Millimeter-wave transmissive array antenna and millimeter-wave radar

Abstract

The present invention provides a millimeter wave transmission array antenna and a millimeter wave radar, the antenna comprises a transmission array and a feed antenna, the substrate surface of the feed antenna is parallel and coaxial with the transmission array; the transmission array comprises a plurality of first transmission units and a plurality of second transmission units arranged periodically in a preset sequence; wherein the first transmission unit and the second transmission unit both comprise a ground plate, the ground plate of the first transmission unit is provided with a "卐"-shaped slit with a variable length, the ground plate of the second transmission unit is provided with a "田"-shaped slit with a variable length, the first transmission unit and the second transmission unit adopt a slot coupling method to perform phase compensation on the electromagnetic wave of the feed antenna within a phase range of 0° to 360°, so as to radiate a plane electromagnetic wave. By setting corresponding slots on the ground plate of the first transmission unit and the ground plate of the second transmission unit to realize slot coupling, 360° phase compensation can be ensured without adding a dielectric substrate, thereby improving the radiation efficiency of the transmission array antenna.

Description

Technical Field

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

[0002] With the continuous progress of science and technology and the continuous development of today's society, high-gain antennas play a very important role in all walks of life. Parabolic antennas have a wide operating frequency band and a simple structure, and can generate high-gain electromagnetic waves, but they are bulky, do not have a planar structure, and require high processing accuracy at high frequencies. Microstrip array antennas can also generate high-gain electromagnetic waves, but the feeding network is complex and the antenna energy loss is large, which seriously affects the gain of electromagnetic waves and antenna efficiency. Planar transmission array antennas combine the advantages of microstrip array antennas and lens antennas, and have received widespread attention from scholars at home and abroad in recent years.

[0003] In order to achieve 360° phase compensation, traditional transmission array antennas generally use multi-layer dielectric plates to increase the phase shift, but this will make the cross-section of the transmission array larger, thereby increasing the transmission loss of the unit, reducing the radiation efficiency of the transmission array, and increasing the processing cost of the antenna. Summary of the invention

[0004] In view of this, the present invention provides a millimeter-wave transmission array antenna and a millimeter-wave radar, aiming to solve the problems of large transmission loss and low radiation efficiency of the transmission array antenna.

[0005] A first aspect of an embodiment of the present invention provides a millimeter wave transmission array antenna, comprising: a transmission array and a feed antenna, wherein a substrate surface of the feed antenna is parallel to and coaxial with the transmission array;

[0006] The transmission array includes a plurality of first transmission units and a plurality of second transmission units which are periodically arranged in a preset order; wherein the first transmission unit and the second transmission unit both include a grounding plate, a swastika-shaped gap with a variable length is opened on the grounding plate of the first transmission unit, and a tian-shaped gap with a variable length is opened on the grounding plate of the second transmission unit, and the first transmission unit and the second transmission unit use a gap coupling method to perform phase compensation on the electromagnetic waves of the feed antenna within a phase range of 0° to 360° to radiate a planar electromagnetic wave.

[0007] In a possible implementation, the first transmission unit further includes: an upper metal patch, a lower metal patch, and a dielectric substrate;

[0008] The dielectric substrate and ground plane of the first transmission unit are arranged between the upper metal patch and the lower metal patch; the electromagnetic path length of the electromagnetic wave of the feed antenna from the lower metal patch to the ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna from the ground plane to the upper metal patch.

[0009] In a possible implementation, the second transmission unit further includes: an upper metal patch, a lower metal patch, and a dielectric substrate;

[0010] The dielectric substrate and the ground plane of the second transmission unit are arranged between the upper metal patch and the lower metal patch; the electromagnetic path length of the electromagnetic wave of the feed antenna from the lower metal patch to the ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna from the ground plane to the upper metal patch.

[0011] In a possible implementation manner, the upper metal patch and the lower metal patch of the second transmission unit are both square in shape, and rectangular grooves of the same size are respectively provided at the same positions on four sides.

[0012] In a possible implementation, the first transmission unit is used to perform phase compensation on the electromagnetic waves of the feed antenna within a phase range of 0° to 315°;

[0013] The second transmission unit is used to perform phase compensation on the electromagnetic waves of the feed antenna within a phase range of 315° to 360°.

[0014] In a possible implementation, the coupling parameters of the first transmission unit are the sizes of the upper metal patch and the lower metal patch of the first transmission unit, and the size of the “卐”-shaped gap; the coupling parameters of the second transmission unit are the gap size of the “田”-shaped gap, the sizes of the upper metal patch and the lower metal patch of the second transmission unit, and the sizes of the rectangular groove of the upper metal patch and the rectangular groove of the lower metal patch of the second transmission unit;

[0015] The first transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna within 7 phase gradients obtained by dividing the phase range of 0° to 315° into 7 equal parts starting from 0°;

[0016] The second transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna within an eighth phase gradient formed by a phase range of 315° to 360°;

[0017] The coupling parameters of the first transmission unit corresponding to different phase gradients are different.

[0018] In a possible implementation, the positions of the first transmission unit and the second transmission unit in the transmission array are determined by the center frequency of the feed antenna; and the total number of the first transmission units and the second transmission units arranged on the transmission array is determined by a preset gain threshold of the millimeter wave transmission array antenna.

[0019] In a possible implementation manner, the positions of the first transmission unit and the second transmission unit in the transmission array are determined by the phase compensation calculation formula and the center frequency; the phase compensation calculation formula is:

[0020]

[0021] in, is the phase compensation required by the first transmission unit or the second transmission unit arranged in the i-th row and j-th column of the transmission array, k0=2π / λ, λ is the free space wavelength of the electromagnetic wave of the feed antenna, d ij is the distance from the first transmission unit or the second transmission unit set in the i-th row and j-th column of the transmission array to the center point of the feed antenna, and F is the distance from the center point of the transmission array to the center point of the feed antenna.

[0022] In a possible implementation, the distance from the center point of the transmission array to the center point of the feed antenna is determined by the size of the transmission array and the beam width of the directional pattern of the feed antenna.

[0023] A second aspect of an embodiment of the present invention provides a millimeter wave radar, characterized in that it includes at least one millimeter wave transmission array antenna as described in the first aspect above.

[0024] The millimeter wave transmission array antenna and millimeter wave radar provided by the embodiment of the present invention include a transmission array and a feed antenna, wherein the substrate surface of the feed antenna is parallel and coaxial with the transmission array; the transmission array includes a plurality of first transmission units and a plurality of second transmission units periodically arranged in a preset sequence; wherein the first transmission unit and the second transmission unit both include a ground plate, a "卐"-shaped slit with a variable length is opened on the ground plate of the first transmission unit, and a "田"-shaped slit with a variable length is opened on the ground plate of the second transmission unit, and the first transmission unit and the second transmission unit use a slot coupling method to perform phase compensation on the electromagnetic wave of the feed antenna within a phase range of 0° to 360° to radiate a plane electromagnetic wave. By setting corresponding slots on the ground plate of the first transmission unit and the ground plate of the second transmission unit to realize slot coupling, 360° phase compensation can be ensured without adding a dielectric substrate, thereby improving the radiation efficiency of the transmission array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 is a schematic structural diagram of a millimeter-wave transmissive array antenna provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic structural diagram of a first transmissive unit provided by an embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a second transmissive unit provided by an embodiment of the present invention;

[0029] Figure 4 is a schematic structural diagram of an upper metal patch or a lower metal patch of a first transmissive unit provided by an embodiment of the present invention;

[0030] Figure 5 is a schematic structural diagram of a ground plane of a first transmissive unit provided by an embodiment of the present invention;

[0031] Figure 6 is a schematic structural diagram of an upper metal patch or a lower metal patch of a second transmissive unit provided by an embodiment of the present invention;

[0032] Figure 7 is a schematic structural diagram of a ground plane of a second transmissive unit provided by an embodiment of the present invention;

[0033] Figure 8 is a schematic distribution diagram of a first transmissive unit and a second transmissive unit on a transmissive array provided by an embodiment of the present invention;

[0034] Figure 9 is a phase distribution diagram of transmissive units on a transmissive array provided by an embodiment of the present invention;

[0035] Figure 10 is a phase gradient distribution diagram of transmissive units on a transmissive array provided by an embodiment of the present invention;

[0036] Figure 11 is a simulation result diagram of the radiation pattern of a feed antenna provided by an embodiment of the present invention;

[0037] Figure 12 is a simulation result diagram of the transmission loss and transmission phase of transmissive units corresponding to 8 phase gradients provided by an embodiment of the present invention;

[0038] Figure 13is a simulation result diagram of the directional pattern of the transmission array provided by the embodiment of the present invention at a frequency of 76 GHz;

[0039] Figure 14 is a simulation result diagram of the directional pattern of the transmission array provided by the embodiment of the present invention at a frequency of 77 GHz;

[0040] Figure 15 is a simulation result diagram of the directional pattern of the transmission array provided by the embodiment of the present invention at a frequency of 78 GHz;

[0041] Figure 16 is a simulation result diagram of the directional diagram of the transmission array provided by the implementation example of the present invention at a frequency of 79 GHz;

[0042] Figure 17 is a simulation result diagram of the directional pattern of the transmission array provided by the implementation example of the present invention at a frequency of 80 GHz;

[0043] Figure 18 is a simulation result diagram of the directional pattern of the transmission array provided by the implementation example of the present invention at a frequency of 81 GHz;

[0044] Figure 19 It is a schematic diagram of the structure of the millimeter wave provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0046] Figure 1 Schematic diagram of the structure of the millimeter wave transmission array antenna provided by the embodiment of the present invention. Figure 1 As shown, in this embodiment, the millimeter wave transmission array antenna includes: a transmission array 11 and a feed antenna 12, and the substrate surface of the feed antenna 12 is parallel to and coaxial with the transmission array 11;

[0047] The transmission array 11 includes a plurality of first transmission units and a plurality of second transmission units that are periodically arranged in a preset order; wherein the first transmission unit and the second transmission unit both include a grounding plate, a "卐"-shaped gap with a variable length is opened on the grounding plate of the first transmission unit, and a "田"-shaped gap with a variable length is opened on the grounding plate of the second transmission unit. The first transmission unit and the second transmission unit use a gap coupling method to perform phase compensation on the electromagnetic waves of the feed antenna 12 within a phase range of 0° to 360° to radiate planar electromagnetic waves.

[0048] In this embodiment, the feed antenna 12 operates in the millimeter wave band and is used to transmit electromagnetic waves to the transmissive array 11. The transmissive array 11 is a passive phase-shifting structure, which realizes the phase compensation of the incident electromagnetic waves by reasonably adjusting the relevant parameters of each transmissive unit, so as to form a specific phase distribution on the aperture surface of the transmissive array, and finally radiate a plane electromagnetic wave.

[0049] Traditional transmissive array antennas usually expand the phase shift range by increasing the thickness of the dielectric layer or the air layer. However, this will increase the profile of the transmissive array, thereby increasing the transmission loss of the unit, reducing the radiation efficiency of the transmissive array, and also increasing the processing cost of the antenna. In this embodiment, gap coupling is realized by setting corresponding gaps on the ground planes of the first transmissive unit and the second transmissive unit. Neither the dielectric substrate needs to be increased nor the air layer needs to be introduced, which can ensure 360° phase compensation, reduce the transmission loss of the transmissive antenna array, and improve the radiation efficiency.

[0050] In some embodiments, the first transmissive unit further includes: an upper metal patch, a lower metal patch, and a dielectric substrate;

[0051] The dielectric substrate and the ground plane of the first transmissive unit are arranged between its upper metal patch and lower metal patch; the electromagnetic path length of the electromagnetic wave of the feed antenna 12 from its lower metal patch to its ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna 12 from its ground plane to its upper metal patch.

[0052] In this embodiment, the dielectric substrate can have multiple layers, which are respectively located on both sides of the ground plane. To ensure that the electromagnetic paths on both sides of the ground plane are equal, if the dielectric constants of each layer of the dielectric substrate are the same, the thicknesses of the dielectric substrates on both sides of the ground plane should be equal. If there is adhesion between the layers of the dielectric substrate, the influence of the dielectric constant and the adhesion thickness of the adhesive on the electromagnetic path should also be considered.

[0053] Figure 2 It is a schematic structural diagram of the first transmissive unit provided by an embodiment of the present invention. As Figure 2 shown, in some embodiments, the dielectric substrate has a total of three layers. The arrangement order of the first transmissive unit from bottom to top is: lower metal patch 212, lower layer dielectric substrate 221, middle layer dielectric substrate 222, ground plane 23, upper layer dielectric substrate 223, upper metal patch 211.

[0054] In some embodiments, the second transmissive unit further includes: an upper metal patch, a lower metal patch, and a dielectric substrate;

[0055] The dielectric substrate and the ground plane of the second transmission unit are disposed between the upper metal patch and the lower metal patch thereof; the electromagnetic path length of the electromagnetic wave of the feed antenna 12 from its lower metal patch to its ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna 12 from its ground plane to its upper metal patch.

[0056] In this embodiment, the dielectric substrate may have multiple layers, which are respectively located on both sides of the ground plane. To ensure that the electromagnetic paths on both sides of the ground plane are equal, if the dielectric constants of the dielectric substrates of each layer are the same, the thicknesses of the dielectric substrates on both sides of the ground plane should be equal. If there is adhesion between the dielectric substrates of each layer, the influence of the dielectric constant and the adhesion thickness of the adhesive on the electromagnetic path should also be considered.

[0057] Figure 3 is a schematic structural diagram of the second transmission unit provided by an embodiment of the present invention. As Figure 3 shown, in some embodiments, the dielectric substrate has a total of three layers. The arrangement order of the second transmission unit from bottom to top is: lower metal patch 312, lower layer dielectric substrate 321, middle layer dielectric substrate 322, ground plane 33, upper layer dielectric substrate 323, upper metal patch 311.

[0058] In some embodiments, the shapes of the upper metal patch 311 and the lower metal patch 312 of the second transmission unit are both square, and rectangular grooves with the same size are respectively provided at the same positions on the four sides.

[0059] In this embodiment, by providing rectangular grooves on the four sides of the upper metal patch 311 and the lower metal patch 312, the phase shift range of the second transmission unit can be increased.

[0060] In some embodiments, the first transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within the phase range of 0° to 315°;

[0061] The second transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within the phase range of 315° to 360°.

[0062] Figure 4 is a schematic structural diagram of the upper metal patch or the lower metal patch of the first transmission unit provided by an embodiment of the present invention. Figure 5 is a schematic structural diagram of the ground plane of the first transmission unit provided by an embodiment of the present invention. Figure 6 is a schematic structural diagram of the upper metal patch or the lower metal patch of the second transmission unit provided by an embodiment of the present invention. Figure 7 is a schematic structural diagram of the ground plane of the second transmission unit provided by an embodiment of the present invention. As Figures 4 - 7As shown, in some embodiments, the coupling parameters of the first transmission unit are the sizes of the upper metal patch 211, the lower metal patch 212, and the size of the “卐”-shaped gap of the first transmission unit; the coupling parameters of the second transmission unit are the size of the “田”-shaped gap, the sizes of the upper metal patch 311 and the lower metal patch 312 of the second transmission unit, and the sizes of the rectangular groove of the upper metal patch 311 and the rectangular groove of the lower metal patch 312 of the second transmission unit;

[0063] The first transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within 7 phase gradients obtained by dividing the phase range of 0° to 315° into 7 equal parts starting from 0°;

[0064] The second transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within the eighth phase gradient formed by the phase range of 315° to 360°;

[0065] The coupling parameters of the first transmission unit corresponding to different phase gradients are different.

[0066] In this embodiment, the size of the upper metal patch 211 (or the lower metal patch 212) of the first transmission unit is specifically the side length a1 of the upper metal patch 211 (or the lower metal patch 212). The size of the "卐"-shaped gap is specifically Figure 5 L shown 11 , L 12 , W1. The size of the upper metal patch 311 (or the lower metal patch 312) of the second transmission unit is specifically Figure 6 The size of the rectangular groove of the upper metal patch 311 (or the lower metal patch 312) of the second transmission unit is specifically Figure 6 b, W as shown. The specific gap size of the "田"-shaped gap is Figure 7 L shown 21 , L 22 、W2.

[0067] In this embodiment, the coupling parameter of the first transmission unit or the second transmission unit is determined according to the gradient where it is located and the center frequency of the feed antenna.

[0068] According to different phase distribution modes, transmission array antennas can be divided into transmission arrays with continuous phase distribution and transmission arrays with discrete phase distribution. The millimeter wave transmission array antenna provided by the present invention belongs to the transmission array with discrete phase distribution, that is, a digital transmission array antenna.

[0069] Compared with the continuous phase distribution transmission array, the digital transmission array antenna has a simple design method, greatly reduces the cross-sectional height of the antenna, reduces dielectric loss, improves radiation efficiency, and saves antenna processing costs.

[0070] The digital transmissive array antenna designs the transmissive array antenna by discretizing the continuously varying compensation phase values. For example, a 1-bit transmissive array antenna includes two types of transmissive elements: "0" and "1"; a 2-bit transmissive array antenna includes four types of transmissive elements: "00", "01", "10", and "11"; a 3-bit transmissive array antenna includes eight types of transmissive elements: "000", "001", "010", "011", "100", "101", "110", and "111". Compared with traditional transmissive arrays, the digital transmissive array is easier to implement.

[0071] The transmissive array 11 in this embodiment uses a high-frequency 3-bit digital transmissive array antenna.

[0072] Figure 8 It is a schematic diagram of the distribution of the first transmissive element and the second transmissive element provided by the embodiment of the present invention on the transmissive array. As Figure 8 shown, the transmissive array is a square array composed of a number of first transmissive elements and a number of second transmissive elements, and the distribution of the transmissive elements on the array presents a centrosymmetric form. In some embodiments, the positions of the first transmissive element and the second transmissive element on the transmissive array 11 are determined by the center frequency of the feed antenna 12; the total number of the first transmissive elements and the second transmissive elements provided on the transmissive array 11 is determined by the preset gain threshold of the millimeter-wave transmissive array antenna.

[0073] In this embodiment, according to the array antenna theory, in order to reduce the side lobes, the sizes of the first transmissive element and the second transmissive element can be set to λ / 2, where λ is the free-space wavelength of the electromagnetic wave of the feed antenna 12.

[0074] In some embodiments, the positions of the first transmissive element and the second transmissive element on the transmissive array 11 are determined by the phase compensation calculation formula and the center frequency; the phase compensation calculation formula is:

[0075]

[0076] where is the phase compensation required for the first transmissive element or the second transmissive element provided in the i-th row and j-th column of the transmissive array 11, k0 = 2π / λ, λ is the free-space wavelength of the electromagnetic wave of the feed antenna 12, d ij is the distance from the first transmissive element or the second transmissive element provided in the i-th row and j-th column of the transmissive array 11 to the center point of the feed antenna 12, and F is the distance from the center point of the transmissive array 11 to the center point of the feed antenna 12.

[0077] In this embodiment, assuming the position of the transmissive element is (x i , y i), the feed is located at a position F directly below the center of the aperture of the transmissive array surface, and the position of the feed is (x f , y f ). The distances from the feed antenna to each transmissive element are as follows:

[0078]

[0079] In some embodiments, the distance from the center point of the transmissive array 11 to the center point of the feed antenna 12 is determined by the size of the transmissive array 11 and the beam width of the radiation pattern of the feed antenna 12.

[0080] The above millimeter-wave transmissive array antenna will be described below through an implementation example, but it is not limited thereto. In this implementation example, the millimeter-wave transmissive array antenna with a center frequency f = 79 GHz of the feed antenna 12 is simulated and calculated using the commercial simulation software HFSS_20.0 and CST Microwave Studio, and the phase distribution of the millimeter-wave transmissive array antenna is calculated using the simulation software Matlab2014.

[0081] The millimeter-wave transmissive array antenna provided in this implementation example operates in the range of 76 GHz to 81 GHz, can generate a high-gain pencil beam, and can be used in fields such as wireless communication.

[0082] In this implementation example, the gain requirement of the millimeter-wave transmissive array antenna is 30 dBi. The transmissive array is a 3-bit transmissive array antenna, with the number of elements on it being 50x50, and the element size being 70x70 mil 2 , and the size of the array aperture is 3500x3500 mil 2 . The gain of the radiation pattern of the feed antenna is 10 dB.

[0083] In this implementation example, both the first transmissive element and the second transmissive element have three dielectric substrates, and the arrangement order is as Figure 2 and Figure 3 shown. (Since the dielectric substrate arrangements of the first transmissive element and the second transmissive element shown in Figure 2 and Figure 3 are the same, the following description of each layer of dielectric substrate is a unified description of the first transmissive element and the second transmissive element) Each layer of dielectric substrate is a Rogers3003 dielectric substrate with a dielectric constant of 3.06. Among them, the thickness of the upper dielectric substrate 112 is 10 mil, the thickness of the middle dielectric substrate 114 is 4 mil, and the thickness of the lower dielectric substrate 115 is 5 mil. Adjacent layers of dielectric substrates need to be bonded with an adhesive layer, and the dielectric constant of the adhesive layer material is similar to that of Rogers3003.

[0084] In this embodiment, the thickness of the upper metal patch (or lower metal patch) of the first transmission unit and the second transmission unit is 0.7 mil. The thickness of the ground plane of the first transmission unit and the second transmission unit is 0.7 mil, and the machining accuracy of the gap is 0.1 mm.

[0085] When working in the millimeter wave band, the antenna size is generally small. For a transmissive array antenna, it is difficult to achieve a 360° phase shift range by using a continuous phase distribution method. Therefore, in this embodiment, a discrete phase distribution method is adopted to design the transmissive array. The specific method is to equally divide the 360° phase shift range into 8 gradients, each gradient being 45°. In the embodiment, 7 gradients from 0° to 315° respectively correspond to 7 types of first transmission units, and the 8th gradient from 315° to 360° corresponds to the second transmission unit. Among them, the a1 of the 7 types of first transmission units are 44.5 mil, 39.2 mil, 36.5 mil, 35 mil, 33.5 mil, 31 mil, and 24.5 mil in sequence. 11 They are 46 mil, 40 mil, 35 mil, 35 mil, 17 mil, 14 mil, and 17 mil respectively. The parameter 12 is 50.5 mil, 52 mil, 46 mil, 5 mil, 10 mil, 12 mil, and 12.5 mil in sequence. The W1 of the 7 types of first transmission units and the W2 of the second transmission unit corresponding to the 8th gradient are both 5 mil. The a2 of the second transmission unit corresponding to the 8th gradient = 45 mil, b = 10 mil, 21 = 40 mil, 22 = 30 mil, W = 12 mil.

[0086] Figure 9 is the phase distribution diagram of the transmission units on the transmissive array provided by the embodiment of the present invention. As Figure 9 shown, the horizontal axis is the x unit number, the vertical axis is the y unit number, and the right side of the figure is the correspondence between the phase and the gray level. Different gray levels are used to represent different phases to show the phase shift amount required at each position on the transmissive array. Figure 10 is the phase gradient distribution diagram of the transmission units on the transmissive array provided by the embodiment of the present invention. As Figure 10 shown, the horizontal axis is the x unit number, the vertical axis is the y unit number, and the right side of the figure is the correspondence between the phase gradient and the gray level. Different gray levels are used to represent different phase gradients to show the phase shift amount required at each position on the transmissive array.

[0087] In this embodiment, the first transmission unit and the second transmission unit can be arranged according to Figure 9 or Figure 10 the corresponding arrangement method.

[0088] Figure 11 This is the simulation result diagram of the radiation pattern of the feed antenna provided by the embodiment of the present invention. As Figure 11 shown, the horizontal axis is the angle of the radiated electromagnetic wave, and the vertical axis is the electromagnetic wave gain. In this embodiment, the gain of the feed antenna in the maximum radiation direction is 10 dBi, the 3 dB beam widths in the phi = 0° and phi = 90° planes are 57° and 60° respectively, and the 10 dB beam widths in the phi = 0° and phi = 90° planes are 114° and 116° respectively.

[0089] Figure 12 This is the simulation result diagram of the transmission loss and transmission phase of the transmission units corresponding to 8 phase gradients provided by the embodiment of the present invention. As Figure 12 shown, the left vertical axis is the transmission amplitude, the right vertical axis is the transmission phase, and the horizontal axis is the frequency. It can be seen from the figure that in the frequency range of 76 - 81 GHz, the transmission losses of the 8 types of transmission units corresponding to 8 phase gradients are all within 2 dB, the transmission phase curves are parallel to each other, and the transmission phase difference between adjacent units is about 45°. Therefore, the simulation results show that the designed transmission units have good transmission performance in the frequency range of 76 - 81 GHz.

[0090] Figure 13 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 76 GHz. Figure 14 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 77 GHz. Figure 15 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 78 GHz. Figure 16 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 79 GHz. Figure 17 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 80 GHz. Figure 18 This is the simulation result diagram of the radiation pattern of the transmission array provided by the embodiment of the present invention at a frequency of 81 GHz. As Figures 12 - 18 shown, the vertical axis is the gain of the antenna, and the horizontal axis is the azimuth angle of the radiated electromagnetic wave. It can be seen from the figure that in the range of 76 GHz - 81 GHz, the gain of this antenna is about 31 dBi, and the 3 dB beam width is 3°. The simulation results show that this antenna has high gain and good electromagnetic wave focusing performance.

[0091] The millimeter-wave transmission array antenna provided by the present invention is a digital transmission array antenna with a low profile, high gain, simple structure, and easy processing. Compared with the prior art, it has the following advantages:

[0092] (1) The transmission unit in the present invention adopts a slot coupling method, and the layers are tightly combined. Compared with the previous transmission unit structure, no air layer is introduced, and there is no need to add a dielectric substrate, which can make the profile of the transmission array antenna lower, achieving the requirements of compact and miniaturized antenna structure.

[0093] (2) In the present invention, the gaps on the grounding plates of the two transmission units are respectively "卐"-shaped and "田"-shaped. Compared with the "十"-shaped gap structure, the gap length variation range is larger and the transmission unit phase shift range is wider. At the same time, the upper metal patch and the lower metal patch of the second transmission unit are opened with four grooves of a certain length and width inward along the midpoints of the four sides, which also plays a role in increasing the phase shift range.

[0094] (3) The transmission array antenna in the present invention does not require a complex feeding network, has simple feeding, and has a planar structure, which is easy to implement and greatly reduces the processing cost.

[0095] Figure 19 Schematic diagram of the structure of the millimeter wave radar provided by the embodiment of the present invention. Figure 19 As shown, the millimeter wave radar 19 includes at least one millimeter wave transmission array antenna 1901 as shown in any of the above embodiments.

[0096] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0097] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0098] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0099] The unit described as a separation component may or may not be physically separated, and the component shown as a unit may or may not be a physical unit, that is, it may be located in one place or may be distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, each functional unit in various embodiments of the present invention may be integrated in a processing unit, may exist separately as individual physical units, or two or more units may be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0101] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0102] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A millimeter-wave transmissive array antenna, characterized in that, include: A transmission array and a feed antenna, wherein a substrate surface of the feed antenna is parallel to and coaxial with the transmission array; The transmission array includes a plurality of first transmission units and a plurality of second transmission units that are periodically arranged in a preset sequence; wherein the first transmission unit and the second transmission unit both include a ground plate, a "卐"-shaped gap with a variable length is opened on the ground plate of the first transmission unit, and a "田"-shaped gap with a variable length is opened on the ground plate of the second transmission unit, and the first transmission unit and the second transmission unit use a gap coupling method to perform phase compensation on the electromagnetic wave of the feed antenna within a phase range of 0° to 360° to radiate a plane electromagnetic wave; The first transmission unit further includes: an upper metal patch, a lower metal patch and a dielectric substrate; The dielectric substrate and the ground plane of the first transmission unit are arranged between the upper metal patch and the lower metal patch; the electromagnetic path length of the electromagnetic wave of the feed antenna from the lower metal patch to the ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna from the ground plane to the upper metal patch; The second transmission unit further includes: an upper metal patch, a lower metal patch, and a dielectric substrate; The dielectric substrate and the ground plane of the second transmission unit are arranged between the upper metal patch and the lower metal patch; the electromagnetic path length of the electromagnetic wave of the feed antenna from the lower metal patch to the ground plane is equal to the electromagnetic path length of the electromagnetic wave of the feed antenna from the ground plane to the upper metal patch; The coupling parameters of the first transmission unit are the sizes of the upper metal patch and the lower metal patch of the first transmission unit and the size of the "卐"-shaped gap; the coupling parameters of the second transmission unit are the gap size of the "田"-shaped gap and the sizes of the upper metal patch and the lower metal patch of the second transmission unit; The first transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within 7 phase gradients obtained by dividing the phase range of 0° to 315° into 7 equal parts starting from 0°; The second transmission unit is used to perform phase compensation on the electromagnetic wave of the feed antenna 12 within the eighth phase gradient formed by the phase range of 315° to 360°; The coupling parameters of the first transmission unit corresponding to different phase gradients are different.

2. The millimeter-wave transmissive array antenna according to claim 1, characterized in that, The upper metal patch and the lower metal patch of the second transmission unit are both in a square shape, and rectangular grooves of the same size are respectively provided at the same positions on four sides.

3. The millimeter-wave transmissive array antenna according to claim 1, wherein The positions of the first transmission unit and the second transmission unit in the transmission array are determined by the center frequency of the feed antenna; the total number of the first transmission units and the second transmission units arranged on the transmission array is determined by the preset gain threshold of the millimeter wave transmission array antenna.

4. The millimeter-wave transmissive array antenna according to claim 3, wherein The positions of the first transmission unit and the second transmission unit in the transmission array are determined by the phase compensation calculation formula and the center frequency; the phase compensation calculation formula is: φ ij = k0 × d ij -F where φ ij is the phase compensation required for the first or second transmission unit provided for the i-th row and j-th column of the transmission array, k0 = 2π / λ, λ is the free space wavelength of the electromagnetic wave of the feed antenna, d ij is the distance from the first or second transmission unit provided for the i-th row and j-th column of the transmission array to the center point of the feed antenna, and F is the distance from the center point of the transmission array to the center point of the feed antenna.

5. The millimeter-wave transmissive array antenna according to claim 4, wherein The distance from the center point of the transmission array to the center point of the feed antenna is determined by the size of the transmission array and the beam width of the directional pattern of the feed antenna.

6. A millimeter-wave radar, characterized in that, It comprises at least one millimeter wave transmission array antenna as described in any one of claims 1 to 5.

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