Radar measuring device for detecting filling level and distance
By integrating the filter unit and dielectric waveguide in the radar measurement device, the problem of interfering signal filtering at high frequencies is solved, the measurement accuracy and signal quality are improved, the manufacturing process is simplified, and the level and distance measurement in a higher frequency range is adapted to the level and distance measurement. .
Patent Information
- Application Number
- CN202410498299.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-30
- Filing Date
- 2024-04-24
- Publication Date
- 2024-12-31
AI Technical Summary
Existing radar measurement devices are difficult to effectively filter interfering signals at frequencies above 100GHz, affecting measurement accuracy and quality, especially in the measurement of level and distance in higher frequency ranges. Traditional hollow conductors are complex in manufacturing and have large signal attenuation. .
Using a filter unit integrated into the radar measurement device, combining dielectric waveguides and hollow conductors, the high-pass filter characteristics are designed to filter interference frequencies, and the high-frequency signal is directly coupled through the dielectric waveguide to reduce signal attenuation and ensure signal quality.
Improves the measurement accuracy and signal quality of the radar measuring device at frequencies above 100GHz, simplifies the manufacturing process, reduces signal attenuation, and adapts to the level and distance measurement requirements in higher frequency ranges.
Smart Images
Figure CN119223397A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a radar measuring device for detecting a filling level and / or a distance and to a system for detecting a filling level and / or a distance. Background Art
[0002] Radar measuring devices are known in the prior art and are used, for example, in the process and chemical industry to monitor the fill level in containers.
[0003] In this context, it is obvious that there is still a need to provide a radar measuring device for detecting a filling level and / or a distance; in particular, there is a need to provide an accurate and efficient radar measuring device for detecting a filling level and / or a distance. Summary of the invention
[0004] These and other objects which will be mentioned upon reading the following description or which can be appreciated by a person skilled in the art are achieved by the independent claims.The dependent claims further develop the central idea of the invention in a particularly advantageous manner.
[0005] According to a first aspect of the present invention, a radar measuring device for detecting a filling level and / or a distance is provided, which comprises: a main radiator for transmitting and receiving radar signals; an antenna unit for transmitting and receiving radar signals; and a filter unit for filtering the radar signals, wherein the filter unit is arranged between the main radiator and the antenna unit.
[0006] The term "primary radiator" is to be understood broadly here and refers to a structural element which is configured to radiate electromagnetic waves, preferably radar signals, which are generated by a circuit, preferably a high-frequency circuit in the GHz range, and / or to receive reflected radar signals. The primary radiator can be designed as one piece or as a plurality of components. The primary radiator can be arranged at least partially on a high-frequency circuit for generating radar signals and for processing reflected radar signals.
[0007] The term "radar measuring device" is to be understood broadly here and preferably refers to a measuring device for detecting a filling level and / or a distance, wherein the measuring device determines the filling level or the distance according to the propagation time measurement principle of a radar signal. Radar measuring devices are used, for example, in containers to detect the filling level and / or the distance. In this case, the filling level to be measured in the container is determined by taking into account the position of the radar measuring device and the propagation time measured between the transmitted radar signal and the received radar signal, i.e. the radar signal reflected by the surface of the bulk material in the container, for example. Different methods can be used to determine the propagation time, for example pulse radar or frequency modulated continuous wave radar. Alternatively, the radar measuring device can also be referred to as a radar level measuring device.
[0008] The term "antenna unit" is to be understood broadly herein and refers to a structural element configured to send and receive radar signals. The antenna unit may be designed as a horn antenna. The antenna unit may be designed as a dielectric lens. The antenna unit preferably sends radar signals to a surface and receives radar signals reflected by the surface.
[0009] The term "filter unit" should be understood broadly here, and refers to a structural passive element configured to filter a frequency below a cutoff frequency, above a cutoff frequency, or between two cutoff frequencies of a signal (preferably a radar signal). The filter unit can be designed as one component or multiple components. The filter unit preferably has a high-pass characteristic. The filter unit can have a low-pass characteristic. The filter unit can have a bandpass characteristic. The filter unit preferably blocks the individual modes of the radar signal generated by the high-frequency circuit. For example, the high-frequency circuit initially generates a basic signal (e.g., 40 GHz). The multiplier multiplies it with an integer to obtain a desired frequency or related mode (e.g., 240 GHz). Now, the filter unit preferably filters the fundamental mode at 40 GHz and the corresponding high-order modes at 80 GHz, 120 GHz, 160 GHz, and 200 GHz that also appear, so that only the desired mode at 240 GHz frequency can pass through the filter unit. Preferably, the filter unit also filters higher undesirable modes or frequencies (e.g., 280 GHz and 320 GHz). The filter unit can also advantageously specify the polarization of the radar signal.
[0010] The invention is based on the following recognition: In radar measuring devices with operating frequencies above 100 GHz, the radar signal is fed directly from the high-frequency circuit into a waveguide (e.g. a dielectric waveguide). However, at operating frequencies below 100 GHz, the radar signal usually first passes through a printed circuit board and is then fed into the waveguide. The transition from the printed circuit board (i.e. the carrier board) to the waveguide is designed so that the desired mode / frequency is set in the waveguide and the unwanted mode / frequency (i.e. the interference signal) is filtered out. The invention solves this problem by a filter unit integrated in the radar measuring device, so that interference frequencies can be filtered even at operating frequencies above 100 GHz. This has a favorable effect on the measurement quality and accuracy of the level measurement and / or distance measurement.
[0011] Modern radar measuring devices for process industry and automation technology are currently gradually opening up the frequency range above 100 GHz. Due to the emergence of new frequency regulations, continuously improved semiconductor processes and more precise manufacturing methods, radar-based level measuring devices up to 250 GHz can be developed, produced and sold. The advantage of the higher frequency range is that narrower aperture angles can be achieved with the same antenna size. Agitators or heating coils installed in containers often generate interfering reflections in the radar signal, but as the antenna aperture angle becomes smaller, the interfering reflections also become smaller or even disappear.
[0012] From a regulatory perspective, wider signal bandwidths are permitted in the higher frequency range, which means better selection between two adjacent radar targets. This presents new challenges for developers of radar measurement technology compared to today’s mature 80 GHz technology.
[0013] One example is the hollow conductor (Hohlleiter), which is mainly used in 80 GHz sensors to transmit the radar signal from the radar module to the antenna. The hollow conductor, which is mainly designed as a round hollow conductor in this case, has a diameter of between 2.5 and 3.0 mm in this frequency range and can be manufactured relatively cheaply and in sufficient length using a deep hole drilling process. The length of the hollow conductor is crucial for the temperature decoupling between the process to be monitored and the sensor electronics. The temperature of the sensor electronics must not exceed 85°C, while the process temperature can be as high as 450°C. Long hollow conductors can be used to achieve temperature decoupling.
[0014] As the frequency increases, the hollow conductor diameter becomes smaller and smaller because the cutoff frequency of the fundamental mode depends on the hollow conductor diameter. For a 250GHz radar signal, the hollow conductor diameter is only 0.87mm. For such a small diameter, it is much more complicated to manufacture a hollow conductor of the same length compared to a hollow conductor diameter at 80GHz. Rectangular hollow conductors are quite unusual for radar level measurement devices because they are more complicated to manufacture.
[0015] The cutoff frequency is the lowest frequency that allows the fundamental mode of the hollow conductor to propagate. If the signal frequency is lower than the cutoff frequency, no signal transmission occurs because the electromagnetic wave cannot propagate. In this case, the wave is reflected at the input end of the hollow conductor. Therefore, the hollow conductor exhibits a high-pass behavior.
[0016] Modes higher than the fundamental mode also have cut-off frequencies, but these cut-off frequencies are higher than the cut-off frequency of the fundamental mode. It is always advantageous for a radar level measuring device to operate the hollow conductor in such a way that the hollow conductor operates in the fundamental mode. The propagation speed of higher-order modes in the hollow conductor is different from that of the fundamental mode, which can lead to incorrect measurements.
[0017] Another difference between rectangular and circular hollow conductors is that in rectangular hollow conductors, the polarization of the electromagnetic wave is predetermined. The electric field vector is parallel to the short side of the hollow conductor. On the other hand, in circular hollow conductors, the polarization is arbitrary and depends on the way the wave is coupled into the waveguide. This can have advantages and disadvantages depending on the type of application.
[0018] Another point to consider for hollow conductors is the surface roughness inside the hole. As the frequency increases, the surface roughness has an increasing impact on the signal attenuation experienced by the radar signal when passing through the hollow conductor. At the same surface roughness, the attenuation of a hollow conductor can be, for example, 0.1 dB / cm at 80 GHz and 1 dB / cm at 250 GHz. For these reasons, hollow conductors are preferably gradually replaced by dielectric waveguides at higher frequencies. Dielectric waveguides consist mainly of plastics with a low relative dielectric constant εr and a low loss factor tan(δ). Examples of plastics include HDPE, PVDF, FEP and PFA. The cross-section can have various geometries, of which circular and rectangular geometries are the most common. In addition to advantages such as low signal attenuation, dielectric waveguides also have disadvantages.
[0019] In a dielectric waveguide, part of the electromagnetic field propagates inside the waveguide and another part of the electromagnetic field propagates outside the waveguide. As a result, dielectric waveguides are susceptible to interference echoes in the vicinity of the waveguide. The amount of field distributed inside the waveguide and the amount of field distributed outside the waveguide depends on the geometry of the waveguide, the frequency of the radar signal and the plastic used. Dielectric waveguides do not have a cutoff frequency in the sense of a hollow conductor.
[0020] Likewise, rectangular dielectric waveguides do not have any polarization filtering properties in contrast to rectangular hollow conductors. Depending on how the fields are coupled, the fields are transmitted in this way.
[0021] Another fundamental difference between sensors below 100 GHz and sensors above 100 GHz is that radar signals generated above 100 GHz are fed directly from the signal generating semiconductor into the waveguide. For radar devices below 100 GHz, the radar signal is usually first guided through a printed circuit board with at least one layer of high-frequency printed circuit board material and then fed into a hollow conductor or coaxial conductor. In this case, the transition from the printed circuit board to the hollow conductor or coaxial conductor is designed so that the desired mode is set in the waveguide and all interfering signal frequencies generated by the high-frequency module are filtered out.
[0022] For example, multipliers are often used in high-frequency modules, which multiply fundamental oscillations with integer factors to obtain higher frequencies. For example, if a 240GHz signal is required, the circuit 302 in the high-frequency module first generates a fundamental oscillation of, for example, 60GHz, and then multiplies it with a factor of 4. This circuit is relatively easy to manufacture. The disadvantage of doing so is that, in addition to the desired 240GHz oscillation, signals near 60GHz and its integer multiples (i.e., 120GHz, 180GHz, 300GHz...) will also appear. These interfering signals must be suppressed to meet existing and future radio standards. Another example is an 80GHz sensor. Here, for example, a fundamental wave is generated at 40GHz. The generated signal is fed downward from the semiconductor to the printed circuit board via a bonding wire 204, and is guided to a transition from the printed circuit board to a hollow conductor. The transition and subsequent hollow conductors filter out the fundamental wave of 40GHz so that the oscillation is no longer radiated.
[0023] Radar level measuring devices using frequencies above 100 GHz usually couple the signal directly into a dielectric waveguide without an additional carrier substrate. For this purpose, a radiator element is also present on the semiconductor material where the high-frequency circuit is located, which radiator element can be combined with an arrangement of coupling elements and resonator elements to form a main radiator. This main radiator can be used for coupling in a dielectric waveguide or for irradiating a dielectric lens. The semiconductor material is usually bonded to the carrier printed circuit board via an adhesive layer.
[0024] The advantage is that the signal experiences the lowest possible signal attenuation as it no longer needs to be guided through a printed circuit board to the transition to the hollow conductor / dielectric waveguide. However, when combining this direct coupling with a dielectric waveguide, there is no implicit filter effect due to the hollow conductor transition or the hollow conductor.
[0025] In a preferred embodiment, the filter unit comprises a hollow conductor. The hollow conductor may be made of metal. The hollow conductor may be a circular hollow conductor. The hollow conductor may be a rectangular hollow conductor. The hollow conductor may be made of plastic coated with metal. The filter characteristics are advantageously set according to the contour of the hollow conductor, the size of the rectangle or the diameter of the hole (i.e. the hollow conductor diameter).
[0026] In a preferred embodiment, the filter unit comprises a circular hollow conductor. The circular hollow conductor has a hollow conductor diameter (i.e., a through hole). As the frequency increases, the hollow conductor diameter becomes smaller and smaller because the cutoff frequency of the fundamental mode depends on the waveguide diameter. The cutoff frequency is the minimum frequency of the fundamental mode that allows the propagation of the hollow conductor. If the signal frequency is lower than the cutoff frequency, signal transmission will not occur because the electromagnetic wave cannot propagate. In this case, the wave is reflected at the input end of the hollow conductor. Therefore, the hollow conductor exhibits a high-pass behavior. The circular hollow conductor can advantageously filter out unwanted modes.
[0027] In a preferred embodiment, the filter unit comprises a rectangular hollow conductor. The rectangular hollow conductor has a rectangular hollow conductor cross-section (i.e., a continuous cavity). Another difference between a rectangular hollow conductor and a circular hollow conductor is that, in a rectangular hollow conductor, the polarization of the electromagnetic wave is predetermined. The electric field vector is parallel to the short side of the rectangular hollow conductor. On the other hand, in a circular hollow conductor, the polarization is arbitrary and depends on the way the wave is coupled into the circular hollow conductor. Depending on the type of application, this may have advantages and disadvantages. A rectangular hollow conductor may advantageously filter out unwanted modes. A rectangular hollow conductor may advantageously specify a polarization direction. This may ensure that the transmitted signal has exactly one polarization direction. This may advantageously ensure transmission quality. This may advantageously facilitate the installation of the radar measurement device, because the technician always knows how to install the device.
[0028] In a preferred embodiment, the filter unit comprises at least one resonator element for setting a low-pass characteristic. The resonator element is preferably a dielectric resonator element. The resonator element produces a low-pass filter characteristic, i.e. only frequencies below the cut-off frequency can pass through the filter unit. In combination with a hollow conductor, a bandpass filter is advantageously created. This has a positive effect on the signal quality.
[0029] In a preferred embodiment, the filter unit comprises at least one aperture for setting a low-pass characteristic. The aperture produces a low-pass filter characteristic, which means that only frequencies below the cut-off frequency can pass through the filter unit. In combination with a waveguide, a bandpass filter is advantageously created. This has a positive effect on the signal quality.
[0030] In a preferred embodiment, the antenna unit comprises a dielectric lens. The term "dielectric lens" is to be understood broadly herein and preferably refers to a lens that is curved on both sides and is made of a dielectric material, which receives radar signals emitted indirectly or directly from a primary radiator and sends them in a directional manner, or receives reflected radar signals and sends them directly or indirectly to the primary radiator in a directional manner. The dielectric lens can influence the shape or direction of the radar signal. The dielectric lens preferably has a spherical shape. Depending on the radius or curvature, there is a focusing distance for the radiation (i.e. the radar signal) emitted by the dielectric lens. The dielectric lens preferably comprises a lossless dielectric material.
[0031] In a preferred embodiment, the antenna unit comprises a horn antenna.The term "horn antenna" should be understood broadly and refers to a funnel-shaped antenna for transmitting and receiving radar signals fed by a hollow conductor.
[0032] In a preferred embodiment, the radar measuring device further comprises at least one dielectric waveguide element for guiding the radar signal. The dielectric waveguide can be made of plastic. Examples thereof include HDPE, PVDF, FEP and PFA. The cross section of the dielectric waveguide can have any geometric shape. Preferably, the dielectric waveguide has a circular cross section or a rectangular cross section. The plastic preferably has a low relative dielectric constant and a low loss factor. This has an overall positive effect on the signal attenuation between the main radiator and the antenna (i.e. low undesirable signal attenuation). This also establishes electrical isolation between the process and the sensor electronics. The dielectric waveguide element is advantageously suitable for carrying high-frequency radar signals because it results in low attenuation compared to a waveguide.
[0033] In a preferred embodiment, the dielectric waveguide element is arranged between the main radiator and the filter unit.The radar signal between the main radiator and the filter unit is advantageously guided in two directions via the dielectric waveguide element.
[0034] In a preferred embodiment, the dielectric waveguide element is arranged between the filter unit and the antenna arrangement.The radar signals between the filter unit and the antenna arrangement are advantageously guided in two directions via the dielectric waveguide element.
[0035] In a preferred embodiment, the radar measurement device is configured to measure at frequencies above 100 GHz.
[0036] A further aspect of the invention comprises a system for detecting fill levels and / or distances, comprising at least one radar measuring device as described in more detail above and a container for storing material.
[0037] In a preferred embodiment, the container comprises a stirrer.
[0038] In a preferred embodiment, the container comprises a heating coil. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The drawings will be described in detail below.
[0040] Figure 1 A schematic diagram of a system for detecting a filling level according to the present invention is shown;
[0041] Figure 2 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0042] Figure 3 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0043] Figure 4 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0044] Figure 5 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0045] Figure 6 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0046] Figure 7 A schematic cross-sectional view of a radar measuring device according to the present invention is shown;
[0047] Figure 8 A schematic cross-sectional view showing a radar measuring device according to the present invention; and
[0048] Fig. 9 Two rectangular hollow conductors with resonator elements and gaps are shown. DETAILED DESCRIPTION
[0049] Figure 1 A schematic diagram of a system 100 for detecting a filling level according to the present invention is shown. The system 100 comprises a radar measuring device 101 which will be described in detail later. The radar measuring device 101 has an antenna 102 in the lower region for sending and receiving radar signals. According to the measuring frequency, an aperture angle 103 of the emitted radar signal is established. The system also comprises a container 105 for storing a material 104 (e.g., a liquid). The container also comprises an agitator 106. As can be seen from the figure, the radiation cone formed by the aperture angle 103 does not overlap with the agitator. This has a favorable effect on the measurement accuracy because no interference reflection occurs. In addition, the system 100 may also comprise a heating coil (not shown).
[0050] Figure 2A schematic cross-sectional view of a radar measuring device 200 according to the present invention is shown. The radar measuring device comprises at least one carrier board (i.e. a printed circuit board) 207. A semiconductor material 201 is attached to the carrier board 207 by means of an adhesive layer 204. A high-frequency circuit (not shown) and a radiator element (not shown) are located on the semiconductor material. A resonator element 202 is located above the radiator element. A coupling element 203 made of PEEK, for example, is arranged above the resonator element 202. In this case, the coupling element 203, the resonator element 202 and the radiator element form a main radiator 206. In this case, the semiconductor material 201 is electrically connected to the carrier board 207 via a bonding wire 208. A dielectric waveguide 205 is arranged above the main radiator 206. The main radiator 206 sends a radar signal generated by the frequency circuit to the dielectric waveguide 205, or receives a radar signal guided by the dielectric waveguide 205 and reflected from the surface of the material.
[0051] Figure 3 A schematic cross-sectional view of a radar measuring device 300 according to the invention is shown in plan view. A semiconductor material 304 is arranged on a carrier 303 and is electrically connected to the carrier 303 via bonding wires 305. A high-frequency circuit 302 and a radiator element 301 are arranged on the semiconductor material 304. A resonator element 306 is arranged above the radiator element 301. The radar signal generated in the high-frequency circuit 302 is forwarded to the radiator element 301 in order to be amplified from there by the resonator element 306. The radar signal reflected from the material surface and the radar signal received by the radar measuring device have the same propagation path, but in opposite directions.
[0052] Figure 4 4 shows a schematic cross-sectional view of a radar measuring device 400 for detecting conditions in a container according to the present invention. The radar measuring device 400 comprises a main radiator 403 for sending and receiving radar signals. The main radiator 403 in the present case corresponds to Figure 2 405. In the present case, the radar measuring device 400 also has two-part dielectric waveguides 404 and 405. The radar signal is first coupled from the main radiator 403 into the dielectric waveguide 404. The filter unit 402 for filtering the radar signal is arranged between the dielectric waveguide 404 and the dielectric waveguide 405. In the present case, the filter unit is designed as a metal circular hollow conductor 401. The radar signal is coupled from the metal hollow conductor 401 into the dielectric waveguide 405. The radar signal is transferred from the dielectric waveguide 405 to the antenna unit (not shown) for transmission and reception. The filter unit 402 designed as the metal hollow conductor 401 filters the mode and frequency of the radar signal.
[0053] Figure 5A schematic cross-sectional view of a radar measuring device 500 according to the present invention is shown. In the present case, the radar measuring device 500 comprises a main radiator 501, a dielectric waveguide 502, a filter unit 503 and an antenna unit 504. The filter unit 503 is designed as a metal hollow conductor. The antenna unit 504 is designed as a lens antenna. The filter unit 503 is arranged between the dielectric waveguide 502 and the antenna unit 504.
[0054] Figure 6 A schematic cross-sectional view of a radar measuring device 600 according to the present invention is shown. In the present case, the radar measuring device 600 comprises a main radiator 601, a dielectric waveguide 602, a filter unit 603 and an antenna unit 604. The dielectric waveguide 602 is arranged between the main radiator 601 and the filter unit 603. The waveguide unit 603 is designed as a metal hollow conductor. The antenna unit 604 is designed as a dielectric lens. The filter unit 603 filters the frequency and mode of the radar signal. In the present case, the filter unit 603 receives the radar signal from the dielectric lens and sends the radar signal to the dielectric lens.
[0055] Figure 7 FIG. 7 is a schematic cross-sectional view of a radar measuring device 700 according to the present invention. Figure 5 In contrast, a metal housing 701 of a radar measuring device 700 is also shown here. In addition, the radar measuring device 700 has an interface 702 for power supply and data exchange, such as an M12 interface. In the present embodiment, the radar measuring device 600 has a plurality of carrier boards 703, 704 and 705 for power supply, controller and high-frequency circuits for generating and processing radar signals. They are electrically connected to each other via a plug connector 706. The radar measuring device 700 has a metal process connection 707 in the lower region of the housing 701. In the present case, dielectric waveguides 708 and 709 are arranged in the process connection 707, as are the filter unit 710 and the antenna unit 711. In the present case, the antenna unit 711 is bonded to the process connection 707 in a sealing manner. The filter unit 710 is designed as a metal hollow conductor here. The metal hollow conductor has an external thread for installation in the process connection 707. The process connection is designed to be connected to the corresponding opening of the container to detect the filling level.
[0056] Figure 8 FIG. 8 shows a cross-sectional view of a radar measuring device 800 according to the present invention. Figure 6 In contrast, housing 801 is also shown here. Figure 7 As shown, the interface 802 and the printed circuit boards 803 to 805 are arranged in the housing 801. In the present case, the filter unit 806 is designed as a metal hollow cylinder and is arranged in the metal process connection by means of threads. The dielectric lens 807 is sealingly bonded to the process connection.
[0057] Fig. 9 Two examples of rectangular hollow conductors are shown. Rectangular hollow conductor 900 has cylindrical dielectric resonator elements 901 to 903 arranged inside the cavity. These resonator elements limit the transmission frequency upward. Rectangular hollow conductor 904 has apertures 905-907 arranged inside the cavity. These apertures limit the passing frequency upward. By using apertures and / or resonator elements in combination with rectangular hollow conductors, radar signal bandpass characteristics can be generated in filters. Such filters can be used to specify the frequency, mode, and polarization of radar signals passing through the filter.
[0058] CROSS-REFERENCE TO RELATED APPLICATIONS
[0059] This application claims the priority of European patent application No. 23 182 603.3 filed on June 30, 2023, the entire contents of which are incorporated herein by reference.
[0060] Reference numerals list
[0061] 100 Systems
[0062] 101, 200, 300, 400, 500, 600, 700, 800 radar measuring devices
[0063] 102 Antenna Device
[0064] 103 Aperture angle
[0065] 104 Materials
[0066] 105 Container
[0067] 106 Mixer
[0068] 201, 304 Semiconductor Materials
[0069] 202, 306 Resonator elements
[0070] 203 Coupling element
[0071] 204 Adhesive layer
[0072] 205, 404, 405, 502, 602, 708, 709 Dielectric waveguide
[0073] 206, 403, 501, 601 main radiators
[0074] 207, 303, 703, 704, 705, 803, 804, 805 carrier board
[0075] 208, 305 bonding wire
[0076] 401 Round Hollow Conductor
[0077] 402, 503, 603, 710, 806 filter units
[0078] 504, 711 antenna units
[0079] 604, 807 Dielectric Lens
[0080] 701, 801 housing
[0081] 702, 802 interfaces
[0082] 706 Plug Connector
[0083] 707 Process Connection
[0084] 900, 904 rectangular hollow conductor
[0085] 901, 902, 903 Resonators
[0086] 905, 906, 907 pores
Claims
1. A radar measuring device for detecting a filling level and / or a distance, comprising: a main radiator, which is used to transmit and receive radar signals; an antenna unit, which is used to transmit and receive the radar signal; A filter unit is used to filter the radar signal, wherein the filter unit is arranged between the main radiator and the antenna unit.
2. The radar measuring device according to claim 1, wherein: The filter unit includes a hollow conductor.
3. The radar measuring device according to claim 1 or 2, wherein: The filter unit includes a circular hollow conductor.
4. The radar measuring device according to any one of the preceding claims, wherein: The filter unit includes a rectangular hollow conductor.
5. The radar measuring device according to any one of the preceding claims, wherein: The filter unit includes at least one resonator element for adjusting a bandpass characteristic.
6. The radar measuring device according to any one of the preceding claims, wherein: The filter unit includes at least one aperture for adjusting a bandpass characteristic.
7. The radar measuring device according to any one of the preceding claims, wherein: The antenna unit includes a dielectric lens.
8. The radar measuring device according to any one of the preceding claims, wherein: The antenna unit includes a horn antenna.
9. The radar measuring device according to any of the preceding claims, further comprising at least one dielectric waveguide element for guiding the radar signal.
10. The radar measuring device according to claim 9, wherein: The dielectric waveguide element is arranged between the main radiator and the filter unit.
11. The radar measuring device according to claim 9 or 10, wherein: The dielectric waveguide element is arranged between the filter unit and the antenna device.
12. The radar measuring device according to any one of the preceding claims, wherein: The radar measurement device is configured to measure at frequencies above 100 GHz.
13. A system for detecting filling levels and / or distances, comprising at least one radar measuring device according to any one of claims 1 to 12 and a container for storing material.
14. The system according to claim 13, wherein: The container includes an agitator.
15. The system according to claim 13 or 14, wherein: The container includes a heating coil.