阅读说明：本技术 波导组件和雷达物位计 (Waveguide assembly and radar level gauge ) 是由 周雷 于 2021-08-19 设计创作，主要内容包括：本文公开一种波导组件和雷达物位计。波导组件包括第一波导体、第二波导体和波导密封件,第一波导体的第一端和第二波导体的第一端邻近,波导密封件设置于第一波导体和第二波导体之间、并将第一波导体的第一端密封；波导密封件采用绝缘材料制成,且包括分隔筋、以及设置于分隔筋两侧的第一导波段和第二导波段,分隔筋设置于第一波导体的第一端和第二波导体的第一端之间,第一和第二导波段分别伸入第一波导体的第一导波通路和第二波导体的第二导波通路内。通过波导密封件实现第一和第二波导体间的绝缘以及密封,使雷达物位计的工作安全可靠；通过第一和第二导波段分别伸入第一和第二导波通路内,可减少电磁波的反射,提高雷达物位计的工作性能。(A waveguide assembly and a radar level gauge are disclosed herein. The waveguide assembly includes a first waveguide, a second waveguide, and a waveguide seal, the first end of the first waveguide and the first end of the second waveguide being adjacent, the waveguide seal being disposed between and sealing the first end of the first waveguide and the second waveguide; the waveguide sealing piece is made of insulating materials and comprises a separation rib, a first waveguide band and a second waveguide band, wherein the first waveguide band and the second waveguide band are arranged on two sides of the separation rib, the separation rib is arranged between the first end of the first waveguide body and the first end of the second waveguide body, and the first waveguide band and the second waveguide band respectively extend into a first waveguide channel of the first waveguide body and a second waveguide channel of the second waveguide body. The insulation and the sealing between the first waveguide body and the second waveguide body are realized through the waveguide sealing piece, so that the radar level meter is safe and reliable in operation; the first and second wave guide sections extend into the first and second wave guide passages respectively, so that reflection of electromagnetic waves can be reduced, and the working performance of the radar level gauge is improved.)

1. A waveguide assembly comprising a first waveguide, a second waveguide, and a waveguide seal, a first end of the first waveguide and a first end of the second waveguide being adjacent, the waveguide seal being disposed between the first waveguide and the second waveguide and sealing the first end of the first waveguide;

the waveguide sealing member is made of insulating materials and comprises a separation rib and a first guide wave band and a second guide wave band which are arranged on two sides of the separation rib respectively, the separation rib is arranged at the first end of the first waveguide body and between the first ends of the second waveguide bodies, the first guide wave band extends into the first guide wave channel of the first waveguide body, and the second guide wave band extends into the second guide wave channel of the second waveguide body.

2. The waveguide assembly of claim 1, wherein the waveguide seal includes an annular sidewall, the spacer rib disposed within the annular sidewall and separating a cavity within the annular sidewall into a first cavity and a second cavity, the first cavity disposed outside the first end of the first waveguide and in sealed connection with the first waveguide, the second cavity disposed outside the first end of the second waveguide.

3. The waveguide assembly of claim 2, wherein the first cavity has an internal thread on an inner sidewall surface thereof, and an external thread on an outer sidewall surface of the first end of the first waveguide, wherein the first cavity is connected to the first end of the first waveguide by the internal thread and the external thread;

the first end of the first waveguide body abuts against the separation rib, and the first end of the second waveguide body abuts against the separation rib.

4. The waveguide assembly of claim 1, wherein the first waveguide segment is tapered, the second waveguide segment is tapered, and the center lines of the first and second waveguide segments coincide;

the tip of the first guided wave band extends into the first guided wave channel, and the tip of the second guided wave band extends into the second guided wave channel.

5. The waveguide assembly of claim 4, wherein the first waveguide pathway includes a first cylindrical cavity and a first tapered cavity in communication, the first tapered cavity disposed proximate the first end of the first waveguide;

the second waveguide path comprises a second conical cavity and a second cylindrical cavity which are communicated, the second conical cavity is arranged close to the first end of the second waveguide body, and the center lines of the first cylindrical cavity, the first conical cavity, the second cylindrical cavity and the second conical cavity are overlapped;

the first guided wave section penetrates through the first conical cavity and then extends into the first cylindrical cavity, and the second guided wave section penetrates through the second conical cavity and then extends into the second cylindrical cavity.

6. The waveguide assembly of claim 1, wherein the first waveguide segment comprises a first tapered transition segment and a first cylindrical segment, the first cylindrical segment being connected between the first tapered transition segment and the spacer rib;

the second guided wave section comprises a second conical transition section and a second cylindrical section, the second cylindrical section is connected between the second conical transition section and the separating ribs, and the central lines of the first cylindrical section, the first conical transition section, the second cylindrical section and the second conical transition section are overlapped.

7. The waveguide assembly of claim 6, wherein the first waveguide pathway includes a first cylindrical cavity and a first tapered cavity in communication, the first tapered cavity disposed proximate the first end of the first waveguide;

the second waveguide path comprises a second conical cavity and a second cylindrical cavity which are communicated, the second conical cavity is arranged close to the first end of the second waveguide body, and the center lines of the first cylindrical cavity, the first conical cavity, the second cylindrical cavity and the second conical cavity are overlapped;

the first cylindrical section extends into the first conical cavity, the tip end of the first conical transition section extends into the first cylindrical cavity, the second cylindrical section extends into the second conical cavity, and the tip end of the second conical transition section extends into the second cylindrical cavity.

8. The waveguide assembly of claim 5 or 7, wherein the waveguide seal is a unitary structure and the first and second waveguide segments are symmetrically disposed;

the first conical cavity and the second conical cavity are symmetrically arranged, and the inner diameter of the first cylindrical cavity is equal to that of the second cylindrical cavity.

9. A waveguide assembly according to any one of claims 1 to 7, wherein the spacer rib is an equi-thick spacer rib having a first surface adjacent the first waveguide and a second surface adjacent the second waveguide, the first and second surfaces being planar, or curved surfaces projecting towards the side on which the first waveguide is located, or curved surfaces projecting towards the side on which the second waveguide is located.

10. A radar level gauge, comprising a gauge housing, a circuit board and a waveguide assembly according to any one of claims 1-9, said circuit board being arranged in said gauge housing, a first waveguide of said waveguide assembly being located closer to said circuit board than a second waveguide, and a second end of said first waveguide extending into said gauge housing.

Technical Field

The present document relates to, but is not limited to, the field of level gauges, in particular to a waveguide assembly and a radar level gauge.

Background

Radar level gauges are measuring instruments based on the time-travel principle, the radar waves run at the speed of light, are reflected back to be received by the instrument when they encounter the material surface, and the running time of the radar waves can be converted into a level signal by electronic components.

In some cases, the waveguide of the radar level gauge needs to meet insulation and sealing requirements to ensure safe and reliable operation of the radar level gauge.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein.

The embodiment of the application provides a waveguide assembly and a radar level gauge, wherein a waveguide sealing member is arranged between a first waveguide and a second waveguide to seal the first waveguide, so that the requirements of insulation and sealing between the first waveguide and the second waveguide are met.

A waveguide assembly comprising a first waveguide, a second waveguide, and a waveguide seal, a first end of the first waveguide and a first end of the second waveguide being adjacent, the waveguide seal being disposed between and sealing the first end of the first waveguide and the second waveguide;

the waveguide sealing member is made of insulating materials and comprises a separation rib and a first guide wave band and a second guide wave band which are arranged on two sides of the separation rib respectively, the separation rib is arranged at the first end of the first waveguide body and between the first ends of the second waveguide bodies, the first guide wave band extends into the first guide wave channel of the first waveguide body, and the second guide wave band extends into the second guide wave channel of the second waveguide body.

A radar level gauge comprising a gauge housing, a circuit board and the waveguide assembly described above, the circuit board being arranged in the gauge housing, a first waveguide of the waveguide assembly being closer to the circuit board than a second waveguide, and a second end of the first waveguide extending into the gauge housing.

Compared with some technologies, the embodiment of the application has the following beneficial effects:

in the embodiment of the application, a waveguide sealing member is arranged between the first waveguide and the second waveguide of the waveguide assembly, the waveguide sealing member seals the first end of the first waveguide, and the waveguide sealing member is made of an insulating material, so that the first waveguide and the second waveguide are insulated and sealed through the waveguide sealing member, and the radar level gauge is ensured to work safely and reliably.

In the waveguide sealing part, the separation rib is arranged between the first end of the first waveguide and the first end of the second waveguide, and the first guide wave band and the second guide wave band respectively extend into the first guide wave channel of the first waveguide and the second guide wave channel of the second waveguide, so that when the radar level gauge works and electromagnetic waves are transmitted between the first guide wave channel and the second guide wave channel, the electromagnetic waves pass through the first guide wave band and the second guide wave band more, reflection of the electromagnetic waves is reduced, and the working performance of the radar level gauge is improved.

Other features and advantages of the present application will be set forth in the description that follows.

Drawings

FIG. 1 is an exploded schematic view of a partial structure of a radar level gauge according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a partial structure of a radar level gauge according to an embodiment of the present application;

FIG. 3 is an enlarged view of the structure of part A in FIG. 2;

FIG. 4 is an enlarged view of the structure of part B in FIG. 2;

FIG. 5 is a schematic cross-sectional view of a partial structure of a radar level gauge according to another embodiment of the present application;

fig. 6 is an enlarged schematic view of the structure of the portion C in fig. 5.

The reference signs are:

1-case, 11-stop step, 2-sealant, 3-circuit board, 31-groove, 4-shield, 41-protrusion, 42-cavity, 5-first waveguide, 51-first waveguide, 511-first cylindrical cavity, 512-first conical cavity, 52-annular rib, 6-second waveguide, 61-second waveguide, 611-second cylindrical cavity, 612-second cylindrical cavity, 7-waveguide seal, 71-separating rib, 72-first waveguide band, 721-first conical transition, 722-first cylindrical segment, 73-second waveguide band, 731-second conical transition, 732-second cylindrical segment, 74-annular sidewall, 75-stop rib.

Detailed Description

Embodiments of the present application will be described below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The first embodiment is as follows:

as shown in FIGS. 1 and 2, embodiments of the present application provide a waveguide assembly that may be used in a radar level gauge.

As shown in fig. 1 to 3, the waveguide assembly includes a first waveguide 5, a second waveguide 6, and a waveguide sealing member 7, a first waveguide passage 51 for directionally guiding an electromagnetic wave is provided in the first waveguide 5, a second waveguide passage 61 for directionally guiding an electromagnetic wave is provided in the second waveguide 6, and the first waveguide 5 may be located above the second waveguide 6, a first end (a lower end in fig. 2) of the first waveguide 5 and a first end (an upper end in fig. 2) of the second waveguide 6 are adjacent, the waveguide sealing member 7 is disposed between the first waveguide 5 and the second waveguide 6 and seals the first end of the first waveguide 5, and the waveguide sealing member 7 is made of an insulating material. In this way, the insulation and sealing between the first waveguide 5 and the second waveguide 6 is achieved by the waveguide seal 7, ensuring safe and reliable operation of the radar level gauge.

The waveguide sealing member 7 includes a partition rib 71, and a first waveguide section 72 and a second waveguide section 73 respectively disposed on two sides of the partition rib 71, wherein the first waveguide section 72 is located above the partition rib 71, and the second waveguide section 73 is located below the partition rib 71. The partition rib 71 is provided between the first end of the first waveguide 5 and the first end of the second waveguide 6, the first waveguide section 72 extends into the first waveguide path 51 of the first waveguide 5, and the second waveguide section 73 extends into the second waveguide path 61 of the second waveguide 6.

When the radar level gauge is in operation, and electromagnetic waves are transmitted between the first wave guide channel 51 and the second wave guide channel 61, for example, when electromagnetic waves radiated by a radiating element of the radar level gauge are transmitted from the first wave guide channel 51 to the second wave guide channel 61 or reflected electromagnetic waves are transmitted from the second wave guide channel 61 to the first wave guide channel 51, the electromagnetic waves pass through the first wave guide section 72 and the second wave guide section 73 more, reflection of the electromagnetic waves is reduced, and the operating performance of the radar level gauge is improved.

In some exemplary embodiments, as shown in fig. 2 and 3, the waveguide seal 7 includes an annular sidewall 74, the separation rib 71 is disposed in the annular sidewall 74 and separates a cavity in the annular sidewall 74 into a first cavity and a second cavity, the first cavity is disposed outside the first end of the first waveguide 5 and is sealingly connected to the first waveguide 5, and the second cavity is disposed outside the first end of the second waveguide 6.

In the waveguide sealing member 7, the partition rib 71 is disposed in the annular sidewall 74, and the periphery of the partition rib 71 is hermetically connected to the annular sidewall 74, so as to partition the cavity in the annular sidewall 74 into a first cavity and a second cavity that are not communicated with each other, the first cavity is sleeved outside the first end of the first waveguide 5 and seals the first end of the first waveguide 5, and the second cavity is sleeved outside the first end of the second waveguide 6. In this way, a sealed connection of the first waveguide 5 and the second waveguide 6 is achieved by the waveguide seal 7.

In some exemplary embodiments, as shown in fig. 2 and 3, an inner side wall surface of the first cavity is provided with an internal thread, an outer side wall surface of the first end of the first waveguide 5 is provided with an external thread, and the first cavity and the first end of the first waveguide 5 are connected through the internal thread and the external thread.

The first cavity and the first end of the first waveguide 5 are connected by means of a screw thread, so that the waveguide seal 7 is firmly connected with the first waveguide 5 and the sealing effect is ensured.

In some exemplary embodiments, as shown in fig. 2 and 3, the first end of the first waveguide 5 abuts against the separation rib 71. The first end of the first waveguide 5 abuts against the upper end face of the partition rib 71 to enhance the sealing effect of the waveguide seal 7 on the first waveguide 5.

In some exemplary embodiments, as shown in fig. 2 and 3, the first end of the second waveguide 6 abuts against the separation rib 71. The first end of the second waveguide 6 abuts against the lower end face of the partition rib 71, so that the second waveguide 6 is positioned when the second waveguide 6 is sleeved with the second cavity.

It should be understood that a gap may also be provided between the first end of the first waveguide 5 and the upper end face of the partition rib 71, and a gap may also be provided between the first end of the second waveguide 6 and the lower end face of the partition rib 71.

In some exemplary embodiments, as shown in fig. 3, the first waveguide section 72 includes a first tapered transition section 721, the cross-sectional area of the first tapered transition section 721 is gradually reduced from bottom to top (i.e., in a direction away from the spacer 71), and a tip (upper end) of the first tapered transition section 721 extends into the first waveguide passage 51; the second waveguide section 73 includes a second tapered transition section 731, the cross-sectional area of the second tapered transition section 731 is gradually reduced from top to bottom (i.e., in a direction away from the spacer rib 71), and the tip (lower end) of the second tapered transition section 731 extends into the second waveguide path 61.

The first tapered transition 721 is provided to guide the electromagnetic wave radiated from the radiating element from the first waveguide 51 to the waveguide seal 7, and the second tapered transition 731 is provided to guide the reflected electromagnetic wave from the second waveguide 61 to the waveguide seal 7, thereby reducing the reflection of the electromagnetic wave.

In some exemplary embodiments, as shown in fig. 3, the first waveguide segment 72 further comprises a first cylindrical segment 722, the first cylindrical segment 722 being connected between the first tapered transition 721 and the spacer rib 71; the second waveguide section 73 includes a second cylindrical section 732, and the second cylindrical section 732 is connected between the second conical transition section 731 and the partition rib 71. Wherein, the end surface of the upper end of the first cylindrical section 722 coincides with the end surface of the lower section of the first conical transition section 721, and the end surface of the lower end of the second cylindrical section 732 coincides with the end surface of the upper section of the second conical transition section 731.

In some exemplary embodiments, as shown in fig. 3, the centerlines of the first cylindrical section 722, the first tapered transition 721, the second cylindrical section 732, and the second tapered transition 731 coincide to form a central axis of the waveguide seal 7. The first waveguide path 51 and the second waveguide path 61 have their center axes coincident with each other and with the center axis of the waveguide seal 7.

In some exemplary embodiments, the first and second tapered transition sections 721, 731 may be conical sections (circular in cross section) or pyramidal sections (polygonal in cross section), and the first and second cylindrical sections 722, 732 may be cylindrical sections (circular in cross section) or prismatic sections (polygonal in cross section).

The waveguide seal 7 is provided so that the electromagnetic wave is transmitted more through the first and second waveguide sections 72 and 73 to the second waveguide path 61 (or the second waveguide path 61 to the first waveguide path 51) from the first waveguide path 51, so that the electromagnetic wave is transmitted more in a single mode in the first and second waveguide paths 51 and 61, and the excited multimode signal is reduced.

In some exemplary embodiments, as shown in fig. 2 and 3, the first waveguide path 51 includes a first cylindrical cavity 511 and a first tapered cavity 512 that communicate with each other, the first tapered cavity 512 is disposed near the first end of the first waveguide 5, and the cross-sectional area of the first tapered cavity 512 increases from top to bottom (i.e., in a direction toward the first end of the first waveguide 5); the second waveguide 61 includes a second tapered cavity 612 and a second cylindrical cavity 611 communicating with each other, the second tapered cavity 612 is disposed near the first end of the second waveguide 6, and the cross-sectional area of the second tapered cavity 612 gradually increases from bottom to top (i.e., in a direction toward the first end of the second waveguide 6); and the center lines of the first cylindrical cavity 511, the first tapered cavity 512, the second cylindrical cavity 611, and the second tapered cavity 612 coincide, i.e., the center axis of the first waveguide 51 coincides with the center axis of the second waveguide 61.

Wherein the first cylindrical section 722 of the first waveguide section 72 extends into the first conical cavity 512, and the tip of the first conical transition section 721 extends into the first cylindrical cavity 511; the second conical section 732 of the second waveguide section 73 extends into the second conical cavity 612 and the tip of the second conical transition section 731 extends into the second cylindrical cavity 611.

The cross-sectional areas of the first cylindrical cavity 511 and the second cylindrical cavity 611 are smaller, electromagnetic wave energy is generally concentrated in the first cylindrical cavity 511 and the second cylindrical cavity 611, and by arranging the first conical cavity 512 and the second conical cavity 612, the cross-sectional areas are increased, and energy concentration and electromagnetic wave reflection can be reduced.

In some exemplary embodiments, as shown in fig. 2 and 3, the first waveguide segment 72 and the second waveguide segment 73 are symmetrically disposed, the first tapered cavity 512 and the second tapered cavity 612 are symmetrically disposed, and a plane of symmetry (horizontal plane) of the first waveguide segment 72 and the second waveguide segment 73 may coincide with a plane of symmetry (horizontal plane) of the first tapered cavity 512 and the second tapered cavity 612. Further, the inside diameter Φ 3 of the first cylindrical cavity 511 and the inside diameter Φ 4 of the second cylindrical cavity 611 are equal, so that the transmission path of the electromagnetic wave from top to bottom and from bottom to top is reversible.

The first waveguide section 72 and the second waveguide section 73 are symmetrically arranged, the diameter phi 1 of the first cylindrical section 722 is equal to the diameter phi 2 of the second cylindrical section 732, the axial height of the first cylindrical section 722 is equal to the axial height of the second cylindrical section 732, the taper angle theta 1 of the first conical transition section 721 is equal to the taper angle theta 2 of the second conical transition section 731, the axial height of the first conical transition section 721 is equal to the axial height of the second conical transition section 731, the taper angle theta 3 of the first conical cavity 512 is equal to the taper angle theta 4 of the second conical cavity 612, and the axial height of the first conical cavity 512 is equal to the axial height of the second conical transition section 731.

In some exemplary embodiments, the diameter Φ 1 of the first cylindrical section 722 and the inner diameter Φ 3 of the first cylindrical cavity 511 may be equal such that Φ 1 ═ 2 ═ 3 ═ 4. The taper angle θ 1 of the first tapered transition section 721 and the taper angle θ 3 of the first tapered cavity 512 may be equal, such that θ 1 ═ θ 2 ═ θ 3 ═ θ 4.

In some exemplary embodiments, the waveguide assembly is suitable for use with electromagnetic waves of 75-82GHz, the first tapered cavity 512 may have an axial height (in the up-down direction in FIG. 3) of 6.3mm to 8.3mm (e.g., 7mm), a diameter of 6.5mm to 8.5mm (e.g., 7mm) at a lower end, a diameter of 2.5mm to 3mm (e.g., 2.73mm) at an upper end, and a taper angle θ 3 of 32 ° -36 ° (e.g., 34 °). That is, φ 1, φ 2, φ 3, φ 4 may be 2.5mm-3mm, θ 1, θ 2, θ 3, θ 4 may be 32 ° -36 °.

In some exemplary embodiments, as shown in fig. 3, the partition rib 71 is an equal-thickness partition rib, and the partition rib 71 has a first surface (upper surface) adjacent to the first waveguide 5 and a second surface (lower surface) adjacent to the second waveguide 6, and the first surface and the second surface are flat surfaces, or curved surfaces that are convex toward the side where the first waveguide 5 is located, or curved surfaces that are convex toward the side where the second waveguide 6 is located.

Of course, the separation rib 71 may also be provided as a non-equal thickness separation rib 71, in which case the first surface and the second surface of the separation rib 71 may protrude towards the side on which the first waveguide 5 is located and the side on which the second waveguide 6 is located, respectively, such as: the first surface of the partition rib 71 is a cambered surface protruding toward the side where the first waveguide 5 is located, and the second surface is a cambered surface protruding toward the side where the second waveguide 6 is located; alternatively, the first surface is an arc surface protruding toward the side where the second waveguide 6 is located, and the second surface is an arc surface protruding toward the side where the first waveguide 5 is located.

In some exemplary embodiments, as shown in fig. 3, the thickness (thickness in the up-down direction in fig. 3) of the separating rib 71 is an integral multiple of a half wavelength, such as a half wavelength, or a single wavelength.

In some exemplary embodiments, as shown in FIG. 2, the annular side wall 74 of the waveguide seal 7 is provided with a stop rib 75, which stop rib 65 is adapted to be positioned against a stop step 11 provided on the meter case 1 of the radar level gauge.

In some exemplary embodiments, as shown in fig. 2, the waveguide seal 7 is a unitary structure.

In some exemplary embodiments, the waveguide seal 7 may be made of PTFE (polytetrafluoroethylene), PFA (fusible polytetrafluoroethylene), fluoroplastic, PP (polypropylene) plastic, or the like.

As shown in fig. 1 and 2, an embodiment of the present application further provides a radar level gauge comprising a meter case 1, a circuit board 3 and a waveguide assembly of any of the above embodiments, the circuit board 3 being arranged in the meter case 1, a first waveguide 5 of the waveguide assembly being closer to the circuit board 3 than a second waveguide 6, and a second end (opposite to the first end of the circuit board 3, the upper end in fig. 2) of the first waveguide 5 extending into the meter case 1.

A radiating element (not shown) is provided on the circuit board 3 in the case 1, and the second end of the first waveguide 5 extends into the case 1 so that electromagnetic waves radiated by the radiating element can enter the first waveguide 51 from the second end of the first waveguide 5. The first end of the first waveguide 5 realizes the functions of insulation and sealing through the waveguide sealing member 7, and the safety and the reliability of the radar level gauge are ensured.

In some exemplary embodiments, as shown in fig. 2 and 4, a first board surface (a lower board surface in fig. 2 and 4) of the circuit board 3 adjacent to the first waveguide 5 is provided with a groove 31, and a second end of the first waveguide 5 extends into the groove 31.

The radar level meter further comprises a shielding shell 4 for shielding electromagnetic waves, the shielding shell 4 is arranged in the meter shell 1, the shielding shell 4 and the waveguide assembly are respectively located on two sides of the circuit board 3, the shielding shell 4 abuts against a second board surface (an upper board surface in fig. 2 and 4) of the circuit board 3, a protrusion 41 is arranged in the shielding shell 4, a protruding end surface (a lower end surface in fig. 2 and 4) of the protrusion 41 abuts against the bottom wall of the groove 31, a concave cavity 42 is arranged on the protruding end surface of the protrusion 41, and the concave cavity 42 forms a resonant cavity.

The waveguide assembly is located on the lower side of the circuit board 3, a groove 31 with an opening facing the first board surface of the circuit board 3 is provided, the radiating element can be arranged in the groove 31, the second end of the first waveguide 5 extends into the groove 31, and the annular convex rib 52 on the first waveguide 5 can be abutted against the first board surface of the circuit board 3. The shielding shell 4 is located on the upper side of the circuit board 3, and the lower end face of the shielding shell 4 abuts against the second board face of the circuit board 3. A protrusion 41 protruding downwards is arranged in the shielding shell 4, the protrusion 41 is arranged corresponding to the groove 31 on the circuit board 3 up and down, and the lower end surface of the protrusion 41 can abut against the bottom wall of the groove 31. A concave cavity 42 is provided on the lower end surface of the boss 41 to form a resonant cavity, and the cross-sectional area of the concave cavity 42 may be equal to the cross-sectional area of the first cylindrical cavity 511 of the first waveguide 51.

In some exemplary embodiments, as shown in figure 2, case 1 may be filled with a sealant 2.

Example two:

embodiments of the present application provide a waveguide assembly and a radar level gauge, which differ mainly from the first embodiment in the waveguide seal.

In the present embodiment, as shown in fig. 5 and 6, the first waveguide section 72 is tapered as a whole, the second waveguide section 73 is tapered as a whole, and the center lines of the first waveguide section 72 and the second waveguide section 73 are overlapped.

Wherein, the sectional area of the first waveguide section 72 is gradually reduced from bottom to top (i.e. along the direction far away from the separating rib 71), and the tip (upper end) of the first waveguide section 72 extends into the first waveguide passage 51; the sectional area of the second waveguide segment 73 gradually decreases from top to bottom (i.e., in a direction away from the spacer 71), and the tip (lower end) of the second waveguide segment 73 extends into the second waveguide path 61.

The first and second waveguide sections 72 and 73 are tapered so as to guide the electromagnetic wave radiated from the radiating element to the waveguide seal 7 through the first waveguide path 51 and to guide the reflected electromagnetic wave to the waveguide seal 7 through the second waveguide path 61, thereby reducing reflection of the electromagnetic wave.

In some exemplary embodiments, as shown in fig. 5 and 6, the first waveguide segment 72 extends into the first cylindrical cavity 511 after passing through the first tapered cavity 512, and the second waveguide segment 73 extends into the second cylindrical cavity 611 after passing through the second tapered cavity 612.

In some exemplary embodiments, as shown in fig. 5 and 6, the first waveguide section 72 may have an axial height (in the up-down direction in fig. 6) of 12mm to 15mm (e.g., 13.8mm), a diameter Φ 5 of the bottom end (lower end) of 4mm to 6mm (e.g., 5mm), and a taper angle θ 5 of 15 ° to 28 ° (e.g., 20 ° or 21 °).

The first and second waveguiding segments 72, 73 may be symmetrically arranged. The second waveguide segment 73 may have an axial height (in the up-down direction in fig. 6) of 12mm to 15mm (e.g., 13.8mm), a diameter Φ 6 of a bottom end (upper end) of 4mm to 6mm (e.g., 5mm), and a taper angle θ 6 of 15 ° to 28 ° (e.g., 20 ° or 21 °).

The first tapered cavity 512 and the second tapered cavity 612 may be symmetrically arranged such that the taper angle θ 3 of the first tapered cavity 512 is equal to the taper angle θ 4 of the second tapered cavity 612. The taper angle θ 3 of the first tapered cavity 512 may be greater than the taper angle θ 5 of the first waveguide segment 72.

The inner diameter φ 3 of the first cylindrical chamber 511 and the inner diameter φ 4 of the second cylindrical chamber 611 may be equal. The diameter φ 5 at the bottom of the first waveguide segment 72 may be larger than the inner diameter φ 3 of the first cylindrical cavity 511.

By adopting the waveguide sealing element 7, the impedance matching is favorably realized, the reflection of electromagnetic waves is reduced, and the measurement performance of the radar level meter is improved.

The above examples only express exemplary embodiments of the present application, and the description thereof is more specific and detailed, but the contents are only the embodiments adopted for understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.