Electromagnetic element for improving marginal definition of radar sensor

Abstract

The utility model discloses an electromagnetic element for improving marginal definition of a radar sensor, which belongs to the technical field of electromagnetic elements and comprises a PCB (printed circuit board), the electromagnetic element is arranged on the PCB and is manufactured on the upper surface of the PCB through a PCB etching process, a main antenna is arranged on the right side of the electromagnetic element, the upper end of the main antenna is connected with a microwave transmission line, and the lower end of the main antenna is connected with the microwave transmission line. The left side of the microwave transmission line is connected with the radar main chip. Through the above mode, unnecessary electromagnetic interference signals in the radar sensor are reduced, and the radar sensor can obtain a wider radiation pattern dB beam width.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic elements, in particular to an electromagnetic element for improving edge clarity of a radar sensor. Background Art

[0002] In radar sensors, millimeter-wave antennas are core components used to transmit electromagnetic signals into space and capture weak electromagnetic signals from space. Their transmission response at different angles in space, known as the amplitude / phase pattern, influences the error level of the radar sensor's detection system. Relatively speaking, the edges of the radar sensor's Field of View (FOV) require the same clarity as the center. However, electromagnetic interference signals from various sources within the radar sensor can easily contaminate the clarity of these edge areas. From a radar functional perspective, radars are required to have a longer detection range, both horizontally and vertically, to detect road targets early and initiate warnings and other responses. This requires millimeter-wave radar system designs to achieve higher transmit power and lower receive sensitivity within a wider FoV. This, in turn, poses a greater challenge in maintaining high clarity at the edges of the FoV.

[0003] In the prior art, absorbing materials or similar structures are distributed around the radar antenna to suppress or absorb electromagnetic signals that propagate from the antenna source to the terminal at the edge of the FoV.

[0004] On the one hand, this technology exacerbates the roll-off trend of the antenna pattern with angle, reducing the maximum distance detection capability at the edge, and on the other hand, increases manufacturing costs and assembly process.

[0005] Based on this, the utility model designs an electromagnetic element for improving the edge clarity of a radar sensor to solve the above problem. Utility Model Content

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides an electromagnetic element for improving the edge clarity of a radar sensor.

[0007] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] An electromagnetic component for improving edge clarity of a radar sensor includes a PCB board, the PCB board being provided with the electromagnetic component, a main antenna being provided on the right side of the electromagnetic component, the upper end of the main antenna being connected to a microwave transmission line, and the left side of the microwave transmission line being connected to a radar main chip;

[0009] The electromagnetic element is connected to the parasitic antenna;

[0010] The electromagnetic element includes a second microstrip transmission line, a slotted gap, a metal patch and a ground via;

[0011] The upper end of the second microstrip transmission line is connected to the parasitic antenna, and the lower end of the second microstrip transmission line is connected to the middle of the metal patch;

[0012] There are two slots, both of which are opened at the upper end of the metal patch, and the two slots are symmetrically arranged on the left and right sides of the second microstrip transmission line;

[0013] A plurality of grounding vias are provided at equal intervals and are all opened at the lower edge of the metal patch.

[0014] Furthermore, the second microstrip transmission line, slots, metal patches and ground vias are arranged in a periodic and repetitive manner in the transverse arrangement on the surface of the parasitic antenna radar antenna board, and the period is an integer multiple of 1 / 2 working wavelength.

[0015] Furthermore, the spacing between the combination of the second microstrip transmission line, the slot, the metal patch, the ground via, and the parasitic antenna and the main antenna in a horizontal arrangement is an integer multiple of 1 / 2 the working wavelength.

[0016] Furthermore, the metal patch and the parasitic antenna have different radiation polarization directions.

[0017] Furthermore, the parasitic antenna has the same polarization direction as the main antenna.

[0018] Furthermore, the structural dimensions of the parasitic antenna and the main antenna may be consistent or inconsistent.

[0019] Furthermore, the parasitic antenna includes a first microstrip transmission line for connecting to other antenna units, a rectangular metal patch with radiation capability, and a series branch for impedance matching; the left side of the first microstrip transmission line is connected to the rectangular metal patch with radiation capability, and the right side of the first microstrip transmission line is connected to the series branch, and the rectangular metal patch is located at the upper end of the series branch.

[0020] Furthermore, the lower end of the first microstrip transmission line is connected to the second microstrip transmission line.

[0021] Compared with the existing technology, the beneficial effects of the present invention are as follows: 1. The solution proposed in this invention can reduce unnecessary electromagnetic interference signals inside the radar sensor;

[0022] 2. The solution proposed in this application can enable the radar sensor to obtain a wider radiation direction Figure 3 dB beamwidth;

[0023] 3. The proposed solution can reduce the amplitude and phase differences of multiple antennas in the radar sensor and improve edge clarity, especially the amplitude and phase differences between channels at the edge of the radar perception FoV. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0025] Figure 1 This is a circuit layout diagram of the combination of the parasitic antenna and the electromagnetic element of the utility model;

[0026] Figure 2 This is a circuit diagram of an electromagnetic element for improving edge clarity of a radar sensor according to the present invention;

[0027] Figure 3 A front view of the circuit layout of a conventional radar sensor including the main antenna;

[0028] Figure 4 A front view of a circuit layout for improving radar edge definition by using electromagnetic elements in an embodiment of the present invention;

[0029] Figure 5 A cross-sectional diagram of the circuit layout of a conventional radar sensor including the main antenna;

[0030] Figure 6 A cross-sectional view of a circuit layout for improving edge definition by using electromagnetic elements in an embodiment of the present invention;

[0031] Figure 7 This is the effect diagram of the radar antenna horizontal diagram with and without the arrangement of electromagnetic components.

[0032] The numbers in the figure represent:

[0033] 100. Electromagnetic component; 101. Parasitic antenna; 102. First microstrip transmission line; 103. Rectangular metal patch; 104. Series branch; 105. Second microstrip transmission line; 106. Slotted gap; 107. Metal patch; 108. Ground via; 200. Main antenna; 201. Microwave transmission line; 202. Radar main chip; 300. Radar sensor housing; 301. Electromagnetic signal; 302. External useful signal; 303. Internal useful signal; 304. First internal interference signal; 305. Second internal interference signal; 306. External interference signal. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0035] Example 1: In some embodiments, please refer to the accompanying drawings of the specification. Figure 1-Figure 7 An electromagnetic component for improving the edge clarity of a radar sensor includes a PCB board on which an electromagnetic component 100 is arranged. The electromagnetic component 100 is manufactured on the upper surface of the PCB board through a PCB etching process.

[0036] A main antenna 200 is provided on the right side of the electromagnetic element 100. The upper end of the main antenna 200 is connected to a microwave transmission line 201. The left side of the microwave transmission line 201 is connected to the radar main chip 202.

[0037] The electromagnetic element 100 is connected to the parasitic antenna 101;

[0038] The electromagnetic component 100 includes a second microstrip transmission line 105, a slot 106, a metal patch 107, and a ground via 108. With the cooperation of the slot 106 and the ground via 108, the electromagnetic component 100 absorbs and attenuates the signal from the parasitic antenna 101, that is, it matches the antenna impedance.

[0039] The upper end of the second microstrip transmission line 105 is connected to the parasitic antenna 101 , and the lower end of the second microstrip transmission line 105 is connected to the middle of the metal patch 107 ;

[0040] There are two slots 106 and both are opened at the upper end of the metal patch 107. The two slots 106 are symmetrically arranged on the left and right sides of the second microstrip transmission line 105.

[0041] The grounding vias 108 are provided in multiples at equal intervals and are all opened at the lower edge of the metal patch 107 . The multiple grounding vias 108 are all away from the radiation edge.

[0042] The second microstrip transmission line 105, the slot 106, the metal patch 107 and the ground via 108 are arranged in a periodic and repetitive manner in the horizontal arrangement on the surface of the radar antenna board of the parasitic antenna 101, and the period is an integer multiple of 1 / 2 working wavelength.

[0043] The transverse spacing between the main antenna 200 and the combination of the second microstrip transmission line 105, slot 106, metal patch 107, ground via 108, and parasitic antenna 101 is an integer multiple of 1 / 2 the operating wavelength. This combination of the second microstrip transmission line 105, slot 106, metal patch 107, ground via 108, and parasitic antenna 101 is placed on the path from the main antenna 200 to the edge of the radar antenna board to absorb interfering electromagnetic signals. By varying the size of the slot 106, metal patch 107, and the number, spacing, and size of the ground vias 108 in the electromagnetic element 100, the absorption of interfering signals can be controlled, thereby affecting the clarity of the radar sensor's edges.

[0044] The parasitic antenna 101 senses the interference electromagnetic signal in the interior space of the radar sensor and transmits it to the end electromagnetic element 100 in the form of current wave / voltage wave and absorbs it. The effect of absorbing the interference signal depends on the input impedance of the electromagnetic element 100.

[0045] The dissipation efficiency of a single combination of the second microstrip transmission line 105, slot 106, metal patch 107, ground via 108, and parasitic antenna 101 depends on the induced impedance to the interfering electromagnetic signal. In this embodiment, a single combination cannot completely dissipate the interfering signal on a particular path to achieve edge clarity. Therefore, this combination is periodically arranged to achieve a superimposed dissipation effect on the interfering electromagnetic signal, with the periodic arrangement spacing being 1 / 2 the operating wavelength.

[0046] The metal patch 107 and the parasitic antenna 101 have different radiation polarization directions.

[0047] The parasitic antenna 101 and the main antenna 200 have the same polarization direction.

[0048] The structural dimensions of the parasitic antenna 101 and the main antenna 200 may be consistent or inconsistent. That is, the patch unit size, patch unit data, and patch unit spacing may be consistent or adjusted according to the circuit layout space.

[0049] The parasitic antenna 101 includes a first microstrip transmission line 102 for connecting to other antenna units, a rectangular metal patch 103 with radiation capability, and a series branch 104 for impedance matching; the left side of the first microstrip transmission line 102 is connected to the rectangular metal patch 103 with radiation capability, and the right side of the first microstrip transmission line 102 is connected to the series branch 104, and the rectangular metal patch 103 is located at the upper end of the series branch 104.

[0050] The lower end of the first microstrip transmission line 102 is connected to the second microstrip transmission line 105 .

[0051] Embodiment 2: In some embodiments, as Figure 3 、 Figure 4 As shown in FIG. 1 , as a preferred embodiment of the present invention, Figure 3 A front view of the antenna circuit layout of a conventional radar sensor is shown. On the top surface of a PCB (typically the top surface of a high-frequency material layer), a radar main chip 202 is connected to a main antenna 200 via a microwave transmission line 201, enabling transmission and reception of radar main chip 202 signals. The key difference between main antenna 200 and parasitic antenna 101 lies in whether the antenna circuit is directly connected to radar main chip 202. When main antenna 200 is in transmit mode, interfering electromagnetic signals are present on the surface of the PCB, which is generally difficult to control and affects the edge clarity of the radar sensor. In particular, interfering electromagnetic signals reaching the edge of the PCB are subject to diffraction, making their propagation path even more uncontrollable.

[0052] In comparison, Figure 4 A front view of a circuit layout illustrating an embodiment employing electromagnetic elements 100 to improve edge definition is provided. Electromagnetic elements 100 are added without changing the layout of components on the PCB surface, namely, the radar main chip 202, microwave transmission line 201, and main antenna 200. Interference electromagnetic signals are easily excited to the left and right sides of the main antenna 200 and propagate along the PCB surface. The longer the propagation path, the more likely it is to degrade the edge definition of the radar sensor. Therefore, electromagnetic elements 100 are periodically placed along the path of the interference electromagnetic signals excited by the main antenna 200, generally parallel to the array arrangement of the main antenna 200, with spacing between them equal to an integer multiple of 1 / 2 the operating wavelength. The number of periods of electromagnetic elements 100 is determined by the length of the interference path.

[0053] Embodiment 3: In some embodiments, as Figure 5 、 Figure 6 As shown in FIG. 1 , as a preferred embodiment of the present invention, Figure 5 This is a cross-sectional view of the circuit layout of a conventional radar sensor, including the main antenna 200. The schematic illustrates the impact of the radar sensor housing 300 on the signal. Similarly, the radar main chip 202, mounted on the PCB, drives the main antenna 200 to generate an electromagnetic signal 301. This signal, originating both inside and outside the radar sensor, includes an external useful signal 302, an internal useful signal 303, a first internal interference signal 304, a second internal interference signal 305, and an external interference signal 306. The external useful signal 302 and the external interference signal 306 together constitute the radar sensor's detection signal. The propagation of the external interference signal 306 affects the radar sensor's edge definition.

[0054] In comparison, Figure 6This is a cross-sectional view of a circuit layout for improving edge clarity using the electromagnetic element 100 in an embodiment according to the present invention; it can be seen that placing the electromagnetic element 100 on the left side of the main antenna 200 results in additional attenuation of the first internal interference signal 304, thereby attenuating the external interference signal 306, and improving the edge clarity of the radar sensor.

[0055] Example 4: Figure 7 The effect of the electromagnetic element 100 on the radar antenna horizontal pattern is shown in Figure 501. The radar external propagation signal is ultimately reflected in the radar amplitude / phase pattern. Curve 501 is the horizontal amplitude pattern of the antenna of a certain transmitting channel of the radar sensor after the electromagnetic element 100 is applied to improve the edge clarity of the radar sensor. Curve 502 is the horizontal amplitude pattern of the antenna of a certain transmitting channel of the radar sensor with a conventional arrangement. In particular, when comparing the effect at an edge angle of -70° to -60°, curve 502 has a 3dB pit 504, which causes the direction Figure 3 In contrast, curve 501 shows a smoother directivity pattern curve 503, which results in a narrower beamwidth and a worsening of the amplitude consistency between channels. Furthermore, a wider beamwidth is achieved, which is desirable for improving edge definition in radar sensors.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An electromagnetic component for improving edge definition of a radar sensor, comprising a PCB board, characterized in that: An electromagnetic element (100) is provided on the PCB board, a main antenna (200) is provided on the right side of the electromagnetic element (100), an upper end of the main antenna (200) is connected to a microwave transmission line (201), and a left side of the microwave transmission line (201) is connected to a radar main chip (202); The electromagnetic element (100) is connected to the parasitic antenna (101); The electromagnetic element (100) includes a second microstrip transmission line (105), a slotted gap (106), a metal patch (107) and a grounding via (108); The upper end of the second microstrip transmission line (105) is connected to the parasitic antenna (101), and the lower end of the second microstrip transmission line (105) is connected to the middle of the metal patch (107); The slotted gaps (106) are provided with two and both are opened at the upper end of the metal patch (107), and the two slotted gaps (106) are symmetrically arranged on the left and right sides of the second microstrip transmission line (105); A plurality of grounding vias (108) are provided at equal intervals and are all opened at the lower edge of the metal patch (107).

2. The electromagnetic element for improving edge definition of a radar sensor according to claim 1, characterized in that: The second microstrip transmission line (105), the slotted gap (106), the metal patch (107) and the grounding via (108) are arranged in a periodic and repeated manner in a lateral arrangement on the surface of the radar antenna board of the parasitic antenna (101), and the period is an integer multiple of 1 / 2 of the working wavelength.

3. The electromagnetic element for improving edge definition of a radar sensor according to claim 2, characterized in that: The spacing between the combination of the second microstrip transmission line (105), the slot (106), the metal patch (107), the ground via (108), the parasitic antenna (101) and the main antenna (200) in a horizontal arrangement is an integer multiple of 1 / 2 working wavelength.

4. The electromagnetic element for improving edge definition of a radar sensor according to claim 3, characterized in that: The metal patch (107) and the parasitic antenna (101) have different radiation polarization directions.

5. The electromagnetic element for improving edge definition of a radar sensor according to claim 4, characterized in that: The parasitic antenna (101) and the main antenna (200) have the same antenna polarization direction.

6. The electromagnetic element for improving edge definition of a radar sensor according to claim 5, characterized in that: The parasitic antenna (101) has the same structural dimensions as the main antenna (200).

7. The electromagnetic element for improving edge definition of a radar sensor according to claim 5, characterized in that: The parasitic antenna (101) and the main antenna (200) have different structural dimensions.

8. The electromagnetic element for improving edge definition of a radar sensor according to claim 7, characterized in that: The parasitic antenna (101) comprises a first microstrip transmission line (102) for connecting to other antenna units, a rectangular metal patch (103) with radiation capability, and a series branch (104) for impedance matching; the left side of the first microstrip transmission line (102) is connected to the rectangular metal patch (103) with radiation capability, the right side of the first microstrip transmission line (102) is connected to the series branch (104), and the rectangular metal patch (103) is located at the upper end of the series branch (104).

9. The electromagnetic element for improving edge definition of a radar sensor according to claim 8, characterized in that: The lower end of the first microstrip transmission line (102) is connected to the second microstrip transmission line (105).

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