Isolation point for a waveguide arrangement and radar sensor

Abstract

The invention relates to an isolation point (100) for the galvanic isolation of a first waveguide (601) from a second waveguide (801). The isolation point has a cylindrical dielectric waveguide (101) which is designed to receive a high-frequency signal at a first end and to emit said high-frequency signal at a second end. The isolation point also has a cylindrical dielectric sleeve (104) which surrounds the dielectric waveguide in a radially spaced manner. The isolation point also has brackets (103a, 103b) extending radially from the dielectric waveguide to the cylindrical sleeve such that the cylindrical dielectric sleeve and the dielectric waveguide have the same cylinder axis and the dielectric waveguide is held centered in the cylindrical dielectric sleeve by the brackets.

Description

VEGA GRIESHABER KG Our ref.: V11264WO / CGS DISCONNECTION POINT FOR A HOLLOW CONDUCTOR ARRANGEMENT AND RADAR SENSOR TECHNICAL AREA

[0001] The invention relates to an isolation point for the galvanic isolation of a first waveguide from a second waveguide, a radar sensor and a use of the isolation point. BACKGROUND OF THE INVENTION

[0002] Modern level gauges are frequently implemented as radar sensors. Advances in semiconductor technology have enabled increasingly higher signal frequencies. FMCW radar sensors, for example, now operate at frequencies of 80 GHz. Access to higher frequency ranges has allowed for smaller antenna designs and greater antenna gain for the same aperture. This results in, for instance, such narrow beamwidths that even in tall, narrow containers, interference reflections no longer fall within the antenna's field of view.

[0003] While antennas in lower frequency ranges around 6 GHz and 24 GHz can be fed with coaxial cables, the high attenuation of these cables necessitates the use of waveguide technology in the frequency range around 80 GHz. Waveguides exhibit very low attenuation in this frequency range and can be manufactured cost-effectively in sufficient lengths. Round horn antennas are frequently used, often incorporating a dielectric filling to reduce the horn's length.

[0004] A new generation of level gauges aims to further leverage the existing positive effects associated with increased transmission frequencies. At frequencies around 180 GHz and 240 GHz, the antennas of these gauges can be made even smaller to achieve comparable antenna gains to those at 80 GHz. Smaller antennas open up new application areas in smaller containers or factory automation, thus unlocking new markets. However, new challenges arise in assembly and connection technology. The attenuation characteristics of coaxial cables in frequency ranges above 150 GHz are too high for practical use in a level gauge.

[0005] Dielectric waveguides can be used to transmit signals from sensor electronics to the antenna, achieving galvanic isolation between the sensor electronics and the antenna. The dielectric waveguide requires no metallic connection for signal transmission, making it ideal for potential isolation. However, it also has disadvantages regarding the temperature resistance of the plastics and the susceptibility to interference from nearby points of contact. Furthermore, the isolation between the sensor electronics and the antenna allows, for example, the replacement of a defective electronic unit without having to unscrew the antenna from the housing opening. Similarly, in the case of defective electronic units, it is not necessary to replace the entire device; it is sufficient to replace only the active component, which is more sustainable. Currently, this isolation for radar sensors up to 80 GHz is achieved either via a CGS: is implemented via coaxial high-frequency connectors or via a plastic sleeve between two waveguides.

[0006] However, when using frequency ranges up to 250 GHz, the dimensions of the isolation point become significantly smaller. For example, if the center frequency increases by a factor of 3 from 80 GHz to 240 GHz, the dimensions of the structures decrease by the same factor. The waveguide diameter of a circular waveguide, for instance, decreases from 2.6 mm to 0.87 mm. Due to this scaling, however, the requirements for galvanic isolation with regard to dielectric strength / voltage resistance can no longer be met, as the component geometry becomes considerably smaller. Furthermore, the requirements for the mechanical properties become so high that this invention cannot be scaled to higher frequency ranges, or only with great difficulty. SUMMARY OF THE INVENTION

[0007] The object of the invention is therefore to provide an improved separation point.

[0008] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments are the subject matter of the dependent claims, the following description, and the figures.

[0009] The described embodiments similarly relate to the separation point, the radar sensor, and the use of the separation point. Synergistic effects may arise from various combinations of the embodiments, although these may not be described in detail.

[0010] According to a first aspect, an isolation junction, which can also be referred to as an isolating element, is provided for the galvanic isolation of a first waveguide from a second waveguide. The isolation junction comprises a cylindrical dielectric waveguide configured to receive a high-frequency signal at one end and output it at the other. The isolation junction further comprises a cylindrical dielectric sleeve that radially surrounds the dielectric waveguide. The isolation junction also includes supports extending radially from the dielectric waveguide to the cylindrical sleeve, such that the cylindrical dielectric sleeve and the dielectric waveguide share a common cylindrical axis, and the dielectric waveguide is held centered within the cylindrical dielectric sleeve by the supports.

[0011] In this disclosure, a waveguide element is understood to be a component with a cylindrical cavity having a metallic or metallized wall for guiding electromagnetic waves. The cylindrical cavity with the wall, realized by a tubular structure, is referred to as a waveguide. The waveguide furthermore has a uniform (inner) diameter. According to this definition, the adapter pieces described herein are not part of the waveguide. Thus, the term "waveguide" here refers only to the inner part of the waveguide element through which the electromagnetic wave travels, including the wall. Conversely, a waveguide element is, in principle, an element of any shape that contains a cylindrical cavity formed by a wall, with the cylindrical cavity and the wall constituting the waveguide.

[0012] An electromagnetic wave, generated in an electronic unit of a device, such as a sensor, travels from the electronic unit through a first waveguide. It exits at the end of this waveguide and is received by the cylindrical dielectric waveguide at its first end. Unlike a waveguide, a dielectric waveguide is a solid material element without a cavity and contains no metallic parts. The dielectric waveguide guides the electromagnetic wave through it until it reaches its second end and exits there. The second waveguide receives the electromagnetic wave and directs it towards an antenna of the device. The interface thus separates the first and second waveguides of the device, firstly by the dielectric waveguide, which transmits the electromagnetic wave even without a metallic inner wall that forms the cavity of the waveguide.Secondly, a stable mechanical connection is created by a cylindrical sleeve surrounding the dielectric waveguide. This connection is simultaneously non-conductive and thus galvanically isolates the metallic waveguide elements that provide the first and second waveguides, respectively. The dielectric waveguide is therefore a continuation of the waveguides between them and thus preferably has the same diameter as the waveguides. Due to the high frequencies addressed in this application, the diameters of the waveguides are small, and consequently, so is the diameter of the dielectric waveguide. This results in low mechanical stability of the dielectric waveguide, which is restored by the sleeve.

[0013] The sleeve surrounds the dielectric waveguide. The inner diameter of the sleeve is larger than the diameter of the dielectric waveguide. The dielectric waveguide is held by supports that extend radially from the surface of the dielectric waveguide to the inner wall of the sleeve. The supports are thus perpendicular to the surface of the dielectric waveguide and to the inner wall of the sleeve. The supports can be designed as spokes. Preferably, however, they extend parallel to the axial axis of the dielectric waveguide or the sleeve and in a plane that contains the axial axis of the dielectric waveguide, along the entire length of the sleeve.

[0014] The ends of the dielectric waveguide preferably protrude from the sleeve so that they can be inserted into the first waveguide or the second waveguide, and so that these elements are mechanically and from the point of view of the waveguide are well connected to each other.

[0015] The inner diameter of the cylindrical sleeve is therefore larger than the diameter of the dielectric waveguide, and the length of the cylindrical sleeve is less than that of the dielectric waveguide. Preferably, the diameter of the dielectric waveguide matches that of the first and second waveguides.

[0016] According to one embodiment, the separation point is rotatable about the common cylinder axis.

[0017] Since the waveguides, the dielectric waveguide, and the sleeve are all cylindrical and share a common cylindrical axis, they can be rotated relative to each other. The dielectric waveguide is a fixed part of the joint and therefore rotates with the entire joint. Consequently, the electronics unit and antenna connected to the waveguides can also be rotated relative to each other. This allows, for example, the polarization of the radar signal within the container to be adjusted, or the electronics unit or a display attached to the sensor to be positioned more conveniently for the user.

[0018] According to one embodiment, the cylindrical dielectric waveguide has two conical ends.

[0019] This means that the dielectric waveguide tapers to a point or cone shape at both ends. This allows the dielectric waveguide to be inserted into the respective waveguides more easily and stably, and the electromagnetic waves can be received and emitted more efficiently.

[0020] According to one embodiment, the separation point is made of ceramic or plastic.

[0021] The dielectric waveguide can therefore be designed, for example, as a plastic cylinder. Examples of suitable materials include PP (polypropylene), PVDF (polyvinylidene fluoride), PTFE (polyetrafluoroethylene), PEEK (polyetheretherketone), HDPE (high-density polyethylene), POM (polyoxymethylene), or recycled plastic. An example of a ceramic material is aluminum oxide (Al₂O₃). The choice of material can be based on the application of the device and may depend, for example, on the requirements of a process environment, such as temperature, stability, and signal attenuation.

[0022] According to one embodiment, the separation point is a single piece.

[0023] For example, the separation point is designed as an injection-molded part or as a part manufactured using 3D printing.

[0024] According to one embodiment, the cylindrical dielectric sleeve has a locking device for connecting the separation point to a waveguide element containing the first or the second waveguide.

[0025] The locking mechanism is, for example, a circumferential locking lug. Alternatively, the locking lug can be segmented and thus designed as a locking hook. The separation point can then be connected to a waveguide element on the antenna side or a waveguide element on the electronics unit side.

[0026] According to another aspect, a radar sensor is provided, featuring a separation point according to one of the preceding claims comprising a cylindrical dielectric waveguide having a first end and a second end, a waveguide element comprising a first waveguide configured to receive the first end of the cylindrical dielectric waveguide, and a second waveguide configured to receive the second end of the cylindrical dielectric waveguide.

[0027] The radar sensor, for example, is a sensor used to measure the fill level of a container.

[0028] According to one embodiment, the waveguide arrangement further comprises a first funnel-shaped adapter between an end of the first waveguide and the separation point and a second funnel-shaped adapter between an end of the second waveguide and the separation point.

[0029] Since the dielectric waveguide is straight, the funnel-shaped adapter pieces of the waveguide are aligned at an angle of 180 degrees to each other. The funnel shape serves to geometrically match the radii of the cylindrical dielectric sleeve and the waveguide, and in particular to improve the transmission parameters, e.g., the insertion loss, compared to a right-angled transition.

[0030] According to one embodiment, the first adapter and the second adapter each have a rounded edge at the transition between the waveguide and the funnel-shaped adapter, i.e., between the first waveguide and its funnel-shaped adapter, and between the second waveguide and its funnel-shaped adapter.

[0031] The rounding can, in principle, represent any arc shape. However, a transition with a defined radius is preferred. Rounding avoids sharp edges, thereby further improving the transmission parameters.

[0032] According to one embodiment, the length of the cylindrical dielectric sleeve is designed to withstand a predetermined minimum flashover voltage strength.

[0033] The flashover voltage resistance depends on the distance between the two waveguides. This distance, in turn, is determined by the length of the sleeve, so the length of the sleeve is defined by the required flashover voltage resistance.

[0034] According to one embodiment, the separation point is rigidly connected to the first waveguide or to the second waveguide in the axial direction.

[0035] Since the first waveguide is axially fixed to the electronics unit, and the second waveguide is fixed to the antenna, the separation point is either rigidly connected to the electronics unit via the first waveguide or axially fixed to the antenna via the second waveguide. Therefore, the separation point is removed either when the antenna or when the electronics unit is removed.

[0036] According to one embodiment, the separation point is rotatable about the cylinder axis of the cylindrical sleeve and the first waveguide is rotatable relative to the second waveguide.

[0037] According to one embodiment, the radar sensor further comprises an electronic unit and an antenna, and the antenna can be rotated relative to the electronic unit by means of the rotatable separation point.

[0038] The rotatable antenna allows, for example, the polarization of the radar signal to be reversed inside the container.

[0039] According to one embodiment, the radar sensor also has a display that is fixedly connected to the electronic unit and can be rotated relative to the antenna.

[0040] Similar to the rotatable antenna, the electronic unit and attached components, such as a display, can also be rotated. This allows the display, which is attached to the sensor, to be positioned as needed by the user.

[0041] According to another aspect, the use of a waveguide separation point described herein in a radar sensor is provided.

[0042] Other variations of the disclosed embodiments can be understood and carried out by a person skilled in the art when carrying out the claimed invention by studying the drawings, the disclosure, and the accompanying claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit can perform the functions of several items or steps listed in the claims. The mere fact that certain measures are specified in interdependent claims does not mean that a combination of these measures cannot be advantageously used. BRIEF DESCRIPTION OF THE FIGURES

[0043] Exemplary embodiments of the invention are described in detail below with reference to the accompanying figures. Neither the description nor the figures are to be interpreted as limiting the invention.

[0044] Fig. 1 shows a representation with a 3D oblique view of a separation point.

[0045] Fig. 2 shows a 2D diagram with a front view of the separation point.

[0046] Fig. 3 shows a representation with a side view of the separation point.

[0047] Fig. 4 shows a representation with a second, rotated 3D oblique view of the separation point.

[0048] Fig. 5 shows a representation with a second, rotated 3D oblique view of the separation point in a section.

[0049] Fig. 6 shows a representation with a 3D oblique view of a waveguide end.

[0050] Fig. 7 shows a representation with a 3D oblique view of a waveguide end in a section.

[0051] Fig. 8 shows a representation with a 3D oblique view of a separation point mounted in the waveguide.

[0052] Fig. 9 shows a 3D oblique view of a separation point mounted in the waveguide in a section.

[0053] Fig. 10 shows a representation with a 3D oblique view of a separation point mounted in the waveguide in a section.

[0054] Fig. 11 shows a representation with a 3D oblique view of a separation point mounted in a first waveguide and in a waveguide element with a second waveguide.

[0055] Fig. 12 shows a representation with a 3D oblique view of a separation point mounted in a waveguide element.

[0056] Fig. 13 shows a representation with a 3D oblique view of a separation point mounted in a waveguide element in a section.

[0057] Fig. 14 shows a representation with another 3D oblique view of a separation point.

[0058] Fig. 15 shows a representation with another side view of a separation point.

[0059] Fig. 16 shows a representation with a 2D sectional view of a separation point.

[0060] Fig. 17 shows a representation with a 2D sectional view of a separation point mounted in a waveguide element.

[0061] Fig. 18 shows a representation with a 2D sectional view of a separation point mounted in a first waveguide and in a waveguide element with a second waveguide.

[0062] Fig. 19 shows an illustration of an application of radar sensors.

[0063] Fig. 20 shows a representation of a radar sensor with the separation point.

[0064] The figures are schematic only and not to scale. Identical or similar parts are generally marked with the same reference symbols. DETAILED DESCRIPTION OF THE INVENTION

[0065] Fig. 19 shows an application of radar sensors in which a radar sensor 1901 is used for level measurement in a container 1905. A stirrer 1906 is located in the center of the container 1905. Due to higher frequency ranges, e.g., 80 GHz, the smaller antenna design allows for a beamwidth of the main lobe 1903 of the antenna radiation pattern that is so small that interference reflectors such as the stirrers 1906 are no longer within the field of view of the antenna 1902, even in slender, tall containers 1905. Waveguides are used here due to their low attenuation characteristics. As shown in Fig. 20, round horn antennas with a dielectric filling 2003 to reduce the length of the horn 2004 are frequently used as antennas 1902. At frequencies around 180 GHz and 240 GHz, the antennas of the measuring instruments can be made even smaller in order to obtain comparable antenna gains as at 80 GHz.

[0066] To replace a defective electronic unit, such as the electronic unit 2001 shown in Fig. 20, modern level radar measuring devices have arrangements that allow the electronic unit 2001 to be separated from the process measuring antenna 1902, since the antenna 1902 does not need to be unscrewed from the tank opening 1904. This can be achieved, for example, by a disconnect point between the electronic unit 2001 and the antenna 2004, as shown in Fig. 20. This disconnect point is currently implemented either via a coaxial high-frequency connector or via a plastic sleeve between two waveguides. Furthermore, in the case of defective electronic units 2001, it is not necessary to replace the entire device 1901; it is sufficient to replace only the active part, which is sustainable.

[0067] This disclosure proposes a disconnect point 100, which allows for replacement directly by the customer without customer service support. The proposed disconnect point 100 also possesses further properties, such as galvanic isolation between the container and the electronic unit 2001, surge resistance, low insertion loss, and rotatability.

[0068] Fig. 1 in conjunction with Fig. 8 shows a 3D oblique view of an isolation point 100 for the galvanic isolation of a first waveguide 601 from a second waveguide 801. The isolation point comprises a cylindrical dielectric waveguide 101, which is designed, for example, as a plastic cylinder 101. The isolation point 100 has a cylindrical sleeve 104, the inner diameter of which is larger than that of the dielectric waveguide 101. The dielectric waveguide 101 is held by supports 103a, 103b, which extend radially from the plastic cylinder 101 to the cylindrical sleeve 104 and axially over the entire length of the sleeve 104. The supports 103a, 103b are arranged crosswise or advantageously designed as two arms perpendicular to each other, and are each perpendicular to the surface of the dielectric waveguide 101 or to the inner surface of the sleeve 104.Simulations show that in this way the modes of the electromagnetic waves are hardly rotated, regardless of the position of the retaining arms 103a, 103b relative to the E-field vector. The interface 100 can therefore be placed between the expanded waveguides 801, 802 with any desired rotation. Furthermore, the cross-shaped arrangement provides high mechanical stability.

[0069] The ends 102a, 102b of the dielectric waveguide 101 are conically shaped. The length of the dielectric waveguide 101 is greater than the length of the sleeve 104, so that the dielectric waveguide 101, including its conical ends 102a, 102b, projects from both open sides of the sleeve 104. Not necessarily, but preferably, the dielectric waveguide 101 projects from the sleeve 104 to the same extent on both sides. The interface 100 is thus mirror-symmetrical with respect to a plane perpendicular to the cylinder axis and through the center of the sleeve 104.

[0070] This isolating unit 100 now makes it possible for a metal antenna 2004, as shown in Fig. 20, to be at the container potential 2005, whereas the electronic unit 2001 and its metallic waveguide 601 of the radar module 2002 can be at a potential 2006 that differs from the container potential 2005 (reference potential of the electronics). The isolating unit 100 eliminates the electrically conductive connection between the antenna 2004 and the electronic unit 2001, thus achieving galvanic isolation.

[0071] Further advantages of the separation point 100 include the fact that dirt particles cannot enter the waveguide 801 of the antenna 2003 during an electronics change, provided that the separation unit 100 is firmly connected to the antenna 2003.

[0072] Furthermore, the separation point 100 provides inherent thermal insulation between antenna 2004 and electronic unit 2001. While antenna 2004 is usually exposed to very high and low process temperatures, precautions must be taken to keep these extreme temperatures away from electronic unit 2001, which can often only be operated between -40°C and +85°C. Such a separation point 100 can be seen as such a measure, since the thermal conductivity of the plastic is many times lower than that of the metallic waveguides 601 and 801.

[0073] Fig. 2 shows a 2D diagram with a front view of the separation point 100. The cross-shaped arrangement of the supports 103a, 103b is visible. That is, depending on whether they are designed with two arms or one arm, there are, for example, two or four supports 103a, 103b, arranged at right angles to each other. The dimensions of the supports 103a, 103b are, in principle, arbitrary and depend primarily on the constraints of the device and the mechanical stability. For example, the radial length, i.e., the distance between the dielectric waveguide 101 and the sleeve 104, is 3 to 10 times the radius of the dielectric waveguide 101.

[0074] Fig. 3 shows a side view of the junction 100. The angles of the conical ends 102a, 102b of the dielectric waveguide 101 are designed such that they receive and emit the electromagnetic wave with minimal loss while maintaining sufficient mechanical stability. In particular, the shallow angles at the wave inlet and outlet prevent reflections.

[0075] Fig. 4 shows a representation with a second, rotated 3D oblique view of the interface 100, and Fig. 5 shows a representation in the same oblique view, but in a central longitudinal section. It can be seen that the dielectric waveguide 101 is solid, i.e., it has no cavity. The interface 100 is preferably a single piece and can be manufactured, for example, by injection molding from a plastic or ceramic. Examples include PP, PVDF, PTFE, PEEK, HDPE, and POM. Recycled plastic can also be used. The choice of plastic or ceramic depends, among other things, on the temperature, stability, and signal attenuation requirements. That is, the separation point 100, comprising the circumferential sleeve 104 attached to the plastic cylinder 101, the plastic cylinder 101, the conical ends 102a 102b and the supports 103a 103b, consists of a single part which may be designed as an injection-molded part.

[0076] Fig. 6 shows a 3D oblique view of a waveguide end, and Fig. 7 shows a view of the waveguide end, but in a central longitudinal section. Fig. 8 shows a 3D oblique view of a separation point 100 mounted in the waveguides 601 and 801. Fig. 9 shows a similar 3D oblique view, but in a central longitudinal section. At the ends of the two waveguides 601 and 801, respectively, there is a funnel-shaped adapter 602 and 802, respectively, which are oriented towards each other. The funnel-shaped adapters 602 and 802 preferably have an outer and inner diameter at their end towards the separation point 100 that correspond to the outer and inner diameters of the sleeve 104, respectively. One waveguide 601 is connected to the electronic unit 2001 shown in Fig. 20, whereas the opposite waveguide 801 is connected to the antenna 2004.The plastic cylinder 101 with its conical ends 102a and 102b is inserted between the two ends of the waveguide. Figures 6 and 7 further show that the transition between the cylindrical waveguide section and the funnel-shaped adapter 602 has a radius 701, i.e., it is rounded. Simulations have shown it to be advantageous to insert a radius 701 between the waveguide 601 and the funnel-shaped expansion 602, thus preventing a sharp edge.

[0077] Fig. 10 shows a representation with a 3D oblique view of a separation point 100 mounted in the waveguide 601 , 801 in a section.

[0078] The functionality of the assembled interface (Figs. 8 to 10 in conjunction with Fig. 20) is as follows: The electromagnetic wave generated in the electronics module 2001 or radar module 2002 is coupled into the first waveguide 601 (or vice versa). At the funnel-shaped adapter 801, the wave couples via the cone 102a into the plastic cylinder 101. This cylinder acts as a dielectric waveguide (DWG) and transmits the signal to the second waveguide 801. The signal is coupled into the second waveguide 802 via the second cone 102a in the same way as it was on the opposite side, but in reverse. Thus, the signal can be transmitted from the first waveguide 601 to the second waveguide 801 and from there to the antenna. The receiving process works in reverse.

[0079] The sleeve 104, located at the separation point 100, defines the distance between the two funnel-shaped adapter pieces 602, 802 of the waveguide elements. This distance, or the length of the separation point 100, or of the sleeve 104, can be selected to achieve the desired minimum breakdown voltage necessary for galvanic isolation.

[0080] Since the components are designed as circular waveguides or circular DWGs, they can be rotated relative to each other. This feature is particularly advantageous because it allows the electronic unit 2001 and the antenna 2004 to be rotated relative to each other. This is important for a radar level gauge so that, for example, the polarization of the radar signal within the container can be adjusted. Similarly, a display attached to the sensor can be rotated to the user's preferred position. The axis of rotation is shown in Fig. 11. It coincides with the cylinder axes.

[0081] The disconnect point 100 can be mechanically attached to the sleeve 104 such that it is either rigidly connected to the electronic unit 2001 or rigidly connected to the antenna 2004. This embodiment is shown in Figures 11 to 18. Alternatively, the disconnect point 100 can be loosely clamped between the antenna 2004 and the electronic unit 2001. Figure 11 shows a 3D oblique view of a disconnect point 100 mounted in a first waveguide 601 and in a waveguide element 1101 with a second waveguide, and Figure 12 shows a 3D oblique view of a disconnect point 100 mounted in a waveguide element 1101.

[0082] Figures 13 to 18 show diagrams with a circumferential locking lug 1301 on the outside of the cylindrical sleeve 104 for attaching the separation point to a waveguide element 1101.

[0083] Figure 13 shows a 3D oblique view of the separation point 100 mounted in the waveguide element 1101 in a cross-sectional view. During the installation of the radar sensor, the separation point 100 can be easily clipped into place and therefore requires neither screws nor adhesive. Additionally, the separation point 100 can be centered by a circumferential locking lug 130. This ensures reliable and cost-effective installation. Alternatively, the circumferential locking lug 130 can also be segmented, resulting, for example, in locking hooks.

[0084] Fig. 14 shows a representation with a 3D oblique view of the separation point 100 alone, including the circumferential locking lug 1301.

[0085] Fig. 15 shows a similar diagram to Fig. 14, but with the separation point including the circumferential locking lug 1301 in a side view.

[0086] Fig. 16 shows a representation with a 2D sectional view of the separation point 100 including the circumferential locking lug 1301 in a side view.

[0087] Fig. 17 shows a 2D sectional view of a separation point 100 mounted in a waveguide element 1101. It is clearly visible how the dielectric waveguide 101 is inserted centered into the waveguide 801 of the waveguide element 1101 when the separation point 100 is inserted into the waveguide element 1101 from right to left in Fig. 17 and the locking lugs 1301 engage in the waveguide element 1101. The radius 701 at the transition between the waveguide 801 and the funnel-shaped adapter 802 is also visible.

[0088] Fig. 18 additionally shows the second waveguide 801 in relation to the first waveguide 601 or the waveguide element 1101, in the assembled state.

[0089] Simulations show that the connection type is robust against gaps that can occur between the waveguides 601, 801 and the interface 100. Simulations also show that the wall thickness of the sleeve has only a minimal influence on the transmission characteristics of the interface 100. In an advantageous design, the insertion loss of such an interface 100 is between 0.5 dB and 1.0 dB. 100 separation point 101 dielectric conductor, plastic cylinder 102a, 102b conical ends 103a, 103b brackets 104 Sleeve 601 first waveguide 602 First funnel-shaped adapter (on the first waveguide) 701 Curve, radius 801 second waveguide 802 second funnel-shaped adapter (on the second waveguide) 1000 waveguide assembly 1001, 1101 Waveguide element 1301 Detent device, circumferential detent lug 1901 Radar device, radar sensor 1902 Antenna, process measurement antenna 1903 Main leg 1904 Container opening 1905 containers 1906 agitators 2001 Sensor electronics, electronic unit 2002 Radar module 2003 dielectric filling 2004 Horn antenna 2005 Container potential 2006 Electronics Potential

Claims

REQUIREMENTS 1. Isolation point (100) for galvanic isolation of a first waveguide (601) from a second waveguide (801), comprising a cylindrical dielectric waveguide (101) configured to receive a high-frequency signal at a first end and emit it at a second end; a cylindrical dielectric sleeve (104) that surrounds the dielectric waveguide (101) at radial intervals; Supports (103a, 103b) extending radially from the dielectric waveguide (101) to the cylindrical sleeve (104) such that the cylindrical dielectric sleeve (104) and the dielectric waveguide (101) have a common cylindrical axis, and the dielectric waveguide (101) is held centered in the cylindrical dielectric sleeve (104) by the supports (103a, 103b).

2. Separation point (100) according to claim 1, wherein the separation point (100) is rotatable about the common cylinder axis.

3. Separation point (100) according to claim 1 or 2, wherein the cylindrical dielectric waveguide (101) has two conical ends (102a, 102b).

4. Separation point (100) according to one of the preceding claims, wherein the separation point (100) is made of ceramic or plastic.

5. Split point (100) according to one of the preceding claims, wherein the split point (100) is a single piece.

6. Disconnect point (100) according to one of the preceding claims, wherein the cylindrical dielectric sleeve (104) has a locking device (1301) for connecting the disconnect point (100) to a waveguide element (1001) containing the first waveguide (601) or the second waveguide (801).

7. Radar sensor (1901), comprising a waveguide arrangement (1000) with a separation point (100) according to one of the preceding claims, comprising a cylindrical dielectric waveguide (101) with a first end and a second end, a cylindrical dielectric sleeve (104) and supports (103a, 103b); a first waveguide (601) which is configured to receive the first end of the cylindrical dielectric waveguide (101), and a second waveguide (801) which is configured to receive the second end of the cylindrical dielectric waveguide (101).

8. Radar sensor (1901) according to claim 7, wherein the waveguide arrangement (1000) further comprises a first funnel-shaped adapter (602) between an end of the first waveguide (601) and the separation point (100) and a second funnel-shaped adapter (802) between an end of the second waveguide (601) and the separation point (100).

9. Radar sensor (1901) according to claim 8, wherein the first adapter and the second adapter each have a rounding at the transition between waveguide and funnel-shaped adapter.

10. Radar sensor (1901) according to one of claims 7 to 9, wherein the length of the cylindrical dielectric sleeve (104) is designed to withstand a predetermined minimum flashover voltage strength.

11. Radar sensor (1901) according to one of claims 7 to 9, wherein the separation point (100) is rigidly connected to the first waveguide (601) or to the second waveguide (801) in the axial direction.

12. Radar sensor (1901) according to claim 11, wherein the separation point (100) is rotatable about the cylinder axis of the cylindrical dielectric sleeve (104) and the first waveguide (601) is rotatable relative to the second waveguide (801).

13. Radar sensor (1901) according to claim 12, wherein the radar sensor (1901) further comprises an electronic unit (2001) and an antenna (2004), and wherein the antenna (2004) is rotatable relative to the antenna (2004) by means of the rotatable separation point (101).

14. Radar sensor (1901) according to claim 13, wherein the radar sensor (1901) further comprises a display which is fixedly connected to the electronic unit (2001) and is rotatable with it relative to the antenna (2004).

15. Use of a waveguide separation point (101) according to one of claims 1-6 in a radar sensor (1901).

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