DIELECTRIC SHAFT CONDUCTOR ARRANGEMENT

Description

Technical field

[0001] The present disclosure relates to measuring instruments for process automation in industrial or private settings. 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. Technical background

[0002] Waveguides are suitable for transmitting high-frequency waves (RF waves), for example, from an RF generator to an antenna. For at least some waveguides—for example, above a certain length—it may be necessary to attach one or more supports and / or other support devices to the waveguide, for example, to stabilize it. However, in at least some waveguides, such as certain types of dielectric waveguides, these supports can lead to RF wave leakage and / or interference reflections in the RF signal.

[0003] DE 10 2021 118 496 A1 describes a level measuring device for determining the level of a fill level of a product in a container with an antenna, a transmitting / receiving unit and a waveguide.

[0004] US 2022 / 0216581 A1 describes a waveguide cable arrangement.

[0005] Martin Geiger et al.: "A Multimodal Dielectric Waveguide-Based Monopulse Radar at 160 GHz", July 15, 2020, XP055719844 describes an HDPE waveguide connected to an MMIC.

[0006] US 2015 / 0362354 A1 describes a mode converter for a level radar. Summary

[0007] 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.

[0008] This problem is solved by the features of the independent patent claims. Further developments of the invention result from the dependent claims and the following description of embodiments.

[0009] A first aspect of the present disclosure relates to a radar device comprising a dielectric, in particular asymmetrical, waveguide arrangement, and in particular a dielectric waveguide arrangement configured for use in a radar device. The radar device may, in particular, be a radar device for process automation in an industrial or private setting, especially a level radar. The dielectric waveguide arrangement comprises a dielectric waveguide configured for propagating radio frequency waves (radar waves). A holder is provided which at least partially encompasses the dielectric waveguide in order to retain it. The holder is configured to be inserted with its end face into a receptacle in the base of an electronics housing containing a radar module of the radar device. For example, the holder has a substantially cylindrical shape.The bracket has at least one recess or protrusion on its front face to ensure rotational alignment of the bracket, and thus of the waveguide, when the bracket is inserted into the recess in the base.

[0010] The term recess or protrusion does not refer exclusively to holes and pins. Rather, it can also refer to other orientation elements attached to the holder, such as a milled edge.

[0011] The dielectric waveguide arrangement can therefore be used with a defined orientation relative to the electronics of the radar device and, in particular, to the radar signal source, in order to couple the RF signal with a defined orientation.

[0012] 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 protrusion has the shape of a cylindrical pin.

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

[0015] According to the invention, the holder is composed of 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 the dielectric waveguide to be centered in the holder.

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

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

[0019] According to another embodiment, the holder is connected to the dielectric waveguide by means of a positive-locking, a force-locking and / or a material-locking 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 the invention, the dielectric waveguide has a first section with a substantially uniform cross-section and a second section with a larger cross-section than the first section.

[0022] The second section can be used to enable the positioning of the dielectric waveguide in the longitudinal direction.

[0023] The dielectric waveguide can be designed as a plastic filament with a cross-sectional area of ​​virtually any shape, which in at least some embodiments can be rectangular or circular. The dielectric waveguide can be suitable or configured for transmitting a high-frequency signal, particularly for transmitting it with low loss. A dielectric waveguide can, for example, have a cross-sectional area between 0.25 mm² and 8 mm². The cross-sectional area can depend on the frequency to be transmitted by the waveguide. In general, a dielectric waveguide with a relatively small cross-sectional area—which can correspond to the first section—can 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 - can be less sensitive to external influences and objects (such as supports) that are located in the immediate vicinity of the waveguide.

[0024] Therefore, the dielectric waveguide described here can be configured as a first section with a substantially uniform cross-section over a predominant part of its length, and as a second section or expansion over at least some parts of its length, the second section having a larger cross-section than the first section. The second section or expansion can be particularly suitable for accommodating, for example, fastening elements (such as brackets). This advantageously achieves a compromise between low signal attenuation, which is a characteristic of the first section(s), and low susceptibility to interference, which is typical of the second section.Furthermore, this minimizes interference from the waveguide supports and improves the radar system's ringing behavior (interference reflections in the antenna area and / or near the antenna). Measurement reliability in the short range can also be increased.

[0025] The production of such dielectric waveguides with expansion can be achieved using various manufacturing processes. For example, production by injection molding, especially plastic injection molding, has proven to be very efficient and / or cost-effective.

[0026] 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, particularly by a factor of 10 to 50, for example by a factor of 15 to 30, particularly by a factor of 3. This has proven to be a particularly efficient compromise between low signal attenuation and low interference when used with (e.g.) mounting brackets.

[0027] In some embodiments, the transition between the first and second sections is stepped, angled, and / or rounded. The transition on the left and right sides of the second section can be identical. The design of the transition may depend on the manufacturing process chosen.

[0028] In some embodiments, the dielectric waveguide has a cross-sectional area between 0.25 mm² and 8 mm², in particular between 0.3 mm² and 3 mm². 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 type of plastic used.

[0029] In some embodiments, the dielectric waveguide has a plurality of second sections, and these second sections are spaced between 10 mm and 300 mm apart. The spacing between the expansions of the dielectric waveguide can be equidistant, but non-uniform spacing is also possible. The spacing between the expansions can be significantly greater than the length of the expansions. This can advantageously emphasize the low signal attenuation.

[0030] 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 as an equilateral polygon. The shape of the cross-section may depend on the selected measurement frequency, the plastic used, the selected manufacturing process, and / or the objects attached to it (e.g., fasteners or supports).

[0031] In some embodiments, the dielectric waveguide has a DK value (relative dielectric constant ε r ) between 2 and 5 and / or loss factors tan(δ) between 0.00001 and 0.1.

[0032] In some embodiments, the dielectric waveguide is made of or comprises a plastic material, in particular a material from the group consisting of 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 exhibit low dielectric constants (Δk) (2 ≤ εr ≤ 3.5) and loss factors (0.00001 ≤ tan(δ) ≤ 0.1).

[0033] Another aspect of the present disclosure relates to a radar device comprising a dielectric waveguide or dielectric waveguide arrangement described above and below.

[0034] Another aspect of the present disclosure relates to the use of a radar device for level measurement, topology determination and / or limit level determination.

[0035] One aspect concerns the 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, particularly for frequencies between 70 GHz and 500 GHz, for example between 100 GHz and 300 GHz.

[0036] The term "process automation in industrial environments" refers to a subfield of engineering that encompasses measures for operating machines and systems without human intervention. One goal of process automation is to automate the interaction of individual components within a production plant in industries such as chemicals, food, pharmaceuticals, petroleum, paper, cement, shipping, or mining. A wide variety of sensors can be used for this purpose, specifically adapted to the requirements of the process industry, such as mechanical stability, resistance to contamination, extreme temperatures, and extreme pressures. Measurement data from these sensors is typically transmitted to a control room where process parameters such as fill level, limit level, flow rate, pressure, and density are monitored, and settings for the entire plant can be adjusted manually or automatically.

[0037] A subfield of process automation in industrial environments concerns the logistics automation of plants and supply chains. Using distance and angle sensors, logistics automation automates processes inside or outside a building or within a single logistics facility. Typical applications include baggage and freight handling at airports, traffic monitoring (toll systems), retail, parcel distribution, and building security (access control). What these examples have in common is that the respective application requires presence detection combined with precise measurement of the size and location of an object.For this purpose, sensors based on optical measurement methods using lasers, LEDs, 2D cameras or 3D cameras that detect distances according to the time-of-flight (ToF) principle can be used.

[0038] Another subfield of process automation in industrial settings concerns factory / production automation. Applications for this can be found in a wide variety of industries, such as automotive manufacturing, food production, pharmaceuticals, 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 allow it to proceed without human intervention. The sensors used here and the specific requirements regarding measurement accuracy in capturing the position and size of an object are comparable to those in the previous example of logistics automation.

[0039] The terms used in the claims should be interpreted in such a way as to give them the broadest possible reasonable interpretation in accordance with the foregoing description. For example, the use of the article "a" or "the" when introducing an element should not be interpreted as excluding a multitude of elements. Likewise, the mention of "or" should be interpreted as including a multitude of elements, so that the mention of "A or B" does not exclude "A and B" unless it is clear from the context or the preceding description that only one of A and B is meant.Furthermore, the phrase "at least one of A, B, and C" is to be understood as one or more elements from a group of elements consisting of A, B, and C, and not 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. Moreover, the mention of "A, B, and / or C" or "at least one of A, B, or C" should be interpreted as encompassing each individual unit of the listed elements, e.g., A; each subset of the listed elements, e.g., A and B; or the entire list of elements A, B, and C.

[0040] The following describes embodiments of the present disclosure with reference to the figures. Where the same reference numerals are used in the following figure descriptions, they denote identical or similar elements. The representations in the figures are schematic and not to scale. Brief description of the characters

[0041] Fig. 1 shows a level radar device with a dielectric waveguide arrangement. Fig. 2 shows the orientation of the E and H fields of the RF measurement signal to the cross-section of the dielectric waveguide. Fig. 3 shows a cross-sectional view of a section of a radar device with a dielectric waveguide arrangement. Fig. 4 shows a half-shell or a cross-sectional view of a dielectric waveguide arrangement for holding the dielectric waveguide. Fig. 5 shows a dielectric waveguide arrangement with two half-shells. Fig. 6 shows another dielectric waveguide arrangement. Fig. 7 shows another dielectric waveguide arrangement. Fig. 8 shows a top view of a dielectric waveguide arrangement. Detailed description of embodiments

[0042] Fig. 1 Figure 200 schematically shows a radar device 200, e.g., for level measurement 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, include a generator or transmitter and / or a receiver of high-frequency waves (HF waves).

[0043] A connection between the sensor electronics and an antenna system for transmitting the RF waves can be implemented, 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 so that, for example, the electronic components of the sensor electronics can be operated within their specified temperature range.

[0044] The dielectric waveguide 101 can be supported by one or more supports 102. The support 102 can at least partially enclose the dielectric waveguide 101. The support 102 can be connected to the dielectric waveguide 101 by means of a form-fit, force-fit, and / or material-fit connection. The support 102 can be detachably connected to the dielectric waveguide 101. The dielectric waveguide 101, together with the support 102 and, optionally, with other components—e.g., a housing—can form a dielectric waveguide assembly 100. The waveguide assembly 100 can, for example, have a length between 1 cm and 50 cm. Such a dielectric waveguide assembly 100 can advantageously exhibit low signal attenuation compared to a waveguide, for example, at frequencies > 100 GHz. Furthermore, a dielectric waveguide assembly 100 can be relatively simple and cost-effective, e.g.,They can be manufactured as injection-molded plastic parts. However, the production of waveguides for frequencies > 100 GHz can be technically demanding, complex, and correspondingly expensive.

[0045] 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 and second sections, which can be, for example, stepped, inclined, and / or rounded.

[0046] The mounting(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 during transmission of the RF waves via the dielectric waveguide 101 can be reduced. This advantageously achieves a compromise between low signal attenuation, which is particularly characteristic of the first section(s), and low interference susceptibility, which is typical of the second section.

[0047] Fig. 2 This shows the orientation of the electric and magnetic fields relative to the cross-section of the dielectric waveguide. The electric field lines are aligned parallel to the narrower side of the dielectric waveguide, and the magnetic field lines are aligned parallel to the longer side of the dielectric waveguide.

[0048] The dielectric waveguide arrangement, which is described in more detail below, enables a defined alignment and orientation of the electronic unit containing the radar module to the dielectric waveguide arrangement with the two half-shells and thus the dielectric waveguide clamped therein, which may have a non-rotationally symmetric or even rectangular cross-section.

[0049] The antenna, which comprises the unit consisting of half-shells and waveguide as well as a lens, and the housing containing the electronics unit are rotationally symmetrical. During assembly, however, the electronics unit must be aligned with the rectangular waveguide in the antenna. Correct alignment results in a defined coupling of the RF signal (electric and magnetic fields) to the cross-section of the waveguide.

[0050] The E-field and the H-field 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, respectively.

[0051] The recesses or protrusions provided on the front surface of the bracket allow for easy orientation and thus mounting of the electronic unit to the antenna system, which includes the waveguide and the bracket.

[0052] Fig. 3 Figure 1 shows a cross-sectional view of a section of a radar device with the bracket 102 described above, which holds the dielectric waveguide 101. The end face 103 of the bracket 102 abuts the base 105 of the electronics housing 107. For improved centering and support, a receptacle 104 is provided in the base 105 of the electronics housing, for example, in the form of a cylindrical section whose inner contour is adapted to the outer contour of the bracket 102, allowing it to be inserted therein. In the embodiment of the Fig. 3 two or more cylindrical pins 106 which are inserted into corresponding bores in the base 105 of the electronic cup 107 to effect a rotational alignment of the holder 102 relative to the radar module 108 of the radar device.

[0053] Fig. 4 Figure 1 shows a first half-shell or cross-sectional view of a dielectric waveguide arrangement 100. The half-shell serves to support 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 of the half-shell, so that the dielectric waveguide 101 is secured against both longitudinal and rotational movement.

[0054] Two bores 106 are provided on the front face of the holder, into which corresponding pins of the electronic cup can engage when the holder is inserted into the receptacle of the electronic cup.

[0055] Fig. 5 shows a dielectric waveguide arrangement 100, consisting of two in Fig. 4 The hemispheres shown are composed of the two halves shown. As in Fig. 5 As can be seen, 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 electronic cup in two positions, both positions having an angle of 180° to each other.

[0056] Fig. 6 Figure 1 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 are located in the electronic cup into which the pins engage.

[0057] Fig. 7 Figure 1 shows another embodiment in which two pins 106 and two holes are provided, wherein there are accordingly two holes and two pins at the bottom of the electronic cup.

[0058] Fig. 8Figure 1 shows a top view of a dielectric waveguide arrangement with the two half-shells 1011 and 1012. It should be noted that only a single protrusion or recess may be provided, which is located in one of the two half-shells 1011, 1012.

[0059] Preferably, the holder 102 consists of two half-shells 1011, 1012 (identical or different half-shells). The half-shells can be screwed, glued, or pinned together, or may have other alignment or fastening options. The dielectric waveguide is attached centrally. The holder can be made of metal, plastic with metallization at the fastening points, or have metallic inserts at the fastening points.

[0060] The cross-section of the dielectric waveguide can be rectangular and non-rotationally symmetric. The radar module is oriented perpendicular or parallel to the rectangular cross-section of the waveguide.

[0061] The dielectric waveguide arrangement can be defined as a pre-assembly and can also fulfill other functions, such as temperature decoupling, galvanic isolation in the case of plastic half-shells, a pressure-bearing function (function as a pressure piece) or a pressure screw in variants with additional thread or as a press fit.

[0062] This results in a simple assembly of the electronics unit, including the radar module, into a unit consisting of the waveguide and the mounting device.

[0063] The level radar measuring device can have a transmission frequency of ≥ 75 GHz and can be specifically designed for object detection.

[0064] The waveguide is held in place within the two plastic half-shells by means of metallic 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 with the assembly consisting of the two half-shells and the waveguide by means of a fitting and dowel pins (at least two). The orientation of the base / electronics unit can also be achieved by an offset drilling pattern, for example, for the screws. Orientation can also be achieved by different designs on the end faces of the two half-shells, for example, by notches or similar features. This ensures precise, perpendicular alignment of the electric or magnetic field with the rectangular cross-section of the waveguide.

Claims

1. A radar device (200), comprising a dielectric waveguide assembly (100) for the radar device (200) and an electronics cup (107), the dielectric waveguide assembly (100) comprising: a dielectric waveguide (101) for propagating high-frequency waves; a bracket (102) that at least partially surrounds the dielectric waveguide (101); wherein the bracket (102) is configured to be inserted with its end face (103) into a receptacle (104) in the form of a cylindrical portion of a bottom (105) of the electronics cup (107) that contains a radar module (106); wherein the bracket (102) has at least one recess (106) or protrusion (106) on its end face (103) in order to effect a rotational alignment of the bracket (102), and thus of the waveguide (101), when the bracket (102) is inserted into the receptacle (104) of the base (105); wherein the holder (102) is constructed from a first half-shell (1011) and a second half-shell (1012) that has a design corresponding to the first half-shell (1011); wherein the dielectric waveguide (101) has a first section with a substantially uniform cross-section, and a second section (110, 111) with a larger cross-section than the first section, which are located in corresponding recesses of the first half-shell (1011), so that the dielectric waveguide (101) is secured against both longitudinal movement and rotational movement.

2. The radar device (200) according to claim 1, wherein the protrusion (106) is designed in the form of a cylindrical pin.

3. The radar device (200) according to claim 1 or 2, wherein the recess (106) is designed in the form of a bore.

4. The radar device (200) according to one of the preceding claims, wherein the first half-shell (1011) has a receptacle for the dielectric waveguide (101).

5. The radar device (200) according to one of the preceding claims, wherein the bracket (102) is made of stainless steel, in particular of 316L stainless steel, or aluminium, and / or of a metal-coated plastic, in particular of HDPE, a foam, in particular a hard foam, for example Rohacell, or comprises this material.

6. The radar device (200) according to one of the preceding claims, wherein the material of the bracket (102) has a lower DK value than the dielectric waveguide (101).

7. The radar device (200) according to one of the preceding claims, wherein the bracket (102) is connected to the dielectric waveguide (101) by means of a form-fitting, force-fitting and / or material-fitting connection.

8. The radar device (200) according to one of the preceding claims, wherein the dielectric waveguide (101) has a non-rotationally symmetrical, in particular a rectangular cross-section.

9. The radar device (200) according to one of the preceding claims, wherein the dielectric waveguide (101) consists of or comprises a plastic material, in particular a material from a group which includes polyetheretherketone, PEEK, polytetrafluoroethylene, PTFE, perfluoroalkoxy, PFA, polyvinylidene fluoride, PVDF, and / or high-density polyethylene, HDPE.

10. Use of a radar device (200) according to one of the preceding claims for fill level measurement, for topology determination and / or for limit level determination.