Antenna arrangement for a radar measuring device and radar measuring device

Abstract

An antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) for a radar measuring device (40) and a radar measuring device (40) having an antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) are provided. The radar measuring device (40) has a radiation source (10). The antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) comprises at least an input lens (102) and an output lens (103). The input lens (102) is configured to focus, toward the output lens (103), electromagnetic waves emitted by the radiation source (101). A distance between at least the input lens (102) and the output lens (103) along a longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) is dependent on a frequency of the electromagnetic waves emitted by the radiation source (101) in such a way that the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) provides, on the basis of the output lens, electromagnetic waves having a substantially plane wavefront (206) for an external component.

Description

[0001] Antenna arrangement for a radar measuring device and radar measuring device

[0002] An antenna arrangement for a radar measuring device and a radar measuring device with an antenna arrangement are provided.

[0003] New radar measuring devices utilize transmission frequencies of 100 GHz and higher to perform their measurement tasks in process automation. These high frequencies reduce the structural size of the active and passive high-frequency components. This reduces the distance between the electronics responsible for radiation emission and the sensor output of the radar measuring device (also called the sensor front end), which is located near the object being measured. This affects heat transfer from the object under investigation to the radar measuring device's electronics. For example, this can cause thermal drift, which affects the control of the radiation source, resulting in varying properties of the electromagnetic radiation. This is accompanied by increased interference effects in signal acquisition, such as increased noise, and thus reduced measurement precision.In some situations, the electronics can even be damaged, leading to the failure of the radar measuring device.

[0004] In radar measuring devices with signal frequencies below 100 GHz, the thermal influence on the electronics is typically amplified by the use of waveguides, such as a waveguide or a coaxial conductor. These waveguides conduct the energy from the radar chip, which acts as the radiation source, to the antenna in the sensor front end and therefore represent an additional thermally conductive connection to the radar chip, thus increasing heat conduction.

[0005] One approach to reducing thermally induced interference is to use appropriately sized waveguides to create relatively large distances between the electronics and the sensor front end. However, this leads to an increase in the required installation space and material consumption. Furthermore, the manufacturing effort for waveguides used at high frequencies is drastically increased in this case, especially if the waveguides need to be of a considerable length due to the required distance between the electronics and the sensor front end.

[0006] EP 3 691 026 Bl discloses an antenna arrangement for waveguideless energy transmission by using at least two dielectric lenses placed one behind the other between the radar chip (radiation source) and the sensor front end. The thermal conductivity properties can be influenced by the distances between the radiation source and the first lens, as well as between the first and second lenses. However, the resulting beam geometry of the electromagnetic waves is complex and unsuitable for certain applications. For example, the waves typically exhibit large beam angles.

[0007] DE 10 2021 123 532 A1 discloses a multi-lens system with an attachment comprising an attachment lens. However, due to the attachment, the system consists of several generally separate components. The resulting mandatory adjustment requires significant manual effort, which is incurred for each individual system due to manufacturing tolerances. Furthermore, these manufacturing tolerances preclude a mechanically rigid design of the multi-lens system, leading to increased interference effects on signal transmission and thus reduced measurement precision.

[0008] The task to be solved can be seen as providing an antenna arrangement and a radar measuring device that enable customized beam geometries with high signal quality and simultaneously low manufacturing costs.

[0009] The problem is solved by the subject matter of the independent patent claims. Advantageous embodiments are specified in the dependent patent claims and the subsequent description, each of which, individually or in (sub-)combination, can represent aspects of the disclosure.

[0010] The problem is solved according to the invention by an antenna arrangement for a radar measuring device with a radiation source. The antenna arrangement has at least one input lens and one output lens. The input lens is configured to focus electromagnetic waves emitted by the radiation source in the direction of the output lens. A distance between at least the input lens and the output lens along a longitudinal direction of the antenna arrangement depends on a frequency of the electromagnetic waves emitted by the radiation source, such that the antenna arrangement, based on the output lens, provides electromagnetic waves to an external component that have a substantially planar wavefront.

[0011] The invention is based on the understanding that the antenna arrangement, through its specific configuration, can provide electromagnetic waves exhibiting a plane wavefront. This ensures a tailored beam characteristic (beam geometry) of the provided electromagnetic waves. The beam geometry is achieved through beam shaping enabled by the lenses. The provided waves therefore have a narrow beamwidth, resulting in a relatively uniform beam intensity across the width of the wavefront and a high antenna gain. Thus, an object or medium under investigation can be detected with electromagnetic waves whose properties precisely meet specific requirements and are homogeneous across the beam diameter. Due to the plane wavefront, the antenna arrangement exhibits the desired directivity.

[0012] Furthermore, the antenna arrangement exhibits fixed geometric relationships, thus providing a mechanically rigid component. This eliminates mechanically induced tolerances, such as those sometimes encountered in previous approaches using add-on lenses. In other words, the antenna arrangement can be used for measurement setups that guarantee very high measurement precision.

[0013] Furthermore, the distance between the input and output lenses ensures thermal decoupling between the input and output sides of the antenna array. This means that heat input from an object or medium under investigation along the antenna array to electronics that are at least indirectly coupled to the input side of the antenna array can be sufficiently reduced by an adjusted distance between the lenses to guarantee the desired properties of the measuring arrangement and / or the provided electromagnetic waves.

[0014] Optionally, the input and output lenses are designed and arranged according to the frequency of the electromagnetic waves emitted by the radiation source, such that the antenna arrangement allows for a reciprocal wave propagation of the electromagnetic waves through the antenna arrangement along its longitudinal axis. Since the electromagnetic waves are provided by the antenna arrangement with a plane wavefront for the object or medium under investigation, waves reflected from the object / medium can propagate again along the same beam path, originating from the output lens and moving towards the input lens.In this case, the lens facing the object / medium under investigation, designated as the output lens with respect to emission, focuses the reflected (incoming) waves towards the lens originally designated as the input lens, which faces away from the object / medium under investigation. Thus, the input and output lenses are reversed with respect to the reflected (captured) waves. Nevertheless, the arrangement of the lenses ensures uniform beam paths for both emission and detection. This results in a high degree of symmetry for the antenna arrangement, thereby reducing manufacturing costs.

[0015] According to one embodiment, the antenna arrangement includes at least one absorber aperture located between the input lens and the output lens, which has an inner diameter that varies at least partially along the longitudinal direction of the antenna arrangement. The absorber aperture ensures attenuation of the sidelobes and / or reflections of the electromagnetic waves propagating within the antenna arrangement. This increases beam conformity, resulting in an overall improved signal-to-noise ratio. The efficiency of the sidelobe / reflection attenuation is further enhanced by the varying inner diameter of the absorber aperture, as this allows the aperture to be shaped to follow (or correspond to) the focusing of the electromagnetic waves provided by the input lens.Provided the antenna arrangement provides a reciprocal wave pattern, the attenuation of the side lobes / reflections provided by the absorber aperture has an equal effect on both emitted and received electromagnetic waves.

[0016] Preferably, the absorber aperture is positioned such that a minimum inner diameter of the absorber aperture, along the longitudinal direction of the antenna arrangement, coincides with a focal point / phase center of the input lens and / or a focal point / phase center of the output lens. This ensures that the arrangement of the absorber aperture corresponds to the beam effect of the input lens and / or the output lens, depending on the direction of propagation of the electromagnetic waves.

[0017] According to one aspect, the absorber aperture can have an outer diameter that varies, at least partially, along the longitudinal direction of the antenna array. This allows for material savings, thereby reducing manufacturing costs.

[0018] Optionally, the absorber aperture may have at least one insulated section, interrupted at least partially along the longitudinal direction of the antenna array. This reduces heat conduction along the absorber aperture, thereby reducing the heat input from the object / medium under investigation towards the radiation source.

[0019] Preferably, the absorber aperture has a dielectric material. This allows unwanted signal components of the propagating electromagnetic waves, such as side lobes or unwanted reflections, to be attenuated particularly effectively.

[0020] Preferably, the dielectric material can have a higher loss factor to effectively attenuate unwanted field components (side lobes / reflections) of the electromagnetic waves. Ultimately, the dielectric material, due to its higher loss factor, acts as an absorber for these unwanted field components (side lobes / reflections). Optionally, the absorber aperture material has a low thermal conductivity. This further reduces heat conduction along the antenna array.

[0021] Preferably the material of the absorber aperture is PEEK (polyetheretherketone), PTFE (polytetrafluoroethylene), or a material with a carbon fiber or graphite content of up to 60 wt.% (weight percent) or less, preferably 50 wt.% or less, further preferably 40 wt.% or less, and more preferably at least 10 wt.%.

[0022] Optionally, the absorber perforated panel can be manufactured using a milling process, a turning process, and / or an injection molding process. This allows absorber perforated panels to be produced whose properties, such as dimensions, precisely meet the respective specifications.

[0023] According to one embodiment, the absorber aperture can have a rotationally symmetrical shape. This further increases the symmetry of the antenna arrangement. It also simplifies manufacturing.

[0024] According to another aspect, the antenna array can include at least one additional input absorber element and / or one output absorber element, generally referred to as absorber elements. The input absorber element is located along the longitudinal axis of the antenna array, either on the input or output side of the input lens. The output absorber element is located along the longitudinal axis of the antenna array, either on the output or input side of the output lens. This means that several separate absorber elements can be provided, for example, to attenuate reflections within the longitudinal axis of the antenna array at different distances along its length. This allows for even more effective attenuation of additional interference, such as sidelobes, and thus further optimization of the antenna array.

[0025] The material properties, shapes, and / or possible manufacturing processes mentioned in relation to the absorber aperture can also apply to the input absorber element and / or the output absorber element. For example, the input absorber element and / or the output absorber element can be rotationally symmetrical.

[0026] Optionally, the input and output lenses can have identical diameters. The antenna assembly can then feature a uniform mounting / holding structure for both the input and output lenses.

[0027] Preferably, the input lens and / or the output lens has a spherical shape, an aspherical shape, a meniscus shape, a biconvex shape, a plano-convex shape, a bi-concave shape, or a plano-concave shape. This allows the antenna arrangement to be tailored to the specific application and the desired beam characteristics.

[0028] In one embodiment, the antenna arrangement can also include at least one additional lens, which may be identical to the input lens and / or the output lens in terms of diameter and / or shape. The additional lens can, for example, be positioned between the input lens and the output lens.

[0029] Alternatively, the additional lens can also be positioned differently, for example, on the input side of the input lens. In this case, the additional lens can also be referred to as the emission lens of the radiation source.

[0030] Optionally, the input and output lenses are arranged within a housing of the antenna assembly. The housing provides a common holding component, rigidly and securely positioning the lenses relative to each other, ensuring consistent and robust structural properties for the antenna assembly, such as proper spacing.

[0031] Optionally, the housing has an outer diameter that is constant, at least in sections, along the longitudinal direction of the antenna array. This provides a homogeneous housing, thereby reducing manufacturing costs. According to one aspect, the input lens and / or the output lens can be coupled to the housing via a snap-fit ​​connection. This snap-fit ​​connection can be reversibly detachable, allowing the lenses to be replaced even during operation, for example, in case of contamination.

[0032] Preferably, the snap-fit ​​connection is ensured by means of the absorber aperture and / or other absorber elements. This allows the absorber aperture and / or absorber elements to be used multifunctionally, resulting in the antenna arrangement having fewer individual components overall.

[0033] Alternatively, the input lens and / or the output lens can be coupled to the housing in such a way that the mechanical connection cannot be broken without damage. This means that while the lenses can be removed from the housing, the coupling structures must be destroyed to do so. This ensures particularly high positional accuracy of the lenses within the housing.

[0034] In one embodiment, a hollow chamber can be formed between the housing and the absorber aperture and / or between the housing and at least one absorber element. This means that the absorber aperture and / or the absorber element does not rest against an inner wall of the housing, at least in sections, along the longitudinal direction of the antenna assembly. The hollow chamber reduces the amount of material required for the absorber aperture or the absorber element. Furthermore, this reduces the weight of the antenna assembly. It also reduces heat conduction along the absorber aperture and / or along the absorber element.

[0035] The absorber aperture and / or absorber element can be positioned within the housing by means of a positive fit and / or a frictional fit between the absorber aperture and / or absorber element and the housing. Alternatively, the absorber aperture and / or absorber element can be coupled to the housing by means of a snap-fit ​​connection. A further alternative involves the absorber aperture and / or absorber element being injection-molded into the housing using a molding process. Optionally, the housing incorporates an electrically conductive material, at least in sections, along the longitudinal direction of the antenna array. This ensures electromagnetic shielding by means of the housing.

[0036] Preferably, the housing has at least a partial decoupling section along its longitudinal direction. This decoupling section is either made of no material or of an electrically non-conductive material. This provides galvanic isolation along the antenna arrangement with respect to the housing between the input and the output. This prevents or at least reduces electromagnetic interference effects emanating from the object / medium under investigation that could affect the radiation source and / or the electronics of the sensor arrangement.

[0037] In one embodiment, the decoupling sections can be manufactured using an injection molding process.

[0038] According to one aspect, the housing is made of an electrically conductive material, a partially metallic plastic, or a combination thereof. This allows for galvanic isolation without an insulating section of the absorber aperture. This means that the housing can be designed in two parts. In this case, the electrically conductive component of the housing follows the beam path provided by the beam effect of the input and / or output lens.

[0039] Preferably, the housing has mounting devices on one output side of the antenna arrangement, by means of which the antenna arrangement can be mechanically coupled to an external component. This allows the antenna arrangement to be effectively and in a defined manner coupled to the external component, for example, the object under investigation.

[0040] In one embodiment, the antenna arrangement can be designed without waveguides, at least in sections along its longitudinal direction. This allows for reduced material usage and avoids interfaces that would influence the properties of the electromagnetic waves propagating within the antenna arrangement.

[0041] According to another aspect, a radar measuring device with an antenna arrangement as previously described is also provided. The radar measuring device has a radiation source and an electronic unit coupled at least to the radiation source. The electronic unit is configured to control the radiation source to emit electromagnetic waves in the direction of the antenna arrangement, in particular in the direction of its input lens.

[0042] The advantages achieved through the antenna arrangement are also realized by the radar measuring device. In particular, an object / medium under investigation can be exposed to electromagnetic waves with specific, desired properties, such as a plane wavefront. This allows for a higher signal-to-noise ratio, thereby increasing measurement precision and thus the accuracy and reliability of the radar detection. In other words, the properties of the object / medium under investigation can be determined more precisely than before.

[0043] Preferably, the radiation source can be a semiconductor chip. Semiconductor chips can emit electromagnetic waves of a characteristic wavelength / frequency when appropriately excited, for example, by a control voltage. This makes semiconductor chips particularly suitable for tuning the emitted electromagnetic waves to the specific antenna arrangement.

[0044] The radiation source can optionally include a horn antenna or a patch antenna. Both configurations are suitable for providing electromagnetic waves with specified properties and high beam quality.

[0045] Optionally, the radiation source is mechanically coupled to the antenna array. The distance between the radiation source and the input lens of the antenna array along the longitudinal axis of the antenna array is predetermined based on the frequency of the electromagnetic waves emitted by the radiation source. This means that the distances between both the radiation source and the input lens, as well as between the input lens and the output lens, are tuned to the frequency of the emitted electromagnetic waves. This ensures that the output lens can provide electromagnetic waves with a substantially planar wavefront.

[0046] A substantially planar wavefront is defined as having a beamwidth of less than a predefined limit, for example, less than 25°, preferably less than 20°, and more preferably less than or equal to 15°. The planar wavefront enables high antenna gain and ensures minimal sidelobes. This improves the antenna's effectiveness for radar-based level measurement.

[0047] In one embodiment, the input lens and / or an additional lens, such as an emission lens, can be an integral part of the radiation source. This eliminates mechanical tolerances in the coupling between the radiation source and the antenna array. Ultimately, the radiation source and the antenna array can then be combined within a single outer housing, such as the antenna array housing.

[0048] According to one aspect, the radar measuring device can additionally have at least one detection element that is coupled to the electronic unit or that is part of it. The radar measuring device is configured to detect electromagnetic waves reflected from an external object using the detection element. Based on the electronic unit (or its detection element), the electromagnetic waves reflected from the object / medium under investigation can be detected. Based on appropriate evaluation methods, such as time-of-flight measurement, properties of the object / medium under investigation can then be determined, for example, by the electronic unit or an evaluation device coupled to it.

[0049] Preferably, the radar measuring device is configured as a level and / or limit level sensor. The radar measuring device is designed, based on its antenna arrangement, to provide electromagnetic waves with advantageous properties. Furthermore, the antenna arrangement ensures thermal decoupling between the object / medium under investigation and the radiation source / electronic unit. Therefore, the radar measuring device can, in particular, utilize a radiation source configured to emit electromagnetic waves with a frequency of 100 GHz or higher. Consequently, the radar measuring device can require only a small installation space and, at the same time, enable thermal decoupling, thus allowing the use of electromagnetic waves with excellent properties.This results in the radar measuring device having a higher measurement precision compared to existing approaches, which exhibits lower thermally induced fluctuations compared to previous approaches.

[0050] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The drawings show:

[0051] - Fig. 1 shows a simplified schematic representation of a radar measuring device with an antenna arrangement according to the prior art, and - Figs. 2 to 16 show simplified schematic representations of a radar measuring device according to the invention with an antenna arrangement according to the invention.

[0052] All features mentioned below with reference to the exemplary embodiments and / or the accompanying figures can be combined alone or in any subcombination with features of the invention, including features of preferred embodiments.

[0053] Fig. 1 shows an antenna arrangement 20 according to the prior art. The antenna arrangement comprises a primary radiator 21, a first lens 22, and a second lens 23 arranged down-beam. The antenna arrangement 20 also includes a high-frequency attenuator 24, which serves to suppress sidelobes. The high-frequency attenuator 24 is, for example, arranged on an inner wall of the antenna arrangement 20 or forms the wall itself. The partial distance between the first lens 22 and the second lens 23, as well as the partial distance between the primary radiator 21 and the first lens 22, are selected such that sufficient thermal decoupling of the primary radiator 21 from the object / medium under investigation is ensured. The separate partial distances together form the process distance 25. Based on the process distance 25, undesirable temperature coupling into the primary radiator 21 or an electronic unit coupled to it can be reduced.However, the lenses 22 and 23 have different diameters, which makes the antenna arrangement 20 complex. The different lenses 22 and 23 are also unsuitable for providing electromagnetic waves with desired beam characteristics for specific applications, such as plane wavefronts.

[0054] With regard to the different embodiments of the radar measuring device 40 shown in Figures 2 to 16, only the respective differences will be discussed. The radar measuring device 40 has different embodiments of the antenna arrangement according to the invention 200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600.

[0055] The radar measuring device 40 has an electronic unit 50 which is coupled to the radiation source 101, see Fig. 2. The electronic unit 50 is configured to excite and control the radiation source 101 to emit electromagnetic waves, for example, based on a control voltage. The electronic unit 50 is also designed as a detection element and evaluation unit with respect to the radiation reflected by an object, for example, a medium.

[0056] According to the embodiment shown in Fig. 2, the antenna arrangement 200 comprises an input lens 102 and an output lens 103. The antenna arrangement 200 thus forms a multi-lens system. The input lens 102 and the output lens 103 have identical diameters. The antenna arrangement 200 includes a housing 201 with a longitudinal orientation. The input lens 102 and the output lens 103 are arranged one behind the other along the longitudinal orientation of the housing 201. The radiation source 101 emits the electromagnetic waves in the direction of the input lens 102, which is illuminated by the radiation source 101. The input lens 102 focuses the waves at the focal point 203 of the input lens 102. Starting from the phase center 204, the electromagnetic waves propagate with a diverging wavefront 205 in the direction of the subsequent output lens 103.The focal point 203 of the input lens 102 can be considered a new feed point for downstream subsystems, whose phase center 204 represents the new reference for the emitted wavefronts with different phases. The curved wavefronts 205 originating from the phase center 204 at the focal point 203 are subsequently corrected by the output lens 103, resulting in the emission of electromagnetic waves with planar wavefronts 206 from the output lens 103. In the far field of the antenna arrangement 200, this is characterized by high beam quality of the emitted electromagnetic waves with low aperture amplitude, high antenna gain, and high sidelobe / reflection suppression.

[0057] The antenna arrangement 200 has mounting devices 209 located at the output end of the antenna arrangement 200. The mounting devices 209 allow the antenna arrangement 200 to be coupled to external components, for example, by mounting them on it.

[0058] The antenna arrangement 200 is advantageously designed without waveguides. This means that the housing 201, in addition to the input lens 102 and the output lens 103, is not filled with any waveguide material. Due to the waveguide-free design of the antenna arrangement 200, heat conduction via the housing 201 (and any absorber elements) is reduced. These effects can be regulated by the lens spacing via the process distance 105.

[0059] The process distance 105 is determined by the partial distances between the radiation source 101 and the input lens 102, as well as between the input lens 102 and the output lens 103. The process distance 105 is used for the thermal decoupling of the radiation source 101 and the electronic unit 50 from the object / medium under investigation. This reduces heat conduction along the antenna arrangement 200. The process distance 105 is thus generated by the arrangement of the lenses 102 and 103, their beam-focusing effect, and the position of the generated phase center 204.

[0060] The antenna arrangement 300, shown in Fig. 3, provides a reciprocal beam path for electromagnetic waves in opposite directions along the longitudinal axis of the antenna arrangement 300. Therefore, electromagnetic waves reflected from an object / medium can pass through the antenna arrangement 300 in the opposite direction, first striking the output lens 103 and then propagating from there towards the input lens 102. The electronic unit 50 is coupled to the radiation source 101 and configured to detect reflected electromagnetic waves. Based on the electronic unit 50, corresponding measurement data can be acquired.

[0061] By determining the transit time or other suitable evaluation methods, the radar measuring device 40 can in particular determine the distance to an object / medium to be examined, so that the radar measuring device 40 can be used as a level sensor and / or limit level sensor.

[0062] The antenna arrangement 400 from Fig. 4 additionally features a dielectric absorber aperture 401, which is designed as a rotationally symmetrical high-frequency attenuator. The absorber aperture 401 is arranged on the inner wall of the housing 201 of the antenna arrangement 400, between the input lens 102 and the output lens 103, in the direction of propagation. The absorber aperture 401 has a varying inner diameter along the longitudinal direction of the antenna arrangement 400. Therefore, the cross-section of the beam path of the antenna arrangement 400 is limited by the absorber aperture 401. According to this embodiment, the absorber aperture 401 is arranged such that its minimum inner diameter along the longitudinal extension direction of the antenna arrangement 400 essentially coincides with the focal point 203 of the input lens 102 and the phase center 204.

[0063] The absorber aperture 401 ensures attenuation of interference reflections and side lobes of the electromagnetic waves. This allows the beam quality of the electromagnetic waves along the antenna array 400 to be improved.

[0064] The absorber perforation 401 generally forms an additional heat conduction path along the antenna assembly 400. Therefore, the absorber perforation 401, corresponding to the antenna assembly 500 (see Fig. 5), can have interruptions in the form of insulating sections 501 along the longitudinal direction of the antenna assembly 500, in which no absorber material is present. This allows partial components of the absorber perforation 401 to be spaced apart from one another and thus thermally decoupled. For example, the antenna assembly 500 comprises the absorber perforation 401 and separate absorber elements 104, with insulating sections 501 arranged between the absorber perforation 401 and the absorber elements 104.

[0065] Optionally, the absorber elements 104 can also be arranged on the input side of the input lens 102 and on the output side of the output lens 103. This means that the absorber elements 104 do not necessarily have to be arranged between the input lens 102 and the output lens 103 along the longitudinal direction of the antenna arrangement 500.

[0066] To further reduce heat conduction along the absorber elements 104 and / or along the absorber aperture 401, the absorber elements 104 and / or the absorber aperture 401 can have a varying outer diameter along the longitudinal direction of the antenna arrangement 600, see Fig. 6. This creates a cavity 601, shown here by way of example between the absorber aperture 401 and the housing 201 of the antenna arrangement 600. By reducing the material of the absorber aperture 401, heat conduction along the antenna arrangement 600 is reduced.

[0067] The radiation source 101 can, for example, be designed as a horn radiator 700, see Fig. 7, which may optionally have an already integrated emission lens 701.

[0068] In another embodiment, the radiation source 101 can be designed as a patch antenna 800, see Fig. 8, which can also already have an integrated emission lens 701.

[0069] The embodiment of the radar measuring device 40 shown in Fig. 9 is characterized in that the radiation source 101 and the input lens 102 are combined as a lens antenna. This means that the radiation source 101 and the input lens 102 are formed as a single unit, ensuring optimized irradiation of the input lens 102. Therefore, the effective antenna area of ​​the lens antenna is fully utilized with respect to the input lens 102, resulting in particularly low beam losses. The input lens 102 and the output lens 103 of the radar measuring device 40 can have different shapes. By way of example, the antenna arrangements 1000 and 1100 from Figs. 10 and 11 show that the input lens 102 and the output lens 103 can have spherical or aspherical shapes, for example, a meniscus shape, a biconvex shape, a plano-convex shape, a bi-concave shape, or a plano-concave shape.

[0070] The input lens 102 and the output lens 103 generally have a dielectric material.

[0071] The antenna arrangement 1200 shown in Fig. 12 illustrates that the input lens 102 and the output lens 103 can be coupled to the housing 201 by means of a snap-fit ​​connection. This snap-fit ​​connection can be formed using or by means of the absorber aperture 401 and / or additional absorber elements 104. The input lens 102 and the output lens 103 can be removed from the housing 201 non-destructively using this snap-fit ​​connection, for example, for maintenance purposes. It can also be seen here that the absorber elements 104 can be arranged on the input side of the input lens 102.

[0072] To ensure galvanic isolation along the longitudinal direction of the antenna arrangement 1300, see Fig. 13, the housing 201, which generally comprises an electrically conductive material, can have decoupling sections 1301 through which the housing 201 is at least partially interrupted along the longitudinal direction of the antenna arrangement 1300. This prevents current flow between opposite ends of the housing 201, i.e., between the input and the output. According to this embodiment of the antenna arrangement 1300, the housing 201 is completely interrupted in the decoupling sections 1301. The decoupling sections 1301 are advantageously arranged such that they coincide along the longitudinal direction of the antenna arrangement 1300 with the region in which the absorber aperture 401 has its minimum inner diameter.Since the focusing by means of the input lens 102 and the absorber aperture 401 results in very few electromagnetic field components that could be radiated from the antenna arrangement 1300, this positioning of the decoupling sections 1301 leads only to a negligible weakening of the electromagnetic shielding. Alternatively or cumulatively, decoupling sections 1301 could of course also be arranged at other positions along the longitudinal direction of the antenna arrangement 1300.

[0073] Since the material of the absorber aperture 401 exhibits a residual, non-negligible electrical conductivity, the absorber aperture 401 can also include absorber decoupling sections 1401, similar to the insulating sections 501, as shown in the embodiment of the antenna arrangement 1400 in Fig. 14. The absorber decoupling sections 1401 can also be provided along the longitudinal direction of the antenna arrangement 1400 in the region where the absorber aperture 401 has its minimum inner diameter. Of course, the absorber decoupling sections 1401 can also be arranged at other alternative or additional positions along the longitudinal direction of the antenna arrangement 1400.

[0074] The absorber decoupling sections 1401, in conjunction with corresponding decoupling sections 1301 of the housing 201, ensure complete galvanic isolation along the antenna assembly 1400. To guarantee the mechanical integrity of the antenna assembly 1400, the decoupling sections 1301 of the housing 201 can be filled with a connecting piece 1402 made of an electrically non-conductive material. This connecting piece 1402 can have a variety of shapes.

[0075] According to the antenna arrangement 1500, see Fig. 15, the connecting piece 1501, for example, has an enclosing shape that completely surrounds the decoupling section 1301 of the housing 201. This ensures high mechanical stability of the antenna arrangement 1500, which is able to withstand stress. The connecting piece 1501 can, for example, be manufactured by an injection molding process.

[0076] The antenna arrangement 1600 of the radar measuring device 40 from Fig. 16 shows that the housing 201 can alternatively comprise a (partially) metallized plastic or a combination of a metal tube 1601 and a metallized plastic. The metallized plastic has a metal layer 1602 and a plastic layer 1603. This allows for galvanic isolation without an interruption in the absorber aperture 401 by means of insulating sections 501 and / or absorber decoupling sections 1401. The two-part housing 201, consisting of the metallized plastic, which has the metal layer 1602 and the plastic layer 1603, and the metal tube 1601, is mechanically connected to each other. In this case, the conductive housing 201 describes the electrically conductive cone of the radiation source 101.

[0077] This results in a radar measuring device 40 with an antenna arrangement of 200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600 mm, which provides electromagnetic waves with high beam quality and sufficient thermal decoupling from the object / medium under investigation, thus increasing the measurement precision compared to previous radar measuring devices. This is ensured in particular by selecting the distances of the corresponding lenses depending on the frequency of the electromagnetic waves emitted by the radiation source, such that electromagnetic waves with a plane wavefront can be emitted onto the object / medium under investigation. The mechanically stable and robust design of the antenna arrangement 200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600 allows disturbances in the measurement process to be avoided or at least reduced compared to previous approaches.

[0078] Although the disclosure has been presented and described with respect to one or more embodiments, the person skilled in the art will be able to make equivalent changes and modifications after reading and understanding this description and the accompanying drawings. Reference numeral list

[0079] 0 Antenna arrangement 206 Plane wavefront 1 Primary radiator 209 Mounting device 22 First lens

[0080] 23 Second lens 401 Absorber pinhole aperture 24 High-frequency damper 501 Isolation section 25 Process distance 601 Cavity

[0081] 0 radar measuring device 700 horn emitter

[0082] 50 Electronic unit 701 Emission lens

[0083] 101 Radiation source 800 Patch antenna

[0084] 102 Inlet lens 1101 Connecting piece 103 Outlet lens 1301 Decoupling section 104 Absorber elements 1401 Absorber decoupling section

[0085] 105 Process spacing 1402 Connecting piece 200, 300, Antenna arrangement 1501 Connecting piece 400, 500,

[0086] 600, 900,

[0087] 1000, 1100,

[0088] 1200, 1300,

[0089] 1400, 1500,

[0090] 1600

[0091] 201 Housing 1601 Metal tube

[0092] 203 Focus point 1602 Metal layer

[0093] 204 Phase center 1603 Plastic layer 205 Curved wavefront

Claims

Patent claims 1. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) for a radar measuring device (40) with a radiation source (101), wherein the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) comprises at least one input lens (102) and one output lens (103), wherein the input lens (102) is configured to focus electromagnetic waves emitted by the radiation source (101) towards the output lens (103), and wherein a distance between at least the input lens (102) and the output lens (103) along a longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) depending on a frequency of the electromagnetic waves emitted by the radiation source (101), such that the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500,1600) based on the output lens (103) provides electromagnetic waves for an external component which has a substantially planar wavefront (206).

2. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to claim 1, wherein the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) comprises at least one absorber pinhole aperture (401) arranged between the input lens (102) and the output lens (103), which provides at least partial coverage along the longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) has varying inner diameters.

3. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to claim 2, wherein the absorber pinhole (401) is positioned such that a minimum inner diameter of the absorber pinhole (401) along the longitudinal extension direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) coincides with a focal point (203) of the input lens (102).

4. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to claim 2 or 3, wherein the absorber aperture (401) has an outer diameter that varies at least partially along the longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600).

5. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of claims 2 to 4, wherein the absorber aperture (401) has at least partially along the longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) at least one isolation section (501) in which the absorber aperture (401) is interrupted.

6. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of claims 2 to 5, wherein the absorber aperture (401) comprises a dielectric material.

7. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of claims 2 to 6, wherein the absorber aperture (401) has a rotationally symmetric shape.

8. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of claims 2 to 7, wherein the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) comprises at least one additional input absorber element (104) and / or an output absorber element (104), wherein the input absorber element (104) extends along the longitudinal direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) is arranged on the input side of the input lens (102), and wherein the output absorber element (104) is arranged along the longitudinal extension direction of the antenna arrangement on the output side of the output lens (103).

9. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to one of the preceding claims, wherein the input lens (102) and the output lens (103) have identical diameters.

10. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any of the preceding claims, wherein the input lens (102) and / or the output lens (103) has a spherical shape, an aspherical shape, a meniscus shape, a biconvex shape, a plano-convex shape, a bi-concave shape or a plano-concave shape.

11. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any of the preceding claims, wherein the input lens (102) and the output lens (103) are arranged within a housing (201) of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600).

12. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to claim 11, wherein the housing (201) comprises an electrically conductive material at least section by section along the longitudinal extent direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600).

13. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to claim 11 or 12, wherein the housing (201) has at least partially at least one decoupling section (1301) along the longitudinal extension direction, wherein the at least one decoupling section (1301) comprises an electrically non-conductive material.

14. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of claims 11 to 13, wherein the housing (201) has mounting devices (209) on an output side of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) by means of which the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) can be mechanically coupled with an external component.

15. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to one of the preceding claims, which is designed without waveguides at least sectionally along the longitudinal extension direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600).

16. Antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to any one of the preceding claims, wherein the input lens (102) and the output lens (103) are designed and arranged depending on a frequency of the electromagnetic waves emitted by the radiation source (101) such that the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) produces a reciprocal wave propagation of the electromagnetic waves through the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) along the longitudinal direction.

17. Radar measuring device (40) with an antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) according to one of the preceding claims, a radiation source (101) and an electronic unit (50) coupled at least with the radiation source (101), wherein the electronic unit (50) is configured to control the radiation source (101) to emit electromagnetic waves in the direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600).

18. Radar measuring device (40) according to claim 17, wherein the radiation source (101) is mechanically coupled to the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600), and wherein a distance between the radiation source (101) and the input lens (102) of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) along the longitudinal extension direction of the antenna arrangement (200, 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600) depending on a frequency of the electromagnetic waves emitted by the radiation source (101).

19. Radar measuring device (40) according to claim 17 or 18, wherein the input lens (102) is an integral part of the radiation source (101).

20. radar measuring device (40) according to one of claims 17 to 19, wherein the radar measuring device (40) is configured to detect electromagnetic waves reflected from an external object by means of the electronic unit (50).

21. Radar measuring device (40) according to one of claims 17 to 20, wherein the radar measuring device (40) is configured as a level and / or limit level sensor.

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