Antenna device and radar

Abstract

An antenna device and a radar wherein the antenna device comprises a decoupling network and at least two antenna units. Each antenna unit comprises a radiating body and a feeder line, one end of the feeder line is connected with the radiating body, and the feeder line is used for feeding a radio frequency signal into the radiating body; and a preset distance is formed between the feeder lines of two adjacent antenna units. The decoupling network is arranged between the feeder lines of the two adjacent antenna units and is in indirect coupling connection with the feeder lines, and the decoupling network is used for enabling the phases of currents transmitted to the decoupling network from the feeder lines of the two adjacent antenna units to be opposite. According to the invention, the decoupling network is arranged, so that the coupling current generated by the feeder lines of the two adjacent antenna units can be introduced into the decoupling network, and two paths of coupling current from different feeder lines can be offset on the decoupling network, thereby achieving the purpose of decoupling. Meanwhile, by arranging the decoupling network, decoupling of the two adjacent antenna units with the distance smaller than 0.5 lambda can be achieved, and the isolation degree of the high-density array antenna is improved.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to an antenna device and a radar. Background Art

[0002] With the expansion of the application scenarios of millimeter-wave radars, millimeter-wave radars are developing towards the direction of long distance, large aperture, and high angular resolution. Currently, in the field of millimeter-wave radars, the arrangement spacing between millimeter-wave antenna arrays is usually greater than 1.5 times the free-space wavelength, which is a non-highly dense array method. In the non-highly dense array method, there are multiple grating lobes in the radiation pattern of the array antenna, and there is a virtual scene problem when encountering a reflection target with a large Radar Cross section (RCS), which directly affects the overall performance of the system.

[0003] In order to reduce the virtual scene problem caused by high grating sidelobe energy and obtain high angular resolution characteristics, a highly dense array arrangement scheme with an element antenna spacing less than 0.5 wavelength and an increased number of transmit and receive channels can be considered. However, when using an antenna spacing less than 0.5 wavelength, there is a problem of poor isolation, and mutual interference occurs between the element antennas, affecting the antenna performance. Summary of the Invention

[0004] In view of this, this application provides an antenna device and a radar to solve the problem of poor isolation between the antennas in the existing highly dense array arrangement.

[0005] In a first aspect, this application provides an antenna device, which includes a decoupling network and at least two antenna elements. Each of the antenna elements includes a radiator and a feeder line. One end of the feeder line is connected to the radiator for feeding a radio frequency signal into the radiator; there is a preset spacing between the feeder lines of two adjacent antenna elements. The decoupling network is arranged between the feeder lines of two adjacent antenna elements, and the two ends of the decoupling network are indirectly coupled and connected to the feeder lines of two adjacent antenna elements respectively, for making the current phases transmitted from the feeder lines of two adjacent antenna elements to the decoupling network opposite.

[0006] The antenna device provided by this application can introduce the coupling current generated by the feeder lines of two adjacent antenna elements into the decoupling network by arranging the decoupling network between two adjacent antenna elements, and can cancel out the two-way coupling currents from different feeder lines on the decoupling network, thereby achieving the purpose of decoupling. At the same time, by setting the decoupling network, decoupling of two adjacent antenna elements with a spacing less than 0.5λ can be realized, and the isolation of the highly dense array antenna can be improved.

[0007] In a possible design, the decoupling network includes a first coupling stub and a second coupling stub. There is a first coupling gap between the first coupling stub and an adjacent one of the feed lines, and the first coupling stub includes a first coupling port. There is a second coupling gap between the second coupling stub and an adjacent other feed line, and the second coupling stub includes a second coupling port. The first coupling port and the second coupling port are coupled together, and the current phases between the first coupling port and the second coupling port are opposite. Among them, the current on the feed line adjacent to the first coupling stub can be coupled to the first coupling stub and transmitted to the first coupling port. The current generated by the feed line adjacent to the second coupling stub can be coupled to the second coupling stub and transmitted to the second coupling port. The directions of the current at the first coupling port and the current at the second coupling port are opposite. Thus, when the current at the first coupling port and the current at the second coupling port are coupled to each other, they can cancel each other out to achieve decoupling.

[0008] In a possible design, the feed line includes an input port and an output port. The feed line is connected to the RF front-end through the input port, and the feed line is coupled to the radiator through the output port. The first coupling port is disposed at one end of the first coupling stub close to the input port; and / or, the second coupling port is disposed at one end of the second coupling stub close to the input port. Among them, the RF signal can be input from the RF front-end into the feed line through the input port of the feed line and fed into the radiator through the output port. When the distance between two adjacent antenna units is relatively close, for example, when the distance between the feed lines of two adjacent antenna units is less than 0.5λ, in the case where no decoupling network is provided, a coupled electric field will be generated on the feed line. Therefore, the decoupling network can be disposed at a position corresponding to the feed line and can be indirectly coupled to the feed line to attract the coupled current caused by the feed line onto the decoupling network, thereby achieving the decoupling effect between the feed lines. Among them, a relatively strong coupled electric field is likely to be generated near the input port on the feed line, and the coupled current on the decoupling network mainly achieves the effect of current cancellation at the first coupling port and the second coupling port. Therefore, making the first coupling port and the second coupling port closer to the input port of the feed line can enable the coupled current near the input port to quickly and efficiently achieve decoupling through the decoupling network.

[0009] In a possible design, the first coupling gap and / or the second coupling gap is greater than or equal to 0.01 mm. Exemplarily, the gap can be between 0.05 mm and 0.15 mm. By keeping the gap within the above range, it is convenient for processing and manufacturing, and at the same time, the coupling effect between the decoupling network and the feed line can be ensured, thereby ensuring the decoupling effect.

[0010] In a possible design, the decoupling network further includes a first decoupling stub and a second decoupling stub. A first end of the first decoupling stub is electrically connected to the first coupling port, a first end of the second decoupling stub is electrically connected to the second coupling port, and a second end of the first decoupling stub is electrically connected to a second end of the second decoupling stub. Wherein, the first decoupling stub and the second decoupling stub can realize the direct electrical connection between the first coupling port and the second coupling port, which is beneficial to the cancellation effect of the coupling current on the decoupling stub. At the same time, by configuring the first decoupling stub and the second decoupling stub, the impedance of the two feed lines can be matched, so that the decoupling effect of the two feed lines meets the operating frequency band of the antenna element.

[0011] In a possible design, the electrical length between the first end and the second end of the first decoupling stub is 0.5Nλ, and the electrical length between the first end and the second end of the second decoupling stub is 0.5Nλ, where N is a positive odd number and λ is the dielectric wavelength. Thus, the decoupling network can produce a current coupling effect with the feed line and can generate a current coupling path on the decoupling network.

[0012] In a possible design, a first isolation port is further included at an end of the first coupling stub away from the first coupling port, and a second isolation port is further included at an end of the second coupling stub away from the second coupling port. The first isolation port is coupled to the second isolation port. Wherein, most of the current coupled from the feed line to the decoupling network will cancel each other out in terms of phase through the first decoupling stub and the second decoupling stub, and very little current or no current is coupled between the first isolation port and the second isolation port. The first isolation port and the second isolation port can play a role in matching the impedance between the decoupling network and the feed line, so that the coupling current generated by the feed line can be coupled to the decoupling network, thereby achieving the decoupling effect.

[0013] In a possible design, the decoupling network further includes an adjustment stub, and two ends of the adjustment stub are respectively electrically connected to the first isolation port and the second isolation port. Wherein, the adjustment stub can realize the direct electrical connection between the first isolation port and the second isolation port, and can adjust the impedance by configuring a suitable adjustment stub, so that the coupling current generated by the feed line can be coupled to the decoupling network, thereby achieving the decoupling effect.

[0014] In a possible design, the electrical length between the first isolation port and the first coupling port is 0.25Nλ, and the electrical length between the second isolation port and the second coupling port is 0.25Nλ, where N is a positive odd number and λ is the dielectric wavelength. Thus, the decoupling network can produce a current coupling effect with the feed line and can generate a current coupling path on the decoupling network.

[0015] In a possible design, the first coupling stub includes a first section, a second section, and a third section. The two ends of the second section are respectively connected to the first section and the third section, and the first section and the third section are bent away from the adjacent feeder on one side of the second section. One end of the first section away from the second section forms the first coupling port, and one end of the third section away from the second section forms the first isolation port. Among them, the first section, the second section, and the third section can form a C-shaped structure, and the length of the second section can be relatively longer, which is conducive to introducing the coupling current generated by the adjacent feeder onto the first coupling stub. The first section protrudes towards one side of the second section, which is conducive to guiding the coupling current to the first coupling port, so as to cancel the reverse current at the second coupling port to achieve decoupling. The third section can achieve impedance matching by cooperating with the second coupling stub.

[0016] In a possible design, the second coupling stub includes a fourth section, a fifth section, and a sixth section. The two ends of the fifth section are respectively connected to the fourth section and the sixth section, and the fourth section and the sixth section are bent away from the adjacent feeder on one side of the fifth section. One end of the fourth section away from the fifth section forms the second coupling port, and one end of the sixth section away from the fifth section forms the second isolation port. Among them, the fourth section, the fifth section, and the sixth section can also form a C-shaped structure, and the length of the fifth section can be relatively longer, which is conducive to introducing the coupling current generated by the adjacent feeder onto the second coupling stub. The fourth section protrudes towards one side of the fifth section, which is conducive to introducing the coupling current into the second coupling port, so as to cancel the reverse current at the first coupling port to achieve decoupling. The sixth section can achieve impedance matching by cooperating with the third section.

[0017] In a possible design, the spacing between the feeders of two adjacent antenna units is greater than or equal to 0.4λ, where λ is the free space wavelength. Thus, by setting up the decoupling network, decoupling of high-density array antennas and non-high-density array antennas can be achieved, and the isolation degree can be improved.

[0018] In a possible design, the decoupling network is integrally formed, that is, the first coupling stub, the second coupling stub, the first decoupling stub, the second decoupling stub, and the adjustment stub are all integrally formed during the preparation process of the decoupling network, making the decoupling network form an overall structure, which is convenient for processing. At the same time, it can also avoid the generation of splicing gaps at the joints of each stub, which affect the current distribution and can ensure the decoupling effect.

[0019] In a second aspect, the present application also provides a radar, which includes the antenna device provided in the first aspect of the present application. Among them, the radar including the aforementioned antenna device also has similar technical effects as the aforementioned antenna device, which will not be elaborated here.

[0020] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the present application. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Structural schematic diagram of an antenna device provided by an embodiment of the present application;

[0023] Figure 2 Structural schematic diagram of an antenna device provided by another embodiment of the present application;

[0024] Figure 3 Partial schematic diagram of an antenna device provided by an embodiment of the present application;

[0025] Figure 4 Partial schematic diagram of an antenna device provided by another embodiment of the present application;

[0026] Figure 5 Schematic diagram of the electric field distribution of the antenna device provided by the present application when no decoupling network is provided;

[0027] Figure 6 Schematic diagram of the electric field distribution of the antenna device provided by the present application when a decoupling network is provided;

[0028] Figure 7 Comparison diagram of S11 simulation curves of an antenna device provided by an embodiment of the present application before and after setting a decoupling network;

[0029] Figure 8 Comparison diagram of horizontal plane radiation patterns of an antenna device provided by an embodiment of the present application before and after setting a decoupling network;

[0030] Figure 9 Comparison diagram of vertical plane radiation patterns of an antenna device provided by an embodiment of the present application before and after setting a decoupling network;

[0031] Figure 10 Comparison diagram of gain curves of an antenna device provided by an embodiment of the present application before and after setting a decoupling network;

[0032] Figure 11 Comparison diagram of isolation simulation curves of an antenna device provided by an embodiment of the present application before and after setting a decoupling network;

[0033] Figure 12Comparison diagram of S11 simulation curves of the antenna device provided by another embodiment of the present application before and after setting the decoupling network;

[0034] Figure 13 Comparison diagram of horizontal plane radiation patterns of the antenna device provided by another embodiment of the present application before and after setting the decoupling network;

[0035] Figure 14 Comparison diagram of vertical plane radiation patterns of the antenna device provided by another embodiment of the present application before and after setting the decoupling network;

[0036] Figure 15 Comparison diagram of isolation simulation curves of the antenna device provided by another embodiment of the present application before and after setting the decoupling network;

[0037] Figure 16 Schematic diagram of the structure of the first coupling stub provided by an embodiment of the present application;

[0038] Figure 17 Schematic diagram of the structure of the second coupling stub provided by an embodiment of the present application.

[0039] Reference numerals:

[0040] 1 - Antenna element;

[0041] 11 - Radiator;

[0042] 12 - Feeder line;

[0043] 121 - Input port;

[0044] 122 - Output port;

[0045] 1A - First antenna element;

[0046] 1A1 - First feeder line;

[0047] 1B - Second antenna element;

[0048] 1B1 - Second feeder line;

[0049] 2 - Decoupling network;

[0050] 21 - First coupling stub;

[0051] 211 - First section;

[0052] 211A - First coupling port;

[0053] 212 - Second section;

[0054] 213 - Third section;

[0055] 213A - First isolation port;

[0056] 22 - The second coupling stub

[0057] 221 - The fourth section

[0058] 221A - The second coupling port

[0059] 222 - The fifth section

[0060] 223 - The sixth section

[0061] 223A - The second isolation port

[0062] 23 - The first decoupling stub

[0063] 24 - The second decoupling stub

[0064] 25 - The adjustment stub

[0065] H - Spacing

[0066] a1 - The first coupling gap

[0067] a2 - The second coupling gap Detailed implementation manners

[0068] For a better understanding of the technical solutions of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0069] It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0070] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application. The singular forms "a", "the" and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0071] It should be understood that the term " / and" used herein is only a description of the associated relationship of associated objects, indicating that there can be three relationships. For example, A / and B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0072] In the description of the present application, unless otherwise clearly specified and defined, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "plurality" means two or more; the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0073] Radiator: It is a device in an antenna for receiving / sending electromagnetic wave radiation. In some cases, "antenna" is understood in a narrow sense as a radiator, which converts the guided wave energy from a transmitter into radio waves, or converts radio waves into guided wave energy, for radiating and receiving radio waves. The modulated high-frequency current energy (or guided wave energy) generated by the transmitter is transmitted to the transmitting radiator through a feeder line. Through the radiator, it is converted into electromagnetic wave energy of a certain polarization and radiated in the required direction. The receiving radiator converts the electromagnetic wave energy of a certain polarization from a specific direction in space back into modulated high-frequency current energy and transmits it to the input end of the receiver through the feeder line.

[0074] The radiator can be a conductor with a specific shape and size, such as a wire antenna. A wire antenna is an antenna composed of one or more metal wires whose wire diameter is much smaller than the wavelength and whose length can be comparable to the wavelength, and can be used as a transmitting or receiving antenna. The main forms of wire antennas include dipole antennas, half-wave dipole antennas, monopole antennas, loop antennas, inverted F antennas (also known as IFA, Inverted F Antenna), planar inverted F antennas (also known as PIFA, Planar Inverted F Antenna), slot antennas or slotted antennas, antenna arrays, etc. For example, for a dipole antenna, each dipole antenna usually includes two radiating branches, and each branch is fed by a feeding part from the feeding end of the radiating branch. For example, for a slot antenna or a slotted antenna, it can include a single radiating branch, and both ends of the branch are grounded to form a slot or a slit.

[0075] The radiator can also be a slot or a slit formed on a conductor. For example, an antenna formed by slitting a conductor surface can also be called a slotted antenna or a slotted antenna. In some embodiments, the shape of the slit is elongated. In some embodiments, the length of the slit is about half a wavelength. In some embodiments, the slit can be fed by a transmission line straddling one or both of its sides, or can be fed by a waveguide or a resonant cavity. An RF electromagnetic field is excited on the slit and radiates electromagnetic waves into space.

[0076] Feeder line: Also known as a transmission line, it refers to the connection line between the transceiver of an antenna and the radiator. The system that connects the radiator of the antenna and the transceiver is called a feeding system. Feeder lines are further divided into wire transmission lines, coaxial transmission lines, waveguides, or microstrip lines, etc., according to different frequencies. The feeding point refers to the connection point on the radiator where the feeder line is connected.

[0077] Wavelength: Or the operating wavelength, which can be the wavelength corresponding to the center frequency of the resonant frequency or the center frequency of the operating frequency band supported by the antenna. For example, assuming the center frequency of the B1 uplink frequency band (resonant frequency from 1920 MHz to 1980 MHz) is 1955 MHz, then the operating wavelength can be the wavelength calculated using the frequency of 1955 MHz. Not limited to the center frequency, the "operating wavelength" can also refer to the wavelength corresponding to a non - center frequency of the resonant frequency or the operating frequency band.

[0078] Electrical length: The electrical length can be expressed as the physical length (i.e., the mechanical length or geometric length) multiplied by the ratio of the transmission time of an electrical or electromagnetic signal in a medium to the time required for this signal to pass through the same distance as the physical length of the medium in free space. Or, the electrical length can also be expressed as the ratio of the physical length (i.e., the mechanical length or geometric length) to the wavelength of the transmitted electromagnetic wave. In some embodiments of the present application, the physical length of the radiator can be understood as the electrical length of the radiator ± 10%. In the embodiments of the present application, the wavelength in a certain wavelength mode of the antenna (such as the half - wavelength mode, etc.) can refer to the wavelength of the signal radiated by the antenna.

[0079] Coupling: Can be understood as direct coupling and / or indirect coupling. "Coupling connection" can be understood as direct coupling connection and / or indirect coupling connection. Direct coupling can also be referred to as "electrical connection", which is understood as the physical contact and electrical conduction of components; it can also be understood as the form of connection between different components in a circuit structure through physical lines such as copper foils or wires on a printed circuit board (PCB) that can transmit electrical signals. "Indirect coupling" can be understood as the electrical conduction of two conductors in a non - contact manner through air separation. In one embodiment, indirect coupling can also be called capacitive coupling, for example, signal transmission is achieved by forming an equivalent capacitance through the coupling between the gaps of two conductive parts.

[0080] Millimeter - wave radar can not only distinguish targets with relatively small sizes but also identify multiple targets simultaneously. Millimeter - wave radar can be applied to vehicles as in - vehicle radar, and of course, it can also be applied to means of transportation other than vehicles. As a key component of the millimeter - wave radar system, the performance of the antenna directly affects the detection range, detection angle, anti - interference ability, and resolution of the radar system.

[0081] With the expansion of millimeter-wave radar application scenarios (such as urban scenarios, highway scenarios, etc.), millimeter-wave radar is developing towards the direction of long distance, large aperture and high angular resolution. Currently, in the field of millimeter-wave radar, the arrangement spacing between millimeter-wave antenna arrays is usually greater than 1.5 times the wavelength, which is a non-high-density array method. In the non-high-density array method, there will be multiple grating lobes in the radiation pattern of the array antenna, and there will be a virtual scene problem when encountering a reflecting target with a large radar cross section (RCS), which directly affects the overall performance of the system.

[0082] In order to reduce the virtual scene problem caused by high grating sidelobe energy and obtain high angular resolution characteristics, a high-density array arrangement scheme with an element antenna spacing less than 0.5 wavelength and an increased number of transmit and receive channels can be considered. Although this arrangement scheme has the characteristics of no grating lobes, low sidelobes, and high angular resolution, when using an antenna spacing less than 0.5 times the wavelength, there is a problem of poor isolation, and mutual interference occurs between the element antennas, affecting the antenna performance.

[0083] The embodiment of the present application provides an antenna device, which can be applied to radar systems such as millimeter-wave radar. The antenna device includes at least two antenna elements 1, and at least two antenna elements 1 can form an antenna array. Exemplarily, Figure 1 is a schematic structural diagram of the antenna device provided by an embodiment of the present application. Referring to Figure 1 , when there are two antenna elements 1, a dual-element antenna array can be formed. When there are three antenna elements 1, a triple-element antenna array can be formed. Figure 2 is a schematic structural diagram of the antenna device provided by another embodiment of the present application. Referring to Figure 2 , when there are five antenna elements 1, a five-element antenna array can be formed. Among them, each antenna element 1 includes a radiator 11 and a feeder 12. One end of the feeder 12 is connected to the radiator 11 for feeding a radio frequency signal into the radiator 11 to make the radiator 11 radiate energy.

[0084] Among them, referring to Figure 1 , in order to ensure that adjacent two antenna elements can work independently and normally, and reduce the mutual interference between adjacent antenna elements 1, there is a preset spacing H between the feeders 12 of adjacent two antenna elements 1. In one embodiment, the preset spacing H can be greater than 1.5λ, where λ is the free space wavelength, so that non-high-density antenna arrays can be formed between the respective antenna elements 1. In one embodiment, the preset spacing H can also be between 0.4λ and 1.5λ, so that high-density antenna arrays can be formed between the respective antenna elements 1.

[0085] Figure 3 is a partial schematic diagram of the antenna device provided by an embodiment of the present application.Figure 4 A partial schematic diagram of the antenna device provided by another embodiment of the present application. Refer to Figure 3 and Figure 4 , the decoupling network 2 is arranged between the feed lines 12 of two adjacent antenna elements 1. The two ends of the decoupling network 2 are indirectly coupled to the feed lines 12 of two adjacent antenna elements 1 respectively, and are used to make the current phases transmitted to the decoupling network 2 by the feed lines 12 of two adjacent antenna elements 1 opposite. Wherein, in the arrangement direction of two adjacent antenna elements 1, there are gaps between the two ends of the decoupling network 2 and the feed lines 12 of the two antenna elements 1 respectively. This gap can form an indirectly coupled connection mode between the decoupling network 2 and the feed lines 12. The coupled currents generated by the feed lines 12 of two adjacent antenna elements 1 can be introduced onto the decoupling network 2, and the phases of the two paths of coupled currents from the two feed lines 12 are opposite, that is, the transmission directions of the two paths of coupled currents are opposite, so that the two paths of coupled currents can cancel each other out on the decoupling network 2 to achieve decoupling. Wherein, the decoupling network 2 is a structure independent of the feed line 12 and does not contact the adjacent feed line 12, and independent adjustment of the decoupling network 2 can be realized, such as adjusting the width, length of the decoupling network 2, and the distance from the adjacent feed line 12, so that the decoupling network 2 can match the operating frequency of the antenna element 1, the impedance between antennas, etc., to achieve decoupling between antenna elements 1 resonating in different operating frequency bands.

[0086] Therefore, for the antenna device provided by the embodiment of the present application, by arranging the decoupling network 2 between two adjacent antenna elements 1, the coupled currents generated by the feed lines 12 of two adjacent antenna elements 1 can be introduced onto the decoupling network 2, and the two paths of coupled currents from different feed lines 12 can cancel each other out on the decoupling network 2, so as to achieve the purpose of decoupling. At the same time, by arranging the decoupling network 2, decoupling of two adjacent antenna elements 1 with a spacing H less than 0.5λ can be realized, and the isolation of the high-density array antenna can be improved.

[0087] In one embodiment, refer to Figure 1 , taking the antenna element 1 being provided with two as an example for illustration. At the same time, for the convenience of illustration, in this embodiment, the two antenna elements 1 are respectively defined as the first antenna element 1A and the second antenna element 1B, the feed line 12 of the first antenna element 1A is the first feed line 1A1, and the feed line 12 of the second antenna element 1B is the second feed line 1B1. Figure 5 A schematic diagram of the electric field distribution of the antenna device provided by the present application when the decoupling network 2 is not provided. Figure 5 The distance between the feed lines 12 of the two antenna elements 1 shown is less than 0.5λ, and the decoupling network 2 provided by the present application is not provided. Refer to Figure 5 , when feeding the radiator 11 of the first antenna element 1A through the first feed line 1A1 ( Figure 5When feeding through Port1, a strong coupled electric field will be generated on the second feeder line 1B1 and the radiator 11 of the second antenna unit 1B (refer to Figure 5 the part of the second antenna unit 1B located in the wire frame M in

[0088] In one embodiment, Figure 6 is a schematic diagram of the electric field distribution of the antenna device provided by this application when the decoupling network 2 is set. Figure 6 and Figure 5 The structural layout and feeding conditions of the antenna unit 1 shown are the same, except that Figure 6 a decoupling network 2 is set between the adjacent first antenna unit 1A and the second antenna unit 1B in Figure 6 . Referring to Figure 5 , the decoupling network 2 can introduce the coupled currents on the first antenna unit 1A and the second antenna unit 1B to the decoupling network 2, and can make the two coupled currents cancel each other out on the decoupling network 2 to achieve decoupling. Compared with Figure 6 where there is a region with a strong coupled electric field shown, Figure 6 the coupled electric field in the region corresponding to the second feeder line 1B1 in

[0089] Figure 7 is a comparison diagram of the S11 simulation curves of the antenna device provided by an embodiment of this application before and after setting the decoupling network 2. Figure 7 The curve a shown is the S11 curve of Figure 5 the dual - element antenna array (without the decoupling network 2) shown, and the curve b is the S11 curve of Figure 6 the dual - element antenna array (with the decoupling network 2) shown. Among them, the abscissa represents frequency, and the ordinate represents the return loss S11. Referring to Figure 7 , in the frequency band of 79.5GHz - 80.5GHz, the S11 of both the curve a and the curve b is below - 15dB. That is to say, after setting the decoupling network 2, the S11 of the antenna device can still meet the requirements.

[0090] Figure 8 is a comparison diagram of the horizontal plane radiation patterns of the antenna device provided by an embodiment of this application before and after setting the decoupling network 2. Among them, the curve c (solid line) is the horizontal plane radiation pattern curve of Figure 5 the dual - element antenna array (without the decoupling network 2) shown, and the curve d (dashed line) is forFigure 6 The horizontal radiation pattern curve of the dual-element antenna array (with the decoupling network 2) shown. Refer to Figure 8 , before and after setting the decoupling network 2, the antenna device has little influence on the horizontal radiation pattern.

[0091] Figure 9 The comparison diagram of the vertical radiation patterns of the antenna device provided by an embodiment of the present application before and after setting the decoupling network 2. Among them, curve e (solid line) is the Figure 5 vertical radiation pattern curve of the dual-element antenna array (without the decoupling network 2) shown, and curve f (dashed line) is the Figure 6 vertical radiation pattern curve of the dual-element antenna array (with the decoupling network 2) shown. Refer to Figure 9 , before and after setting the decoupling network 2, the antenna device has little influence on the vertical radiation pattern.

[0092] Figure 10 The comparison diagram of the gain curves of the antenna device provided by an embodiment of the present application before and after setting the decoupling network 2. Among them, curve g (solid line) is the Figure 5 antenna gain curve of the dual-element antenna array (without the decoupling network 2) shown, and curve h (dashed line) is the Figure 6 antenna gain curve of the dual-element antenna array (with the decoupling network 2) shown. Refer to Figure 10 , before and after setting the decoupling network 2, the influence of the antenna device on the antenna gain is small and can be ignored.

[0093] Figure 11 The comparison diagram of the isolation simulation curves of the antenna device provided by an embodiment of the present application before and after setting the decoupling network 2, Figure 11 the curve j shown is the Figure 5 isolation curve of the dual-element antenna array (without the decoupling network 2) shown, and curve k is the Figure 6 isolation curve of the dual-element antenna array (with the decoupling network 2) shown. Among them, the abscissa represents frequency and the ordinate represents isolation. Refer to Figure 11 , in the frequency band of 79.5 GHz to 80.5 GHz, the isolation of curve j is less than 25 dB, and the isolation corresponding to the frequency of 79.5 GHz is 22 dB; the isolation of curve k is greater than 25 dB, and the isolation corresponding to the frequency of 79.5 GHz is 28.9 dB. That is to say, after setting the decoupling network 2 in the antenna device, the isolation can be significantly improved, and in the frequency band of 79.5 GHz to 80.5 GHz, the isolation improvement is at least greater than or equal to 6 dB.

[0094] It can be seen from this that, compared with the antenna device before the decoupling network 2 is set, after the decoupling network 2 is set, the isolation degree between two adjacent antenna units 1 is significantly improved, and the performance such as S11, the radiation patterns in the horizontal and vertical planes, and the antenna gain, etc., other than the isolation degree, can still meet the requirements.

[0095] In one embodiment, for Figure 2 the five-element array antenna shown below, the performance of each aspect of the antenna before and after the decoupling network 2 is set will be described in detail with reference to the drawings.

[0096] Figure 12 FIG. is a comparison diagram of S11 simulation curves of the antenna device provided in another embodiment of the present application before and after the decoupling network 2 is set. Among them, Figure 12 (a) represents the S11 curve when the decoupling network 2 is not set in the five-element array antenna, and within the frequency band of 79.5 GHz to 80.5 GHz, S11 is below -15 dB. Figure 12 (b) represents the S11 curve when the decoupling network 2 is set in the five-element array antenna (refer to Figure 2 ), and within the frequency band of 79.5 GHz to 80.5 GHz, S11 is below -15 dB. That is to say, before and after the decoupling network 2 is set, the S11 of the antenna device is basically the same and still meets the requirements.

[0097] Figure 13 FIG. is a comparison diagram of the horizontal plane radiation patterns of the antenna device provided in another embodiment of the present application before and after the decoupling network 2 is set. Among them, curve m (solid line) is the horizontal plane radiation pattern curve of the five-element antenna array when the decoupling network 2 is not set, and curve n (dashed line) is Figure 2 the horizontal plane radiation pattern curve of the five-element antenna array shown below when the decoupling network 2 is set (refer to Figure 2 ). Referring to Figure 13 , before and after the decoupling network 2 is set for the antenna device, the influence on the horizontal plane radiation pattern is small.

[0098] Figure 14 FIG. is a comparison diagram of the vertical plane radiation patterns of the antenna device provided in another embodiment of the present application before and after the decoupling network 2 is set. Among them, curve p (solid line) is the vertical plane radiation pattern curve of the five-element antenna array when the decoupling network 2 is not set, and curve q (dashed line) is Figure 2 the vertical plane radiation pattern curve of the five-element antenna array shown below when the decoupling network 2 is set (refer to Figure 2 ). Referring to Figure 14 , before and after the decoupling network 2 is set for the antenna device, the influence on the vertical plane radiation pattern is small.

[0099] Figure 15 FIG. is a comparison diagram of the isolation degree simulation curves of the antenna device provided in another embodiment of the present application before and after the decoupling network 2 is set. Among them,Figure 15 (a) shows the isolation curve when the decoupling network 2 is not set in the five-element array antenna. In the frequency band of 79.5 GHz to 80.5 GHz, the isolation between some adjacent two antenna elements 1 is less than 25 dB, and the isolation corresponding to the frequency of 79.5 GHz is 22 dB; Figure 15 (b) shows the isolation curve when the decoupling network 2 is set in the five-element array antenna (refer to Figure 2 ). It can be seen that in the frequency band of 79.5 GHz to 80.5 GHz, the isolation is greater than 25 dB, and the isolation corresponding to the frequency of 79.5 GHz is 28 dB. That is to say, after the decoupling network 2 is set in the antenna device, the isolation can be significantly improved. In the frequency band of 79.5 GHz to 80.5 GHz, the isolation improvement is at least greater than or equal to 6 dB.

[0100] It can be seen from this that compared with the antenna device before the decoupling network 2 is set, after the decoupling network 2 is set, the isolation between adjacent two antenna elements 1 is significantly improved, and other performances such as S11, the radiation patterns in the horizontal and vertical planes, and the antenna gain can still meet the requirements.

[0101] Of course, in some other embodiments, for multi-element array antennas including other numbers, by setting the decoupling network 2, the isolation between adjacent two antenna elements 1 can be significantly improved, and no further examples will be given here.

[0102] In one embodiment, the feeder line 12 and the decoupling network 2 can be set on a dielectric board, and the dielectric board can be a printed circuit board (PCB). In one embodiment, the feeder line 12, the radiator 11 and the decoupling network 2 are etched on the circuit board. In one embodiment, the feeder line 12, the radiator 11 and the decoupling network 2 can also be metal sheets, such as copper sheets, and such metal sheets can be set on a dielectric material.

[0103] In one embodiment, refer to Figure 3, the decoupling network 2 includes a first coupling stub 21 and a second coupling stub 22. There is a first coupling gap a1 between the first coupling stub 21 and an adjacent feeder 12, and the first coupling stub 21 includes a first coupling port 211A. There is a second coupling gap a2 between the second coupling stub 22 and another adjacent feeder 12, and the second coupling stub 22 includes a second coupling port 221A. The first coupling port 211A is coupled to the second coupling port 221A, and the current phases between the first coupling port 211A and the second coupling port 221A are opposite. Among them, the coupling current generated by the feeder 12 adjacent to the first coupling stub 21 can be coupled to the first coupling stub 21 and can be transmitted to the first coupling port 211A. The coupling current generated by the feeder 12 adjacent to the second coupling stub 22 can be coupled to the second coupling stub 22 and can be transmitted to the second coupling port 221A. The directions of the currents at the first coupling port 211A and the second coupling port 221A are opposite. Thus, when the currents at the first coupling port 211A and the second coupling port 221A are coupled to each other, they can cancel each other out to achieve decoupling.

[0104] In one embodiment, referring to Figure 3, the feeder 12 includes an input port 121 and an output port 122. The feeder 12 is connected to the RF front-end through the input port 121. The RF front-end may include devices such as a power amplifier and a filter. The feeder 12 is coupled to the radiator 11 through the output port 122. The first coupling port 211A is disposed at one end of the first coupling stub 21 close to the input port 121; and / or, the second coupling port 221A is disposed at one end of the second coupling stub 22 close to the input port 121. For ease of explanation, in this embodiment, it is taken as an example that the first coupling port 211A is disposed at one end of the first coupling stub 21 close to the input port 121, and the second coupling port 221A is disposed at one end of the second coupling stub 22 close to the input port 121 for illustration. Among them, the RF signal can be input from the RF front-end to the feeder 12 through the input port 121 of the feeder 12 and can be fed into the radiator 11 through the output port 122. When the distance between two adjacent antenna elements 1 is relatively close, for example, when the distance between the feeders 12 of two adjacent antenna elements 1 is less than 0.5λ, in the case where the decoupling network 2 is not provided, a coupling electric field will be generated on the feeder 12. Therefore, the decoupling network 2 can be disposed at a position corresponding to the feeder 12 and can be indirectly coupled to the feeder 12 to lead the coupling current generated by the feeder 12 to the decoupling network 2, thereby realizing the decoupling effect between the feeders 12. Among them, a relatively strong coupling electric field is likely to be generated near the input port 121 on the feeder 12, and the coupling current on the decoupling network 2 mainly achieves the effect of current cancellation at the first coupling port 211A and the second coupling port 221A. Therefore, making the first coupling port 211A and the second coupling port 221A closer to the input port 121 of the feeder 12 can enable the coupling current near the input port 121 to be decoupled quickly and efficiently through the decoupling network 2.

[0105] In one embodiment, referring to Figure 3 , the first coupling gap a1 and / or the second coupling gap a2 is greater than or equal to 0.01 mm. Exemplarily, the gap may be between 0.05 mm and 0.15 mm. By keeping the gap within the above range, it is convenient for processing and manufacturing, and at the same time, the coupling effect between the decoupling network 2 and the feeder 12 can be ensured, thereby ensuring the decoupling effect.

[0106] In one embodiment, referring to Figure 4, the decoupling network 2 further includes a first decoupling stub 24 and a second decoupling stub 24. The first end of the first decoupling stub 24 is electrically connected to the first coupling port 211A, and the first end of the second decoupling stub 24 is electrically connected to the second coupling port 221A. The second end of the first decoupling stub 24 is electrically connected to the second end of the second decoupling stub 24. Among them, the first decoupling stub 24 and the second decoupling stub 24 can realize the direct electrical connection between the first coupling port 211A and the second coupling port 221A, which is beneficial to the cancellation effect of the coupling current on the decoupling stub. At the same time, by configuring the first decoupling stub 24 and the second decoupling stub 24, the impedance of the two feed lines 12 can be matched, so that the decoupling effect of the two feed lines 12 meets the operating frequency band of the antenna element 1.

[0107] In one embodiment, in order to enable the decoupling network 2 to generate a current coupling effect with the feed line 12 and generate a current coupling path on the decoupling network 2, the electrical length between the first end and the second end of the first decoupling stub 24 is 0.5Nλ, and the electrical length between the first end and the second end of the second decoupling stub 24 is 0.5Nλ, where N is a positive odd number, such as N = 1, 3, 5, 7, 9..., and λ is the dielectric wavelength.

[0108] In one embodiment, referring to Figure 3 , one end of the first coupling stub 21 away from the first coupling port 211A further includes a first isolation port 213A, and one end of the second coupling stub 22 away from the second coupling port 221A further includes a second isolation port 223A. The first isolation port 213A is coupled to the second isolation port 223A. Among them, most of the current coupled from the feed line 12 to the decoupling network 2 will cancel each other out in phase through the first decoupling stub 24 and the second decoupling stub 24, and very little current or no current is coupled between the first isolation port 213A and the second isolation port 223A. The first isolation port 213A and the second isolation port 223A can play a role in matching the impedance between the decoupling network 2 and the feed line 12, so that the coupled current generated by the feed line 12 can be coupled to the decoupling network 2, thereby realizing the decoupling effect.

[0109] In one embodiment, referring to Figure 4, the decoupling network 2 further includes an adjusting stub 25, and both ends of the adjusting stub 25 are electrically connected to the first isolation port 213A and the second isolation port 223A respectively. Among them, the adjusting stub 25 can realize the direct electrical connection between the first isolation port 213A and the second isolation port 223A, and can adjust the impedance by configuring a suitable adjusting stub 25. Among them, the impedance can be adjusted by adjusting the width, shape, etc. of the adjusting stub 25 to achieve the impedance matching between the decoupling network 2 and the feeder line 12 at different operating frequency bands. Of course, the widths or shapes of the first coupling stub 21, the second coupling stub 22, the first decoupling stub 24 and the second decoupling stub 24 can also be adaptively adjusted to cooperate with the adjustment of the impedance of the decoupling network 2.

[0110] In one embodiment, in order to enable the decoupling network 2 between any two adjacent feeder lines 12 to have a decoupling effect and be able to generate a current coupling path on the decoupling network 2, the electrical length between the first isolation port 213A and the first coupling port 211A is 0.25Nλ, and the electrical length between the second isolation port 223A and the second coupling port 221A is 0.25Nλ, where N is a positive odd number, such as N = 1, 3, 5, 7, 9..., and λ is the dielectric wavelength.

[0111] In one embodiment, the decoupling network 2 is an integrally formed structure, that is, the first coupling stub 21, the second coupling stub 22, the first decoupling stub 24, the second decoupling stub 24 and the adjusting stub 25 are all integrally formed during the preparation of the decoupling network 2, so that the decoupling network 2 forms an overall structure, which is convenient for processing. At the same time, it can also avoid the generation of splicing gaps at the joints of each stub, which affects the current distribution and can ensure the decoupling effect.

[0112] In one embodiment, Figure 16 is a schematic structural diagram of the first coupling stub 21 provided by the embodiment of the present application. Refer to Figure 16, the first coupling stub 21 includes a first section 211, a second section 212, and a third section 213. The two ends of the second section 212 are respectively connected to the first section 211 and the third section 213, and the first section 211 and the third section 213 are bent away from the adjacent feeder 12 towards the second section 212. One end of the first section 211 away from the second section 212 forms a first coupling port 211A, and one end of the third section 213 away from the second section 212 forms a first isolation port 213A. Among them, the first section 211, the second section 212, and the third section 213 can form a C-shaped structure, and the length of the second section 212 can be relatively longer, which is beneficial to introducing the coupling current generated by the adjacent feeder 12 onto the first coupling stub 21. The first section 211 protrudes towards the second section 212, which is beneficial to guiding the coupling current to the first coupling port 211A, so as to cancel the reverse current at the second coupling port 221A to achieve decoupling. The third section 213 can achieve impedance matching by cooperating with the second coupling stub 22.

[0113] Similarly, in one embodiment, Figure 17 is a schematic structural diagram of the second coupling stub 22 provided by the embodiment of the present application. Refer to Figure 17 , the second coupling stub 22 includes a fourth section 221, a fifth section 222, and a sixth section 223. The two ends of the fifth section 222 are respectively connected to the fourth section 221 and the sixth section 223, and the fourth section 221 and the sixth section 223 are bent away from the adjacent feeder 12 towards the fifth section 222. One end of the fourth section 221 away from the fifth section 222 forms a second coupling port 221A, and one end of the sixth section 223 away from the fifth section 222 forms a second isolation port 223A. Among them, the fourth section 221, the fifth section 222, and the sixth section 223 can also form a C-shaped structure, and the length of the fifth section 222 can be relatively longer, which is beneficial to introducing the coupling current generated by the adjacent feeder 12 onto the second coupling stub 22. Among them, the length of the fifth section 222 needs to satisfy 0.25Nλ, N is a positive odd number, such as N = 1, 3, 5, 7, 9..., and λ is the dielectric wavelength. The fourth section 221 protrudes towards the fifth section 222, which is beneficial to introducing the coupling current into the second coupling port 221A, so as to cancel the reverse current at the first coupling port 211A to achieve decoupling. The sixth section 223 can achieve impedance matching by cooperating with the third section 213.

[0114] Among them, both the first coupling stub 21 and the second coupling stub 22 are integral structures. In order to facilitate the description of each part of the first coupling stub 21 and the second coupling stub 22 in this embodiment, the first coupling stub 21 is divided into a first section 211, a second section 212, and a third section 213, and the second coupling stub 22 is divided into a fourth section 221, a fifth section 222, and a sixth section 223. However, there is no clear boundary between the first section 211, the second section 212, and the third section 213, nor is there a clear boundary between the fourth section 221, the fifth section 222, and the sixth section 223.

[0115] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An antenna device, characterized in that, Comprising: At least two antenna units, each of the antenna units including a radiator and a feeder line, one end of the feeder line being connected to the radiator for feeding a radio frequency signal into the radiator; There is a preset spacing between the feeder lines of two adjacent antenna units; A decoupling network is provided between the feeder lines of two adjacent antenna units, and both ends of the decoupling network are indirectly coupled and connected to the feeder lines of two adjacent antenna units respectively, for making the current phases transmitted to the decoupling network by the feeder lines of two adjacent antenna units opposite.

2. The antenna device according to claim 1, characterized in that, The decoupling network includes a first coupling stub and a second coupling stub, the first coupling stub having a first coupling gap with one of the adjacent feeder lines, and the first coupling stub including a first coupling port; The second coupling stub has a second coupling gap with the other adjacent feeder line, and the second coupling stub includes a second coupling port; The first coupling port is coupled to the second coupling port, and the current phases between the first coupling port and the second coupling port are opposite.

3. The antenna device according to claim 2, characterized in that, The feeder line includes an input port and an output port, the feeder line being connected to a radio frequency front end through the input port, and the feeder line being coupled to the radiator through the output port; The first coupling port is disposed at one end of the first coupling stub close to the input port; and / or, the second coupling port is disposed at one end of the second coupling stub close to the input port.

4. The antenna device according to claim 2, characterized in that, The first coupling gap and / or the second coupling gap is greater than or equal to 0.01 mm.

5. The antenna device according to any one of claims 2 - 4, characterized in that, The decoupling network further includes a first decoupling stub and a second decoupling stub, a first end of the first decoupling stub being electrically connected to the first coupling port, a first end of the second decoupling stub being electrically connected to the second coupling port, and a second end of the first decoupling stub being electrically connected to a second end of the second decoupling stub.

6. The antenna device according to claim 5, characterized in that, The electrical length between the first end and the second end of the first decoupling stub is 0.5Nλ, and the electrical length between the first end and the second end of the second decoupling stub is 0.5Nλ, where N is a positive odd number and λ is the dielectric wavelength.

7. The antenna device according to any one of claims 2 - 6, characterized in that, One end of the first coupling stub far from the first coupling port further includes a first isolation port, and one end of the second coupling stub far from the second coupling port further includes a second isolation port, and the first isolation port is coupled to the second isolation port.

8. The antenna device according to claim 7, characterized in that, The decoupling network further includes an adjustment stub, and both ends of the adjustment stub are electrically connected to the first isolation port and the second isolation port respectively.

9. The antenna device according to claim 7 or 8, characterized in that, The electrical length between the first isolation port and the first coupling port is 0.25Nλ, and the electrical length between the second isolation port and the second coupling port is 0.25Nλ, where N is a positive odd number and λ is the dielectric wavelength.

10. The antenna device according to any one of claims 7 - 9, characterized in that, The first coupling stub includes a first section, a second section, and a third section. Two ends of the second section are respectively connected to the first section and the third section, and the first section and the third section are bent toward a side of the second section away from an adjacent feeder line. One end of the first section away from the second section forms the first coupling port, and one end of the third section away from the second section forms the first isolation port.

11. The antenna device according to any one of claims 7 - 10, characterized in that, The second coupling stub includes a fourth section, a fifth section, and a sixth section. Two ends of the fifth section are respectively connected to the fourth section and the sixth section, and the fourth section and the sixth section are bent toward a side of the fifth section away from an adjacent feeder line. One end of the fourth section away from the fifth section forms the second coupling port, and one end of the sixth section away from the fifth section forms the second isolation port.

12. The antenna device according to any one of claims 1 - 11, characterized in that, The distance between feeder lines of two adjacent antenna units is greater than or equal to 0.4λ, where λ is the free space wavelength.

13. The antenna device according to any one of claims 1 - 12, characterized in that, The decoupling network is integrally formed.

14. A radar, characterized in that, Comprising the antenna device according to any one of claims 1-13.

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