Waveguide coupling device for radar sensor

Abstract

A waveguide coupling device (100) for a radar sensor (300) is disclosed. The waveguide coupling device (100) comprises a waveguide tube (102) for transmitting and / or receiving a radar signal (302) and a high-frequency substrate (200). The waveguide tube (102) has at least a first excitation element (112) and a second excitation element (114), which are each arranged at an excitation end (132) in an inner volume (120) of the waveguide tube (102). The first excitation element (112) has a first length (116) measured in a longitudinal extension direction (134) of the waveguide tube (102), and the second excitation element (114) has a second length (118) measured in the longitudinal extension direction (134) of the waveguide tube (102) which is different from the first length (116) of the first excitation element (112), such that at least a first resonance wave having a first resonance frequency and a second resonance wave having a second resonance frequency different from the first resonance frequency can be excited by an excitation wave at the first excitation element (112) and the second excitation element (114), which first and second resonance waves can superimpose in the waveguide tube (102) to form the radar signal (302).

Description

Technical Field

[0001] This invention generally relates to the fields of radar technology and / or radar measurement technology. In particular, the invention relates to waveguide coupling devices for radar sensors, radar sensors having such waveguide coupling devices, level measuring devices having such waveguide coupling devices, uses of such waveguide coupling devices, and methods for generating radar signals using such waveguide coupling devices. Background Technology

[0002] Radar measurement equipment or radar sensors are particularly useful in automation technologies in industrial environments. For example, they can be designed as radar level measuring devices for determining the filling level of a medium. Such radar level measuring devices (hereinafter also referred to as level measuring devices) typically have an antenna, such as a horn antenna, which can be supplied with radar signals through a waveguide and can transmit radar signals through the antenna and can receive the portion of the radar signal reflected on a surface.

[0003] Here, the radar signal, or the electromagnetic wave (e.g., microwave) upon which the radar signal is based, can be generated by the radar module using a radar signal source and coupled, for example, to a waveguide capable of transmitting the radar signal via a substrate-integrated waveguide. The substrate-integrated waveguide can be input into the waveguide, for example, via a patch antenna with a resonant can or via a λ / 4 board with a resonant can. However, the manufacturing cost of such waveguide couplers (or waveguide coupling devices) can be high, for example, because the resonant cans are regularly inserted into the printed circuit board. Summary of the Invention

[0004] By utilizing embodiments of the present invention, it is possible to provide, in an advantageous manner, an improved waveguide coupling device for radar sensors, as well as a corresponding radar sensor and a corresponding level measurement device.

[0005] The following description also relates to waveguide coupling devices, radar sensors, the applications of waveguide coupling devices and / or radar sensors, methods for generating radar signals using waveguide coupling devices, and level measuring devices having radar sensors and / or waveguide coupling devices. In other words, the features, components, and / or functions described below with reference to waveguide coupling devices also apply to radar sensors, the applications of waveguide coupling devices, methods for generating radar signals using waveguide coupling devices, and level measuring devices, and vice versa.

[0006] A first aspect of the invention relates to a waveguide coupling device for a radar sensor. The waveguide coupling device includes a waveguide (Hohlleiter) for radiating and / or transmitting radar signals and a high-frequency substrate (Hochfrequenzsubstrates). The high-frequency substrate has at least one input conductor at a first end for feeding at least one excitation wave into the high-frequency substrate, a radiating region at a second end opposite the first end for coupling the excitation wave out of the high-frequency substrate, and a waveguide (Hohlleiter) coupled to the input conductor and the radiating region. One end of the waveguide (hereinafter referred to as the excitation end of the waveguide) is arranged at, adjacent to, and / or on the radiating region of the high-frequency substrate, such that the excitation wave can be coupled to, coupled to, and / or enter the excitation end of the waveguide through the radiating region of the high-frequency substrate. The waveguide also includes at least a first excitation element and a second excitation element, both arranged within the internal volume of the waveguide at the excitation end. The first excitation element has a first length measured in the longitudinal extension direction of the waveguide, and the second excitation element has a second length measured in the longitudinal extension direction of the waveguide that is different from the first length of the first excitation element, such that at least a first resonant wave having a first resonant frequency and a second resonant wave having a second resonant frequency can be excited at the first and second excitation elements via, based on, and / or by an excitation wave, the first and second resonant waves being able to at least partially superimpose and interfere in the waveguide to form a radar signal, the first and second resonant waves being able to at least partially superimpose, superimpose with each other, interfere with, and / or interfere with each other in the waveguide.

[0007] The excitation wave can typically be an electromagnetic wave, such as microwaves provided by a radar module. The high-frequency substrate can be arranged to transmit and / or guide the excitation wave along its direction of travel, and at least partially couple it into a waveguide, and, if necessary, couple a received signal from the waveguide into the substrate. A first end of the high-frequency substrate can be opposite to and / or upstream of a second end of the high-frequency substrate in the direction of travel of the excitation wave. For example, the high-frequency substrate can be designed as a circuit board, a printed circuit board (PCB).

[0008] The input conductor located at the first end of the high-frequency substrate can be a wire, a microstrip line, and / or a stripline. The excitation wave can be fed into the high-frequency substrate through the input conductor, for example from a microwave source, a radar module, a radar signal source, etc., and guided in the direction of the radiation region through a waveguide, or alternatively through a stripline, a coplanar line, a microstrip, etc.

[0009] For example, the waveguide can be a substrate integrated waveguide (SIW). A waveguide can be viewed as a filled waveguide. For instance, the waveguide can have a flat top side and a flat bottom side in the form of, for example, a copper layer and / or a conductive layer, with substrate material located between the top and bottom sides, and can be electrically interconnected through vias or apertures forming the "sidewalls" of the "waveguide". However, alternatively, any other type of waveguide can be used.

[0010] The radiating region can be part of a high-frequency substrate, and at least part of the excitation wave can be coupled to the excitation end of the waveguide through the radiating region.

[0011] It should be noted that, similar to the transmission and / or emission of radar signals, radar signals reflected from a surface can also be received using a waveguide coupling device. Therefore, all the above and following disclosures relating to the transmission or emission of radar signals are similarly applicable to the reception of radar signals using a waveguide coupling device.

[0012] Waveguides can, in principle, have any geometric shape and / or cross-sectional geometry. For example, waveguides can be designed as circular, elliptical, oval, or rectangular waveguides. The excitation end of the waveguide can represent the end of the waveguide facing the high-frequency substrate, which can be opposite the radiating end of the waveguide in the direction of radar signal transmission and / or in the longitudinal extension direction of the waveguide. The longitudinal extension direction of the waveguide can be substantially parallel to the direction of radar signal transmission and / or propagation (or direction of travel) inside the waveguide. For example, radar signals can be coupled and radiated through the waveguide to antennas, such as those of radar sensors and / or level measuring devices. For example, waveguides can be made of metals and / or conductive materials.

[0013] In the context of this invention, "excitation element" can refer to a geometry designed to form and / or generate one or more resonant waves within the internal volume of the waveguide. Here, the resonant wave can be generated by, at, and / or within one of the excitation elements. Alternatively or additionally, a resonant wave can be generated between two excitation elements and / or between one of the excitation elements and another structure of the waveguide. Here, each resonant wave can represent an electromagnetic wave generated by one or more (or based on one or more) excitation elements and having a defined resonant frequency. Here, the resonant frequencies of different resonant waves can be different from each other.

[0014] Typically, the length of an excitation element can be represented by its dimension measured parallel to the longitudinal extension direction of the waveguide and / or parallel to the transmission direction of the radar signal. For example, the length of each excitation element can be measured from its lower edge to its upper edge, which is opposite to the lower edge in the longitudinal extension direction of the waveguide. Here, the lower edges of multiple excitation elements can be arranged at different or equal distances relative to the end face of the waveguide at the excitation end. In particular, at least a portion of the lower edges of the excitation elements are flush with the end face of the waveguide at the excitation end. However, it is also conceivable that at least a portion of the excitation elements are offset relative to each other in the longitudinal extension direction.

[0015] Here, the lengths of the excitation elements can be selected such that the upper edges of the different excitation elements are spaced apart from the end face of the waveguide at the excitation end by a distance different from each other. Specifically, the lengths of the excitation elements can be selected and coordinated to generate or excite at least two resonant waves with two distinct resonant frequencies in the waveguide. In particular, the first length of the first excitation element and the second length of the second excitation element can be selected and / or coordinated in relation to each other to generate a first resonant wave with a first resonant frequency and a second resonant wave with a second resonant frequency. For example, the first and second resonant waves can interfere in the waveguide and at least partially form a radar signal.

[0016] In principle, each excitation element can have any geometry, shape, size, cross-sectional geometry, etc. For example, at least in some regions, one or more excitation elements can be designed as plate-shaped, pin-shaped, fin-shaped, and / or square. However, other geometries are also considered. Furthermore, different excitation elements can have similar or identical geometries and / or cross-sectional geometries. Alternatively, different excitation elements can have geometries and / or cross-sectional geometries that differ from each other.

[0017] The waveguide coupling device according to the invention can advantageously feed an excitation wave broadbandly into the waveguide and / or generate a broadband radar signal. Furthermore, the resonant tank used to feed the excitation wave into the waveguide, which is typically used in waveguide coupling devices and integrated into a printed circuit board substrate, can be eliminated. Therefore, manufacturing costs can be reduced on the one hand, and installation space can be reduced on the other. In particular, tolerances in the manufacture of the resonant tank no longer affect the radar signal, or at least have a smaller impact.

[0018] According to one embodiment, both the first and second excitation elements of the waveguide coupling device protrude at least partially from the wall and / or inner surface of the waveguide into the internal volume of the waveguide. In other words, the excitation elements can be arranged adjacent to and / or adjacent to the waveguide wall. For example, the first and second excitation elements can contact the wall and / or inner surface of the waveguide.

[0019] According to one embodiment, a first excitation element and a second excitation element protrude from the wall and / or inner surface of the waveguide, for example toward the center of the waveguide, on two opposite sides and / or two different sides of the waveguide. For example, the first and second excitation elements, as well as one or more optional excitation elements, may protrude from the wall and / or inner surface of the waveguide at different locations, regions, and / or sides of the waveguide along the inner circumference of the waveguide.

[0020] According to one embodiment, the first length of at least a first excitation element and the second length of a second excitation element are coordinated to generate a second resonant wave with a time delay relative to a first resonant wave. This allows the first and second resonant waves to be superimposed, for example, at least partially in phase and / or constructively interfering. The excitation wave can enter the waveguide from a radiation region, where the first resonant wave can be generated first by at least one or two excitation elements. As the excitation wave and / or the first resonant wave propagates in the waveguide, the second resonant wave can also be generated with a time delay by at least one or two excitation elements. This second resonant wave can interfere with or be added to the first resonant wave propagating in the waveguide. This enables the provision of broadband radar signals.

[0021] According to one embodiment, a first resonant wave is generated at and / or through a second excitation element. Alternatively or additionally, a second resonant wave is generated between the first and second excitation elements. For example, a second resonant wave may be formed between the upper edges of the first and second excitation elements.

[0022] According to one embodiment, the waveguide of the waveguide coupling device is integrally formed with the first and second excitation elements. For example, the waveguide can be manufactured together with the excitation elements during a casting and / or die-casting process, or in 3D printing and subsequent metallization of metal or plastic. This can particularly improve the mechanical stability of the waveguide and enable precise formation of the excitation elements. However, alternatively, at least a portion of the excitation element can be welded to, adhered to, or otherwise attached to the waveguide.

[0023] According to one embodiment, the waveguide coupling device further includes a third excitation element disposed at an excitation end within the internal volume of the waveguide. The third excitation element has a third length, measured in the longitudinal extension direction of the waveguide, which differs from the first length of the first excitation element and the second length of the second excitation element. The dimension of the third length is determined such that an excitation wave between the first and third excitation elements can excite a third resonant wave having a third resonant frequency different from the first and second resonant frequencies. Optionally, one or more other excitation elements may also be provided. Unless otherwise expressly stated, all the above and following disclosures regarding one of the excitation elements equally apply to all other excitation elements. The third resonant wave can advantageously further improve the bandwidth.

[0024] According to one embodiment, a first, second, and third resonant wave can be superimposed to form a radar signal. In other words, the three resonant waves can interfere with each other, particularly at least partially in phase. As described above regarding the first and second excitation elements and the first and second resonant waves, a third length of the third excitation element can be selected, and / or this third length can be coordinated with the first and second lengths, such that the third resonant wave is generated with a time delay relative to the first and second resonant waves, and can be added to the first and second resonant waves inside the waveguide as the wave propagates. In this way, a broadband radar signal can be generated based on the first, second, and third resonant waves, which can also include the first, second, and third resonant frequencies. Signals of the same frequency can be amplified when superimposed, while signals of different frequencies can cause a certain frequency shift when superimposed, thereby giving the radar signal a certain broadband capacity.

[0025] According to one embodiment, the third excitation element is designed as a wall protrusion. The third excitation element may also be referred to as the wall or the edge of the wall protrusion. This particularly enables a compact structure for the waveguide and improves mechanical stability.

[0026] According to one embodiment, the second excitation element protrudes from a wall protrusion formed by the third excitation element into the internal volume. In this case, it is conceivable that the second and third excitation elements can be integrally formed.

[0027] According to one embodiment, the first length is greater than the second length, and the third length is greater than the first length. Other relative length ratios of the excitation element lengths can also be considered and used. For example, the lengths and / or length ratios can be selected based on the desired frequency band of the radar signal and / or based on the desired resonant frequency.

[0028] Alternatively, other parameters, such as geometry, shape, size, mutual alignment, and / or relative arrangement of excitation elements, can be selected and / or coordinated according to the desired frequency band.

[0029] According to one embodiment, the high-frequency substrate has a rectangular cross-section in at least a local region. This enables a compact structure for the substrate-integrated waveguide and efficient propagation of the excitation wave.

[0030] According to one embodiment, the waveguide of the waveguide coupling device is a circular waveguide. Therefore, the waveguide can have a circular cross-section and / or a circular cross-sectional geometry. However, other geometries are also possible.

[0031] For example, a substrate-integrated waveguide can have a rectangular cross-section, and the waveguide can be designed as a circular waveguide. The design of the waveguide coupling device according to the invention, having a radiating region and at least two excitation elements, advantageously enables the excitation wave to transition from such a rectangular and substrate-integrated waveguide to a circular waveguide without the need for additional modules for converting a rectangular waveguide into a circular waveguide.

[0032] According to one embodiment, the high-frequency substrate includes an upper copper layer and a lower copper layer, which are at least partially connected via vias. The upper and lower copper layers may also be referred to as the top side and bottom side. A substrate integrated waveguide may be formed between the two copper layers. The vias can electrically connect the two copper layers to each other. The vias appear to form and / or define the boundaries of the substrate integrated waveguide.

[0033] According to one embodiment, the radiation region of the high-frequency substrate is limited by a via. The via that limits the radiation region can be considered as a "sidewall" of the radiation region and is often referred to as a via.

[0034] Another aspect of the invention relates to a radar sensor having a waveguide coupling device as described above and below. The radar sensor can be of any type. It can be a level radar sensor, a distance sensor, a limiting level sensor, a motion radar sensor, a weather radar sensor, or a ground radar sensor. For example, the radar sensor may include one or more antennas such as a horn antenna. The radar sensor can also typically be a field device for detecting one or more measurement variables.

[0035] Sometimes, radar sensors can generate transmission or radar signals covering a certain frequency range. In level measurement technology, for example, the transmission frequency within a measurement period can be increased within a certain frequency range; this is also known as frequency-modulated continuous wave radar. This frequency shift can be implemented or achieved by providing a broadband radar signal via a waveguide coupling device.

[0036] Another aspect of the invention relates to a level measuring device having a radar sensor and / or waveguide coupling device as described above and below. The level measuring device can be designed to detect the level of a medium, such as a medium in a container.

[0037] Another aspect of the invention relates to the use of waveguide coupling devices as described above and below in radar sensors and / or level measurement devices.

[0038] Another aspect of the present invention relates to a method for generating and / or receiving radar signals using a waveguide coupling device as described above and below. The method includes the following steps:

[0039] - Feed at least one excitation wave into the high-frequency substrate of the waveguide coupling device;

[0040] - The excitation wave is coupled to the excitation end of the waveguide of the waveguide coupling device through the radiation region of the high-frequency substrate of the waveguide coupling device;

[0041] - An excitation wave passing through at least the first and second excitation elements of the waveguide and / or based on at least the first and second excitation elements, at least a first resonant wave having a first resonant frequency and a second resonant wave having a second resonant frequency are excited; and

[0042] -Based on the superposition of at least the first and second resonant waves, a radar signal is transmitted using a waveguide of a waveguide coupling device; and / or a reflected radar signal is received using a waveguide of a waveguide coupling device.

[0043] Exemplary embodiments will now be described with reference to the accompanying drawings. The illustrations in the drawings are schematic and not drawn to scale. If the same or similar reference numerals are used in the following description of the drawings, they denote the same or similar elements. Attached Figure Description

[0044] Figure 1 A waveguide coupling device according to one embodiment is shown.

[0045] Figure 2 A plan view of a high-frequency substrate according to one embodiment is shown.

[0046] Figure 3 A perspective view of a high-frequency substrate according to an embodiment is shown.

[0047] Figure 4a , 4b 4c shows a waveguide coupling device according to one embodiment in three different views.

[0048] Figure 5 A level measuring device and / or radar sensor according to one embodiment are shown.

[0049] Figure 6 The curves are shown as measured in a waveguide coupling device according to one embodiment.

[0050] Figure 7A flowchart illustrating the steps of a method for generating radar signals using a waveguide coupling device according to an embodiment is shown. Detailed Implementation

[0051] Figure 1 A waveguide coupling device 100 according to one embodiment is shown.

[0052] The waveguide coupling device 100 includes a high-frequency substrate 200 having an input conductor 106 disposed at a first end of the high-frequency substrate 200. The input conductor may not protrude relative to the substrate. One or more excitation waves may be fed into the high-frequency substrate 200, for example from a radar module, via the input conductor. The first end is opposite to a second end of the high-frequency substrate 200 on which a radiating region 108 of the high-frequency substrate 200 is disposed in the direction of propagation of the excitation wave, the direction of travel of the excitation wave, and / or the longitudinal direction of the high-frequency substrate 200. The input conductor 106 and the radiating region 108 are coupled through a substrate-integrated waveguide 110 through which the excitation wave propagates from the input conductor 106 to the radiating region 108.

[0053] The waveguide coupling device 100 also includes a waveguide 102 having an excitation end 132, which is disposed at, above, and / or above the radiation region 108 of the high-frequency substrate 200. The excitation wave can be coupled at least partially via the radiation region 108 into the internal volume 120 of the waveguide 102.

[0054] At least a first excitation element 112 and a second excitation element 114 are arranged in the region of the excitation end 132 of the waveguide 102. Each excitation element 112, 114 has a length 116, 118 measured in the longitudinal extension direction 134 of the waveguide 102. Here, the lengths 116, 118 of the excitation elements 112, 114 are measured from the lower edge to the upper edge of the respective excitation element 112, 114. Figure 1 In the example shown, the lower edges of the excitation elements 112 and 114 are flush with the end face of the waveguide 102 at the excitation end 132. However, the excitation elements 112 and 114 may also be arranged to be offset from each other in the longitudinal extension direction 134.

[0055] At least two resonant waves with different resonant frequencies can be generated based on excitation elements 112 and 114 using excitation waves. For example, a first resonant wave can be formed at one of the excitation elements 112 and 114, and a second resonant wave can be formed between the two excitation elements 112 and 114 (e.g., between their upper edges). Alternatively or additionally, one of the resonant waves can be formed at one of the excitation elements 112 and 114 and at another structure and / or another excitation element of the waveguide 102. In particular, the lengths 116 and 118 of the two excitation elements 112 and 114 can be coordinated to allow the resonant waves to superimpose, for example, when the wave propagates in the waveguide 102, these resonant waves are at least partially in phase and / or at substantially the same phase position (and / or with a certain phase offset from each other) to form at least a portion of the radar signal. Therefore, the desired broadband capacity of the radar signal 302 can be achieved. The bandwidth of the signal can be, for example, in the range of 1-50 GHz, and particularly at a frequency of 80 GHz with a bandwidth of approximately 10 GHz. Using this type of coupling, bandwidths exceeding 10%, for example 12-15%, or approximately 12-13%, can be achieved.

[0056] Basically, two different types of superposition can be distinguished. On one hand, signals of the same frequency can be superimposed in phase. At different frequencies, the phase will inevitably differ. However, signals of different frequencies can also be superimposed, and a certain broadband capacity is achieved due to the frequency shift from one frequency to another (see, for example...). Figure 6 By superimposing two exciters or signals with the same frequency in phase, they can be amplified. This improves the efficiency of the entire device. For example, this effect can be utilized between two exciters 112 and 122. The phase can also be set, influenced, and / or adjusted accordingly by the spatial distance and signal transmission time.

[0057] Figure 1 In an exemplary embodiment, the two excitation elements 112, 114 are designed as rectangular and / or fin-shaped. The waveguide 102 is also designed as a typical circular waveguide 102, but it can also be designed as, for example, a rectangular waveguide. The excitation elements 112, 114 are spaced apart from each other in the radial direction of the waveguide 102. Here, the two excitation elements 112, 114 protrude from opposite sides of the wall and / or inner surface of the waveguide 102.

[0058] The excitation elements 112 and 114 of the waveguide 102 can also be regarded as fins or double fins. The first excitation element 112 can also be referred to as an exciter or resonator, while the second excitation element 114 can be referred to as a sub-exciter or sub-resonator, and vice versa.

[0059] As an option for coordinating lengths 116 and 118, the geometry, size, shape, position, relative arrangement, and / or relative orientation of excitation elements 112 and 114 can also be adjusted and / or mutually adjusted to influence the resonant wave and / or resonant frequency. One or more additional excitation elements may also be provided.

[0060] Figure 2 A high-frequency substrate 200 according to one embodiment is shown in plan view. The high-frequency substrate 200 includes an input conductor 106 for inputting an incoming excitation wave. The high-frequency substrate 200 has a rectangular cross-section and includes a substrate integrated waveguide 110. The substrate integrated waveguide 110 is formed between an upper copper layer 204a and a lower copper layer (not shown). A dielectric may be formed between the copper layers 204a and 204b. Therefore, the substrate integrated waveguide 110 is analogous to a filled waveguide. The two layers are connected by a via 202.

[0061] The upper copper layer 204a has perforations in the region of the radiation area 108, allowing the excitation wave to enter the waveguide 102. The radiation area 108 is also defined or bounded by vias 202.

[0062] Waveguide 102 can be positioned at Figure 2 On a circular portion 150 of a high-frequency substrate 200 in an exemplary embodiment, the end face of a waveguide 102 faces an upper copper layer 204a and / or is disposed thereon, such that a radiation region 108 is surrounded and / or enclosed by the waveguide 102 along its outer circumference.

[0063] The substrate integrated waveguide 110 has a via 202 forming a wall. Alternatively or additionally, the via 202 may define a radiation region 108. The via 202 connects the device copper layer 204a and the lower copper layer 204b. Figure 2 Not shown in the image, see [link / reference]. Figure 3 They are electrically connected to each other.

[0064] Figure 3 A perspective view of a high-frequency substrate 200 according to one embodiment is shown. Unless otherwise stated, Figure 3 The high-frequency substrate 200 has the same characteristics as Figure 2 The same components and / or parts as the high-frequency substrate 200. Figure 3 The three layers of the high-frequency substrate 200 are clearly visible. The lower copper layer 204a is located on the substrate layer 140, and the substrate layer 140 is arranged on the lower copper layer 204b. The two copper layers 204a and 204b, or copper films, are interconnected through vias 202. Figure 3 In the example of the embodiment, the perforation of the upper copper layer 204a in the radiation region 108 can be clearly seen.

[0065] Figure 4aA waveguide coupling device 100 according to another embodiment is shown. Unless otherwise stated, Figure 4a The waveguide coupling device 100 has the same elements and / or components as the waveguide coupling device 100 in the above figures. Figure 4a The waveguide 102 in the embodiment is a circular waveguide 102. Figure 4a The exemplary embodiment of the waveguide 102 further includes a third excitation element 122. This third excitation element 122 is designed as a wall protrusion and protrudes from the wall or inner surface of the waveguide 102 into the internal volume 120. The third excitation element 122 can also be considered as part of the wall of the waveguide 102. Here, a second excitation element 114 protrudes from the third excitation element 122 into the internal volume 120. The length 124 of the third excitation element 122, measured in the longitudinal extension direction 134, is greater than the length 116 of the first excitation element, which in turn is greater than the length 118 of the second excitation element. The height 124 of the third excitation element 122 is adjusted such that a third resonant wave is excited with a slight time delay relative to the first and second resonant waves. In particular, a third resonant wave having a third resonant frequency different from the first and second resonant frequencies can be excited between the first excitation element 112 and the third excitation element 122 (or between their upper edges). A radar signal 302 is formed by superimposing the three resonant waves, which can then propagate in the output direction of the waveguide 102 and can be transmitted through the end opposite the excitation end 132.

[0066] Figure 4b The invention is shown Figure 4a The waveguide coupling device 100 of the embodiment along Figure 4a The cross-section intercepted by line A. Here, Figure 4b The viewpoint of the cross-sectional view is along the direction of radar signal transmission and / or the longitudinal extension direction 134 of waveguide 102. Figure 4b The waveguide 102 also includes two cavities 126 located on either side of the second excitation element 114. The cavities 126 can be used to improve the manufacturability of the waveguide 102. For example... Figure 4b As shown, Figure 4a and 4b The waveguide 102 is integrally formed with three excitation elements 112, 114, and 122.

[0067] Figure 4c A top view of a waveguide coupling device 100 according to one embodiment is shown. Figure 4c This shows how the radiation region 108 is annularly surrounded by the waveguide 102, allowing the excitation wave to enter the internal volume of the waveguide 102.

[0068] Figure 5 A level measuring device 400 and / or radar sensor 400 according to one embodiment are shown. Figure 5 An exemplary embodiment of the level measuring device 400 includes a radar module 300 and a waveguide coupling device 100. An excitation wave can be input into the waveguide coupling device 100 via the radar module 300 and transmitted, for example, via an antenna 301.

[0069] Figure 6 The curves measured in a waveguide coupling device 100 according to one embodiment are shown. Specifically, Figure 6 The curve shown is the return loss curve as a function of frequency. This curve... Figure 6 This is illustrated in a graph. The vertical axis of the graph represents the amplitude of the return loss curve (in any unit). For example, the amplitude can be expressed in dB. The horizontal axis represents the frequency (in any unit). For example, the frequency can be expressed in GHz or MHz. Figure 6 The measurement curve can be generated by superimposing and / or adding three resonant waves. Figure 6 The diagram shows three resonant frequencies f1, f2, and f3. These can be achieved using one of the excitation elements 112 or 114 (see...). Figure 1 The first resonant wave formed at (or 4a) may have a resonant frequency f1. The second resonant wave formed between the two excitation elements 112, 114 (e.g., between their upper edges) may have a resonant frequency f2. The first excitation element 112 and the third excitation element 122 (see...) Figure 4a A third resonant wave excited between (or between their upper edges) can have a resonant frequency f3. The three resonant frequencies f1, f2, and f3 are different from each other.

[0070] In addition, Figure 6 The graphs also show the possible bandwidth of the measurement curves achieved through the design of the waveguide coupling device, particularly through the design of excitation elements 112, 114, and 122. The design of the waveguide coupling device, particularly through the design of excitation elements 112, 114, and 122 (see...) Figure 1 , 4a The bandwidth of the radar signal 302 implemented by the design in section 5) can be directly or indirectly related to the bandwidth of the measurement curve. For example, this can indicate the frequency range of the measurement curve within which it falls below a predetermined amplitude value B without interruption. For example, this amplitude value B could be -10 dB. However, other values ​​of B can also be considered. Figure 6 In the example, the frequency range is between frequencies f- and f+.

[0071] Figure 7 A flowchart illustrating a method according to one embodiment is shown.

[0072] In step S1, at least one excitation wave is fed into the high-frequency substrate 200 of the waveguide coupling device 100.

[0073] In step S2, the excitation wave is coupled to the excitation end 132 of the waveguide 102 of the waveguide coupling device 100 through the radiation region 108 of the high-frequency substrate 200 of the waveguide coupling device 100. In step S3, the excitation wave at least at the first excitation element and the second excitation element 112, 114 of the waveguide 102 excites at least a first resonant wave with a first resonant frequency and a second resonant wave with a second resonant frequency.

[0074] In step S4, radar signal 302 is transmitted using waveguide 102 of waveguide coupling device 100, based at least on the superposition of the first and second resonant waves.

[0075] Furthermore, it should be noted that "comprising" and "having" do not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. It should also be pointed out that features or steps described with reference to one of the above exemplary embodiments may also be used in combination with other features or steps of the other above exemplary embodiments. Reference numerals in the claims should not be considered limiting.

[0076] Cross-references to related applications

[0077] This application claims priority to European Patent Application No. 20,190,652.6, filed on August 12, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A waveguide coupling device (100) for a radar sensor (300), comprising: Waveguide (102) for transmitting and / or receiving radar signals (302); as well as A high-frequency substrate (200) has at least one input conductor (106) at a first end for feeding at least one excitation wave into the high-frequency substrate (200), a radiation region (108) at a second end opposite to the first end for coupling the excitation wave out of the high-frequency substrate (200), and a waveguide (110) coupled to the input conductor (106) and the radiation region (108). The excitation end (132) of the waveguide (102) is arranged on the radiation region (108) of the high-frequency substrate (200), so that the excitation wave can be coupled to the excitation end (132) of the waveguide (102) through the radiation region (108) of the high-frequency substrate (200). The waveguide (102) includes at least a first excitation element (112) and a second excitation element (114), both of which are arranged at the excitation end (132) within the internal volume (120) of the waveguide (102). The first excitation element (112) has a first length (116) measured in the longitudinal extension direction (134) of the waveguide (102), and the second excitation element (114) has a second length (118) measured in the longitudinal extension direction (134) of the waveguide (102) that is different from the first length (116) of the first excitation element, such that at least a first resonant wave with a first resonant frequency and a second resonant wave with a second resonant frequency can be excited at the first excitation element (112) and the second excitation element (114) by the excitation wave, the first resonant wave and the second resonant wave being superimposed in the waveguide (102) to form the radar signal (302).

2. The waveguide coupling device (100) for a radar sensor (300) according to claim 1, in, Both the first excitation element (112) and the second excitation element (114) protrude at least partially from the wall of the waveguide (102) into the internal volume (120) of the waveguide (102).

3. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, The first excitation element (112) and the second excitation element (114) protrude from the wall of the waveguide (102) on two opposite sides of the waveguide (102).

4. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, At least the first length (116) of the first excitation element (112) and the second length (118) of the second excitation element (114) are coordinated to generate the second resonance wave with a time delay relative to the first resonance wave, thereby enabling the first resonance wave and the second resonance wave to be superimposed.

5. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, At least the first length (116) of the first excitation element (112) and the second length (118) of the second excitation element (114) are coordinated to generate the second resonance wave with a time delay relative to the first resonance wave, so that the first resonance wave and the second resonance wave can be at least partially superimposed in phase.

6. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, The first resonant wave is generated at the second excitation element (114), and the second resonant wave is generated between the first excitation element (112) and the second excitation element (114).

7. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, The waveguide (102) of the waveguide coupling device (100) is integrally formed with the first excitation element (112) and the second excitation element (114).

8. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, further comprising: A third excitation element (122) is arranged in the internal volume (120) of the waveguide (102) at the excitation end (132); The third excitation element (122) has a third length (124) measured in the longitudinal extension direction (134) of the waveguide (102), which is different from the first length (116) of the first excitation element (112) and the second length (118) of the second excitation element (114). The third length (124) is sized such that a third resonant wave with a third resonant frequency can be excited between the first excitation element (112) and the third excitation element (122) by the excitation wave.

9. The waveguide coupling device (100) for a radar sensor (300) according to claim 8, in, The first resonance wave, the second resonance wave, and the third resonance wave are superimposed to form the radar signal (302).

10. The waveguide coupling device (100) for a radar sensor (300) according to claim 9, in, The second excitation element (114) protrudes from the wall protrusion formed by the third excitation element (122) into the internal volume (120) of the waveguide (102).

11. The waveguide coupling device (100) for a radar sensor (300) according to claim 8, in, The first length (116) is greater than the second length (118), and the third length (124) is greater than the first length (116).

12. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, The high-frequency substrate (200) has a rectangular cross-section in at least a portion of its area.

13. The waveguide coupling device (100) for a radar sensor (300) according to claim 1 or 2, in, The waveguide (102) of the waveguide coupling device (100) is a circular waveguide (102).

14. A radar sensor (300) having a waveguide coupling device (100) according to any one of claims 1-13.

15. A level measuring device (400) having a waveguide coupling device (100) according to any one of claims 1-13.

16. Use of the waveguide coupling device (100) according to any one of claims 1 to 13 in a radar sensor (300) and / or a level measuring device (400).

17. A method for generating and / or receiving radar signals (302) using a waveguide coupling device (100) according to any one of claims 1 to 13, comprising: Step S1: Feed at least one excitation wave into the high-frequency substrate (200) of the waveguide coupling device (100); Step S2: The excitation wave is coupled to the excitation end (132) of the waveguide (102) of the waveguide (100) through the radiation region (108) of the high-frequency substrate (200) of the waveguide coupling device (100); Step S3: By excitation waves, at least a first resonant wave with a first resonant frequency and a second resonant wave with a second resonant frequency are excited at at least the first excitation element and the second excitation element (112, 114) of the waveguide (102). Step S4: Based on the superposition of at least the first resonant wave and the second resonant wave, the radar signal (302) is transmitted using the waveguide (102) of the waveguide coupling device (100); and / or the reflected radar signal is received using the waveguide (102) of the waveguide coupling device (100).

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