Radar module with microwave chip

Abstract

A radar module configured for factory monitoring includes a microwave chip having a radar signal source, a coupling element, and a resonant chamber, wherein the coupling element protrudes into the resonant chamber.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of German patent application 10 2019 204680.0, filed on April 2, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to radar measurement technology for process automation. In particular, the present invention relates to a radar module configured for plant monitoring, a radar measuring device having such a radar module, the use of the radar module for fill level measurement, limit level measurement, or plant automation, and a method for manufacturing the radar module. Background Art

[0004] Radar measuring devices are used in process automation, in particular for plant monitoring such as fill level measurement, point level detection or object recognition.

[0005] The radar signal is generated by a radar signal source and coupled into a waveguide or antenna, and then the radar signal is transmitted from the waveguide or antenna to the object or filling material to be monitored.

[0006] To this end, waveguide coupling structures are typically designed with metal pins, fins, patch antennas, or similar structures. The microwave signal is typically connected to circuit components (e.g., microstrip structures) on a carrier board via a bonded connection. Antennas can also be integrated directly on the chip (on-chip antennas), but they only achieve good directional results when combined with dielectric lenses.

[0007] For example, such radar modules are used in level radar devices and are implemented for W-band frequencies in the 80 GHz range. Summary of the Invention

[0008] The object of the present invention is to provide an alternative radar module for plant monitoring.

[0009] A first aspect of the present invention relates to a radar module configured for use in automation technology (i.e., factory monitoring), comprising a microwave chip. The microwave chip comprises a radar signal source configured to generate a radar signal. The microwave chip further comprises a coupling element, wherein the coupling element and the radar signal source are connected via a signal connection, for example in the form of a microstrip line. However, since the connection is located on the chip itself, it is most likely that very short electrical connections for the circuit components on the chip can be used. A resonant chamber is provided in the microwave chip, into which the coupling element protrudes, wherein the coupling element is configured to couple the radar signal into the resonant chamber.

[0010] The term "automation technology" can be understood as a subfield of technology encompassing all measures for operating machines and systems without human intervention. One goal of process automation, in this context, is to automate the interaction of individual plant components in the chemical, food, pharmaceutical, oil, paper, cement, shipping, or mining industries. For this purpose, a wide range of sensors can be used, which are particularly well-suited to the specific requirements of the process industry, such as mechanical stability, insensitivity to contaminants, and extreme temperatures and pressures. The measured values ​​of these sensors are typically transmitted to a control room, where process parameters such as fill level, limit level, flow, pressure, or density can be monitored, and settings for the entire plant can be modified manually or automatically.

[0011] One subfield of automation technology involves logistics automation. In the field of logistics automation, processes within buildings or individual logistics equipment are automated with the help of distance sensors and angle sensors. Typical applications are logistics automation systems for the following areas: baggage handling and cargo handling at airports, traffic monitoring (toll collection systems), trade, parcel delivery, or building security (access control). The common point of the examples listed above is that each application requires the combination of presence detection with the precise measurement of the size and position of objects. For this purpose, sensors based on optical measurement methods using lasers, LEDs, 2D cameras, or 3D cameras can be used, which detect distances according to the time of flight principle (ToF).

[0012] Another subfield of automation technology involves factory / manufacturing automation. Examples of this application can be found in many industries, such as automotive, food, pharmaceutical, and general packaging. The goal of factory automation is to automate the production of goods using machines, production lines, and / or robots—that is, to operate without human intervention. The sensors used here, and the specific requirements for measurement accuracy when detecting the position and size of objects, are comparable to those used in the logistics automation example mentioned above.

[0013] For example, plant monitoring could be fill level or limit level measurement. The radar module can also be configured to monitor hazardous areas of a machine, for example to detect or even identify objects in the context of hazardous area monitoring, or to detect and count objects on a conveyor belt or determine the mass flow of bulk material on a conveyor belt.

[0014] The high-frequency signal (radar signal) of the microwave chip does not first need to be transmitted to the printed circuit board. This is usually done by means of wire bonding as a connection technology, which can be disadvantageous in terms of HF technology. Flip-chip mounting is also possible here.

[0015] The signal connection between the radar signal source and the coupling element can be configured to minimize attenuation, thereby minimizing the impact on the radar module's sensitivity. Because there are no bond wires connecting the coupling element to the radar signal source, fluctuations in the length and position of the bond wires do not negatively impact the radar module's performance.

[0016] Since the radar signal (microwave signal) can be coupled directly from the microwave chip into the waveguide or antenna, mechanical tolerances can be minimized, in particular since the coupling element is part of the microwave chip.

[0017] In addition to the coupling elements, the resonant chamber is also integrated into the chip. This is particularly advantageous for very high frequencies, such as those exceeding 200 GHz, because the structures and dimensions of the coupling elements, waveguides, and antennas are correspondingly small in this frequency range. In particular, microwave chips with coupling structures can be flexibly used for different antennas.

[0018] The core aspect can be considered as coupling the radar signal from the microwave chip directly into the waveguide, where the coupling element and the resonant chamber are part of the microwave chip. The size of the coupling element and the resonant chamber can be much smaller, or on the order of the microwave chip size.

[0019] According to one embodiment, the resonant chamber is formed by a metal can, in which the microwave chip is completely or at least partially arranged. The resonant chamber is part of the feed geometry and is located in / on or around the chip. The chip can be embedded in the resonant chamber.

[0020] For example, an area of ​​the chip may be milled out so that a "can" can be placed on the chip, or the chip can be located substantially entirely within the resonant chamber formed by the can.

[0021] According to another embodiment, the resonant chamber has a metallized bottom and a lateral metallization formed in the microwave chip.For example, the lateral metallization can be implemented in the form of a ring structure of metallized through-holes (vias).

[0022] According to another embodiment, the microwave chip has a cavity forming a resonant chamber. The inner surface of the cavity may be metallized.

[0023] According to another embodiment, the radar module comprises a waveguide which is configured to guide the coupled radar signal in the direction of an object to be monitored, such as filling material, loose material or a person.

[0024] According to another embodiment, the radar module includes a lens configured to focus the radar signal. In particular, the microwave chip, the waveguide and the lens can be manufactured in one piece, ie, connected to one another, for example, using a multi-component injection molding process.

[0025] According to another embodiment, the waveguide is arranged on the upper side of the microwave chip, wherein the bottom of the metal can is arranged on the lower side of the microwave chip, so that the waveguide and the metal can at least partially surround the microwave chip to form a resonant chamber. The signal connection between the coupling element and the radar signal source is arranged on the upper side or inside the microwave chip.

[0026] According to another embodiment, the coupling element includes a coupling pin, a patch antenna, or another structure suitable for coupling a radar signal. According to another embodiment, the radar module includes an antenna configured to transmit the coupled radar signal in the direction of the object to be monitored. The antenna can be, for example, an antenna horn, or a combination of a waveguide portion and an antenna horn or antenna connector connected thereto.

[0027] The microwave chip may have a top layer (also referred to as upper layer or upper side) and a bottom layer (also referred to as lower layer or lower side), wherein the signal connection between the coupling element and the radar signal source is arranged on the top layer of the microwave chip or within the microwave chip, and wherein the antenna is arranged on the bottom layer.

[0028] The coupling element thus radiates the radar signal to be transmitted through the chip in order to be subsequently emitted by the antenna.

[0029] According to a further embodiment, the radar module is embodied to generate a radar signal having a transmission frequency greater than 200 GHz.

[0030] According to another embodiment, the diameter of the resonance chamber is smaller than 1.5 mm.

[0031] According to another embodiment, the diameter of the resonance chamber is smaller than the diameter of the microwave chip.

[0032] Another aspect relates to a radar measuring device having a radar module described above and below.

[0033] Another aspect relates to the use of a radar module as described above and below for fill level measurement, limit level measurement or factory automation.

[0034] Another aspect relates to a method for producing the aforementioned radar module described below, wherein a radar signal source, a coupling element, a signal connection between the radar signal source and the coupling element, and a resonant chamber are arranged on or in a microwave chip, wherein the coupling element protrudes into the resonant chamber.

[0035] For example, the resonant chamber can be designed as a cavity in the chip, the inner walls of which are metallized. It is also possible to provide a continuous or discontinuous annular metallization, for example in the form of a plurality of metal lines arranged along a circular path, to form a resonant chamber in the chip, for example in the form of a metallized through-hole (via).

[0036] The embodiments will be described below with reference to the accompanying drawings. These drawings are schematic and not drawn to scale. If the same reference numerals are used in the following description of the drawings, they represent the same or similar elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A radar module according to an embodiment is shown.

[0038] Figure 2 A radar module according to another embodiment is shown.

[0039] Figure 3 A flow chart of a method according to an embodiment is shown. DETAILED DESCRIPTION

[0040] Figure 1 1. A small part of a radar module 100 of a radar measuring device 114 according to an embodiment is shown. Radar modules are used in the field of process automation, in particular for plant monitoring.

[0041] The radar module comprises a microwave chip 101 on which or in which a radar signal source 104 is formed. A coupling element 102, such as a coupling pin or an antenna patch, is provided, wherein the coupling element and the radar signal source are connected to each other via a signal connection 103. The chip itself forms a resonant chamber 105 surrounded by metallizations 106 and 107. Figure 1 In this case, the metallization is designed in the form of a metal can with a bottom 106 located on the underside. Coupling element 102 is configured to couple the radar signal generated by the radar signal source into resonant chamber 105 and waveguide 109. Waveguide 109 then transmits the coupled radar signal to an antenna, which transmits the radar signal toward the object to be monitored.

[0042] Radar signals are coupled directly from the microwave chip into waveguide 109. At very high frequencies (greater than 200 GHz), waveguide 109 is smaller than, or at least similar in size to, the microwave chip. For example, in the frequency range above 200 GHz, the diameter of circular waveguide 109 is less than 1.5 mm. The dimensions of the microwave chip are in a similar range. Waveguide 109 is fully coupled to or in conjunction with the microwave chip.

[0043] A coupling element 102, for example in the form of a coupling pin, is located on the chip surface (top layer). A waveguide 109 is arranged on the coupling element 102. This means that the chip is located (at least partially or even completely) inside the waveguide or the adjacent pots 106, 107.

[0044] The resonance chamber 105 is made of the material of the microwave chip. The side walls of the "can" formed in this way are metallized structures. The metallization at the bottom side of the can can be produced by grinding the chip to the corresponding thickness and then adhering it to the bottom 106 in a conductive manner.

[0045] The coupling element 102 may be located on a top layer or may be disposed in an inner layer of the microwave chip.

[0046] Lenses for signal focusing can be placed on the entire assembly or within the waveguide 109 (see Figure 2 The lens 110 in FIG. 1 can be mounted on the assembly together with the sheet-filled waveguide 109. A small antenna horn 111 with a circular waveguide 109 can also be provided (see FIG. Figure 2 ).

[0047] In one embodiment, the chip is injection molded with a waveguide section (possibly including an optional lens) as an insert and can be used as an SMD component in standard housing formats (QFN, etc.). This also applies to small antenna horns with corresponding circular waveguide terminals. Here, the horn diameter is in the range of a few millimeters.

[0048] Figure 2 Another embodiment is shown in which the emission direction is rotated 180° (i.e., through the chip). Here, an antenna 111 with a circular waveguide connector 109 or waveguide is placed on the back side of the chip. In this case, reference numeral 112 denotes the top side (top layer) of the chip, on which the bonding pads 116 and backside metallization 106 are arranged. Reference numeral 113 denotes the back side or bottom side (bottom layer) of the microwave chip, on which the circular waveguide 109 with the antenna 111 is arranged.

[0049] The chip must be placed accurately for this. One advantage of this arrangement is that the remaining contacts 116 of the chip (for power supply, etc.) can be mounted on the top layer. The mechanical terminals of the antenna are arranged on the other side of the chip so that they do not damage the bonded connections.

[0050] Carrier 115 can receive signals via bonding pads 116 and corresponding bonding connectors. Carrier 115 can be made of various materials. It can be implemented as a small wiring board. Antenna connectors 109, 111 can be configured in various ways. Resonance chamber 105 is integrated into the chip, for example, in the form of a cavity or recess 108. As an alternative to the recess, metallization 107 is embedded in chip 101.

[0051] Figure 3A flow chart of a method according to one embodiment is shown. In step 301, a microwave chip with a radar signal source is manufactured. In step 302, a resonant chamber is created in the chip, in particular by providing a cylindrical continuous or discontinuous metallization in the chip or, alternatively, on the inner wall of a groove in the chip. In step 303, a coupling element protruding into the resonant chamber is connected to the radar signal source via a signal connector. These steps can be performed in a different order.

[0052] In addition, it should be noted that "comprising" and "having" do not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. It should also be noted that features or steps described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference signs in the claims should not be considered as limitations.

Claims

1. A radar module (100) configured for factory monitoring, the radar module (100) comprising: A microwave chip (101), wherein the microwave chip (101) comprises: a radar signal source (104) configured to generate a radar signal; A coupling element (102), wherein the coupling element and the radar signal source are connected via a signal connector (103); a resonant chamber (105), wherein the coupling element (102) protrudes into the resonant chamber; wherein the coupling element (102) is configured to couple the radar signal into the resonant chamber, wherein the resonant chamber (105) is integrated into the microwave chip (101), The microwave chip (101) includes a top layer (112) and a bottom layer (113). wherein the signal connection member (103) between the coupling element (102) and the radar signal source (104) is arranged on the top layer (112) or inside the microwave chip (101); and an antenna (111) configured to radiate the coupled radar signal in the direction of the object to be monitored, Wherein, the antenna (111) is arranged on the bottom layer (113).

2. The radar module (100) according to claim 1, in, The resonance chamber (105) is formed by a pot lined with a conductive material, and the pot is arranged entirely or partially in the microwave chip (101).

3. The radar module (100) according to claim 1, in, The resonant chamber has a metallized bottom (106) and a lateral metallization (107) formed in the microwave chip (101).

4. The radar module (100) according to claim 1, in, The microwave chip (101) has a cavity (108) forming the resonance chamber.

5. The radar module (100) according to claim 1, further comprising: A waveguide (109) is configured to guide the coupled radar signal toward an object to be monitored.

6. The radar module (100) according to claim 5, further comprising: a lens (110) configured to focus the radar signal; The microwave chip (101), a section of the waveguide (109) as an insert, and the lens (110) are integrally injection molded.

7. The radar module (100) according to claim 6, in, The integral injection molding is achieved using a multi-component injection molding process.

8. The radar module (100) according to claim 5, in, The waveguide (109) is arranged on the upper side of the microwave chip (101), and the bottom (106) of the metal can is arranged on the lower side of the microwave chip, so that the waveguide (109) and the metal can at least partially surround the microwave chip and form the resonance chamber.

9. The radar module (100) according to claim 1, in, The coupling element (102) is a coupling pin and / or a patch antenna.

10. The radar module (100) according to claim 1, The radar module is configured to generate a radar signal with a transmission frequency greater than 200 GHz.

11. The radar module (100) according to claim 1, in, The diameter of the resonance chamber (105) is less than 1.5 mm.

12. The radar module (100) according to claim 1, in, The diameter of the resonance chamber (105) is smaller than the diameter of the microwave chip (101).

13. A radar measuring device (114) comprising the radar module (100) according to any one of claims 1 to 12.

14. Use of the radar module (100) according to any one of claims 1 to 12 for fill level measurement, limit level measurement or factory automation.

15. A method for manufacturing a radar module (100), the method comprising the following steps: A radar signal source (104), a coupling element (102), a signal connection piece (103) between the radar signal source and the coupling element, and a resonance chamber (105) are arranged on or in a microwave chip (101). wherein the coupling element protrudes into the resonance chamber (105), The resonance chamber (105) is integrated into the microwave chip (101). The microwave chip (101) includes a top layer (112) and a bottom layer (113). wherein the signal connection element (103) between the coupling element (102) and the radar signal source (104) is arranged on the top layer (112) or inside the microwave chip (101), The radar module (100) comprises an antenna (111) configured to radiate a coupled radar signal in the direction of an object to be monitored, Wherein, the antenna (111) is arranged on the bottom layer (113).

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