Millimeter wave radar and liquid level meter antenna thereof

Abstract

The utility model discloses a millimeter wave radar and a liquidometer antenna thereof. The liquidometer antenna comprises a housing, a circuit board, a lens, a lens cover and an electromagnetic wave adjusting assembly. The distance from the lens port of the shell to the circuit board mounting position is shortened; the circuit board is mounted at a circuit board mounting position in the shell and is provided with an antenna excitation source; the lens is arranged at the lens port of the shell and is fixed through the lens cover; the distance between the antenna excitation source and the lens is shortened; the electromagnetic wave adjusting assembly is installed between the antenna excitation source and the lens and used for adjusting the propagation direction of electromagnetic waves emitted by the antenna excitation source so that the electromagnetic waves can be received or focused by the lens, and the gain of the whole antenna can be supplemented or improved. Therefore, the problems of large size and heavy structure of the millimeter-wave radar liquid level meter antenna can be solved, and certainly, the cost of the millimeter-wave radar liquid level meter antenna can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a millimeter-wave radar and its liquid level gauge antenna. Background Technology

[0002] like Figure 1 and Figure 2 As shown, the antennas of existing FMCW (Frequency Modulated Continuous Wave) millimeter-wave radar level gauges typically use dielectric lens antennas. The distance between the lens and the antenna excitation source on the circuit board is generally about 10 wavelengths, which makes the antenna large and bulky. Utility Model Content

[0003] In view of this, the present invention provides a millimeter-wave radar level gauge antenna, which can overcome the problems of large size and bulky structure of millimeter-wave radar level gauge antennas, and of course, it will also reduce the cost of millimeter-wave radar level gauge antennas.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A millimeter-wave radar level gauge antenna includes: a housing, a circuit board, a lens, a lens cover, and an electromagnetic wave adjustment assembly;

[0006] The distance from the lens port of the housing to the circuit board mounting position is shortened;

[0007] The circuit board is mounted in the circuit board mounting position inside the housing and has an antenna excitation source;

[0008] The lens is mounted on the lens port of the housing and fixed by the lens cover; wherein the distance from the antenna excitation source to the lens is shortened;

[0009] The electromagnetic wave adjustment component is installed between the antenna excitation source and the lens, and is used to adjust the propagation direction of the electromagnetic wave emitted by the antenna excitation source so that the electromagnetic wave can be received or focused by the lens.

[0010] Preferably, the electromagnetic wave adjustment component includes: a dielectric substrate and multiple copper foils;

[0011] The dielectric substrate is mounted between the antenna excitation source and the lens;

[0012] Multiple copper foils are arranged in a preset dot matrix on the first surface of the dielectric substrate facing the antenna excitation source. The first portion of copper foils located in the middle corresponds one-to-one with multiple array elements of the antenna excitation source. The second portion of copper foils located around the perimeter are distributed at preset positions around the first portion of copper foils. The distance between the array element and the corresponding copper foil is a preset distance. The aspect ratio of the copper foils is the same as that of the array elements, and the area of ​​the copper foils is smaller than that of the array elements according to a preset ratio.

[0013] Preferably, the copper sheet in the first part includes eight first copper sheets, four of which correspond one-to-one with the four array elements of the antenna excitation source and are concentrically distributed, and the remaining four first copper sheets are distributed in pairs at preset positions on both sides of the four first copper sheets.

[0014] The copper sheet described in Part Two includes: four second copper sheets and eight third copper sheets;

[0015] The four second copper sheets are distributed in pairs at predetermined positions on both sides of the eight first copper sheets, and their areas are smaller than the areas of the first copper sheets according to a predetermined ratio.

[0016] The eight third copper sheets are distributed in half on the other two sides of the eight first copper sheets at predetermined positions, and their areas are smaller than the areas of the first copper sheets according to a predetermined ratio.

[0017] Preferably, the remaining four first copper sheets are distributed in pairs at predetermined positions on the first and second sides of the four first copper sheets;

[0018] The four second copper sheets are distributed in pairs at predetermined positions on the first and second sides of the eight first copper sheets;

[0019] The eight third copper sheets are distributed in half at predetermined positions on the third and fourth sides of the eight first copper sheets;

[0020] The relative directions of the first and second sides of the four first copper sheets and the relative directions of the first and second sides of the eight first copper sheets are all first directions and are parallel to the width direction of the array element. The relative directions of the third and fourth sides of the eight first copper sheets are second directions and are parallel to the length direction of the array element.

[0021] Preferably, the center-to-center distance between two adjacent first copper sheets along the first direction and the center-to-center distance between two adjacent third copper sheets along the first direction are both a first preset distance, and the distance between adjacent first copper sheets and second copper sheets along the first direction is a third preset distance.

[0022] The center-to-center distance between two adjacent first copper sheets along the second direction, and the center-to-center distance between two adjacent second copper sheets along the second direction are both second preset distances, and the distance between adjacent first copper sheets and the third copper sheet along the second direction is a fourth preset distance.

[0023] Preferably, the length of the first copper sheet is 0.6117 times the length of the array element, and the width is 0.6117 times the width of the array element;

[0024] The length of the second copper sheet is 0.8664 times the length of the first copper sheet, and the width is 0.8664 times the width of the first copper sheet;

[0025] The length of the third copper sheet is 0.7443 times the length of the first copper sheet, and the width is 0.7443 times the width of the first copper sheet;

[0026] The first preset spacing is 1.56 mm;

[0027] The second preset spacing is 2.33mm;

[0028] The third preset spacing is 1.42mm;

[0029] The fourth preset spacing is 1.66mm.

[0030] Preferably, the thickness of the first copper sheet, the second copper sheet, and the third copper sheet is 35 μm.

[0031] Preferably, the distance from the array element to the corresponding first copper foil is 12.6 mm, and the distance to the lens is 20.352 mm.

[0032] Preferably, the dielectric substrate has a thickness of 1.5 mm and a dielectric constant Er of 2.0.

[0033] A millimeter-wave radar includes a level gauge antenna, wherein the level gauge antenna is a millimeter-wave radar level gauge antenna as described above.

[0034] As can be seen from the above technical solution, the millimeter-wave radar level gauge antenna provided by this utility model, with the shortening of the distance between the antenna excitation source and the lens, which helps to reduce the size of the antenna, can also overcome the problem of large size and bulky structure of the millimeter-wave radar level gauge antenna by adding an electromagnetic wave adjustment component between the antenna excitation source and the lens to adjust the propagation direction of the electromagnetic wave emitted by the antenna excitation source, so that the electromagnetic wave can be received or focused by the lens, thereby supplementing or improving the gain of the entire antenna. Of course, this will also reduce the cost of the millimeter-wave radar level gauge antenna. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of an existing millimeter-wave radar level gauge antenna;

[0037] Figure 2 This is a cross-sectional view of the structure of an existing millimeter-wave radar level gauge antenna;

[0038] Figure 3 This is a schematic diagram showing the positions of the lens and the antenna excitation source of another existing millimeter-wave radar level gauge antenna.

[0039] Figure 4 for Figure 3 Schematic diagram of antenna gain for millimeter-wave radar level gauge antenna;

[0040] Figure 5 This is a schematic diagram showing the position of the lens and the antenna excitation source of another existing millimeter-wave radar level gauge antenna;

[0041] Figure 6 for Figure 5 Schematic diagram of antenna gain for millimeter-wave radar level gauge antenna;

[0042] Among them, 5 is the outer shell, 6 is the circuit board, 7 is the third lens, 8 is the lens cover, 9 is the fixing base, 10 is the base, 11 is the first lens, and 12 is the second lens;

[0043] Figure 7 A schematic diagram showing the positions of the lens, dielectric substrate, and antenna excitation source of the millimeter-wave radar level gauge antenna provided in this embodiment of the utility model;

[0044] Figure 8 Another schematic diagram showing the positions of the lens, dielectric substrate, and antenna excitation source of the millimeter-wave radar level gauge antenna provided in this embodiment of the utility model;

[0045] Figure 9 A schematic diagram of the projection of the copper foil on the dielectric substrate onto the antenna excitation source provided in an embodiment of this utility model;

[0046] Figure 10 A schematic diagram showing the distribution of copper foil on a dielectric substrate provided in an embodiment of this utility model;

[0047] Figure 11 A schematic diagram of the antenna gain of the millimeter-wave radar level gauge antenna provided for an embodiment of this utility model;

[0048] Wherein, 1 is a lens, 2 is an antenna excitation source, 21 is an array element, 3 is a dielectric substrate, 4 is a copper foil, 41 is the first copper foil, 42 is the second copper foil, and 43 is the third copper foil. Detailed Implementation

[0049] Figure 3 The image shows the typical lens antenna structure of a millimeter-wave radar level gauge. The microstrip circuit below is the antenna excitation source, and the lens antenna is above. The lens antenna has a loop with three steps inside and two or three steps outside. The distance between the microstrip circuit and the lens antenna is generally 10 wavelengths to meet the antenna gain requirements.

[0050] Figure 4 What is shown is Figure 3 The example antenna gain shows that the highest gain reaches 24.7 dB. Such a high gain will make the radar beam very sharp, so as to achieve the purpose of accurately detecting targets. Since the beam of the microstrip antenna excitation source is fixed, the higher the gain after passing through the lens antenna, the sharper the beam becomes.

[0051] Figure 5 The diagram shows another existing miniaturized millimeter-wave radar level gauge antenna structure. The microstrip circuit below is the antenna excitation source, and the top is a lens antenna. The lens antenna has a loop with three steps inside and two or three steps outside. The microstrip circuit is 5 wavelengths away from the lens antenna.

[0052] Figure 6 What is shown is Figure 5 The example antenna gain shows that the highest antenna gain is only 23.6dB, because... Figure 3 and Figure 5 The excitation source for the example microstrip antenna is exactly the same. Figure 5 The highest gain of the example is less than Figure 3 The highest gain in the example, explanation Figure 5 The example antenna beam is not like Figure 3 The example is so sharp that, in practical applications, it might lead to insufficient accuracy in target detection. In other words, shortening the distance between the microstrip excitation source and the dielectric lens would reduce the overall antenna gain, while maintaining the original spacing would result in a larger antenna size. Therefore, to avoid this problem after shortening the distance between the antenna excitation source and the dielectric lens, this solution adds an electromagnetic wave adjustment component between them. This component adjusts the propagation direction of the electromagnetic waves from the antenna excitation source, ensuring that the dielectric lens, which is closer to the antenna excitation source, can receive or focus the electromagnetic waves, thus preventing a decrease in the overall antenna gain. In other words, the electromagnetic wave adjustment component compensates for and improves the antenna gain.

[0053] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0054] The millimeter-wave radar level gauge antenna provided in this embodiment of the utility model, such as Figure 7 and Figure 8 As shown, it includes: a housing, a circuit board, a lens 1, a lens cover, and an electromagnetic wave adjustment assembly;

[0055] The distance from the lens port of the housing to the circuit board mounting position is shortened;

[0056] The circuit board is mounted in the circuit board mounting position inside the housing and has an antenna excitation source 2;

[0057] Lens 1 is mounted on the lens port of the housing and fixed by a lens cover; wherein, the distance between the antenna excitation source 2 and lens 1 is shortened;

[0058] The electromagnetic wave adjustment component is installed between the antenna excitation source 2 and the lens 1, and is used to adjust the propagation direction of the electromagnetic wave emitted by the antenna excitation source 2 so that the electromagnetic wave can be received or focused by the lens 1.

[0059] It should be noted that the lens port and circuit board mounting position of the housing can be found in the following reference. Figure 1 In existing liquid level gauge antennas, the distance from the lens port of the housing to the circuit board mounting position is shortened, meaning the axial length of the housing is shortened; the circuit board is still mounted to the circuit board mounting position inside the housing via a bolt assembly; such as Figure 1 As shown, lens 1 is still mounted on the lens port of the housing, and the lens cover is still used to fix lens 1 to the lens port of the housing. Since the distance from the lens port of the housing to the circuit board mounting position is shortened, the distance between the antenna excitation source 2 and lens 1 is also shortened accordingly. To avoid a decrease in the gain of the millimeter-wave radar level gauge antenna, an electromagnetic wave adjustment component is added between the antenna excitation source 2 and lens 1 to adjust the propagation direction of the electromagnetic waves emitted by the antenna excitation source 2. This also changes the distribution of the electromagnetic field of the electromagnetic waves emitted by the antenna excitation source 2, so that the electromagnetic waves can be received or focused by lens 1. This shortens the distance between the antenna excitation source 2 and lens 1, thereby reducing the size of the antenna (i.e., the housing), while ensuring the gain of the millimeter-wave radar level gauge antenna. Furthermore, the shortened distance between lens 1 and antenna excitation source 2 allows for a corresponding reduction in the diameter of lens 1, which in turn reduces the diameter of the lens port of the housing, further reducing the size of the antenna. In addition, as... Figure 1 and Figure 2As shown, the millimeter-wave radar level gauge antenna also includes a mounting bracket and a base.

[0060] In other words, the millimeter-wave radar level gauge antenna provided by this solution, with the distance between the antenna excitation source 2 and the lens 1 shortened, which helps to reduce the size of the antenna, can also overcome the problem of large size and bulky structure of the millimeter-wave radar level gauge antenna by adding an electromagnetic wave adjustment component between the antenna excitation source 2 and the lens 1 to adjust the propagation direction of the electromagnetic waves emitted by the antenna excitation source 2, so that the electromagnetic waves can be received or focused by the lens 1. This will also reduce the cost of the millimeter-wave radar level gauge antenna.

[0061] In this plan, such as Figure 7 As shown, the electromagnetic wave adjustment assembly includes: a dielectric substrate 3 and multiple copper foils 4;

[0062] The dielectric substrate 3 is installed between the antenna excitation source 2 and the lens 1;

[0063] like Figure 7 As shown, multiple copper foils 4 are arranged in a preset dot matrix on the first surface of the dielectric substrate 3 facing the antenna excitation source 2, as follows. Figure 9 As shown, the first part of the copper skin 4 located in the middle corresponds one-to-one with multiple array elements 21 of the antenna excitation source 2, and the second part of the copper skin 4 located around the perimeter is distributed at preset positions around the first part of the copper skin 4. The distance between the array element 21 and the corresponding copper skin 4 is a preset distance. The aspect ratio of the copper skin 4 is the same as that of the array element 21, and the area is smaller than the area of ​​the array element 21 according to a preset ratio.

[0064] It should be noted that the dielectric substrate 3 is installed inside the housing and is located between the antenna excitation source 2 and the lens 1; as Figure 7 As shown, multiple copper sheets 4 are rectangular copper sheets, and are arranged on the first surface of the dielectric substrate 3 according to a preset dot matrix; wherein, as shown in the figure... Figure 9As shown, the first copper sheet 4 located in the middle corresponds one-to-one with and is concentric with the multiple array elements 21 of the antenna excitation source 2. The second copper sheet 4 located around the perimeter is also distributed in a preset dot matrix at preset positions around the first copper sheet 4. The distance between each array element 21 of the antenna excitation source 2 and the corresponding copper sheet 4 on the dielectric substrate 3 is a preset distance. The aspect ratio of each copper sheet 4 is the same as that of the array element 21, and its area is smaller relative to the area of ​​the array element 21 according to a preset ratio. Among them, the closer the copper sheet 4 is to the center of the multiple array elements 21, the larger its area; conversely, the farther the copper sheet 4 is from the center of the multiple array elements 21, the smaller its area. In addition, a specific copper sheet 4 is added and arranged between the antenna excitation source 2 and the lens 1. The dielectric substrate 4, through the copper foil 4 specifically distributed on the dielectric substrate 4, alters the propagation path, phase, and electromagnetic field distribution of the electromagnetic waves of the antenna excitation source 2 element 21, thereby achieving the control of the electromagnetic waves and enabling them to be received or focused by the lens 1. Simply put, the copper foil 4 reshapes the electromagnetic field distribution of the antenna excitation source 2 element 21 on the dielectric substrate 3 through mechanisms such as reflection, impedance modulation, boundary constraints, and energy conversion, achieving precise control of the electromagnetic wave phase, thereby reshaping the wavefront and focusing it. Of course, this method of adjusting electromagnetic waves can also use existing technologies, and the shape and position of the copper foil 4 must be carefully designed, as random placement may introduce stray reflections and interference, which may reduce antenna performance.

[0065] In other words, this scheme has a dielectric substrate 3 with a specific copper foil 4 design installed between the antenna excitation source 2 and the lens 1, which can compensate and improve the gain of the entire antenna and avoid the problem of antenna gain reduction caused by shortening the distance between the antenna excitation source 2 and the lens 1.

[0066] Specifically, such as Figure 10 As shown, the first copper sheet 4 includes eight first copper sheets 41, wherein, as Figure 9 As shown, the four first copper sheets 41 correspond one-to-one with the four array elements 21 of the antenna excitation source 2 and are concentrically distributed, while the remaining four first copper sheets 41 are distributed in pairs at preset positions on both sides of the four first copper sheets 41.

[0067] like Figure 10 As shown, the second copper sheet 4 includes: four second copper sheets 42 and eight third copper sheets 43;

[0068] Four second copper sheets 42 are distributed in pairs at predetermined positions on both sides of eight first copper sheets 41, and their areas are smaller than the areas of the first copper sheets 41 according to a predetermined ratio.

[0069] Eight third copper sheets 43 are distributed in half on the other two sides of the eight first copper sheets 41 at predetermined positions, and their areas are smaller than the areas of the first copper sheets 41 according to a predetermined ratio.

[0070] Among them, such as Figure 9As shown, the four first copper foils 41 correspond one-to-one with the four array elements 21 of the antenna excitation source 2, and are distributed in the same center; the four array elements 21 of the antenna excitation source 2 can be referred to Figure 8 As shown; Figure 10 As shown, the four first copper sheets 41 are the four first copper sheets 41 located in the middle. Among the remaining four first copper sheets 41, two first copper sheets 41 and the other two first copper sheets 41 are distributed at preset positions on both sides of the four first copper sheets 41 located in the middle. In other words, they can be distributed at preset positions on both sides of the four first copper sheets 41 along the X direction (its width direction). The area of ​​each first copper sheet 41 is smaller than the area of ​​the array element 21 according to a preset ratio.

[0071] like Figure 10 As shown, among the four second copper sheets 42, two second copper sheets 42 and the other two second copper sheets 42 are distributed at preset positions on both sides of the eight first copper sheets 41, that is, they can be distributed at preset positions on both sides of the eight first copper sheets 41 along the X direction. The area of ​​each second copper sheet 42 is smaller than the area of ​​the first copper sheet 41 by a preset ratio.

[0072] like Figure 10 As shown, among the eight third copper sheets 43, four third copper sheets 43 and another four third copper sheets 43 are distributed at preset positions on the other two sides of the eight first copper sheets 41, that is, they can be distributed at preset positions on both sides of the eight first copper sheets 41 along the Y direction (its length direction). The area of ​​each third copper sheet 43 is smaller than the area of ​​the first copper sheet 41 by a preset ratio.

[0073] Furthermore, such as Figure 10 As shown, the remaining four first copper sheets 41 are distributed in pairs at preset positions on the first and second sides of the four first copper sheets 41;

[0074] Four second copper sheets 42 are distributed in pairs at predetermined positions on the first and second sides of eight first copper sheets 41;

[0075] Eight third copper sheets 43 are distributed in half on the third and fourth sides of the eight first copper sheets 41 at predetermined positions;

[0076] Among them, the relative directions of the first and second sides of the four first copper sheets 41 and the relative directions of the first and second sides of the eight first copper sheets 41 are all first directions and are parallel to the width direction of the array element 21. The relative directions of the third and fourth sides of the eight first copper sheets 41 are second directions and are parallel to the length direction of the array element 21.

[0077] Of the remaining four first copper sheets 41, two are located at predetermined positions on the first side of the four first copper sheets 41, and the other two are located at predetermined positions on the second side of the four first copper sheets 41. The relative direction between the first and second sides of the four first copper sheets 41 is the first direction, which is the X-direction mentioned above; that is, as... Figure 10 As shown, the eight first copper foils 41 are divided into four groups and distributed at equal intervals in the X direction on the first surface of the dielectric plate 3;

[0078] Of the four second copper sheets 42, two second copper sheets 42 are distributed at predetermined positions on the first side of the eight first copper sheets 41, and the other two second copper sheets 42 are distributed at predetermined positions on the second side of the eight first copper sheets 41; the relative direction between the first side and the second side of the eight first copper sheets 41 is the first direction, which is the X direction mentioned above; that is, as Figure 10 As shown, the four second copper sheets 42 are divided into two groups and distributed along the X direction at preset positions on both sides of the eight first copper sheets 41.

[0079] Of the eight third copper sheets 43, four are located at predetermined positions on the third side of the eight first copper sheets 41, and the other four are located at predetermined positions on the fourth side of the eight first copper sheets 41; the relative direction between the third and fourth sides of the eight first copper sheets 41 is the second direction, which is the Y-direction mentioned above; that is, as Figure 10 As shown, the eight third copper sheets 43 are divided into two groups and distributed along the Y direction at preset positions on both sides of the eight first copper sheets 41; of course, the X direction and Y direction mentioned above are the two orthogonal directions of the preset dot matrix.

[0080] Furthermore, the center-to-center distance between two adjacent first copper sheets 41 along the first direction and the center-to-center distance between two adjacent third copper sheets 43 along the first direction are both the first preset distance, and the distance between the adjacent first copper sheet 41 and the second copper sheet 42 along the first direction is the third preset distance.

[0081] The center-to-center distance between two adjacent first copper sheets 41 along the second direction and the center-to-center distance between two adjacent second copper sheets 42 along the second direction are both second preset distances, and the distance between the adjacent first copper sheet 41 and the third copper sheet 43 along the second direction is a fourth preset distance.

[0082] Among them, such as Figure 10As shown, the center-to-center distance between two adjacent first copper sheets 41 along the X direction and the center-to-center distance between two adjacent third copper sheets 43 along the X direction are both first preset distances, and the distance between adjacent first copper sheets 41 and second copper sheets 42 along the X direction is a third preset distance; the center-to-center distance between two adjacent first copper sheets 41 along the Y direction and the center-to-center distance between two adjacent second copper sheets 42 along the Y direction are both second preset distances, and the distance between adjacent first copper sheets 41 and third copper sheets 43 along the Y direction is a fourth preset distance, so that the eight first copper sheets 41, four second copper sheets 42 and eight third copper sheets 43 are distributed in a preset dot matrix on the first surface of the dielectric substrate 3.

[0083] Preferably, the length of the first copper sheet 41 is 0.6117 times the length of the array element 21, and the width is 0.6117 times the width of the array element 21.

[0084] The length of the second copper sheet 42 is 0.8664 times the length of the first copper sheet 41, and the width is 0.8664 times the width of the first copper sheet 41;

[0085] The length of the third copper sheet 43 is 0.7443 times the length of the first copper sheet 41, and the width is 0.7443 times the width of the first copper sheet 41.

[0086] The first preset spacing is 1.56mm;

[0087] The second preset spacing is 2.33mm;

[0088] The third preset spacing is 1.42mm;

[0089] The fourth preset spacing is 1.66mm.

[0090] It should be noted that the length and width of each copper sheet, as well as the preset spacing mentioned above, can be determined through extensive computer calculations and simulations, from which the best-performing option can be selected; among them, the length (along the Y direction) of array element 21 is 1.08mm and the width (along the X direction) is 0.94mm.

[0091] The four first copper sheets 41 located in the center correspond one-to-one with the centers of the four array elements 21, and they coincide in the Z direction. The length of the first copper sheet 41 is 0.6117 times the length of the array element 21, and the width is 0.6117 times the width of the array element 21. In the X direction, the distance between the centers of two adjacent first copper sheets 41 is 1.56 mm, and in the Y direction, the distance between the centers of two adjacent first copper sheets 41 is 2.33 mm.

[0092] The length of the second copper sheet 42 is 0.8664 times the length of the first copper sheet 41, and the width is 0.8664 times the width of the first copper sheet 41. In the X direction, the interval between the second copper sheet 42 and the first copper sheet 41 is 1.42 mm, and in the Y direction, the distance between the centers of two adjacent second copper sheets 42 is 2.33 mm.

[0093] The length of the third copper sheet 43 is 0.7443 times the length of the first copper sheet 41, and the width is 0.7443 times the width of the first copper sheet 41. In the X direction, the distance between the centers of two adjacent third copper sheets 43 is 1.56 mm, and in the Y direction, the distance between the third copper sheet 43 and the first copper sheet 41 is 1.66 mm.

[0094] Specifically, the thickness of the first copper sheet 41, the second copper sheet 42, and the third copper sheet 43 is 35 μm. That is, the thickness of the first copper sheet 41, the second copper sheet 42, and the third copper sheet 43 is 1 oz; of course, the thickness of these copper sheets can also be 0.5 oz; wherein, the first surface of the dielectric substrate 3 has copper, and the unwanted areas of the first surface of the dielectric substrate 3 can be etched away, leaving only the aforementioned copper sheets 4.

[0095] Furthermore, the distance from the array element 21 to the corresponding first copper foil 41 is 12.6 mm, and the distance to the lens 1 is 20.352 mm. Specifically, the distance from the array element 21 of the antenna excitation source 2 to the first copper foil 41 of the dielectric substrate 3 is 12.6 mm, and the distance to the lens 1 is 5.3 lamda. This is shorter than the existing distance of approximately 10 wavelengths between the antenna excitation source and the lens; of course, lamda is the wavelength, 1 lamda is 3.84 mm, meaning the center frequency is 78.1 GHz.

[0096] Furthermore, to avoid the thickness of the dielectric substrate 3 affecting the electromagnetic field, the thickness of the dielectric substrate 3 is 1.5 mm, and the dielectric constant Er is 2.0; the length and width of the dielectric substrate 3 must be sufficient to accommodate multiple copper foils 4.

[0097] Furthermore, it should be noted that the millimeter-wave radar level gauge antenna provided in this solution can... Figure 5 Based on the example millimeter-wave radar level gauge antenna, a dielectric plate 3 is inserted between the antenna excitation source and the lens. The dielectric plate 3 has some copper foil 4 obtained from optimization simulation. These copper foils 4 are evenly distributed, with larger ones near the center and smaller ones further away from the center. At this time, although the antenna excitation source is only 5 wavelengths away from the lens, the gain of the entire antenna is improved.

[0098] Figure 11 The gain curve of the millimeter-wave radar level gauge antenna provided for this solution shows that the antenna's highest gain reaches 24.8 dB. This is because this solution and... Figure 3The microstrip antenna excitation source in the example is exactly the same, and the highest gain of this scheme is... Figure 3 The example has the same maximum gain, indicating that the antenna beam of this scheme is as high as... Figure 3 The example is just as sharp, so in practical applications, the accuracy of this scheme in detecting targets is similar to... Figure 3 The detection accuracy is just as high in the real-world examples;

[0099] This plan and Figure 3 Compared to the example, its height (spacing) is reduced by nearly half. Simultaneously, because the lens is closer to the microstrip circuit, the diameter of the lens antenna is also correspondingly reduced. Overall, the volume of the level gauge antenna in this design is... Figure 3 The sample level gauge antenna is about one-quarter the size, and due to the reduced size, the cost and weight of the lens antenna in this design are also significantly lower. Figure 3 The number of examples has been reduced.

[0100] The housing of the level gauge is also a significant component of the cost, as the size of the level gauge antenna in this solution is... Figure 3 The example level gauge antenna is about 1 / 4 the size, and the housing is also smaller and less expensive. Figure 3 The number of examples has been reduced.

[0101] In addition, because the volume of the level gauge has been greatly reduced, it can be used in more applications where size requirements are stringent.

[0102] In conclusion, this solution has produced positive results and has practical engineering value.

[0103] In addition, it should be noted that, Figure 1 and Figure 2 The diagram shows the structure of an existing millimeter-wave radar level gauge antenna. The distance between the circuit board and the lens is approximately 10 lamda.

[0104] Figure 3 This is a simulated 3D image of the circuit board at a distance of approximately 10*lambda from the lens. Figure 4 for Figure 3 The simulated gain curve;

[0105] Figure 5 This is a simulated 3D image of the circuit board at a distance of approximately 5*lambda from the lens. Figure 6 for Figure 5 The simulated gain curve; from Figure 6 It can be seen that the maximum gain ratio Figure 4 The maximum gain is reduced by about 2dB;

[0106] To address this gain reduction issue, this solution specifically adds a dielectric board with a specific copper foil between the circuit board and the lens.

[0107] Figure 7 and Figure 8 This is a simulation 3D image of a circuit board approximately 5 laminas from a lens, with a dielectric substrate inserted into it. Figure 9 and Figure 10 This is a distribution map of the copper foil;

[0108] Figure 11 The gain curve for this scheme shows that the maximum gain and Figure 4 The maximum gain of the examples is comparable;

[0109] Therefore, this solution mainly solves the problem of gain decrease when the distance between the circuit board and the lens becomes smaller. This is the inventive point of this solution, and it also helps to reduce the size of the antenna.

[0110] In other words, the distance between the microstrip antenna excitation source and the lens antenna in this scheme is only half that of the traditional design, but the gain of the entire antenna system is as high as that of the traditional design. This indicates that the antenna beam of this scheme is as sharp as that of the antenna beam of the traditional design. Thus, in practical applications, the target detection accuracy of this scheme is as high as that of the traditional design.

[0111] Compared with the traditional design, the height of this solution is reduced by nearly half. At the same time, because the lens antenna is closer to the microstrip circuit, the diameter of the lens antenna is also reduced accordingly. Overall, the liquid level gauge system of this solution is about 1 / 4 the size of the liquid level gauge system of the traditional design. Moreover, due to the reduction in size, the cost and weight of the lens antenna are also greatly reduced compared with the traditional design.

[0112] The diameter of a lens antenna decreases as the distance between it and the microstrip circuit (or feed antenna) decreases, mainly due to the influence of the electromagnetic wave divergence angle and the principle of energy concentration.

[0113] When a microstrip circuit is used as a feed source, it will emit electromagnetic waves within a certain angular range;

[0114] When the lens antenna is far from the microstrip circuit, the electromagnetic waves will continue to diverge during propagation, and the beam coverage area will increase. Therefore, the diameter of the lens needs to be larger to receive or focus as many electromagnetic waves as possible.

[0115] When the lens antenna is closer to the microstrip circuit, the electromagnetic waves do not have enough time to diverge significantly, and its beam area is smaller.

[0116] Therefore, a smaller diameter lens is sufficient to receive most or all of the energy;

[0117] This utility model embodiment also provides a millimeter-wave radar, including a level gauge antenna, which is the millimeter-wave radar level gauge antenna described above. Since this solution uses the aforementioned millimeter-wave radar level gauge antenna, it also has corresponding beneficial effects, as detailed in the preceding description, which will not be repeated here.

[0118] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0119] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A millimeter wave radar liquid level meter antenna, characterized by, include: The outer casing, circuit board, lens (1), lens cover, and electromagnetic wave adjustment assembly; The distance from the lens port of the housing to the circuit board mounting position is shortened; The circuit board is mounted in the circuit board mounting position inside the housing and has an antenna excitation source (2). The lens (1) is mounted on the lens port of the housing and fixed by the lens cover; wherein the distance between the antenna excitation source (2) and the lens (1) is shortened; The electromagnetic wave adjustment component is installed between the antenna excitation source (2) and the lens (1) and is used to adjust the propagation direction of the electromagnetic wave emitted by the antenna excitation source (2) so that the electromagnetic wave can be received or focused by the lens (1).

2. The millimeter wave radar liquid level meter antenna according to claim 1, characterized in that, The electromagnetic wave adjustment component includes: a dielectric plate (3) and multiple copper foils (4). The dielectric substrate (3) is installed between the antenna excitation source (2) and the lens (1); Multiple copper sheets (4) are arranged in a preset dot matrix on the first plate surface of the dielectric substrate (3) facing the antenna excitation source (2). The first part of the copper sheets (4) located in the middle corresponds one-to-one with multiple array elements (21) of the antenna excitation source (2). The second part of the copper sheets (4) located around the perimeter are distributed at preset positions around the first part of the copper sheets (4). The distance between the array element (21) and the corresponding copper sheet (4) is a preset distance. The aspect ratio of the copper sheet (4) is the same as that of the array element (21), and the area is smaller than the area of ​​the array element (21) according to a preset ratio.

3. The millimeter-wave radar level gauge antenna according to claim 2, characterized in that, The copper sheet (4) in the first part includes eight first copper sheets (41). Four of the first copper sheets (41) correspond one-to-one with the four array elements (21) of the antenna excitation source (2) and are concentrically distributed. The remaining four first copper sheets (41) are distributed in pairs at preset positions on both sides of the four first copper sheets (41). The copper sheet (4) described in Part 2 includes: four second copper sheets (42) and eight third copper sheets (43); The four second copper sheets (42) are distributed in pairs at predetermined positions on both sides of the eight first copper sheets (41), and their areas are smaller than the areas of the first copper sheets (41) according to a predetermined ratio; The eight third copper sheets (43) are distributed in half on the other two sides of the eight first copper sheets (41) at predetermined positions, and their areas are smaller than the areas of the first copper sheets (41) according to a predetermined ratio.

4. The millimeter wave radar liquid level meter antenna according to claim 3, characterized in that The remaining four first copper sheets (41) are distributed in pairs at preset positions on the first and second sides of the four first copper sheets (41); The four second copper sheets (42) are distributed in pairs at predetermined positions on the first and second sides of the eight first copper sheets (41); The eight third copper sheets (43) are distributed in half on the third and fourth sides of the eight first copper sheets (41) at predetermined positions; Among them, the relative directions of the first and second sides of the four first copper sheets (41) and the relative directions of the first and second sides of the eight first copper sheets (41) are all first directions and are parallel to the width direction of the array element (21). The relative directions of the third and fourth sides of the eight first copper sheets (41) are second directions and are parallel to the length direction of the array element (21).

5. The millimeter wave radar liquid level meter antenna according to claim 4, characterized in that The center-to-center distance between two adjacent first copper sheets (41) along the first direction and the center-to-center distance between two adjacent third copper sheets (43) along the first direction are both the first preset distance, and the distance between the adjacent first copper sheet (41) and the second copper sheet (42) along the first direction is the third preset distance. The center-to-center distance between two adjacent first copper sheets (41) along the second direction and the center-to-center distance between two adjacent second copper sheets (42) along the second direction are both second preset distances, and the distance between the adjacent first copper sheets (41) and the third copper sheet (43) along the second direction is a fourth preset distance.

6. The millimeter wave radar liquid level meter antenna according to claim 5, characterized in that The length of the first copper sheet (41) is 0.6117 times the length of the array element (21), and the width is 0.6117 times the width of the array element (21); The length of the second copper sheet (42) is 0.8664 times the length of the first copper sheet (41), and the width is 0.8664 times the width of the first copper sheet (41); The length of the third copper sheet (43) is 0.7443 times the length of the first copper sheet (41), and the width is 0.7443 times the width of the first copper sheet (41); The first preset spacing is 1.56 mm; The second preset spacing is 2.33mm; The third preset spacing is 1.42mm; The fourth preset spacing is 1.66mm.

7. The millimeter-wave radar liquid level meter antenna according to claim 6, characterized in that The thickness of the first copper sheet (41), the second copper sheet (42) and the third copper sheet (43) is 35 μm.

8. The millimeter-wave radar level gauge antenna according to claim 6, characterized in that, The distance between the array element (21) and the corresponding first copper sheet (41) is 12.6 mm, and the distance between the array element (21) and the lens (1) is 20.352 mm.

9. The millimeter wave radar liquid level meter antenna according to claim 2, characterized in that, The dielectric substrate (3) has a thickness of 1.5 mm and a dielectric constant Er of 2.

0.

10. A millimeter wave radar, characterized by, Includes a level gauge antenna, wherein the level gauge antenna is a millimeter-wave radar level gauge antenna as described in any one of claims 1-9.

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