Waveguide antenna and vehicle radar system

Abstract

The utility model discloses a waveguide antenna and a vehicle radar system, and relates to the radar technology field, the waveguide antenna comprises a first waveguide part, a second waveguide part and a backstop structure, the first waveguide part and the second waveguide part are enclosed to form a waveguide cavity, the backstop structure is arranged on the annular side of the waveguide cavity, and the backstop structure is arranged on the annular side of the waveguide cavity. The stopping structure comprises an inserting part arranged on one of the first waveguide part and the second waveguide part and a matching part arranged on the other one of the first waveguide part and the second waveguide part, and the inserting part is inserted into the matching part; in the technical scheme provided by the utility model, the leakage path of the electromagnetic wave is bent from the original straight line to the current straight line, and the bending position improves the stopping effect on the electromagnetic wave through the cooperation between the structures, and further prolongs the leakage path of the electromagnetic wave. Besides, the backstop structure also provides a firm mechanical connection, the overall stability of the structure is enhanced, and the performance of the waveguide antenna can be maintained under various environmental conditions.

Description

TECHNICAL FIELD

[0001] The utility model relates to radar technical field, especially waveguide antenna and vehicle radar system. BACKGROUND

[0002] Waveguide antenna is a kind of antenna that uses waveguide structure to transmit and radiate electromagnetic waves, it guides microwave signal to specific direction through metal waveguide cavity, realizes efficient energy transmission and radiation, has low loss, high gain and good directivity, and is widely used in radar, communication and remote sensing etc. Especially in vehicle-mounted millimeter wave radar system, waveguide antenna with its excellent performance and compact structure provides accurate environment perception ability for vehicle, is the key component of realizing advanced driver assistance system (ADAS) and automatic driving technology, they are responsible for transmitting and receiving millimeter wave signal, help radar system to quickly and accurately obtain the physical environment information around vehicle body.

[0003] Compared with traditional microstrip antenna, high-efficiency, large-bandwidth waveguide antenna begins to receive more and more attention and use. The use of waveguide antenna can significantly improve the performance of millimeter wave radar, waveguide antenna can confine electromagnetic wave in hollow metal, greatly reduce energy loss, have low insertion loss, enhanced shielding and high power handling capability. These characteristics make waveguide antenna more easily realize large-bandwidth working mode, obtain higher resolution, and then play a greater role in automobile collision avoidance, pedestrian detection and traffic monitoring etc. It is an indispensable component in modern vehicle radar system.

[0004] However, due to the use of plastic metallization process in waveguide antenna production, due to the particularity of injection molding, waveguide antenna basically needs to be spliced by two to four layers of plastic metallization layer, but because good electrical contact is needed between adjacent waveguide layers, this waveguide structure is easily affected by manufacturing and assembly tolerance, especially for automobile millimeter wave waveguide antenna array antenna.

[0005] In related technology, waveguide antenna has higher requirements for reliability and consistency of processing technology, when manufacturing tolerance is larger, it cannot maintain high-efficiency radiation of waveguide antenna, and there is the possibility of interlayer electromagnetic wave leakage affecting the normal function of waveguide antenna. UTILITY MODEL CONTENTS

[0006] The main purpose of the utility model is to provide a kind of waveguide antenna and vehicle radar system, to solve the problem that when manufacturing tolerance is larger, it cannot maintain high-efficiency radiation of waveguide antenna, and there is the possibility of interlayer electromagnetic wave leakage affecting the normal function of waveguide antenna.

[0007] In order to achieve the above object, the utility model provides a waveguide antenna, including first waveguide part, second waveguide part and stop structure, the first waveguide part with the second waveguide part enclose and form the waveguide cavity, the stop structure is located the ring side of waveguide cavity,

[0008] The stop structure includes a plug-in part and a matching part, the plug-in part is inserted into the matching part.

[0009] In an embodiment, the plug-in part is a plug-in convex, the matching part is a plug-in slot, and the plug-in convex is provided with an abutting surface on one side facing the plug-in slot, and the abutting surface abuts with the inner bottom wall of the plug-in slot.

[0010] In an embodiment, the first waveguide part and the second waveguide part are respectively provided with a signal input port and a radiation output port, the signal input port is communicated with the waveguide cavity and a radio frequency unit, and the radiation output port is communicated with the waveguide cavity and the outside.

[0011] In an embodiment, the second waveguide part is provided with a plurality of radiation output ports, and the radiation output ports are in the shape of a rectangle, a circle or an ellipse.

[0012] In an embodiment, the two side walls of the plug-in convex respectively form a first guide inclined surface, the two inner side walls of the plug-in slot respectively form a second guide inclined surface, and each first guide inclined surface abuts with a second guide inclined surface.

[0013] In an embodiment, the first waveguide part is provided with two annular plug-in convexes on one side facing the second waveguide part, and the two annular plug-in convexes are arranged at intervals, and one of the annular plug-in convexes is located in the waveguide cavity.

[0014] The second waveguide part is formed with an annular slot on one side facing the first waveguide part, and the other annular plug-in convex is inserted into the annular slot.

[0015] In an embodiment, the two annular plug-in convexes and the first waveguide part are in an integral molding structure.

[0016] In an embodiment, the materials of the first waveguide part and the second waveguide part are metal materials.

[0017] The surfaces of the first waveguide part and the second waveguide part are respectively provided with a metal plating layer.

[0018] In an embodiment, the waveguide antenna further includes a circuit board, and the circuit board is coupled with the second waveguide part.

[0019] The utility model also provides a vehicle radar system, and the vehicle radar system includes the waveguide antenna.

[0020] The technical solution of the present utility model proposes a waveguide antenna and vehicle radar system, wherein the waveguide antenna includes a first waveguide portion, a second waveguide portion, and a stop structure. The first waveguide portion and the second waveguide portion enclose a waveguide cavity. The stop structure includes a plug-in portion and a matching portion. One of the plug-in portion and the matching portion is provided on the first waveguide portion, and the other is provided on the second waveguide portion. The plug-in portion and the matching portion are plugged together to form a stop structure. The stop structure is provided on the ring side of the waveguide cavity. Based on the precise matching of the mechanical structure and the continuity of the electromagnetic wave, the stop structure ensures the close connection between the various parts of the waveguide by physical means, so that the leakage path of the electromagnetic wave is bent from the original straight line to the current straight line. The matching between the structures at the bend improves the stopping effect on the electromagnetic wave and further extends the leakage path of the electromagnetic wave. In addition, the stop structure also provides a firm mechanical connection, enhances the overall stability of the structure, and helps to maintain the performance of the waveguide antenna under various environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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 use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0022] Figure 1 A schematic structural diagram of an embodiment of a waveguide antenna provided by the present utility model;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure of the medium waveguide antenna from another angle;

[0024] Figure 3 for Figure 1 Cross-sectional view of the medium waveguide antenna;

[0025] Figure 4 A structural comparison diagram of a traditional waveguide antenna and the waveguide antenna provided by the present utility model;

[0026] Figure 5 A comparison diagram of the electromagnetic wave movement directions of a traditional waveguide antenna and the waveguide antenna provided by the present invention;

[0027] Figure 6 A cross-sectional view of another embodiment of the waveguide antenna provided by the present invention;

[0028] Figure 7 A cross-sectional view of another embodiment of the waveguide antenna provided by the present invention;

[0029] Figure 8 To provide a traditional waveguide antenna in the up and down gap to lift the different height of the elevation pattern;

[0030] Figure 9 To provide a waveguide antenna in the up and down gap to lift the different height of the elevation pattern.

[0031] Brief Description of the Drawings:

[0032] 100, waveguide antenna; 1, first waveguide part; 11, signal input port; 2, second waveguide part; 21, radiation output port; 3, stop structure; 31, plug convex; 311, abutting surface; 312, first guide slope; 32, plug slot; 321, second guide slope; 33, ring-shaped plug convex; 34, ring-shaped slot; 4, waveguide cavity.

[0033] The implementation, functional features and advantages of the utility model will be further described with reference to the drawings in conjunction with embodiments. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0035] It should be noted that if the embodiments of the utility model involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0036] In addition, if the embodiments of the utility model involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0037] The utility model provides a waveguide antenna, aim at solving when the manufacturing tolerance is bigger, then exist unable to keep waveguide antenna high efficiency radiation, and exist interlayer electromagnetic wave leak's possibility influence waveguide antenna normal function's problem. Figures 1 to 9 The structure diagram of an embodiment provided by the waveguide antenna of the utility model.

[0038] Please refer to Figures 1 to 9 The utility model provides a waveguide antenna 100, including first waveguide part 1, second waveguide part 2 and stop structure 3, first waveguide part 1 and second waveguide part 2 enclose and form with waveguide cavity 4, stop structure 3 is located the ring side of waveguide cavity 4, stop structure 3 includes the plug-in part of being located one of first waveguide part 1 and second waveguide part 2 and the cooperation part of the other, and the plug-in part is inserted in the cooperation part.

[0039] In the above scheme, the plug-in part can be located in the first waveguide part 1, and the corresponding cooperation part is located in the second waveguide part 2. Alternatively, the plug-in part can be located in the second waveguide part 2, and the corresponding cooperation part is located in the first waveguide part 1. The utility model does not limit this. In an embodiment of the utility model, the plug-in part is located in the first waveguide part 1, and the cooperation part is located in the second waveguide part 2. The plug-in part cooperates to prevent horizontal displacement and prevent electromagnetic leakage caused by vertical displacement.

[0040] It should be noted that the shape of the waveguide cavity 4 of the waveguide antenna 100 can be a rectangular waveguide cavity 4, a circular waveguide cavity 4, or an irregular waveguide cavity 4. The utility model does not limit this. Different shapes can be adopted according to application requirements and design requirements, including common rectangular, circular, and cylindrical shapes. These different shapes are suitable for different working frequencies, electromagnetic wave modes, physical size limitations, and cost and manufacturing process requirements. Designers can flexibly select or customize the shape of the waveguide cavity 4 according to these factors to achieve optimal performance and efficiency. Therefore, the shape of the waveguide cavity 4 can be adjusted and optimized according to specific application scenarios.

[0041] The utility model discloses a kind of waveguide antenna 100 and vehicle radar system, wherein, waveguide antenna 100 includes first waveguide part 1, second waveguide part 2 and stop structure 3, first waveguide part 1 and second waveguide part 2 are enclosed to form waveguide cavity 4, stop structure 3 includes inserting part and cooperation part, one of inserting part and cooperation part is located in first waveguide part 1, another one is located in second waveguide part 2, inserting part and cooperation part are inserted to constitute stop structure 3, stop structure 3 is located in the ring side of waveguide cavity 4, based on the precision fit of mechanical structure and the continuity of electromagnetic wave. Stop structure 3 ensures the close connection between each part of waveguide by physical method, so that the leakage path of electromagnetic wave is from original straight line to now straight line forms bending, bending is improved by the cooperation between structures The stop effect of electromagnetic wave is also further prolonged the leakage path of electromagnetic wave. In addition, stop structure 3 also provides a firm mechanical connection, enhances the overall stability of structure, helps to maintain the performance of waveguide antenna 100 under various environmental conditions.

[0042] Further, waveguide antenna 100 is generally processed by SMT (Surface Mount Technology) high-temperature reflow soldering process, and the main reason for generating solder impurities in the processing of waveguide antenna 100 is that in the SMT process, the solder paste is melted and flows to form a solder joint, connecting electronic components and circuit boards. Since the solder paste is composed of solder alloy and flux, gas may be generated during the melting process, and these gases cannot completely escape before the solder joint solidifies, forming voids or pores in the solder joint. In addition, factors such as printing of solder paste, placement of components, and temperature control during reflow soldering can affect the formation and quality of solder joints, leading to the generation of solder impurities. The presence of solder impurities can affect the performance of waveguide antenna 100, including electromagnetic wave leakage and mechanical strength of solder joints. Stop structure 3 in the present solution can also block solder from entering the interior of waveguide cavity 4, and can effectively prevent particles such as dust and water mist from entering the interior of the cavity.

[0043] The utility model does not limit the specific structure of inserting part and cooperation part, in an embodiment of the utility model, the inserting part is a plug-in convex, and correspondingly, the cooperation part is a plug-in groove 32, specifically, please further refer to Figures 1 to 3The presence of the plug-in convex and the plug-in slot 32 forms a U-shaped stop structure 3 at the joint of the first waveguide part 1 and the second waveguide part 2, that is, the partial structure of the first waveguide part 1 is embedded in the second waveguide part 2, and the sealing of the two is better. The depth of the plug-in slot 32 and the height of the plug-in convex can be designed according to the inner size of the waveguide antenna 100. The inner size of the waveguide antenna 100, also known as the width and height size of the waveguide, is one of the key parameters in waveguide design, which directly affects the working frequency range and mode of the waveguide. According to the waveguide size and working frequency band summary table, different types of waveguides (such as WR-10, WR-12, etc.) have their specific inner sizes, which determine the working frequency range of the waveguide antenna 100. Therefore, when designing the plug-in slot 32, the inner size of the waveguide should be referred to to ensure that the depth of the plug-in slot 32 matches the size of the waveguide, so as to guarantee the performance of the waveguide antenna 100 and prevent wave leakage.

[0044] In the technical scheme of the utility model, the first waveguide part 1 and the second waveguide part 2 are respectively provided with a signal input port 11 and a radiation output port 21, and specifically, please further refer to Figure 1 and Figure 2 The signal input port 11 of the waveguide antenna 100 is used to introduce radio frequency signals from a signal source into the interior of the waveguide structure for transmission and processing, and the radiation output port 21 is responsible for effectively radiating electromagnetic wave energy inside the waveguide to free space, realizing the transmitting and receiving functions of the antenna. These two ports together ensure that the waveguide antenna 100 can efficiently transmit signals and perform wireless communication within a specific frequency range. It should be noted that the shape of the radiation output port 21 can be rectangular, circular or elliptical, etc., which is mainly to meet different application requirements and performance optimization. These different shapes can result in different polarization characteristics, such as linear polarization or circular polarization, while also affecting the radiation mode and directivity of the antenna. For example, a horn antenna can be designed with curved sides, which can minimize internal reflections and make the impedance close to constant within a very wide frequency range. A sector horn may be parallel to one side of a corner horn instead of a horn shape, producing a sector beam pattern. Different shapes also help to achieve specific beam pointing and coverage, as well as optimize the gain and radiation efficiency of the antenna.

[0045] In an embodiment of the utility model, in order to facilitate the plug-in fixing of the first waveguide part 1 and the second waveguide part 2, the two side walls of the plug-in convex are respectively provided with first guide inclined surfaces 312, and correspondingly, the two inner side walls of the plug-in slot 32 are respectively provided with second guide inclined surfaces 321, and specifically, please further refer to Figure 7The existence of the second guide inclined surface 321 makes the opening of the insertion slot 32 larger than the area of the abutting surface 311 of the insertion protrusion, so that the insertion protrusion can be easily inserted into the insertion slot 32, and the first guide inclined surface 312 and the second guide inclined surface 321 further prolong the length of the leaky wave path, so that the electromagnetic wave is more difficult to leak.

[0046] The scheme also includes a circuit board and a radio frequency unit, and the waveguide antenna 100, the radio frequency unit and the circuit board constitute the core part of the wireless communication system: the waveguide antenna 100 is responsible for radiating radio frequency signals in the form of electromagnetic waves to space or receiving signals from space, the radio frequency unit is responsible for signal generation, amplification, filtering and frequency conversion and other processing work, and the circuit board is a platform for connecting and supporting these components, providing a signal transmission path and mechanical fixation, ensuring that the waveguide antenna 100 and the radio frequency unit can work accurately together to achieve efficient wireless signal transmission and reception.

[0047] In an embodiment, one side of the first waveguide part 1 towards the second waveguide part 2 is provided with two annular insertion protrusions 33, and the two annular insertion protrusions 33 are arranged at intervals, one of which is located in the waveguide cavity 4, and specifically, please further refer to Figure 3 , and the other side of the second waveguide part 2 towards the first waveguide part 1 is formed with an annular slot 34, and the other annular insertion protrusion 33 is inserted into the annular slot 34. In this embodiment, the two annular insertion protrusions 33 have a double blocking effect on electromagnetic waves, thereby ensuring the leak-proof performance of the waveguide antenna 100.

[0048] The waveguide antenna 100 can be made of two different materials: plastic metalization after injection molding or direct use of metal materials. The waveguide antenna 100 made of plastic metalization after injection molding is first manufactured by injection molding process, and then a metal layer is formed on its surface by using electroplating and other metalization technologies. This method can realize the lightweight and cost-effectiveness of the antenna while maintaining the conductivity of the metal. The waveguide antenna 100 made of metal materials is usually made of aluminum alloy and other metal materials by machining. The antenna made by this method has high structural strength and conductivity, but it is heavy and expensive. The present application does not limit this.

[0049] The cross-sectional structure of the traditional waveguide and the mortise-tenon waveguide provided by the present application and the cross-sectional structure after lifting are shown in the drawings Figure 4 and Figure 5 , wherein the traditional waveguide Figure 4 is shown in the left drawing, which is spliced by two layers of metal plates or plastic metalization plates (metal plates are all metal, and plastic metalization plates are coated with metal on the outer layer, which have the same actual effect). The first waveguide part 1 and the second waveguide part 2 have a splicing part, and the splicing part is achieved by abutting two planes.Figure 4 The right drawing in the figure is a waveguide structure provided by the utility model, which is also spliced by two layers of metal plates or plastic metalized plates. The difference is that the first waveguide part 1 is provided with an insertion protrusion 31 facing the second waveguide part 2, and correspondingly, the second waveguide part 2 is provided with an insertion slot 32, and the two parts are combined to form a mortise and tenon structure. When the two parts are spliced in the actual processing and manufacturing process, there is a vertical error. When the ordinary rectangular waveguide is lifted, because the contact surface is parallel contact, only a little vertical gap exists, which breaks the electromagnetic balance of the internal cavity, so that the internal energy flows to the outside from the gap of the splicing part. When the mortise and tenon waveguide is lifted, because of the existence of the mortise and tenon structure, the internal electromagnetic wave which should be leaked is still well fixed in the cavity of the waveguide, preventing electromagnetic leakage.

[0050] Specifically, referring to the drawings in the specification Figure 8 , the case where the antenna is lifted by 0.03mm without the mortise and tenon structure is shown in the elevation direction diagram. It can be found that when the upper layer of the antenna is lifted by 0.03mm, the beam center of the antenna deflects (about 5 degrees), the side lobe is lifted (about 16dB), and the gain is attenuated (about 2.7dB). In this way, the error of the automobile millimeter wave radar system is greatly improved, and the lifting distance is only allowed to be within 0.01mm. However, in actual processing, it is difficult to control the tolerance within 0.01mm. Even if it can be done, it will inevitably bring great difficulty in processing and increase the manufacturing cost.

[0051] Therefore, the drawings in the specification Figure 9 show the case where the antenna is lifted by 0.25mm without the mortise and tenon structure, and the elevation direction diagram is shown. It can be found that when the upper layer of the antenna is lifted by 0.25mm, the elevation direction diagram of the antenna still maintains good radiation characteristics, the beam does not deflect, the gain decreases by 1.2dB, and the side lobe level does not appear to be lifted. When the antenna is lifted by 0.2mm, the gain decreases by 0.8dB (close to the gain attenuation of 0.01mm without the mortise and tenon structure). It can be found that the robustness to the vertical tolerance is increased by nearly twenty times after the mortise and tenon structure is added. This robustness brings great tolerance to the manufacturing of the automobile millimeter wave radar antenna, and well avoids the problems of antenna radiation characteristic attenuation and waveguide electromagnetic leakage caused by the deviation in actual processing.

[0052] The utility model also provides a vehicle radar system, the vehicle radar system includes waveguide antenna 100, the specific structure of waveguide antenna 100 refers to the above embodiment, because the vehicle radar system adopts all the technical schemes of the above all embodiments, so it has all the beneficial effects brought by the technical schemes of the above embodiments at least, and here will not be repeated.

[0053] The above merely illustrates the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation or direct / indirect application in other related technical fields within the technical concept of the present application and the content of the present application are included in the patent protection scope of the present application.

Claims

1. A waveguide antenna, characterized in that: The waveguide comprises a first waveguide portion, a second waveguide portion and a stop structure, wherein the first waveguide portion and the second waveguide portion enclose a waveguide cavity, and the stop structure is provided on a ring side of the waveguide cavity; The stopping structure includes an inserting portion provided on one of the first waveguide portion and the second waveguide portion and a matching portion on the other one thereof, wherein the inserting portion is inserted into the matching portion.

2. The waveguide antenna according to claim 1, wherein The plug-in portion is a plug-in protrusion, the matching portion is a plug-in slot, and a contact surface is provided on a side of the plug-in protrusion facing the plug-in slot, and the contact surface contacts the inner bottom wall of the plug-in slot.

3. The waveguide antenna according to claim 2, wherein: The first waveguide portion and the second waveguide portion are respectively provided with a signal input port and a radiation output port, the signal input port is connected to the waveguide cavity and the radio frequency unit, and the radiation output port is connected to the waveguide cavity and the outside world.

4. The waveguide antenna according to claim 3, wherein The second waveguide portion is provided with a plurality of radiation output ports, and the radiation output ports are in a rectangular, circular or elliptical shape.

5. The waveguide antenna according to claim 2, wherein: The two side walls of the plugging protrusion respectively form first guiding inclined surfaces, and the two inner side walls of the plugging groove respectively form second guiding inclined surfaces, and each of the first guiding inclined surfaces is in contact with one of the second guiding inclined surfaces.

6. The waveguide antenna according to any one of claims 1 to 5, wherein: Two annular plug-in protrusions are provided on one side of the first waveguide portion facing the second waveguide portion, the two annular plug-in protrusions are arranged at intervals, and one of the annular plug-in protrusions is located in the waveguide cavity; An annular groove is formed on one side of the second waveguide portion facing the first waveguide portion, and the other annular plug-in protrusion is inserted into the annular groove.

7. The waveguide antenna according to claim 6, wherein: The two annular plug-in protrusions and the first waveguide portion are an integrally formed structure.

8. The waveguide antenna according to any one of claims 1 to 5, wherein: The first waveguide portion and the second waveguide portion are made of metal; or Surfaces of the first waveguide portion and the second waveguide portion are respectively provided with metal plating layers. 9 . The waveguide antenna according to claim 1 , further comprising a circuit board coupled to the second waveguide portion.

10. A vehicle radar system, characterized in that: Comprising the waveguide antenna according to any one of claims 1 to 9.

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