Microstrip antenna and millimeter wave radar

Abstract

The embodiment of the invention provides a microstrip antenna and a millimeter wave radar. The microstrip antenna comprises a top substrate; one side, facing the top substrate, of the bottom substrate is provided with a 3dB bridge, and the 3dB bridge comprises a signal port and a feed port; the multiple antenna substrates are located between the top layer substrate and the bottom layer substrate, each antenna substrate is provided with a radiation patch, and at least part of the antenna substrates are provided with parasitic patches on the outer sides of the radiation patches; the grounding substrate is arranged between the bottom substrate and the antenna substrate; wherein the top substrate, the antenna substrate, the grounding substrate and the bottom substrate form a substrate microstrip antenna through a substrate processing technology, the bottom substrate and the grounding substrate are provided with signal via holes corresponding to the signal ports, and the signal ports of the 3dB bridge are electrically connected with the radiation patch through the signal via holes.

Description

Technical Field

[0001] The present application relates to the technical field of radar antennas, and in particular to a microstrip antenna and a millimeter wave radar. Background Art

[0002] As millimeter wave wireless communication systems develop towards a highly integrated direction, the demand for small, high-performance electronic devices has also been growing in recent years. Antenna packaging technology integrates the antenna with other electronic components of the system to achieve a compact and efficient system. This integration not only reduces the space occupied by the system itself, but more importantly, it can effectively reduce the manufacturing cost of the equipment.

[0003] At present, antenna packaging technology mainly adopts PCB process. The antenna is generally a multi-layer PCB, which is integrated with back-end chips and other devices by welding. However, the cost of PCB process technology is relatively high. Due to the use of welding integration, the overall thickness of the integrated antenna will reach at least 2-3 mm, and it is easy to cause mismatching and other disadvantages such as large insertion loss. Summary of the invention

[0004] In order to solve the existing technical problems, the present application provides a microstrip antenna and millimeter wave radar that can effectively expand the antenna bandwidth, reduce the antenna thickness, and realize dual circular polarization operation of the antenna.

[0005] In a first aspect, an embodiment of the present application provides a microstrip antenna, including:

[0006] a top substrate;

[0007] A bottom substrate, a side of which faces the top substrate is provided with a 3dB bridge, wherein the 3dB bridge comprises a signal port and a feeding port;

[0008] A plurality of antenna substrates, located between the top substrate and the bottom substrate, each of the antenna substrates being provided with a radiation patch, wherein at least some of the antenna substrates are provided with a parasitic patch on the outside of the radiation patch;

[0009] A ground substrate, disposed between the bottom substrate and the antenna substrate;

[0010] Among them, the top substrate, the antenna substrate, the ground substrate and the bottom substrate form a substrate microstrip antenna through a substrate processing process, and the bottom substrate and the ground substrate are provided with signal vias corresponding to the signal port, and the signal port of the 3dB bridge is electrically connected to the radiation patch through the signal vias.

[0011] In a second aspect, an embodiment of the present application provides a millimeter wave radar, including an antenna array, a millimeter wave radar processor, and a memory;

[0012] Among them, the transmitting antenna and / or receiving antenna in the antenna array is the microstrip antenna described in any embodiment of the present application.

[0013] The microstrip antenna provided in the above embodiment adopts a top substrate, an antenna substrate, a ground substrate and a bottom substrate to form a substrate microstrip antenna through a substrate processing technology, wherein the antenna substrate includes multiple, each of which is provided with a radiation patch, and some antenna substrates are provided with a parasitic patch on the outside of the radiation patch. The combination of multiple radiation patches can form an array, thereby increasing the antenna gain, and a wider coverage range can be achieved, and the parasitic patch can be used to effectively expand the antenna working bandwidth; a 3dB bridge is set on the bottom substrate, and the signal port of the 3dB bridge is electrically connected to the radiation patch on the antenna substrate through a signal via, so as to realize dual circular polarization operation; and a substrate microstrip antenna with a multi-layer substrate formed by multiple substrates using a substrate processing technology can effectively reduce the thickness of the antenna.

[0014] The millimeter wave radar provided in the above embodiment belongs to the same concept as the corresponding microstrip antenna embodiment, and thus has the same technical effect as the corresponding microstrip antenna embodiment, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 FIG. 4 is a schematic diagram of an exploded view of a microstrip antenna in an embodiment.

[0016] Figure 2 FIG. 1 is a top view of a top substrate in one embodiment.

[0017] Figure 3 FIG. 4 is a top view of the first antenna substrate or the second antenna substrate in one embodiment.

[0018] Figure 4 FIG. 4 is a top view of a third antenna substrate in an embodiment.

[0019] Figure 5 A top view of a bottom substrate in one embodiment.

[0020] Figure 6 FIG. 4 is a schematic diagram of the structure of a millimeter wave radar in one embodiment.

[0021] Component Symbols:

[0022] Top substrate 11, shielding hole 110, first antenna substrate 12, second antenna substrate 13, third antenna substrate 14, ground substrate 15, signal via 150, bottom substrate 16, 3dB bridge 161, signal port 163, feeding port 165, antenna substrate 18, radiation patch 181, parasitic patch 182. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0025] In the following description, the expression "some embodiments" is involved, which describes a subset of all possible embodiments. It should be noted that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.

[0026] It should also be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "inside", "outside", "left", "right" and similar expressions used herein are only for the purpose of explanation in conjunction with the embodiments of the accompanying drawings and do not represent the only implementation method.

[0027] Please refer to Figure 1 and Figure 2 An embodiment of the present application provides a microstrip antenna, comprising: a top substrate 11; a bottom substrate 16, a 3dB bridge 161 is provided on the side facing the top substrate 11, and the 3dB bridge 161 includes a signal port 163 and a feeding port 165; a plurality of antenna substrates 18, located between the top substrate 11 and the bottom substrate 16, each antenna substrate is provided with a radiation patch 181, wherein at least part of the antenna substrates 18 are provided with a parasitic patch 182 on the outside of the radiation patch 181; a ground substrate 15, located between the bottom substrate 16 and the antenna substrate 18; wherein the top substrate 11, the antenna substrate 18, the ground substrate 15 and the bottom substrate 16 are formed into a substrate microstrip antenna through a substrate processing process, and a signal via 150 corresponding to the signal port 163 is provided on the bottom substrate 16 and the ground substrate 15, and the signal port 163 of the 3dB bridge 161 is electrically connected to the radiation patch 181 through the signal via 150.

[0028] The substrate refers to the dielectric substrate in the microstrip antenna, which has a thickness much smaller than the working wavelength and is usually made of a low-loss dielectric. A thin metal layer is applied to the surface of the substrate, which can be used to produce a metal patch with a specific target shape as a radiator through substrate processing methods such as photolithography and corrosion. In this embodiment, the number of antenna substrates 18 includes at least 3, and the metal patch of a specific shape on the antenna substrate 18 as a radiator is called a radiating patch 181. The combination of multiple radiating patches 181 on multiple antenna substrates 18 can form an antenna array.

[0029] The parasitic patch 182 refers to a parasitic element on the additional antenna substrate 18. In this embodiment, the parasitic patch 182 is arranged outside the radiation patch 181 on a portion of the antenna substrate 18, and an additional resonant frequency point can be introduced into the antenna structure to achieve the multi-frequency characteristics of the antenna; and the parasitic patch 182 can widen the frequency bandwidth of the antenna by coupling adjacent working frequency bands.

[0030] The 3dB bridge 161, also known as a co-frequency combiner, is used to divide the input signal into two output signals of equal amplitude and 90° phase difference, and the amplitude of each output signal is half of the input signal (i.e. -3dB). The 3dB bridge 161 is set on the bottom substrate 16, and the signal port 163 of the 3dB bridge 161 is electrically connected to the radiation patch 181 on the antenna substrate 18 through the signal via 150 on the bottom substrate 16 and the ground substrate 15, and is fed through the 3dB bridge 161, so that dual circular polarization can be achieved, and the antenna can achieve a wide-band standing wave ratio characteristic, thereby improving the stability of the antenna performance.

[0031] The substrate processing technology mainly includes the main process steps of providing a substrate, forming a radiator of a desired shape and size on the substrate, and connecting the multi-layer substrates between layers by bonding, pressing, etc. Among them, the substrate can be a dielectric substrate with a metal layer on the surface. The radiator of the desired shape and size is formed on the substrate by using a photolithography process, through the steps of coating photoresist, exposure, development, etc., to produce a metal thin layer with a specific shape on the front metal layer of the substrate. The interlayer connection of the multi-layer substrate can be achieved by alternately stacking multiple dielectric layers and metal layers, and connecting the layers by conductive glue or welding.

[0032] The microstrip antenna provided in the above embodiment adopts a top substrate 11, an antenna substrate 18, a ground substrate 15 and a bottom substrate 16 to form a substrate microstrip antenna through a substrate processing technology, wherein the antenna substrate 18 includes multiple, each of which is provided with a radiation patch 181, and a parasitic patch 182 is provided on the outside of the radiation patch 181 on some antenna substrates 18. The combination of multiple radiation patches 181 can form an array, thereby increasing the antenna gain and achieving a wider coverage range, and the parasitic patch 182 can effectively expand the antenna working bandwidth; a 3dB bridge 161 is provided on the bottom substrate 16, and the signal port 163 of the 3dB bridge 161 is electrically connected to the radiation patch 181 on the antenna substrate 18 through a signal via 150, so as to realize dual circular polarization operation; and a substrate microstrip antenna that uses multiple substrates to be superimposed and interlayered to form a multi-layer substrate through a substrate processing technology can effectively reduce the thickness of the antenna.

[0033] In the above embodiment, the microstrip antenna is formed into a multi-layer substrate by using a multi-layer antenna substrate 18 and a top substrate 11 and a bottom substrate 16 through a substrate processing process. The antenna substrate 18 can achieve wide bandwidth scanning performance of the antenna by loading a parasitic patch 182, and can achieve dual circular polarization operation by feeding with a 3dB bridge 161. In this way, the microstrip antenna is particularly suitable for use in a millimeter wave wireless communication system to form a broadband millimeter wave dual circular polarization substrate microstrip antenna.

[0034] In some embodiments, the antenna substrate 18 includes a first antenna substrate 12, a second antenna substrate 13, and a third antenna substrate 14 stacked up and down; radiation patches 181 are respectively provided on the first antenna substrate 12, the second antenna substrate 13, and the third antenna substrate 14; parasitic patches 182 are provided on the first antenna substrate 12 and the second antenna substrate 13 on the outer sides of the corresponding radiation patches 181. In this embodiment, there are three antenna substrates 18, and the three antenna substrates 18, the top substrate 11, the bottom substrate 16, and the ground substrate 15, a total of 6 substrates, are integrated together to form a substrate microstrip antenna of a multi-layer substrate. According to the stacking order of the multiple substrates, the second, third, and fourth layers of substrates are all antenna substrates 18, and parasitic patches 182 are provided on the outer sides of the radiation patches 181 on the second and third layers of antenna substrates 18, the fifth layer is the ground substrate 15, and the sixth layer is the bottom substrate 16. Among them, by setting up three antenna substrates 18 respectively including radiation patches 181, the combination of the three radiation patches 181 can form an antenna array, thereby increasing the antenna gain and achieving a wider coverage range, and the use of parasitic patches 182 on two of the antenna substrates 18 can effectively expand the antenna working bandwidth.

[0035] Optionally, the radiation patches 181 are rectangular in shape, and the parasitic patches 182 are arranged around the corresponding radiation patches 181. In this embodiment, the parasitic patches 182 are arranged on the four sides of the radiation patches 181, and the single side of each radiation patch 181 can represent the resonant frequency. For each antenna substrate 18, the four parasitic patches 182 arranged on the four single sides of the radiation patch 181 can introduce additional resonant frequency points by coupling the working frequency band of the corresponding side of the radiation patch 181 where they are located, so as to broaden the frequency bandwidth of the antenna. In some embodiments, on each antenna substrate 18, the size of the radiation patch 181 is 2.48mm×2.48mm, and the length of each parasitic patch 182 is 2.48mm, and it is aligned with the side of the corresponding radiation patch 181. In this way, the total substrate thickness of the substrate microstrip antenna formed can be less than 1mm, and the antenna resonance frequency and radiation characteristics of the broadband millimeter-wave radar can be achieved. In a specific example, the total substrate thickness of the substrate microstrip antenna is only 0.705mm.

[0036] In some embodiments, in the microstrip antenna, shielding holes 110 are respectively arranged around the edges of the top substrate 11 and the antenna substrate 18. Taking the number of antenna substrates 18 as an example, shielding holes 110 are respectively arranged around the edges of the 1st, 2nd, 3rd, and 4th layers of substrates. By setting the shielding holes 110 around the edges of the corresponding substrates, the shielding holes 110 on each substrate can form a wall in the electromagnetic wave radiation direction of the corresponding substrate, thereby reducing the surface waves generated on the substrate surface when the substrate microstrip wire is working, eliminating the energy loss caused by the surface waves and affecting the radiation efficiency. According to the direction of the current in the substrate microstrip antenna, shielding holes 110 are selected to be arranged around the edges of the 1st, 2nd, 3rd, and 4th layers of substrates that are relatively far from the feeding point of the bottom substrate 16, which can improve the directional characteristics of the antenna, make the main lobe of the antenna sharper, and reduce the side lobe, which helps to enhance the radiation intensity of the antenna in a specific direction, thereby improving the gain and directivity of the antenna; and can also reduce the mutual coupling between antennas to avoid signal interference.

[0037] Optionally, the shielding holes 110 on the top substrate 11 and the antenna substrate 18 are respectively concentric through holes, that is, in the microstrip antenna, the shielding holes 110 on multiple substrates can be designed with concentric circles. In the manufacturing process of the substrate microstrip antenna, multiple substrates can be integrated into a multi-layer substrate using a substrate processing process, and then holes are punched from the 1st layer to the 4th layer.

[0038] Optionally, in the top substrate 11 and the antenna substrate 18, the shielding holes 110 between the two adjacent layers of substrates are offset overlapping holes with different aperture sizes. In the two adjacent layers of substrates, the aperture sizes of the shielding holes 110 are different. In the manufacturing process of the substrate microstrip antenna, the corresponding shielding holes 110 can be pre-formed on the outer periphery of the substrate. When a plurality of substrates are integrated to form a substrate microstrip antenna of a multi-layer substrate using a substrate processing process, the shielding holes 110 on the two adjacent layers of substrates can be allowed to be offset to a certain extent on the basis of achieving superposition and connectivity. This is conducive to reducing the hole processing accuracy during the microstrip antenna forming process and avoiding the problem of large process errors affecting the performance of the formed substrate microstrip antenna.

[0039] In some embodiments, the shielding holes 110 between the top substrate 11 and the first antenna substrate 12 are respectively concentric and have different aperture sizes; the shielding holes 110 between the second antenna substrate 13 and the third antenna substrate 14 are respectively concentric and have different aperture sizes; the shielding holes 110 between the first antenna substrate 12 and the second antenna substrate 13 are staggered. In this embodiment, shielding holes 110 are respectively provided at the edges of the top substrate 11 and the three antenna substrates 18, and the top substrate 11 and the first antenna substrate 12 are grouped as one group, and the second antenna substrate 13 and the third antenna substrate 14 are grouped as one group. In the two layers of substrates included in each group, the shielding holes 110 of the upper and lower layers are designed with staggered overlapping holes, so that the apertures of the shielding holes 110 on each layer of substrate can be allowed to differ by a certain size, thereby reducing the requirements for the punching accuracy of the substrate and the alignment accuracy requirements when multiple substrates are integrated in the substrate processing process.

[0040] In some embodiments, in the microstrip antenna, the signal vias 150 on the bottom substrate 16 and the ground substrate 15 are also formed as staggered stacked holes with different aperture sizes. The signal via 150 passes from the bottom substrate 16 located below the ground substrate 15 to the antenna substrate 18 located above the ground substrate 15, and is used to electrically connect the signal port 163 of the 3dB bridge 161 on the bottom substrate 16 with the radiation patch 181. In this way, the signal via 150 needs to pass through the 6th and 5th layers of substrates and then contact the 4th layer of substrate. The aperture sizes of the signal vias 150 on the 6th and 5th layers of substrates are different, and a certain degree of misalignment can be allowed on the basis of achieving superposition and connectivity, thereby reducing the requirements for the punching accuracy of the substrate and reducing the alignment accuracy requirements when multiple substrates are integrated in the substrate processing process.

[0041] In some embodiments, the side of the grounding substrate 15 facing the antenna substrate 18 is a metal grounding layer; the side of the bottom substrate facing away from the antenna substrate 18 is a metal grounding layer. In the manufacturing process of the substrate microstrip antenna, the metal layer on the upper surface of the grounding substrate 15 facing the antenna substrate 18 can be retained as the grounding metal layer of the radiation patches 181 on the multiple antenna substrates 18, and the metal layer on the lower surface of the grounding substrate 15 facing the bottom substrate 16 can be removed by etching and other substrate processes to achieve the purpose of isolating the 3dB bridge 161 on the bottom substrate 16 and the radiation patch 181 in the antenna substrate. The 3dB bridge 161 on the bottom substrate is only connected to the radiation patch 181 on the antenna substrate 18 through the signal port 163 and the signal via 150 to achieve dual circular polarization operation. In the manufacturing process of the substrate microstrip antenna, the metal layer on the upper surface of the bottom substrate 16 facing the grounded substrate 15 forms a 3dB bridge 161 through substrate processes such as etching, while the metal layer on the lower surface of the bottom substrate 16 can retain another grounded metal layer, which can better isolate and absorb noise and interference from other layers to provide better electromagnetic compatibility, circuit protection, heat dissipation design and design flexibility, and help improve the stability and reliability of the circuit.

[0042] In summary, the microstrip antenna provided in the embodiments of the present application has at least the following characteristics:

[0043] First, a substrate microstrip antenna is formed by stacking multiple substrates and using substrate processing technology. At the same time, the substrate processing technology can be used to achieve integrated packaging with chips and other devices, which can reduce the total thickness of the antenna substrate and reduce manufacturing costs.

[0044] Second, the multiple substrates include three antenna substrates 18 with radiation patches 181, and parasitic patches 182 are set on the periphery of the radiation patches 181 on two antenna substrates 18. These parasitic patches 182 interact with the corresponding radiation patches 181 to form additional resonance points, which can expand the antenna bandwidth and achieve a total antenna substrate thickness of only 0.705 mm.

[0045] Third, among the multiple substrates, the bottom substrate 16 is fed by a 3dB bridge 161, so that the antenna can achieve dual circular polarization operation.

[0046] Fourth, in multiple substrates, the shielding holes 110 between adjacent layers are designed with staggered holes of different aperture sizes, which can realize the feasibility of multi-layer hole processing, reduce the punching accuracy requirements and reduce the manufacturing process requirements for the substrate microstrip antenna, which is conducive to reducing manufacturing costs.

[0047] See also Figure 6On the other hand, an embodiment of the present application further provides a millimeter wave radar, including an antenna array 21, a millimeter wave radar processor 22 and a memory 23; wherein the transmitting antenna and / or the receiving antenna in the antenna array 21 is a microstrip antenna of any embodiment of the present application.

[0048] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0049] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A microstrip antenna, characterized in that: include: a top substrate; A bottom substrate, a side of which faces the top substrate is provided with a 3dB bridge, wherein the 3dB bridge comprises a signal port and a feeding port; A plurality of antenna substrates, located between the top substrate and the bottom substrate, each of the antenna substrates being provided with a radiation patch, wherein at least some of the antenna substrates are provided with a parasitic patch on the outside of the radiation patch; A ground substrate, disposed between the bottom substrate and the antenna substrate; Among them, the top substrate, the antenna substrate, the ground substrate and the bottom substrate form a substrate microstrip antenna through a substrate processing process, and the bottom substrate and the ground substrate are provided with signal vias corresponding to the signal port, and the signal port of the 3dB bridge is electrically connected to the radiation patch through the signal vias.

2. The microstrip antenna according to claim 1, characterized in that: The antenna substrate comprises a first antenna substrate, a second antenna substrate and a third antenna substrate which are stacked up and down; The radiation patches are respectively arranged on the first antenna substrate, the second antenna substrate and the third antenna substrate; and parasitic patches are arranged on the first antenna substrate and the second antenna substrate at the outer sides corresponding to the radiation patches.

3. The microstrip antenna according to claim 2, characterized in that: The radiation patches are respectively rectangular; The parasitic patch is arranged around the corresponding radiation patch.

4. The microstrip antenna according to claim 3, characterized in that: The size of the radiation patch is 2.48 mm×2.48 mm, and the length of each parasitic patch is 2.48 mm and is aligned with the side of the corresponding radiation patch.

5. The microstrip antenna according to claim 2, characterized in that: Shielding holes are arranged around the edges of the top substrate and the antenna substrate.

6. The microstrip antenna according to claim 5, characterized in that: The shielding holes on the top substrate and the antenna substrate are respectively concentric through holes; or, In the top substrate and the antenna substrate, the shielding holes between two adjacent substrates are staggered overlapping holes with different aperture sizes.

7. The microstrip antenna according to claim 5, characterized in that: The shielding holes between the top substrate and the first antenna substrate are respectively concentric and have different aperture sizes; The shielding holes between the second antenna substrate and the third antenna substrate are respectively concentric and have different aperture sizes; The shielding holes between the first antenna substrate and the second antenna substrate are staggered with each other.

8. The microstrip antenna according to claim 1, characterized in that: The signal vias on the bottom substrate and the ground substrate are staggered and stacked vias with different aperture sizes.

9. The microstrip antenna according to claim 1, characterized in that: A side of the ground substrate facing the antenna substrate is a metal ground layer; The side of the bottom substrate facing away from the antenna substrate is a metal grounding layer.

10. A millimeter wave radar, characterized in that: Includes antenna array, millimeter wave radar processor and memory; Wherein, the transmitting antenna and / or receiving antenna in the antenna array is the microstrip antenna according to any one of claims 1 to 9.

Images