, regardless of whether A, B, and C are related as categories or otherwise.Furthermore, the mention of "A, B and / or C" or "at least one of A, B or C" should be interpreted to include any single entity of the listed elements, e.g., A, any subset of the listed elements, e.g., A and B, or the entire list of elements A, B and C.

[0038] Embodiments of the present disclosure are described below with reference to the figures. Where the same reference numerals are used in the following description of the figures, they denote identical or similar elements. The representations in the figures are schematic and not to scale.

[0039] Short description of the characters

[0040] Fig. 1 shows a level radar device with a dielectric waveguide arrangement.

[0041] Fig. 2 shows the orientation of the E and H fields of the RF measurement signal to the cross section of the dielectric waveguide.

[0042] Fig. 3 shows a cross-sectional view of a portion of a radar device with a dielectric waveguide arrangement.

[0043] Fig. 4 shows a half-shell or a cross-sectional view of a dielectric waveguide arrangement for supporting the dielectric waveguide. Fig. 5 shows a dielectric waveguide arrangement with two half-shells.

[0044] Fig. 6 shows another dielectric waveguide arrangement.

[0045] Fig. 7 shows another dielectric waveguide arrangement.

[0046] Fig. 8 shows a plan view of a dielectric waveguide arrangement.

[0047] Detailed description of embodiments

[0048] Fig. 1 schematically shows a radar device 200, e.g., for level measurement technology in process or factory automation, according to one embodiment. The radar device 200 has sensor electronics arranged in a housing. The sensor electronics can, for example, comprise a generator or transmitter and / or a receiver of high-frequency waves (RF waves).

[0049] A connection between the sensor electronics and an antenna system for transmitting the RF waves can be realized, for example, using a dielectric waveguide 101. This can be particularly advantageous for applications at high process temperatures, where a certain spatial distance between the sensor electronics and the antenna system may be required, for example, so that the electronic components of the sensor electronics can be operated within their specified temperature range.

[0050] The dielectric waveguide 101 can be supported by one or more holders 102. The holder 102 can at least partially enclose the dielectric waveguide 101. The holder 102 can be connected to the dielectric waveguide 101 by means of a positive, force-fitting and / or material-fitting connection. The holder 102 can be detachably connected to the dielectric waveguide 101. The dielectric waveguide 101 can form a dielectric waveguide arrangement 100 with the holder 102 and, optionally, with further components - e.g., a housing. The waveguide arrangement 100 can, for example, have a length between 1 cm and 50 cm. Such a dielectric waveguide arrangement 100 can advantageously have low signal attenuation compared to a waveguide, e.g., at frequencies > 100 GHz. Furthermore, a dielectric waveguide arrangement 100 can be relatively simple and inexpensive, e.g.,as a plastic injection-molded part. However, the production of waveguides for frequencies > 100 GHz can be technically challenging, complex, and correspondingly costly.

[0051] The dielectric waveguide 101 can have one or more first sections with a substantially uniform cross-section. Furthermore, the dielectric waveguide 101 can have one or more second sections. The second section(s) have a larger cross-section (or a widening) than the first section. A transition is arranged between the first section and the second section, which transition can be configured, for example, in a stepped, angled, and / or rounded manner.

[0052] The holder(s) 102 are preferably arranged on the second section. This can be advantageous because it allows for an optimized electric field distribution in and / or on the dielectric waveguide 101. In particular, interference reflections in the RF signal can be reduced when the RF waves are transmitted via the dielectric waveguide 101. This advantageously allows a compromise to be achieved between low signal attenuation, which is particularly characteristic of the first section(s), and low interference sensitivity, which is typical of the second section.

[0053] Fig. 2 shows the orientation of the E and H fields relative to the cross-section of the dielectric waveguide. Here, the E field lines are aligned parallel to the narrower side of the dielectric waveguide, and the H field lines are aligned parallel to the longer side of the dielectric waveguide.

[0054] The dielectric waveguide arrangement, which is described in more detail below, enables a defined alignment and orientation of the electronics unit containing the radar module to the dielectric waveguide arrangement with the two half-shells and thus the dielectric waveguide clamped therein, which can have a non-rotationally symmetric or even rectangular cross-section.

[0055] The antenna, which contains the half-shell unit and waveguide, as well as a lens, and the housing, which houses the electronics unit, are rotationally symmetrical. However, during assembly, the electronics unit must be aligned with the rectangular waveguide in the antenna. Correct alignment results in a defined coupling of the RF signal (E and H fields) to the cross-section of the waveguide.

[0056] The E and H fields must be aligned perpendicular to the dielectric waveguide as well as to the longer and shorter legs of the rectangular cross-section of the dielectric waveguide.

[0057] The recesses or protrusions provided on the front surface of the holder allow for easy orientation and thus assembly of the electronics unit to the antenna system, which contains the waveguide including the holder.

[0058] Fig. 3 shows a cross-sectional view of a portion of a radar device with the above-described holder 102, which holds the dielectric waveguide 101. With the end face 103, the holder 102 abuts the base 105 of the electronics can 107. For better centering and support, a receptacle 104 is provided in the base 105 of the electronics can, for example in the form of a cylindrical section whose inner contour is adapted to the outer contour of the holder 102 so that the latter can be inserted therein. In the embodiment of Fig. 3, the holder 102 has two or more cylindrical pins 106, which are inserted into corresponding bores in the base 105 of the electronics can 107 in order to effect a rotational alignment of the holder 102 relative to the radar module 108 of the radar device.

[0059] Fig. 4 shows a first half-shell or cross-sectional view of a dielectric waveguide arrangement 100. The half-shell serves to hold the dielectric waveguide 101. The dielectric waveguide 101 has a first section with a substantially uniform cross-section and two second sections 110, 111, which have a larger cross-section than the first section. These are located in corresponding recesses in the half-shell, so that the dielectric waveguide 101 is secured against both longitudinal and rotational movement. Two bores 106 are provided on the end face of the holder, into which corresponding pins of the electronics can engage when the holder is pushed into the receptacle of the electronics can.

[0060] Fig. 5 shows a dielectric waveguide assembly 100 composed of two half-shells shown in Fig. 4. As can be seen in Fig. 5, the four holes 106 are not arranged at 90° angles to each other, so that the holder can only be inserted into the receptacle of the electronics cup in two positions, both positions being at an angle of 180° to each other.

[0061] Fig. 6 shows another embodiment of a dielectric waveguide arrangement 100, in which protrusions 106 in the form of cylindrical pins are provided on the end face. Corresponding bores into which the pins engage are located in the electronics can.

[0062] Fig. 7 shows a further embodiment in which two pins 106 and two bores are provided, with two bores and two pins being located correspondingly at the bottom of the electronics can.

[0063] Fig. 8 shows a plan view of a dielectric waveguide arrangement with the two half-shells 1011 and 1012. At this point, it should be noted that only a single protuberance or recess can be provided, which is provided in one of the two half-shells 1011, 1012.

[0064] Preferably, the holder 102 consists of two half-shells 1011, 1012 (identical or different half-shells). The half-shells can be screwed, glued, pinned, or have other alignment or fastening options. The dielectric waveguide is attached centrally. The holder can be metallic, made of plastic with metallization at the holding points, or have metallic inserts at the holding points.

[0065] The cross-section of the dielectric waveguide can, in particular, be rectangular and non-rotationally symmetric. The radar module is oriented perpendicular or parallel to the rectangular cross-section of the waveguide. The dielectric waveguide arrangement can be defined as a subassembly and also fulfill additional functions, such as thermal decoupling, galvanic isolation in plastic half-shells, a pressure-bearing function (function as a pressure piece), or a pressure screw in variants with an additional thread or as a press-fit joint.

[0066] This results in a simple assembly of the electronics unit including the radar module to the unit consisting of the waveguide and the holding device.

[0067] The level radar measuring device can have a transmission frequency of > 75 GHz and can be designed in particular for object detection.

[0068] The waveguide is held in the two plastic half-shells by metal inserts. The circuit board with the radar module is screwed onto the base of the electronics unit. The base of the electronics unit is aligned to the subassembly consisting of the half-shells and the waveguide by means of a fit and cylindrical pins (at least two cylindrical pins). The orientation of the base of the electronics unit / electronics unit can also be achieved using an offset drilling pattern, for example, with screws. Orientation can also be achieved by differently designing the end faces of the two half-shells, for example, with notches or the like. This enables a perpendicular, precise alignment of the E or H field to the rectangular cross-section of the waveguide.

Claims

Patent claims 1. A dielectric waveguide arrangement (100) for a radar device (200), comprising: a dielectric waveguide (101) for propagating high-frequency waves; a holder (102) which at least partially encloses the dielectric waveguide (101); wherein the holder (102) is configured to be inserted with its end face (103) into a receptacle (104) of a base (105) of an electronics can (107) which contains a radar module (106); wherein the holder (102) has at least one recess (106) or protuberance (106) on its end face (103) in order to bring about a rotational alignment of the holder (102), and thus of the waveguide (101), when the holder (102) is inserted into the receptacle (104) of the base (105).

2. Dielectric waveguide arrangement (100) according to claim 1, wherein the protuberance (106) is designed in the form of a cylindrical pin.

3. Dielectric waveguide arrangement (100) according to claim 1 or 2, wherein the recess (106) is designed in the form of a bore.

4. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the holder (102) is constructed from a first half-shell (1021) and a second half-shell (1022) which has a design corresponding to the first half-shell (1021).

5. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the first half-shell (1021) has a receptacle for the dielectric waveguide (101).

6. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the holder (102) consists of stainless steel, in particular of 316L stainless steel, or of aluminum, and / or of a metallically coated plastic, in particular HDPE, of a foam, in particular of a rigid foam, for example Rohacell, or comprises this material.

7. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the material of the holder (102) has a lower DK value than the dielectric waveguide (101).

8. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the holder (102) is connected to the dielectric waveguide (101) by means of a positive, non-positive and / or material connection.

9. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the dielectric waveguide (101) has a non-rotationally symmetrical, in particular a rectangular, cross-section.

10. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the dielectric waveguide (101) a first section having a substantially uniform cross-section, and a second section (110, 111) having a larger cross-section than the first section.

11. Dielectric waveguide arrangement (100) according to one of the preceding claims, wherein the dielectric waveguide (101) consists of a plastic or comprises this material, in particular a material from a group comprising polyetheretherketone, PEEK, polytetrafluoroethylene, PTFE, perfluoroalkoxy, PFA, polyvinylidene fluoride, PVDF, and / or hard polyethylene, HDPE.

12. Radar device (200) comprising a dielectric waveguide arrangement (100) according to one of claims 1 to 11.

13. Use of a radar device (200) according to claim 12 for level measurement, topology determination and / or limit level determination.

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