Substrate integrated waveguide antenna and radar device

Abstract

The utility model provides a substrate integrated waveguide antenna and radar equipment, and belongs to the technical field of antennae, and the substrate integrated waveguide antenna comprises a substrate which is provided with a first surface and a second surface opposite to the first surface; the first metal layer covers the first surface of the substrate and comprises a plurality of slits for generating a radiation field and a microstrip feeder for providing a feed port, the slits are alternately distributed up and down in the X-axis direction, and the length-width ratio of every two adjacent slits is a fixed proportion; and the second metal layer covers the second surface of the substrate and is a grounding layer. The problem that a traditional substrate integrated waveguide antenna is narrow in bandwidth in a millimeter wave frequency band can be solved, and the bandwidth characteristic and the transmission performance are improved.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a substrate integrated waveguide antenna and a radar device. Background Art

[0002] SIW (Substrate Integrated Waveguide) technology is a new technology that uses printed circuit board technology on dielectric substrates to make microwave and millimeter waveguide structures. SIW technology can achieve performance similar to traditional metal waveguide cavity slot antennas, while having the advantages of low profile and light weight, and can be made using traditional circuit board technology.

[0003] In millimeter-wave radar systems, the bandwidth of traditional SIW slot antennas in the millimeter-wave frequency band is usually narrow (about 2% to 3%), but the bandwidth can be extended to 5% by adding additional matching circuits. However, if you want to obtain a wider bandwidth, simply adding matching circuits is far from enough. In addition, although microstrip matching branch technology can increase the bandwidth, its own radiation will have an adverse effect on the antenna's radiation pattern, which will lead to large fluctuations in the beam or asymmetric elevation patterns. Utility Model Content

[0004] The present application provides a substrate integrated waveguide antenna and a radar device to solve the problem of narrow bandwidth of traditional substrate integrated waveguide antennas in the millimeter wave frequency band.

[0005] In a first aspect, the present application provides a substrate integrated waveguide antenna, the substrate integrated waveguide antenna comprising:

[0006] A substrate having a first surface and a second surface opposite thereto;

[0007] A first metal layer, covering the first surface of the substrate, includes a plurality of slots for generating a radiation field and a microstrip feed line for providing a feeding port, wherein the slots are alternately distributed up and down along the X-axis direction, and the length-to-width ratio of two adjacent slots is a fixed ratio;

[0008] The second metal layer covers the second surface of the substrate and is a grounding layer.

[0009] In one embodiment of the present application, in the X-axis direction, the size of the latter gap is greater than the size of the former gap.

[0010] In one embodiment of the present application, in the X-axis direction, the center distance between two adjacent gaps and the distance from each gap to the X-axis gradually increase.

[0011] In an embodiment of the present application, the first metal layer is further provided with a plurality of through holes penetrating the substrate, and the plurality of through holes are arranged around the gap.

[0012] In one embodiment of the present application, the through hole is a metal through hole with a cylindrical structure.

[0013] In one embodiment of the present application, the diameters of each metal through hole are equal, and the ratio of the center distance between two adjacent metal through holes to their diameters is less than a preset value.

[0014] In one embodiment of the present application, the plurality of slits are located on both sides of the X-axis, and the long side of each slit is parallel to the X-axis.

[0015] In one embodiment of the present application, the plurality of slits are located on both sides of the X-axis, and the inclination directions of two adjacent slits are opposite.

[0016] In an embodiment of the present application, the length of each slot is half the wavelength of the antenna resonant length, and the center distance between two adjacent slots is equal to half the wavelength of the antenna resonant length.

[0017] In a second aspect, the present application further provides a radar device, comprising a substrate integrated waveguide antenna as described in any one of the first aspects.

[0018] The substrate-integrated waveguide antenna and radar device provided by the present application are characterized in that the substrate-integrated waveguide antenna is configured to be alternately distributed up and down along the X-axis direction, and the aspect ratio of two adjacent slots is a fixed ratio. This distribution form helps to increase the bandwidth characteristics of the antenna in the millimeter wave frequency band, and improves the working frequency band of the antenna by appropriately designing the parameters and structure of the slots. In addition, the substrate-integrated structure can provide a better electromagnetic coupling effect, and the use of a microstrip feeder for feeding helps to reduce the transmission loss of the antenna in the millimeter wave frequency band, thereby improving the bandwidth problem.

[0019] Therefore, the present application can solve the problem of narrow bandwidth of traditional substrate integrated waveguide antennas in the millimeter wave frequency band and improve bandwidth characteristics and transmission performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a schematic diagram of a substrate integrated waveguide antenna provided by the present application;

[0022] Figure 2 is a cross-sectional view of a stepped frequency waveform provided by the present application;

[0023] Figure 3 is a schematic diagram of the gap electric field distribution provided by the present application;

[0024] Figure 4 is a schematic diagram of antenna return loss provided in an embodiment of the present application;

[0025] Figure 5 is the antenna pattern provided in the embodiment of the present application;

[0026] Figure 6 It is a schematic diagram of a substrate integrated waveguide antenna provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0029] In order to solve the problem of narrow bandwidth of traditional substrate integrated waveguide antennas in the millimeter wave band, the present application provides a substrate integrated waveguide antenna and a radar device, wherein the substrate integrated waveguide antenna sets the slots to be alternately distributed up and down along the X-axis direction. This layout can increase the effective length of the antenna, improve the radiation efficiency, and expand the working frequency band in the millimeter wave band. The aspect ratio of two adjacent slots is a fixed ratio. By controlling the aspect ratio of the slots, better resonance characteristics can be achieved, which enables the antenna to have a wider operating frequency range in the millimeter wave band. And the first metal layer includes a plurality of slots for generating a radiation field and a microstrip feeder providing a feeding port, which helps to improve the bandwidth and working efficiency of the antenna, thereby improving the performance of the millimeter wave band. The second metal layer acts as a ground layer, which can help reduce radiation losses, while improving the antenna efficiency of the antenna, and further optimizing the performance of the millimeter wave band.

[0030] Therefore, this application aims to improve the bandwidth characteristics of the antenna by rationally arranging the gaps, controlling the gap parameters, optimizing the metal layer design, etc., based on the characteristics of the millimeter wave frequency band in design and structure, so as to solve the problem of narrow bandwidth in the traditional millimeter wave frequency band. For example, the substrate integrated waveguide antenna described in this application can achieve an 11% broadband millimeter wave antenna array. This means that the antenna array has a relatively wide operating frequency range in the millimeter wave frequency band, covering a large frequency range.

[0031] Combine the following Figure 1-Figure 6 The substrate integrated waveguide antenna and radar device of the present application are described.

[0032] Please refer to Figure 1 , Figure 2 , Figure 1 is a schematic diagram of a substrate integrated waveguide antenna provided in this application, Figure 2 A substrate integrated waveguide antenna includes a substrate 10, a first metal layer 20 and a second metal layer 30.

[0033] Exemplarily, the substrate 10 has a first surface 101 and a second surface 102 opposite thereto.

[0034] The function of the substrate 10 is to provide structural support for the entire antenna, so that the antenna can maintain a stable shape and size. In addition, the material of the substrate 10 generally has good insulation properties, which can effectively isolate different parts of the antenna, such as isolating the first metal layer 20 and the second metal layer 30, to prevent mutual interference and energy loss of electromagnetic waves. This insulation effect helps to improve the performance and working efficiency of the antenna. Therefore, the substrate 10 plays a vital role in the substrate integrated waveguide antenna, providing both physical support and electromagnetic isolation and insulation, ensuring the stability and performance of the antenna.

[0035] Exemplarily, the first metal layer 20 covers the first surface 101 of the substrate 10, and the first metal layer 20 includes a plurality of slots 201 for generating a radiation field and a microstrip feed line 202 for providing a feeding port, wherein the slots 201 are alternately distributed up and down along the X-axis direction, and the aspect ratio of two adjacent slots is a fixed ratio.

[0036] The first metal layer 20 generates a radiation field, provides a feeding port, and optimizes antenna performance. Specifically, through the designed slots 201 and microstrip feeder 202, the first metal layer 20 can generate a specific radiation field pattern, realize the radiation function of the antenna, and convert the radio frequency signal into an electromagnetic wave for transmission. The microstrip feeder 202 is used to connect the radio frequency signal source and input the radio frequency signal into the antenna element to drive the radiation of the antenna. This ensures the electromagnetic wave energy required for the normal operation of the antenna. By alternating the slots 201 up and down along the X-axis direction and controlling the length-to-width ratio of two adjacent slots, the resonant characteristics and radiation pattern of the antenna can be adjusted to achieve a wider frequency response and higher radiation efficiency. Therefore, the design of the first metal layer 20 plays a key role in the substrate integrated waveguide antenna, which not only realizes the radiation function and feeding requirements of the antenna, but also optimizes the performance and working efficiency of the antenna through reasonable structural design.

[0037] Specifically, the aspect ratio of two adjacent gaps is a fixed ratio τ or approximately a fixed ratio τ. The derivation process of τ is described below.

[0038] Please refer to Figure 3 , Figure 3 Schematic diagram of the slot electric field distribution provided by the present application. In an ideal slot antenna, no matter what excitation method is used, there is only tangential electric field strength inside the slot 201, and there is no normal electric field component along the slot. In other words, the direction of the electric field strength (i.e., the electric field direction) is always parallel to the short side of the slot and perpendicular to the long side of the slot. In addition, the electric field strength presents a vertically symmetrical standing wave distribution at the midpoint of the slot, that is, the distribution of the electric field forms a standing wave pattern along the slot direction inside the slot, showing a vertically symmetrical distribution feature.

[0039] As for the excitation method of the resonant slot array antenna. Specifically, in the waveguide structure of the slot array, transverse currents are applied at symmetrical positions on both sides of the wide wall center line, and these currents are allowed to flow in the opposite direction to produce opposite current distribution. g / 2(λ g is the operating wavelength in the waveguide, λ g / 2 represents the half distance of the working wavelength in the waveguide) has the characteristic of reverse field strength, which is used to excite the slot array. The longitudinal slots are arranged at intervals of λ g The distance of / 2 is alternately distributed on both sides of the wide wall center line to ensure that each slot is in the same phase of excitation, coordinate its radiation effect and achieve ideal antenna performance. Therefore, this excitation method can help optimize the working state of the resonant slot array antenna, so that each slot is kept in the same phase of excitation to achieve better antenna performance and radiation effect.

[0040] The working principle of the log-periodic array antenna. Specifically, when the operating frequency is f1 (λ1), only the first oscillator (i.e., the first slot) works, and its electrical size is L1 / λ1, and the other oscillators do not work. When the operating frequency increases to f2 (λ2), only the second oscillator works, and its electrical size is L2 / λ2, and the other oscillators do not work. When the operating frequency increases to f3 (λ3), only the third oscillator works, and its electrical size is L3 / λ3, and the other oscillators do not work. And so on. These frequencies can ensure that the following relationship holds:

[0041]

[0042] Then at these frequencies, the antenna will have unchanged electrical characteristics. That is, at these frequencies, the antenna's performance will remain stable and consistent. This is because the dimensions of each oscillator of the log-periodic oscillator antenna satisfy L n+1 / L n =τ, which requires that the wavelength ratio between different frequencies satisfies λ n+1 / λ n =τ, or the frequency ratio also satisfies f n+1 / f n =1 / τ. If the value of τ is very close to 1, the operating frequency of the antenna that can meet the above requirements can approach continuous change. If the geometric structure of the antenna is infinite, then the operating frequency band of the antenna can be infinitely wide. In other words, the demand for continuous frequency change can be met, and the frequency flexibility of the antenna can be enhanced. When the geometric structure of the antenna is infinite, according to the characteristics of the log-periodic oscillator antenna, the operating frequency band of the antenna will be infinitely wide, because the size ratio between adjacent oscillators is always consistent, allowing the frequency to change continuously.

[0043] Since the frequency at which the antenna electrical performance remains unchanged needs to satisfy f n+1 / f n =1 / τ, so taking its logarithm gives:

[0044] Ln(f n+1 )-ln(f n ) = ln(1 / τ);

[0045] This equation shows that the electrical performance of the antenna can only remain unchanged when the logarithm of the operating frequency is changed periodically. Therefore, when the antenna is transformed by a factor of τ while maintaining its original structure, the antenna has the same performance at frequencies f and τf. In other words, when the operating frequency of the antenna is changed by a factor of τ while maintaining the electrical dimensions of the antenna, the antenna can maintain the same electrical performance at these frequencies.

[0046] Therefore, when the aspect ratio of two adjacent slots is a fixed ratio τ, it means that in the log-periodic dipole antenna, the size ratio between the dipoles remains consistent. This is very important for maintaining the stability of the antenna's electrical performance at different operating frequencies. Specifically, if the aspect ratio of two adjacent slots is a fixed ratio τ, it means that when the frequency changes according to the ratio τ, the size of each dipole will also be adjusted according to the same ratio while keeping the overall structure unchanged. In this way, even if the frequency changes, the structure of the antenna remains consistent, so that the same electrical performance can be maintained at these frequencies.

[0047] Exemplarily, the second metal layer 30 covers the second surface 102 of the substrate 10 and is a ground layer.

[0048] The function of the second metal layer 30 is to form a ground reference plane below the substrate 10, which can effectively provide a ground reference, help reduce the electromagnetic coupling between the antenna and the ground, and improve the radiation efficiency and performance of the antenna. Through close contact with the ground, the second metal layer 30 can effectively reduce radiation loss, improve the radiation efficiency and signal transmission quality of the antenna. As a grounding layer, the second metal layer 30 can effectively shield external electromagnetic interference, improve the anti-interference ability of the antenna, and ensure the stability and reliability of the antenna. The presence of the second metal layer 30 helps to balance the electrical properties of the antenna and improve the antenna efficiency and working performance of the antenna. Therefore, the second metal layer 30 plays an important role in the substrate integrated waveguide antenna as a grounding layer, which can provide a ground reference plane, reduce radiation loss, prevent external interference, and balance the electrical properties of the antenna, thereby optimizing the performance of the antenna.

[0049] In some embodiments of the present application, in the X-axis direction, the size of the subsequent gap 201 is larger than the size of the previous gap 201 .

[0050] That is, the length L and width W of the slot 201 will gradually increase as the distance from the antenna feed port increases. This design can adjust the size of the slot 201 to achieve a better radiation effect according to the need for electromagnetic waves to propagate in the antenna. By gradually increasing the size of the slot 201, appropriate radiation and beam shape of electromagnetic waves can be achieved, thereby optimizing the performance of the antenna.

[0051] In some embodiments of the present application, in the X-axis direction, the center distance Dy between two adjacent slits 201 and the distance Dx from each slit to the X-axis gradually increase.

[0052] That is, in the X-axis direction, the center distance Dy between two adjacent slots and the distance Dx from each slot to the X-axis will gradually increase. This layout design helps to adjust the characteristics of electromagnetic wave radiation, change the radiation characteristics and beam shape of the antenna, thereby optimizing the performance of the antenna and meeting specific communication requirements.

[0053] In some embodiments of the present application, the first metal layer 20 is further provided with a plurality of through holes penetrating the substrate 10 , and the plurality of through holes are arranged around the gap 201 .

[0054] Specifically, the plurality of through holes may be metal through holes 203 of a cylindrical structure, and the metal through holes 203 are also called grounding holes.

[0055] The metal vias 203 can reduce the electromagnetic resonance of the antenna because the shape and distribution of the conductor can be changed through the vias, thereby affecting the resonance characteristics of the overall antenna structure. In addition, the metal vias 203 can also help reduce the interconnection interference between different conductive layers and improve the anti-interference ability of the antenna system. By adjusting the position and shape of the metal vias 203, the characteristic impedance, radiation pattern, etc. of the antenna can be adjusted to achieve better frequency response and antenna performance. At the same time, the metal vias 203 can help reduce some edge effects, reduce the loss caused by electromagnetic signal reflection, and improve the transmission quality of the signal.

[0056] Specifically, the diameters of each metal through hole 203 are equal, and the ratio of the center distance between two adjacent metal through holes 203 to their diameters is less than a preset value.

[0057] When the diameter of the metal through hole 203 and the center distance S between two adjacent metal through holes (i.e., the hole spacing) meet certain conditions, the electromagnetic energy leaked out between the metal through holes 203 is very weak and can be ignored. This means that in this design, the structure of the metal through hole 203 can effectively reduce electromagnetic leakage and ensure that the electromagnetic energy is transmitted inside the through hole.

[0058] Figure 1 The upper and lower rows of metallized holes shown can be equivalently regarded as two metal walls, which together with the upper and lower copper layers of the substrate 10 (the upper and lower copper layers can constitute the first metal layer 20 and the second metal layer 30) constitute a dielectric-filled metal waveguide structure. This waveguide structure can effectively guide and transmit electromagnetic waves. There is a circle of metal through holes 203 around the gap 201, which serves as the electrical wall of the waveguide, which can prevent energy leakage. These metal through holes 203 play a role similar to that of the waveguide wall, ensuring that the electromagnetic energy is effectively transmitted in the desired direction.

[0059] For example, the arrangement of the metal vias 203 satisfies the inequality S / D<2, where S represents the center distance between two adjacent metal vias and D represents the diameter of the metal vias. This condition helps to ensure the stability and efficiency of the waveguide structure.

[0060] Please refer to Figure 4 , Figure 4Schematic diagram of antenna return loss provided by the embodiment of the present application. When the center distance Dy of the short-circuit end slot of the present application is selected to be one quarter or three quarters of the waveguide wavelength, the return loss of the antenna at this time is obtained as follows: Figure 4 shown. Figure 4 It is shown that in this case, the working bandwidth of the antenna is about 8.4 GHz, which is much higher than the working bandwidth of the traditional substrate integrated waveguide (SIW) antenna. This means that the antenna can effectively transmit and receive electromagnetic signals in the range of about 8.4 GHz. Therefore, by selecting a suitable short-circuit end slot center distance, the performance of the antenna can be improved, its working bandwidth can be expanded, and it can work effectively in a wider frequency range.

[0061] Please refer to Figure 5 , Figure 5 The antenna pattern provided by the embodiment of the present application. By looking at the antenna pattern (or radiation pattern), the following features can be observed:

[0062] Gain greater than 0dB: Within ±90°, the antenna gain is greater than 0dB, which means that the antenna can provide forward radiation gain within this range, and has better signal radiation and reception effects.

[0063] 3dB beamwidth reaches 156°: The 3dB beamwidth of the antenna refers to the angle range in the horizontal direction where the maximum gain of the main lobe is reduced by 3dB. Here, it is described that the beamwidth can reach 156°. This means that the antenna can provide radiation and reception functions within a fairly wide angle range.

[0064] Therefore, within the designed 8.4GHz frequency band, the antenna has good omnidirectional radiation characteristics in the horizontal direction, and its radiation direction range and gain meet the requirements of the vehicle-mounted millimeter-wave radar for the scene field of view (FOV). This omnidirectional radiation and wide operating angle range make the antenna suitable for vehicle-mounted millimeter-wave radar applications that require wide scene coverage.

[0065] In some embodiments of the present application, Figure 1 As shown, a plurality of slits are located on both sides of the X-axis, and the long side of each slit is parallel to the X-axis.

[0066] The arrangement of the slots parallel to the x-axis can bring the following effects: First, it is convenient for manufacturing and adjustment. The arrangement of the slots parallel to the x-axis is relatively simple and intuitive, which is conducive to manufacturing and adjustment. This arrangement may make it easier to control the position, size and spacing of the slots, thereby achieving the design requirements. Second, it affects the radiation characteristics of the antenna. The direction and arrangement of the slots affect the radiation characteristics of the antenna. The arrangement of the slots parallel to the x-axis may give the antenna specific radiation directivity and frequency response characteristics. Third, it optimizes antenna performance. According to specific design requirements, the arrangement of the slots parallel to the x-axis may help optimize the antenna's gain, beam width, polarization characteristics and other performance indicators, making it more suitable for specific application scenarios. Therefore, the arrangement of the slots parallel to the x-axis can simplify the design, improve manufacturing efficiency, and achieve specific radiation and performance characteristics.

[0067] In some other embodiments of this application, please refer to Figure 6 , Figure 6 Schematic diagram of a substrate integrated waveguide antenna provided in an embodiment of the present application. A plurality of slots 201 may be located on both sides of the X-axis, and the inclination directions of two adjacent slots 201 are opposite.

[0068] Specifically, the tilt directions of adjacent tilted slots are opposite. This helps to improve the directivity and polarization characteristics of the antenna. This is because the opposite tilt directions of adjacent tilted slots can produce a phase difference, similar to the array elements in a phased array antenna. By properly designing the tilt direction of the slots, a specific radiation pattern can be formed to enhance the directivity of the antenna. The tilted slots also affect the polarization characteristics of the antenna. For a specific tilt direction and antenna structure, radiation in a specific polarization direction, such as horizontal polarization or vertical polarization, can be achieved.

[0069] Moreover, when the current directions on the waveguide wall surfaces on both sides of the slot are opposite, this helps to achieve the radiation and reception effects of the antenna. This is because the opposite current directions on the waveguide wall surfaces on both sides of the slot can produce a phase difference, causing the current to concentrate or cancel out near the slot. This phase difference helps to form the main lobe and side lobe of the antenna, and control the radiation direction and radiation power distribution. By controlling the distribution of current on the waveguide wall surface, the radiation power, radiation directivity and frequency response of the antenna can be adjusted to achieve the desired radiation and reception effects.

[0070] In addition, the slots 201 are arranged on both sides of the x-axis. Such an arrangement can affect the radiation pattern and radiation directivity of the antenna. This is because the slots are arranged on both sides of the x-axis, which will change the radiation pattern of the antenna. Generally, slots located at different positions will introduce phase shifts in different directions, causing the antenna to produce a specific radiation pattern in space. This arrangement may introduce changes in side lobes, main lobe peak gain, beam width, etc., thereby affecting the radiation characteristics of the antenna. Since the slots are arranged on both sides of the x-axis, the radiation capability of the antenna in different directions will be affected. Specifically, this arrangement may adjust the main lobe direction of the antenna and the horizontal and vertical strength of the side lobes. These changes will directly affect the radiation directivity of the antenna, that is, the direction in which energy is radiated or received in space.

[0071] and, Figure 6 The size and spacing of adjacent slots shown also follow a logarithmic periodic distribution. This distribution is used to optimize the frequency characteristics of the antenna and ensure stable radiation performance within a certain range. Among them, the logarithmic periodic distribution is a spacing distribution method that changes on a logarithmic scale and is used in antenna design to optimize frequency characteristics and radiation performance. Its characteristic is that the spacing between adjacent elements does not increase or decrease linearly, but changes according to the law of a logarithmic function.

[0072] For example, if you want to design the substrate integrated waveguide antenna described in this application, you need to maintain good radiation performance within the frequency range. You can choose to use a logarithmic periodic distribution to arrange the elements in the array. In this case, the spacing between adjacent antenna elements will gradually increase or decrease on a logarithmic scale. The substrate integrated waveguide antenna can be an antenna array designed in a millimeter wave frequency band (for example, 30 GHz to 300 GHz) so that it has good radiation performance throughout the frequency band. The logarithmic periodic distribution can be used to determine the position of each antenna element. At the low frequency end, the spacing between adjacent antenna elements is relatively small because the wavelength is longer, and at the high frequency end, the spacing between adjacent antenna elements will gradually increase because the wavelength is shorter.

[0073] This logarithmic periodic distribution ensures that the antenna array has stable radiation performance over the entire frequency range while maximizing the use of available space. The antenna array designed in this way can maintain good radiation characteristics over the frequency range and is suitable for a wide range of communication and radar application scenarios.

[0074] Exemplarily, the length L of each slot is half the wavelength of the antenna resonant length, and the center distance Dy between two adjacent slots is equal to half the wavelength of the antenna resonant length. Such a design can achieve specific radiation characteristics and gain.

[0075] That is to say, setting the length L of each slot to half the wavelength of the antenna resonant length and ensuring that the center distance Dy between two adjacent slots is also equal to half the wavelength of the resonant length is a design method for achieving specific radiation characteristics and gain. Specifically, such a design can achieve the following effects:

[0076] Resonance characteristics optimization: Setting the length of the slot to half the wavelength of the antenna resonant length and arranging adjacent slots at equal distances can effectively achieve the antenna's resonant characteristics. Such a design can ensure that the antenna produces a good resonance effect at a specific frequency and improve radiation efficiency.

[0077] Gain improvement: Through the reasonable arrangement of the resonant length, the radiation pattern of the antenna can be adjusted so that the antenna can achieve higher gain in a specific direction. In particular, the main lobe can be formed in certain directions to improve the radiation capability, thereby achieving the desired radiation characteristics and gain level.

[0078] Therefore, by designing the length L of the slot to be half the wavelength of the antenna resonant length and adjusting the distance Dy between the slots, the antenna's resonant characteristics and radiation pattern can be regulated to achieve specific radiation characteristics and gain levels. This method provides an effective means to optimize the performance of the antenna to better meet specific communication or radar application requirements.

[0079] In some embodiments of the present application, the present application further provides a radar device, wherein the radar device includes the substrate integrated waveguide antenna as described in any of the above embodiments.

[0080] Specifically, the substrate integrated waveguide antenna can be directly integrated on the substrate of the radar device, which can reduce the connection points and interfaces, thereby improving the reliability and anti-interference ability of the system. Through the substrate integrated waveguide antenna, the radar device can optimize and adjust the performance at the radar system level to meet specific frequency, gain, directivity and beam width requirements. In addition, the substrate integrated waveguide antenna can operate in different frequency bands as needed to adapt to different radar applications.

[0081] In summary, the present application provides a substrate integrated waveguide antenna and a radar device, which have the following advantages compared with the traditional substrate integrated waveguide antenna:

[0082] Broadband: It has a wider working bandwidth within the frequency range. The antenna structure and layout can be optimized to maintain stable performance within a wider frequency range.

[0083] In-band gain flatness: The gain of the antenna varies little within the operating frequency range. This can be achieved by optimizing the antenna structure and waveguide design, as well as controlling the radiation pattern, so that stable gain can be obtained over the entire frequency range.

[0084] Wide beam width: refers to the width of the antenna's main beam. This can be achieved by adjusting the spacing and layout of the elements in the antenna array to obtain a wider radiation coverage.

[0085] It should be noted that the realization of these advantages of the present application involves multi-faceted engineering design and optimization, including but not limited to: antenna structure design, waveguide layout and optimization, arrangement and size adjustment of elements in the antenna array, etc. By comprehensively considering these factors, the desired antenna performance can be achieved, making it suitable for a wide range of communication and radar application scenarios.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application 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 do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A substrate integrated waveguide antenna, characterized in that: The substrate integrated waveguide antenna comprises: A substrate having a first surface and a second surface opposite thereto; A first metal layer, covering the first surface of the substrate, includes a plurality of slots for generating a radiation field and a microstrip feed line for providing a feeding port, wherein the slots are alternately distributed up and down along the X-axis direction, and the length-to-width ratio of two adjacent slots is a fixed ratio; The second metal layer covers the second surface of the substrate and is a grounding layer.

2. The substrate integrated waveguide antenna according to claim 1, characterized in that: In the X-axis direction, the size of the latter gap is larger than the size of the former gap.

3. The substrate integrated waveguide antenna according to claim 1, characterized in that: In the X-axis direction, the center distance between two adjacent gaps and the distance from each gap to the X-axis gradually increase.

4. The substrate integrated waveguide antenna according to claim 1, characterized in that: The first metal layer is also provided with a plurality of through holes penetrating the substrate, and the plurality of through holes are arranged around the gap.

5. The substrate integrated waveguide antenna according to claim 4, characterized in that: The through hole is a metal through hole with a cylindrical structure.

6. The substrate integrated waveguide antenna according to claim 5, characterized in that: The diameters of each metal through hole are equal, and the ratio of the center distance between two adjacent metal through holes to their diameters is less than a preset value.

7. The substrate integrated waveguide antenna according to claim 1, characterized in that: The plurality of slits are located on both sides of the X-axis, and a long side of each slit is parallel to the X-axis.

8. The substrate integrated waveguide antenna according to claim 1, characterized in that: The plurality of slits are located on both sides of the X-axis, and the inclination directions of two adjacent slits are opposite.

9. The substrate integrated waveguide antenna according to claim 1, characterized in that: The length of each slot is half the wavelength of the antenna resonant length, and the center distance between two adjacent slots is equal to half the wavelength of the antenna resonant length.

10. A radar device, characterized in that: The radar device comprises the substrate integrated waveguide antenna according to any one of claims 1 to 9.

Images