Microwave transmission arrangement, communication and / or measurement system and radar level gauge system

Abstract

A microwave transmission device includes a microwave circuit board having a patch, microwave transceiver circuitry coupled to the patch, a conductive hollow waveguide arranged to guide a microwave signal between a first end and a second end, and a septum disposed between the microwave circuit board and the first end of the hollow waveguide, the septum configured to allow the microwave to pass between the patch and the hollow waveguide through the septum. The septum is included in an enclosure that encloses an enclosed interior of the microwave transmission device from an exterior outside of the enclosure, the patch and the microwave transceiver circuitry being located in the enclosed interior and the hollow waveguide being located in the exterior outside of the enclosure.

Description

Technical Field

[0001] This invention relates to microwave transmission devices, communication and / or measurement systems, and radar level gauge systems. Background Technology

[0002] The current trend in microwave transmission for measurement and communication is toward higher frequencies. In particular, compared to existing radar level gauge systems, microwave transmission increases the demand for available energy, which in turn necessitates new strategies for meeting Ex certification requirements for explosive atmospheres and / or new solutions to allow for large-capacity energy storage.

[0003] One such strategy is to encapsulate the electronics of the microwave transmission device (e.g., according to IEC 610079-11, Clause 6.6) to avoid spark ignition requirements. This means that the amount of energy storage (capacitor) may increase, but difficulties remain because the signal lines from the microwave transceiver circuitry of the microwave transmission device need to comply with all applicable Ex-related requirements while still being able to radiate sufficient microwave energy.

[0004] US 2014 / 0007674 discloses a method in which a dielectric sealing element is arranged inside a hollow waveguide to provide a seal between the main region of the waveguide and the starting region of the waveguide, thereby forming a cavity in which radiator elements are arranged.

[0005] In the event of a leak at the interface between the dielectric sealing element and the hollow waveguide, there is a risk that flammable gas may come into contact with radiator components and other unprotected parts of the microwave transceiver circuitry inside the hollow waveguide.

[0006] Therefore, it is desirable to provide an improved microwave transmission device with an improved packaging solution. Summary of the Invention

[0007] In view of the above, the overall objective of the present invention is to provide an improved microwave transmission device, and in particular, to provide a microwave transmission device with an improved packaging solution.

[0008] According to one aspect of the present invention, a microwave transmission device is thus provided, comprising: a microwave circuit board including a dielectric carrier and a first conductor pattern located on a first side of the dielectric carrier, the first conductor pattern including a patch for radiating or receiving microwave signals, patch lines, and a first ground plane surrounding the patch and patch feed lines; a microwave transceiver circuit system disposed on the microwave circuit board, the microwave transceiver circuit system having an output terminal for providing microwave signals generated by the microwave transceiver circuit system and an input terminal for receiving microwave signals, wherein the patch lines are connected to at least one of the output terminal and the input terminal; and a conductive... A hollow waveguide extending from a first end to a second end and arranged to guide microwave signals radiated by the patch from the first end toward the second end, and / or to guide received microwave signals from the second end toward the first end; and a spacer disposed between a microwave circuit board and the first end of the hollow waveguide, the spacer being configured to allow microwaves to pass through the spacer between the patch and the hollow waveguide, wherein the spacer is included in a package that separates the packaged interior of the microwave transmission device from the exterior outside the package, the patch, patch lines and microwave transceiver circuitry being located inside the package, and the hollow waveguide being located outside the package.

[0009] A “microwave transceiver circuit system” can be implemented as a functional unit capable of transmitting and receiving microwave signals, or it can be a system comprising separate transmitter and receiver units.

[0010] This invention is based on the understanding that leakage sensitivity at the sealed interface can be avoided by placing a spacer between the microwave circuit board and the first end of the hollow waveguide. In this way, any leakage along the contact surface between the first end of the hollow waveguide and the spacer can be prevented from reaching the patch or patch line. By placing the spacer between the microwave circuit board and the first end of the hollow waveguide, the spacer will be in direct contact with the microwave circuit board, eliminating the presence of an internal cavity between the microwave circuit board and the spacer. Advantageously, the hollow waveguide can be pressed towards the microwave circuit board, thereby applying pressure to the spacer.

[0011] With this configuration, in which the separator is placed between the microwave circuit board and the first end of the hollow waveguide, the only possible leakage path between the interior of the hollow waveguide and the patch or patch line on the microwave circuit board is through the material of the separator. This leakage is less likely to occur than through the seal between the two parts, making the seal provided by the separator considered absolutely reliable.

[0012] To efficiently transmit microwaves through the separator, the separator may advantageously include a dielectric portion disposed between the patch and the interior of the hollow waveguide. This dielectric portion then acts as a microwave transmission window. The dielectric portion may suitably extend through the entire thickness of the separator located between the interior of the hollow waveguide and the patch in the microwave circuit board. Furthermore, the dielectric portion may advantageously extend substantially through the entire internal cross-sectional region of the hollow waveguide at a first end of the hollow waveguide.

[0013] For safety reasons and to prevent energy transfer through dielectric breakdown in the dielectric portion, the thickness of the separator within the dielectric portion can be at least 0.5 mm.

[0014] Furthermore, according to various embodiments, the separator may include: a dielectric substrate having a first side and a second side opposite to the first side; a first conductive layer located on the first side of the substrate; a second conductive layer located on the second side of the substrate; and a plurality of conductive vias passing through the dielectric substrate and conductively connecting the first conductive layer and the second conductive layer.

[0015] For effective grounding of the conductive hollow waveguide, the first conductive layer of the separator can be conductively connected to the first ground plane of the microwave circuit board; and the second conductive layer of the separator can be conductively connected to the first end of the hollow waveguide.

[0016] The corresponding electrical connection can be advantageously achieved by pressing the hollow waveguide toward the microwave circuit board, thereby pressing the first conductive layer of the separator against the first ground plane of the microwave circuit board and pressing the second conductive layer against the first end of the hollow waveguide.

[0017] Microwave transmission devices according to various embodiments of the invention can be advantageously included in a communication and / or measurement system, which further includes a processing circuit system coupled to a microwave transceiver circuit system and configured to control the microwave transceiver circuit system to provide microwave signals and / or perform signal processing on microwave signals received by the microwave transceiver circuit system.

[0018] According to one particular embodiment, the microwave transmission device may advantageously be included in a radar level gauge system for determining the fill level of a product in a tank, the radar level gauge system further comprising: an antenna coupled to a second end of a hollow waveguide of the microwave transmission device for radiating an electromagnetic emission signal from the microwave transmission device toward the surface of the product, and for returning an electromagnetic reflection signal generated by reflection of the electromagnetic emission signal at the surface toward the microwave transmission device; and a processing circuit system coupled to a microwave transceiver circuit system included in the microwave transmission device and configured to determine the fill level based on the time relationship between the emitted signal and the reflected signal.

[0019] For all implementations, it should be noted that the processing circuitry system can be configured as a single device or several devices working together.

[0020] In summary, the present invention therefore relates to a microwave transmission device comprising: a microwave circuit board including a patch; a microwave transceiver circuit system coupled to the patch; a conductive hollow waveguide arranged to guide microwave signals between a first end and a second end; and a separator disposed between the microwave circuit board and the first end of the hollow waveguide, the separator being configured to allow microwaves to pass through the separator between the patch and the hollow waveguide. The separator is included in a package that separates the encapsulated interior of the microwave transmission device from an exterior outside the package, wherein the patch and the microwave transceiver circuit system are located within the encapsulated interior, and the hollow waveguide is located outside the encapsulated exterior. Attached Figure Description

[0021] These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, which illustrate the presently preferred embodiments of the invention, in which:

[0022] Figure 1 An example application of a microwave transmission device according to an embodiment of the present invention is illustrated schematically;

[0023] Figure 2 This is a schematic side view of an example application of a microwave transmission device according to an embodiment of the present invention, in the form of an exemplary radar level gauge system; and

[0024] Figures 3A to 3C A microwave transmission apparatus according to an exemplary embodiment of the present invention is schematically illustrated. Detailed Implementation

[0025] In this detailed description section, various embodiments of the microwave transmission device according to the present invention are discussed with reference to a radar level gauge system.

[0026] It should be noted that this does not limit the scope of the invention, which also includes microwave transmission devices for other applications such as communication systems, for example, microwave links that can be used, for example, in 5G communication systems.

[0027] Figure 1 An industrial site 1, such as a processing industry, is schematically illustrated, including a refinery or similar factory. Figure 1 The industrial site 1, schematically illustrated, includes storage tanks 3 and various processing equipment 5. Depending on the type of industry, the industrial site 1 may present a hazardous environment, thus requiring certification of the equipment used on site 1 according to applicable standards. Appropriately, at least some of the equipment used on site 1 may meet the relevant intrinsic safety requirements, meaning that the equipment is certified as not capable of causing ignition in a hazardous environment. Examples of applicable standards for intrinsic safety are IEC 610079-0 and IEC 610079-11.

[0028] Examples of equipment that can be advantageously configured to meet intrinsic safety requirements at an industrial site 1 may include Figure 1 The microwave link 7 and the radar level gauge system 9 are schematically indicated in the diagram. A common feature of such systems according to embodiments of the invention is that each system includes a microwave transmission device for transmitting microwave signals between the transceiver circuitry and the antenna. As is known to those skilled in the art, various specifications can differ for the equipment used in the microwave link 7 and the radar level gauge system 9, respectively. For example, the antenna configuration can be particularly adapted to the environment in which the antenna is positioned. However, the microwave transmission devices used in various applications can have substantially the same configuration.

[0029] Figure 2 This is a schematic side view of an example application of a microwave transmission device according to an embodiment of the present invention, in the form of an exemplary radar level gauge system 9.

[0030] like Figure 2 As conceptually indicated, the radar level gauge system 9 includes a microwave transceiver circuit system 11, a microwave transmission device 13 including a hollow waveguide 15, an antenna 17, a processing circuit system 19, a communication circuit system 21, and a process connector in the form of a flange 23.

[0031] The microwave transceiver circuit system 11 has: an output terminal 25—shown herein as a combined microwave output port and input port—for providing microwave signals generated by the microwave transceiver circuit system 11; and an input terminal 25 for receiving microwave signals. For example... Figure 2As schematically indicated, the microwave transceiver circuit system 11 also has a measurement data interface 27, which is coupled to a corresponding measurement data interface 29 of the processing circuit system 19. The processing circuit system 19 also has a communication interface 31, which is coupled to a corresponding communication interface 33 of the communication circuit system 21.

[0032] In the operation of the radar level gauge system 9, the processing circuit system 19 controls the microwave transceiver circuit system 11 to generate and transmit microwave signals. The microwave signals are provided by the microwave transceiver circuit system 11 to the microwave transmission device 13, which then transmits the microwave signals to the antenna 17. (Briefly referenced...) Figure 1 Antenna 17 radiates a microwave transmission signal ST to the surface 4 of product 6 in storage tank 3. The microwave transmission signal ST is reflected back towards antenna 17, at least partially as a microwave reflection signal SR. The microwave reflection signal SR reaches antenna 17 and is guided by hollow waveguide 15, and microwave transmission device 13 converts the microwave reflection signal SR from a signal guided by hollow waveguide 15 into a signal guided by microwave circuit board (…). Figure 2 The signal carried on the stripline (not shown) is returned to the microwave transceiver circuit system 11. Based on the time relationship between the microwave transmitted signal ST and the microwave reflected signal SR, the processing circuit system 19 determines the fill level of product 6 in the storage tank 3 in a manner known per se. A communication signal indicating the determined fill level is transmitted by the communication circuit system 21 to an external host.

[0033] In microwave link 7, the distance need not be determined. Instead, the data can be encoded on the transmitted signal in a manner known to those skilled in the art, and the data can be obtained by decoding the received signal.

[0034] Figures 3A to 3C A microwave transmission device 13 according to an exemplary embodiment of the present invention is schematically illustrated. Figures 3A to 3C The microwave transmission device 13 schematically shown in the diagram can be used in various systems, such as Figure 1 The microwave link 7 and radar level gauge system 9 are included.

[0035] First refer to Figure 3A , Figure 3A This is an exploded view of the microwave transmission device 13, which includes: a microwave circuit board 35; a microwave transceiver circuit system 11, which is in the form of an MMIC (monolithic microwave integrated circuit); a conductive hollow waveguide 15; and a separator 37.

[0036] like Figure 3A As shown, but Figure 3CAs can be seen more clearly, the microwave circuit board 35 includes a dielectric carrier 39 and a portion located on a first side of the dielectric carrier 39. Figure 3A The first conductor pattern is located on the top side of the waveguide 15. The first conductor pattern includes a patch 43 for radiating or receiving microwave signals, patch lines 45, and a first ground plane 47 surrounding the patch 43 and patch lines 45. A gap 48 separates the patch 43 and the ground plane 47 within the first conductor pattern. The patch 43 is shown herein as generally rectangular because it is adapted to the hollow waveguide 15. Other patch configurations may be suitable for other waveguide configurations, as will be understood by those skilled in the art.

[0037] exist Figures 3A to 3C In the example configurations (preferably in) Figure 3C As observed in [the study], the microwave circuit board 35 also has a second conductor pattern located on a second side of the dielectric carrier 39, opposite to the first side. The second conductor pattern includes a second ground plane 50 arranged opposite to the patch 43 and the first ground plane 47. (As shown in the image...) Figure 3C As schematically shown, the first ground plane 47 and the second ground plane 50 are interconnected by conductive vias 52 that extend through the dielectric carrier 39.

[0038] like Figure 3A As can be observed, the microwave transceiver circuit system 11 is arranged on the microwave circuit board 35. Although not shown in the figures, the microwave transceiver circuit system 11 has an output for providing microwave signals generated by the microwave transceiver circuit system 11 and an input for receiving microwave signals. The output and input can be separated from each other, but... Figures 3A to 3C In the embodiment shown, the output and input terminals of the microwave transceiver circuit system are implemented through a common I / O, which is connected to the patch 43 via a patch line 45.

[0039] A conductive hollow waveguide 15 extends from a first end 49 to a second end 51 and is arranged to guide microwave signals radiated by the patch 43 from the first end 49 toward the second end 51 and to guide microwave signals received from the second end 51 toward the first end 49.

[0040] The hollow waveguide 15 has a hollow interior defined by the conductive waveguide body 53. Therefore, the first end 49 of the hollow waveguide 15 includes the first end surface of the conductive waveguide body 53 and a waveguide opening facing the patch 43.

[0041] The hollow waveguide 15 is configured to guide microwave signals within a predetermined wavelength range along a signal propagation path defined by the hollow waveguide 15 in a predetermined propagation mode. The predetermined wavelength range may be, for example, 77 GHz to 81 GHz, and the predetermined propagation mode may be, for example, TE10, but other wavelength ranges and / or propagation modes are possible and may be advantageous depending on the application.

[0042] exist Figures 3A to 3C In an exemplary embodiment, a single patch 43 is provided for transmitting and receiving microwaves. It should be noted that the first conductor pattern may also include separate transmitter and receiver patches. These separate transmitter and receiver patches can advantageously be combined with a hollow waveguide having a separate hollow waveguide opening at a first end 49 of the hollow waveguide, with each patch in the first conductor pattern corresponding to one hollow waveguide opening.

[0043] The separator 37 is placed between the microwave circuit board 35 and the first end 49 of the hollow waveguide 15, and is configured to allow microwaves to pass through the separator 37 between the patch 43 (or multiple patches in an embodiment with multiple patches) and the hollow waveguide 15.

[0044] The separator 37 is included in a package that separates the encapsulated interior of the microwave transmission device 13 from the exterior outside the package. The patch 43, patch line 45, and microwave transceiver circuit system 11 are located inside the package, and the hollow waveguide 15 (the interior of the hollow waveguide) is located outside the package.

[0045] Possibly Figure 3B As best observed, the separator 37 is positioned between the top surface of the microwave circuit board 35 and the first end 49 of the hollow waveguide (the first end surface of the conductive waveguide body 53 and the waveguide opening facing the patch 43). Therefore, the first side 55 of the separator 37 contacts the top surface of the microwave circuit board 35, and the second side 57 of the separator 37 contacts the first end 49 of the hollow waveguide 15.

[0046] In addition to the spacer 37, the encapsulation also includes a potting compound 59 that at least partially fills the housing 61 of the microwave transmission device 13. The hollow waveguide 15 can be pressed against the microwave circuit board 35, for example, using screws. Figures 3A to 3C (Not shown) is pressed. Therefore, the potting compound 59 can be moved away from the pressurized stack formed by the microwave circuit board 35, the separator 37, and the hollow waveguide 15. However, the potting compound 59 will cover the edge surface of the separator 37, such that the interface between the hollow waveguide 15 and the separator 37, as well as the interface between the separator 37 and the microwave circuit board 35, are covered by the potting compound 59.

[0047] like Figure 3A As schematically shown, a through-hole 70 may be provided in the waveguide body 53, configured to accommodate the MMIC 11. A barrier may be provided to prevent the potting compound 59 from entering the narrow space between the MMIC 11 and the microwave circuit board 35 before the potting compound 59 is applied. Such a barrier may be provided, for example, by dispensing another potting compound with a higher viscosity through the through-hole 70 and / or by inserting a sealant into the through-hole 70.

[0048] Reference Figure 3A The separator 37 may include a dielectric portion 63 disposed at a first end 49 of the hollow waveguide 15 between the patch 43 and the interior of the hollow waveguide 15 to allow microwave signals to propagate through the dielectric portion 63 of the separator 37 between the patch 43 and the interior of the hollow waveguide 15. To provide an explosion-proof configuration compliant with relevant standards, the thickness of the separator 37 within the dielectric portion 63 may be at least 0.5 mm. The material of the dielectric portion may advantageously be robust and durable and have relatively high dielectric strength. Examples of suitable dielectric materials include low-loss substrates suitable for high-frequency microwave applications. Examples of suitable materials may include ceramics, PTFE, and hybrid configurations including PTFE with various fillers.

[0049] To provide an advantageous combination of the sealing and electrical separation provided by the separator 37 with the microwave transmission performance of the microwave transmission device 13, the separator 37 can be advantageously configured to additionally provide grounding for the hollow waveguide 15. Therefore, referring to... Figure 3A and Figure 3C The separator 37 may include: a dielectric substrate 65; a first conductive layer 67 located on a first side of the dielectric substrate 65; a second conductive layer 69 located on a second side of the dielectric substrate 65; and a plurality of conductive vias 71 passing through the dielectric substrate 65 and conductively connecting the first conductive layer 67 and the second conductive layer 69. The vias 71 are filled and not open.

[0050] exist Figures 3A to 3C In an example embodiment, the first conductive layer 67 of the separator 37 is electrically connected to the first ground plane 47 of the microwave circuit board, and the second conductive layer 69 of the separator is electrically connected to the first end 49 of the hollow waveguide (to the end surface of the hollow waveguide body 53).

[0051] To provide the aforementioned dielectric portion 63 of the separator 37, the first conductive layer 67 of the separator 37 may have an opening, and the second conductive layer 69 of the separator 37 may have an opening aligned with the opening of the first conductive layer 67. This example configuration is in Figure 3A and Figure 3C It is shown schematically in the middle.

[0052] In addition, the first conductive layer 67 defines an open channel 73 that is aligned with the patch line 45 of the microwave circuit board 35 to further reduce any impact of the separator 37 on the microwave transmission performance of the microwave transmission device 13.

[0053] Those skilled in the art will recognize that the present invention is by no means limited to the preferred embodiments described above. Rather, many modifications and variations are possible within the scope of the appended claims.

Claims

1. A microwave transmission device, comprising: A microwave circuit board, the microwave circuit board including a dielectric carrier and a first conductor pattern located on a first side of the dielectric carrier, the first conductor pattern including a patch for radiating or receiving microwave signals, a patch line and a first ground plane surrounding the patch and the patch line; A microwave transceiver circuit system is arranged on the microwave circuit board, the microwave transceiver circuit system having an output terminal for providing microwave signals generated by the microwave transceiver circuit system and an input terminal for receiving microwave signals, wherein the surface mount line is connected to at least one of the output terminal and the input terminal; A conductive hollow waveguide extending from a first end to a second end and arranged to guide microwave signals radiated by the patch from the first end toward the second end, and / or to guide received microwave signals from the second end toward the first end; and A separator is placed between the microwave circuit board and the first end of the hollow waveguide, the separator being configured to allow microwaves to pass through the separator between the patch and the hollow waveguide. The separator is included in a package that separates the encapsulated interior of the microwave transmission device from the exterior of the package, wherein the patch, the patch wires, and the microwave transceiver circuitry are located within the encapsulated interior, and the hollow waveguide is located in the exterior of the package. The spacer includes a dielectric portion disposed between the patch and the interior of the hollow waveguide to allow microwave signals to propagate through the dielectric portion of the spacer between the patch and the interior of the hollow waveguide.

2. The microwave transmission device according to claim 1, wherein, The thickness of the dielectric portion of the separator is at least 0.5 mm.

3. The microwave transmission device according to claim 1, wherein, The separator includes: A dielectric substrate having a first side portion and a second side portion opposite to the first side portion; A first conductive layer is located on the first side of the substrate; A second conductive layer, the second conductive layer being located on the second side portion of the substrate; and Multiple conductive vias pass through the dielectric substrate and conductively connect the first conductive layer and the second conductive layer.

4. The microwave transmission device according to claim 3, wherein: The first conductive layer of the separator is electrically connected to the first ground plane of the microwave circuit board; and The second conductive layer of the separator is electrically connected to the first end of the hollow waveguide.

5. The microwave transmission device according to claim 3, wherein: The first conductive layer of the separator has an opening; and The second conductive layer of the separator has an opening portion aligned with the opening portion of the first conductive layer.

6. The microwave transmission device according to claim 1, wherein, The microwave circuit board has a second conductor pattern located on a second side of the dielectric carrier of the microwave circuit board, the second side being opposite to the first side. The second conductor pattern includes a second ground plane arranged opposite to the patch and the first ground plane of the microwave circuit board. The first ground plane and the second ground plane are interconnected by conductive vias extending through the dielectric carrier.

7. The microwave transmission device according to claim 1, wherein, The microwave transceiver circuit system includes a microwave MIC having: a bottom surface attached to the microwave circuit board; a top surface opposite to the bottom surface; and an edge connecting the bottom surface and the top surface.

8. The microwave transmission device according to claim 1, wherein, The encapsulation includes a potting compound that at least partially covers the microwave circuit board.

9. A communication and / or measurement system, comprising: The microwave transmission device according to claim 1; as well as A processing circuit system coupled to the microwave transceiver circuit system and configured to control the microwave transceiver circuit system to provide microwave signals and / or perform signal processing on microwave signals received by the microwave transceiver circuit system.

10. A radar level gauge system for determining the fill level of a product in a storage tank, comprising: The microwave transmission device according to claim 1; An antenna coupled to the second end of the hollow waveguide of the microwave transmission device for radiating electromagnetic emission signals from the microwave transmission device toward the surface of the product, and for returning electromagnetic reflection signals generated by the reflection of the electromagnetic emission signals at the surface toward the microwave transmission device. as well as A processing circuit system coupled to the microwave transceiver circuit system included in the microwave transmission device and configured to determine the fill level based on the time relationship between the transmitted signal and the reflected signal.

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