Radar sensor and waveguide isolation

Abstract

The invention relates to a radar sensor (100) comprising a waveguide (104) having a waveguide inner wall (110), a first section (112) and a second section (114) isolated from the first section, and a waveguide isolation (700) for isolating the first section (112) from the second section (114), the waveguide isolation (700) being an element comprising a first component (710) and a second component (720) made of different materials.

Description

Technical Field

[0001] The present invention relates to a radar sensor, a waveguide isolation section (Hohlleiter-Trennstelle), and the use of the waveguide isolation section. Background Art

[0002] In a radar sensor, for example, used to measure the level of liquids and bulk materials to monitor industrial processes, electromagnetic waves generated by an RF chip are coupled into a waveguide, which is, for example, expanded into a horn radiator to radiate the waves conducted in the waveguide as space waves, or used as an antenna feeder. If a current isolation device is inserted during the coupling process, the waves escape from the waveguide. In this case, these waves propagate along, for example, housing components or other structures and are reflected. The resulting different propagation times interfere with the waves in the waveguide. To avoid this, absorbers are used. The radar sensor can be configured such that the absorber can be inserted into the radar sensor within the sensor housing. To provide the absorber, mount it in the sensor, and hold it in its specific position, logistical and mechanical efforts are required, and in terms of the sensor, manufacturing efforts are also required. Grooves for seals must be introduced in a way that does not impair the function of the absorber. Summary of the Invention

[0003] The object of the present invention is to provide an improved radar sensor.

[0004] This object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims, the following description, and the drawings.

[0005] The described embodiments similarly relate to a radar sensor, a waveguide isolation section, and the use of the isolation section as a radio frequency (RF) absorbing component in a radar sensor. Although the various combinations of the embodiments are not described in detail, they can produce synergistic effects.

[0006] Technical terms are used in the usual way. When certain terms are given a specific meaning, the definitions of these terms will be given below in the context in which they are used.

[0007] According to a first aspect, there is provided a radar sensor comprising a waveguide having a waveguide inner wall, a first section, and a second section isolated from the first section. The waveguide further has a waveguide isolation section for isolating the first section from the second section, wherein the waveguide isolation section is an element comprising a first component and a second component made of different materials.

[0008] For transmitting a radar signal, a waveguide guides the radio frequency electromagnetic wave generated by the electronic unit of the radar sensor from the electronic unit to an exit point, for example to an opening of the waveguide or an antenna. For receiving a radar signal, the wave received at the opening or the antenna takes a reverse path to reach the electronic unit. The waveguide has, for example, a separating section for potential isolation. Thus, the separating section divides the waveguide into a first section and a second section, the first section being connected to the electronic unit, into which the electronic unit couples the wave, and the second section having an exit hole, so that the separating section is an intermediate part between the two sections.

[0009] Even if in the present disclosure the direction of the wave from the electronic unit to the antenna (i.e., the direction for transmission) is described exemplarily, this embodiment is equally applicable to the opposite direction, i.e., for example, receiving the wave at the antenna and guiding the wave from the second section via the waveguide separating section to the first section and the electronic device.

[0010] Herein, a “component” is understood as a component or sub-region forming the separating section.

[0011] In the present disclosure, expressions such as “energy leaks from the waveguide” are used. It is known to those skilled in the art that waveguide waves propagate in a material-free inner space defined by the inner walls of the waveguide. Thus, “leaking from the waveguide” means that energy leaks from the inner space of the waveguide. Similar expressions should be understood accordingly.

[0012] According to an embodiment, a first component and a second component made of different materials have different RF characteristics.

[0013] The different RF characteristics of the two components of the separating section are based on the different materials of these components.

[0014] According to an embodiment, the different RF characteristics relate to the absorption rate and the radio frequency conductivity.

[0015] For example, the radio frequency conductivity is reflected in the two-port characteristics (Zweitoreigenschaften), where the two-port characteristics are the transmission coefficient and the reflection coefficient. In addition, these materials can have different electrical insulation characteristics.

[0016] For example, the first component is designed to provide better absorption than the second component, while the second component provides better insulation than the first component, and the second component is designed to allow the wave to pass through as losslessly and with low reflection as possible on the path of the wave from the first section to the second section of the waveguide. This means that, for example, the second component has a better transmission coefficient as well as a better reflection coefficient, where the transmission coefficient is, for example, the value of the S12 parameter of the two-port (Zweitor), and the reflection coefficient is, for example, the value of the S11 parameter of the two-port. In the receiving direction, the S21 or S22 parameter values are correspondingly involved.

[0017] According to an embodiment, the shape of the waveguide isolation part is designed such that at least a part of the first component partially surrounds the first section, and the first component has better absorption characteristics than the second component.

[0018] The first component has, for example, a cylindrical part. The inner diameter of the cylinder is equal to the diameter of the first waveguide section having the same axis of rotation. This means that the first component is not responsible or only secondarily responsible for transmitting waveguide waves, but mainly surrounds the waveguide to absorb the energy leaking from the first component. The second section of the waveguide can be designed in this cylindrical part such that it surrounds the first component and thus also separates the first section from the cylindrical part in this area.

[0019] According to an embodiment, the shape of the isolation part is designed such that the second component at least partially continues the inner wall of the waveguide at the isolation part, and the second component has better transmission and / or reflection characteristics than the first component.

[0020] The second component is responsible for electrical insulation and the transmission of waveguide waves and thus has the advantageous characteristics described above and below.

[0021] According to an embodiment, the second component is made of a low-loss dielectric.

[0022] Here, "low-loss" refers to the continuity of the wave. For example, the following materials are all suitable for the second component: so-called low-loss dielectrics, i.e., low-loss dielectrics such as polypropylene (PP) or polytetrafluoroethylene (PTFE), or other materials with similar properties, i.e., insulating materials with only low losses in the radio frequency range in radio frequency technology.

[0023] For example, PEEK CF30 or PTFE CA25 is suitable for the first component. PEEK CF30 is a polyetheretherketone material filled with 30% carbon fiber, while PTFE CA25 contains 25% carbon (by weight). Due to the presence of carbon fiber or carbon, these materials have an absorption effect and are almost impermeable to radio frequency.

[0024] According to an embodiment, the first component is connected to the second component without a gap.

[0025] This measure reduces energy leakage and reflection and improves the transmission rate.

[0026] According to an embodiment, the first component and the second component are connected to each other in one or more of the following ways: bonding, screwing, welding, and / or pressing.

[0027] According to an embodiment, the waveguide isolation part is integral.

[0028] For example, the waveguide isolation section can be manufactured using a two-component injection molding process or by turning it from a prefabricated two-component rod. One-piece production simplifies handling and logistics and reduces the manufacturing cost of the radar sensor.

[0029] According to one embodiment, the radar sensor is a fill level sensor, a limit level sensor, a flow sensor, or a pressure sensor.

[0030] The radar sensor is used, for example, in systems of automation technology, where the term "automation technology" should be interpreted broadly here and includes process automation and factory automation, etc. For example, the radar sensor is used in a processing plant to monitor chemical or physical processes.

[0031] According to one embodiment, the radar sensor includes an electronic unit having RF components and an adapter element, wherein the adapter element is designed such that the electronic unit is located on a first side of the adapter element and a first section of the waveguide is located on an opposite second side of the adapter element, and wherein the waveguide isolation section abuts against the adapter element.

[0032] The adapter element is particularly used for the mechanical fixation or stabilization of the waveguide at the connection to the circuit board. Here, the adapter element can extend radially into the housing of the radar sensor. By abutting the waveguide isolation section against the adapter element, the waveguide itself also has mechanical stability.

[0033] According to another aspect, there is provided a waveguide isolation section that is an element including a first part and a second part made of different materials; wherein the waveguide isolation section is configured to electrically isolate a first section of the waveguide from a second section of the waveguide.

[0034] For example, the waveguide isolation section is the isolation section for the radar sensor described herein. For example, the isolation section electrically isolates the electronic device from the antenna.

[0035] According to one embodiment, the material of at least the second part is a non-conductive material in order to achieve the electrical isolation between the first section and the second section.

[0036] Other embodiments of the isolation section have been described for the radar sensor and are not repeated here.

[0037] According to another aspect, there is provided the use of the waveguide isolation section described herein in a radar sensor.

[0038] The isolation section can also be used in other waveguide devices that require isolation (for example, potential isolation).

[0039] According to one embodiment, the waveguide isolation section is used for the potential isolation of the waveguide. Description of the Drawings

[0040] The exemplary embodiments of the present invention will be described in more detail below with reference to the schematic diagrams.

[0041] Figure 1 A schematic diagram showing a first isolation portion made of a first material is presented.

[0042] Figure 2 A schematic diagram showing a first series of components and the reflection, transmission, and leakage of microwave energy from the waveguide to adjacent components occurring herein is presented.

[0043] Figure 3 A graph showing the variation of the transmission rate (S21) and reflectivity (S11) of the first series of components with frequency is presented.

[0044] Figure 4 A schematic diagram showing a second isolation portion made of a second material is presented.

[0045] Figure 5 A schematic diagram showing the second isolation portion and the reflection, transmission, and leakage of microwave energy from the waveguide to adjacent components occurring herein is presented.

[0046] Figure 6 A graph showing the variation of the transmission rate (S21) and reflectivity (S11) of the second series of components with frequency is presented.

[0047] Figure 7 A schematic diagram showing a third isolation portion made of the first and second materials is presented.

[0048] Figure 8 A schematic diagram showing the third isolation portion and the reflection, transmission, and leakage of microwave energy from the waveguide to adjacent components occurring herein is presented.

[0049] Figure 9 A graph showing the variation of the transmission rate (S21) and reflectivity (S11) of the third series of components with frequency is presented.

[0050] Figure 10 A schematic diagram showing a fourth isolation portion made of the first and second materials is presented.

[0051] Figure 11 A schematic diagram showing the fourth isolation portion and the reflection, transmission, and leakage of microwave energy from the waveguide to adjacent components occurring herein is presented.

[0052] Figure 12 A graph showing the variation of the transmission rate (S21) and reflectivity (S11) of the fourth series of components with frequency is presented.

[0053] Figure 13 A schematic diagram showing a fifth isolation portion made of the first and second materials is presented.

[0054] Figure 14Schematic diagram showing the fifth isolation section and the reflection, transmission, and leakage of microwave energy from the waveguide to adjacent components occurring herein.

[0055] Figure 15 Graph showing the variation of the transmission rate (S21) and reflectivity (S11) of the fifth series of components with frequency.

[0056] Figure 16 Schematic diagram showing a radar sensor. Detailed description of the invention

[0057] In all the figures, corresponding components have the same reference numerals. The present invention is mainly described based on an exemplary embodiment in which waves are guided from the electronic unit towards the antenna. However, this example does not limit the present invention. The exemplary embodiment is similarly applicable to the opposite direction.

[0058] Figures 1 - 15 Variant of the schematic diagram showing a waveguide device with five different embodiments of an isolation section, diagrams showing energy leakage from or at the isolation section and entering different regions of the corresponding waveguide device, and graphs showing the variation of two-port S-parameters with frequency plotted in each case.

[0059] Figure 16 Schematic diagram showing a radar sensor 100. The radar sensor 100 includes a housing 1606 and an electronic board having an electronic unit 1602. An RF chip 1604 mounted on the electronic board feeds a radio frequency wave to a first section 112 of a waveguide 104 to transmit a radar signal. The radio frequency wave propagates through a second component 720 of an isolation section 700 to a second section 114 of the waveguide 104 and finally reaches an antenna 1608 (a horn antenna 1608 in Figure 16 . When an echo signal is received, the path of the radio frequency wave is reversed accordingly. That is, a reflected wave is received at the antenna 1608, and this reflected wave reaches the receiving module on the electronic board via the second section 114 of the waveguide 104 having a waveguide inner wall 110, the second component 720, and the first section 112.

[0060] Figure 1 Schematic diagram showing an isolation section 120 composed of components for isolating the first section 112 of a waveguide 104 from the second section 114. Such isolation is used, for example, for potential isolation. Figures 1 - 6 the isolation component 120 in Figures 7 - 15 or the insulation thickness of 720 in Figure 1The material of the isolation part 120 in [it] conducts radio frequency waves and at the same time has absorbency. For example, this material is called PTFE TFM 1600. When the measurement frequency is 80 GHz, its parameter values, the dielectric constant (DK value), are approximately 2.055, and the dissipation factor (DF: dissipation factor) tanδ is approximately 0.00073. Depending on the material, these two values may be frequency-dependent. In the figure, the isolation part (the isolation part 120 in Figure 1 [it] is the isolation part 120) contacts the component 1610, which can be an adapter element for mechanically and / or electrically connecting the waveguide 104, and can be connected to the housing 102 of the radar sensor 100, thereby achieving mechanical stability. For simulation, a simple structure (as shown in the schematic diagram in Figures 1 - 15 [it]) will be selected. The regions 118, 119 marked with longitudinal lines form the first segment 112 and the second segment 114, and thus form the waveguide 104. The waveguide 104 can be, for example, a metal tube with holes. Suitable materials include, for example, silver or aluminum, but stainless steel can also be used. At least for simulation purposes, the region 116 is empty or is air. The electromagnetic waveguide wave generated by the electronic unit 1602 of the sensor 100 is fed into, for example, the first segment 112 of the waveguide 104 and passes through the isolation part 120 into the second segment 114 of the waveguide 104.

[0061] Figure 2 The schematic diagram of the waveguide 104 with the first isolation part 120 is shown, as well as the reflection, transmission, and leakage of microwave energy from the waveguide 104 to the isolator 700 and the adjacent region 116 that occur here. In Figure 2 [it], the reflection of the waveguide wave in the first segment 112 of the isolation part 120 can be seen. Therefore, the circle 202 representing the energy of the waveguide wave propagating in the waveguide 104 is significantly larger than the circle representing the energy of the waveguide wave propagating in the second segment 114 of the waveguide 104. In addition, part of the energy leaks at the isolation part 120 and passes through the solid region of the isolation part 120 into the region 116. Here illustratively, Figure 2 [it], the region 204 shown in black represents the position of high energy. Notably, the energy strongly propagates into the isolation part 120 and the adjacent region 116. Different from the binary black-and-white representation in the figure, the transition between the high-energy position and the low-energy position is smooth. The low-energy positions that are almost anywhere in the Figure 2 region 116 cannot be recognized due to this binary representation. It is desired that the energy distribution in the waveguide 104 is the same in the two segments 112, 114, that is, the circle sizes in the figure are the same, and the energy region shown in black disappears in the region 116.

[0062] Figure 3Shows a schematic diagram of the input reflection coefficient S11 and the forward transmission coefficient S21 of the first series of parts varying with frequency in the frequency range of 70 GHz to 90 GHz. The transmission is almost constant throughout the frequency range. In the range of 76 GHz to 84 GHz, the reflectivity is below -21.5 dB, with a negative peak at approximately 78.2 GHz, where the S21 value is -50 dB. At Figures 1 - 15 the selected comparison frequency of 80 GHz, the S11 parameter value is -28.125 dB, and the S21 parameter value is -0.765 dB.

[0063] In this specification, the input reflection coefficient S11 is also referred to as "Reflexion", and the forward transmission coefficient S21 is also referred to as "Transmission".

[0064] Figure 4 Shows a schematic diagram of the isolation part 120, which is made of a material called PEEK CF30. At the measurement frequency of 80 GHz, the parameter values of this material are DK value of 12.32 and DF value of tanδ of 0.525.

[0065] Figure 5 Shows Figure 4 a diagram of the isolation part 120 in , and the cases of microwave energy reflected, transmitted, and leaked from the waveguide 104 to the isolator 700 and the adjacent area 116 occurring here. It can be clearly seen that in this case, although the microwave energy leaked from the waveguide 104 to the adjacent components is very small, there is strong absorption and small reflection, so there is weak transmission to the second section 114 of the waveguide 104.

[0066] Figure 6 Shows the relevant S-parameter diagram. The transmission rate is almost constant throughout the frequency range. In the range of 76 GHz to 84 GHz, the reflectivity is below -11.5 dB and approximately linearly decreasing. At Figures 1 - 15 the selected comparison frequency of 80 GHz, the S11 parameter value is -15.9 dB, and the S11 parameter value is -10.2 dB. Therefore, good absorption characteristics are achieved at the cost of poor S-parameter values.

[0067] Figure 7Shows a schematic diagram of the third isolation section 700. Different from the first isolation section and the second isolation section 120, the third isolation section 700 includes a first component 710 made of a first material and a second component 720 made of a second material. The first component 710 is shown as solid black, while the second component 710 is shown as having a checkerboard pattern. The material of the first component 710 is, for example, PTFE in the above embodiments, and the material of the second component 720 is PEEK CF30. The first component 710 is designed to be in the shape of a can with a vertically protruding edge 712, where the axis of rotation 712 of the can coincides with the axis of rotation 712 of the annular second component 720 and the axis of rotation 712 of the waveguide 104, and the side surface 704 of the can surrounds the first section 112 of the waveguide 104. The bottom 716 of the can has a certain thickness and has a diameter larger than that of the inner wall 110 of the waveguide to form the can shape. Additionally, the bottom 716 has an opening, which in Figure 7 the view is represented by a white line in the bottom 116, and the diameter of the bottom is equal to the diameter of the inner wall 110 of the waveguide 104. Since this component 710 is directly connected to the first section 112, the bottom 716 with the opening constitutes an extension of the first section 112 of the waveguide 104. The side surface 714 of the can with the protruding edge 712 surrounds a part of the waveguide region 119 (i.e., the first section 112) and is used for electromagnetic shielding of the isolation section 700. In addition, the side surface 714 is surrounded by a part of the waveguide component 118 (i.e., the second section 114). The protruding edge 702 is located at the "top of the can" and is perpendicular and outward, that is, radially away from the waveguide component 119. In Figure 7 and other figures, the protruding edge 712 forms the end of the region 116 on one side or contacts other components of the adapter part 1610 or the sensor. The other side of the protruding edge 712 abuts against the waveguide component 118. However, the shape of the first component 710 can also be different from the shown shape. For example, if the waveguide 104 is a rectangular waveguide, the first component 710 can also be designed to be, for example, rectangular. In addition, the bottom 716, the side surface 714, and the edge 712 do not have to be aligned perpendicular to each other. In addition, the side surface 714 can also be thicker than shown and can lack the protruding edge 712. Other embodiments are also possible. For example, the second component 720 is cylindrical as Figure 7 shown and is oriented towards the second section 114 of the waveguide 104. However, the second component 720 can also be arranged mirror-image so that it is oriented towards the first section 112 of the waveguide 104. The second component 720 also continues the inner wall 110 of the waveguide. The first component 710 and the second component 720 can be bonded, screwed, or otherwise connected to each other, for example. Alternatively, the isolation section 700 can be constructed integrally.

[0068] Figure 8 Shows according to Figure 7A diagram of the isolation section 700, and the reflection, transmission, and leakage of microwave energy occurring here from the waveguide 104 into the isolator 700 and the adjacent region 116. Compared with Figure 2 the energy leakage is lower, and is comparable to the energy leakage in Figure 5 . The reflection situation is similar to that in Figure 5 , but it can be seen that the transmission rate has been significantly improved.

[0069] In Figure 9 the graph of, the reflection and transmission coefficients S11, S12 related to frequency of the device in Figure 7 and Figure 8 are plotted. In the frequency range between 76 GHz and 80 GHz, the reflection coefficient S11 is approximately between -11 dB and -15 dB, so it is comparable to the reflection coefficient S11 shown in Figure 6 . In the range up to 84 GHz, the reflection coefficient S11 has decreased by about 4 dB. However, the transmission coefficient is -2.5 dB, so it is significantly better than the transmission coefficient in Figure 6 , and the transmission coefficient in Figure 6 is -10 dB + / - 2 dB in the said frequency range between 76 GHz and 84 GHz. In the reference value at 80 GHz, the S11 parameter value is -14 dB and the S21 parameter value is -2.6 dB. Therefore, Figure 7 the isolation section 700 composed of two components shown has good absorption characteristics with an acceptable reflection coefficient value S11 and a good transmission coefficient value S21.

[0070] Figure 10 shows a schematic diagram of the isolation section 700 including two components 710, 720 made of different materials in an alternative embodiment. In this embodiment, the second component 720 alone continues the waveguide inner wall 110, that is, the second component 720 is adjacent to both the first section 112 and the second section 114 of the waveguide 104, and has an opening through which waves can pass between the first section 112 and the second section 114. Compared with that according to Figure 7The embodiment is similar, where the first component 710 has a can shape, and the bottom 716 has an opening. However, this opening now houses the second component 720 such that the remaining outer edge of the bottom 716 surrounds the first component 710 in its thickness, i.e., the bottom edge at least partially surrounds the first component 710. Thus, along the rotation axis 712, the first component 710 and the second component 720 preferably partially overlap, for example, in the area adjacent to the first segment 112, where the first component surrounds the waveguide component 119, and the second component 710 extends towards the second segment 114 along the direction of the antenna 1608. However, the overlapping area can also be located at other positions, such as in the middle of the second component 720 or in the area adjacent to the second segment 114. The overlapping area can further cover the entire second component 720 or even extend beyond the second component 720. That is, the thickness of the edge of the bottom 716 can be equal to or greater than the length of the second component 720 in the direction of the rotation axis 730. According to Figure 7 the embodiment, for example, in the case of a rectangular waveguide, the shapes of the waveguide 104 and the two components 710, 720 can be different. In this case, the rotation axis 730 will correspond to the central longitudinal axis of the rectangular waveguide. The can shape will be described as a rectangular can shape. The first component 710 and the second component 720 can be bonded, screwed, or otherwise connected to each other, for example. Alternatively, the isolation part 700 can be integrally constructed. Here, the expression "the opening at the bottom houses the second component 114" does not mean that the two components are assembled together during the manufacturing process, but refers to a structure that can also be completed in a single manufacturing step so as to manufacture the isolation part integrally, in particular.

[0071] Figure 11 shows a diagram of the isolation part 700 according to Figure 10 and the cases where microwave energy is reflected, transmitted, and leaked from the waveguide 104 to the isolation part 700 and the adjacent area 116. Compared with Figure 8 , the energy leakage is approximately the same. However, as confirmed by the curves shown in Figure 12 , significant improvements can be seen in both reflection and transmission.

[0072] In Figure 12 , the frequency-dependent Figure 10 and Figure 11 reflection and transmission coefficients S11, S12 of the devices in Figure 10The shown isolation section 700 composed of two components has good absorption characteristics in the case of very good reflection coefficient value S11 and very good transmission coefficient value S21, and these reflection coefficient value S11 and transmission coefficient value S21 exceed those according to Figure 1 the values of the device, that is, better than the reflection coefficient value S11 and transmission coefficient value S21 of the device of Figure 1 Compared with the device of Figure 4 which also has good absorption characteristics, the parameter values S11 and S21 significantly exceed the parameter values of the device of Figure 4 .

[0073] Figure 13 FIG. shows a schematic diagram of the isolation section 700 composed of two components 710 and 720 according to another embodiment. As shown in Figure 7 and Figure 10 , in this embodiment, the bottom 716 of the first component 710 is entirely made of the second material. That is, the first component 710 includes a cylinder 704 which has a protruding edge 712 at one end and is open at this end and at the opposite end facing the second section 114 of the waveguide 104, and the cylinder abuts or adjoins the second component 720 at the opposite end. The second component 720 includes a disk 1006 corresponding to the bottom 716 of the first component 710 in Figure 7 and Figure 10 , where the disk 1006 adjoins the first component 710 on the first side and adjoins the cylinder 1010 on the second side. Thus, the first component 710 completely surrounds the waveguide component 119, while the second component 710 only continues the waveguide inner wall 110 between the first section 112 and the second section 114. In this case, the modification examples as described above are also possible.

[0074] Figure 14 FIG. shows a diagram of the isolation section 700 according to Figure 13 , and the cases where microwave energy is reflected, transmitted and leaked from the waveguide 104 to the isolator 700 and the adjacent area 116. As can be seen from the substantially same circles in the two sections of the waveguide 104, compared with Figure 11 , the energy leakage is similar, but the transmission rate is higher and the reflectivity is lower.

[0075] Figure 15 FIG. shows a diagram depicting the variation of the transmission rate (S11) and reflectivity (S21) of the device according to Figure 12 with frequency.

[0076] Compared with Figure 8 , the energy leakage is substantially the same. However, as confirmed by the curve shown in Figure 12 , obvious improvements can be seen in both the reflectivity and transmission rate.

[0077] In Figure 12 the diagram depicts frequency-related Figure 10 and Figure 11 the reflection and transmission coefficients S11, S12 of the device in Figure 13 The isolation section 700 composed of two components shown in

[0078] It is also possible to form a hybrid form composed of the Figure 7 , Figure 10 and Figure 13 isolation section design. In particular, the embodiment selected for the sensor can depend on the frequency of the sensor. In addition, the frequency-related two-port values can be affected by changing the size of the isolation section or the components of the isolation section.

[0079] Those skilled in the art can understand and implement other variations of the disclosed embodiments when implementing the claimed invention by studying the drawings, the disclosure, and the appended 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 implement the functions of multiple subjects or steps listed in the claims. The fact that specific measures are recited in mutually dependent claims does not mean that combinations of these measures cannot be used advantageously. The reference signs in the claims should not be construed as limiting the scope of the claims.

[0080] Cross-reference to related applications

[0081] This application claims priority to European Patent Application 24 151 425.6, filed on January 11, 2024, the entire content of which is incorporated herein by reference.

[0082] List of reference signs 100 Radar sensor 102 Housing of the radar sensor 104 Waveguide 110 Inner wall of the waveguide 112 First section of the waveguide 114 Second section of the waveguide 116 Region adjacent to the waveguide 118 Waveguide component forming the second section 112 The waveguide component forming the first segment 114 Isolation section 120 RF energy in the waveguide Evasive RF energy Isolation section 700 composed of two components The first component of the isolation section 710 Protruding edge 712 The side surface of the can-shaped first component, cylinder 714 The bottom of the can-shaped first component 716 The second component of the isolation section, cylinder 720 The common rotation axis of the waveguide and the isolation section 730 The disk of the second component according to the embodiment 1006 The cylinder of the second component according to the embodiment 1010 Electronic unit 1602, circuit board RF chip 1604 Housing 1606 Horn antenna 1608 Adapter element 1610

Claims

1. A radar sensor (100), comprising: A waveguide (104) having a waveguide inner wall (110), a first section (112), and a second section (114) isolated from the first section; and A waveguide isolation part (700) for isolating the first section (112) from the second section (114), Wherein the waveguide isolation part (700) is an element including a first component (710) and a second component (720) made of different materials.

2. The radar sensor (100) according to claim 1, wherein, The first component (710) and the second component (720) made of different materials have different RF characteristics.

3. The radar sensor (100) according to claim 2, wherein, The different RF characteristics relate to absorption rate and radio frequency conductivity.

4. The radar sensor (100) according to any one of the preceding claims, wherein, The shape of the waveguide isolation part is designed such that at least a part of the first component (710) partially surrounds the first section (112), and the first component (710) has better absorption characteristics than the second component (720).

5. The radar sensor (100) according to any one of the preceding claims, wherein, The shape of the isolation part (700) is designed such that the second component (720) at least partially continues the waveguide inner wall (110) at the isolation part, and the second component (720) has better conductivity than the first component (710).

6. The radar sensor (100) according to any one of the preceding claims, wherein, The second component (720) contains a low-loss dielectric.

7. The radar sensor (100) according to any one of the preceding claims, wherein, The first component (710) is connected to the second component (720) without a gap.

8. The radar sensor (100) according to any one of the preceding claims, wherein, The first component (710) and the second component (720) are connected to each other in one or more of the following ways: Bonding, Welding, Screwing, and / or Pressing.

9. The radar sensor (100) according to any one of claims 1 to 7, wherein, The waveguide isolation part (700) is integral.

10. The radar sensor (100) according to any one of the preceding claims, wherein, The radar sensor (100) is a filling level sensor, a limit level sensor, a flow sensor or a pressure sensor.

11. The radar sensor (100) according to any one of the preceding claims, wherein, The radar sensor (100) includes an electronic unit (1602) having an RF component (1604) and an adapter element (1610), wherein the adapter element (1610) is designed such that the electronic unit (1602) is located on a first side of the adapter element (1610), and the first section (112) of the waveguide (104) is located on an opposite second side of the adapter element (1610), wherein the waveguide isolation part (700) abuts against the adapter element (1610).

12. A waveguide isolation section (100), which is an element including a first component (710) and a second component (720) made of different materials; wherein, The waveguide isolation part (700) is configured to electrically isolate the first section (112) of the waveguide (104) from the second section (114) of the waveguide (104).

13. A waveguide isolation section (700), wherein, At least the material of the second component is a non-conductive material to achieve electrical isolation between the first section (112) and the second section (114).

14. Use of the waveguide isolation part (700) according to claim 11 or 12 in a radar sensor (100).

15. Use of the waveguide isolation part (700) according to claim 11 or 12 for potential isolation of the waveguide (104).

Images