Broadband dipole antenna and radar system

Abstract

The utility model provides a broadband dipole antenna and a radar system. The broadband dipole antenna comprises a dielectric substrate, a first radiation oscillator and a first impedance converter which are arranged on the top layer of the dielectric substrate, a second radiation oscillator and a second impedance converter which are arranged on the bottom layer of the dielectric substrate, and an antenna interface, the first end of the first impedance converter is connected with the signal end of the antenna interface, and the second end of the first impedance converter is connected with the feeder line end of the first radiation oscillator; the first end of the second impedance converter is connected with the grounding end of the antenna interface, and the second end of the second impedance converter is connected with the feeder line end of the second radiation oscillator; the first radiation oscillator and the second radiation oscillator are arranged in a left-right axial symmetry mode, and the first radiation oscillator and the second radiation oscillator are both of a gradual change structure. According to the antenna, the radiation oscillator is of a gradual change structure, resonance can be achieved in a wide frequency range, the working frequency range of the antenna is widened, and the percentage bandwidth of the antenna is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, in particular to a broadband dipole antenna and a radar system. Background Art

[0002] Phased array technology is the main research direction of current radar technology, among which high-performance antenna units and their array technology are the key to its realization. Antenna units usually need to meet the requirements of large bandwidth, medium gain, small size, and phased array radar in agile frequency anti-interference, wide-angle scanning (-45°~+45° or -60°~+60°) and large-scale array integration.

[0003] In the prior art, the antenna unit usually adopts a dipole antenna. The dipole antenna has a simple structure and is composed of a pair of symmetrically placed quarter-wavelength conductors. The two ends of the conductors close to each other are respectively connected to the feeder. The dipole antenna is a half-wave resonant antenna, and the percentage bandwidth can only reach about 15% at most. The limited bandwidth affects the development of radar technology. Utility Model Content

[0004] The embodiments of the utility model provide a broadband dipole antenna and a radar system to solve the problem in the prior art that the bandwidth of the dipole antenna is limited, which affects the development of radar technology.

[0005] In a first aspect, an embodiment of the utility model provides a broadband dipole antenna, comprising: a first radiating element, a second radiating element, a first impedance transformer, a second impedance transformer, a dielectric substrate, and an antenna interface;

[0006] The first radiation array and the first impedance transformer are both arranged on the top layer of the dielectric substrate;

[0007] The first end of the first impedance converter is connected to the signal end of the antenna interface, and the second end of the first impedance converter is connected to the feeder end of the first radiating element;

[0008] The second radiation array and the second impedance converter are both arranged on the bottom layer of the dielectric substrate;

[0009] A first end of the second impedance converter is connected to the ground end of the antenna interface, and a second end of the second impedance converter is connected to the feeder end of the second radiating array;

[0010] The first radiation array and the second radiation array are symmetrically arranged about the left-right axis, and both the first radiation array and the second radiation array are gradient structures.

[0011] Optionally, the first radiation array and the second radiation array are both trapezoidal structures;

[0012] The feeder end of the first radiating array and the feeder end of the second radiating array are both upper and lower sides of the trapezoidal structure.

[0013] Optionally, the length of the upper bottom side of the trapezoidal structure of the first radiation array and the upper bottom side of the trapezoidal structure of the second radiation array are both equal to the width of a 150-ohm impedance line;

[0014] The lengths of the lower base of the trapezoidal structure of the first radiation array and the lower base of the trapezoidal structure of the second radiation array are both the thickness of the dielectric substrate;

[0015] The height of the trapezoidal structure of the first radiation array and the height of the trapezoidal structure of the second radiation array are both

[0016] Optionally, the first impedance converter and the second impedance converter are both of a trapezoidal structure;

[0017] The second end of the first impedance converter and the second end of the second impedance converter are both upper bases of the trapezoidal structure; the first end of the first impedance converter and the first end of the second impedance converter are both lower bases of the trapezoidal structure;

[0018] The upper bottom side of the trapezoidal structure of the first impedance transformer is the same length as the upper bottom side of the trapezoidal structure of the first radiation array; the upper bottom side of the trapezoidal structure of the second impedance transformer is the same length as the upper bottom side of the trapezoidal structure of the second radiation array.

[0019] Optionally, the upper bottom side of the trapezoidal structure of the first impedance transformer is the same as the upper bottom side of the trapezoidal structure of the first radiation array, both being the width of a 150-ohm impedance line;

[0020] The length of the lower bottom side of the trapezoidal structure of the first impedance transformer is equal to the width of the 50-ohm impedance line; the length of the lower bottom side of the topographic structure of the second impedance transformer is three times the width of the 50-ohm impedance line.

[0021] Optionally, the broadband dipole antenna further includes: a metal reflector;

[0022] The metal reflector is vertically arranged on the dielectric substrate, and the first end of the second impedance converter is connected to the ground terminal of the antenna interface through the metal reflector;

[0023] The first end of the second impedance converter, the metal reflector and the grounding end of the antenna interface are grounded to a common ground.

[0024] Optionally, the metal reflector is circular, and the diameter of the metal reflector is

[0025] The vertical distances between the metal reflector and the first and second radiation arrays are

[0026] Optionally, the broadband dipole antenna further comprises: a cylindrical radome;

[0027] The antenna cover and the metal reflector form a closed cavity, and the first radiation array, the second radiation array, the first impedance converter, the second impedance converter and the dielectric substrate are all arranged inside the closed cavity.

[0028] Optionally, the closed cavity is filled with polyurethane foam.

[0029] In a second aspect, an embodiment of the utility model provides a radar system, including the broadband dipole antenna provided in the first aspect of the embodiment of the utility model.

[0030] The embodiment of the utility model provides a broadband dipole antenna and a radar system. The broadband dipole antenna comprises a first radiating array, a second radiating array, a first impedance transformer, a second impedance transformer, a dielectric substrate and an antenna interface; the first radiating array and the first impedance transformer are both arranged on the top layer of the dielectric substrate; the first end of the first impedance transformer is connected to the signal end of the antenna interface, and the second end of the first impedance transformer is connected to the feeder end of the first radiating array; the second radiating array and the second impedance transformer are both arranged on the bottom layer of the dielectric substrate; the first end of the second impedance transformer is connected to the ground end of the antenna interface, and the second end of the second impedance transformer is connected to the feeder end of the second radiating array; the first radiating array and the second radiating array are arranged symmetrically about the left and right axes, and the first radiating array and the second radiating array are both gradient structures. The embodiment of the utility model designs a radiating array with a planar structure, and the radiating array is a gradient structure; because the radiating array is a gradient structure, it can resonate within a wider frequency range, broadens the working frequency range of the antenna, and effectively improves the percentage bandwidth of the antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 It is a structural schematic diagram of a broadband dipole antenna provided by an embodiment of the utility model;

[0033] Figure 2 It is a structural schematic diagram of another broadband dipole antenna provided by an embodiment of the utility model;

[0034] Figure 3 It is a schematic diagram of the dimensions of a broadband dipole antenna provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0035] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0036] The term "including" and any other variations in the specification and claims of this solution and the above drawings mean "including but not limited to", and is intended to cover non-exclusive inclusions and is not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, not to describe a specific order.

[0037] The following is a detailed description of the implementation of the present invention in conjunction with the specific drawings:

[0038] Figure 1 A schematic diagram of the structure of a broadband dipole antenna provided by an embodiment of the utility model. Figure 1 The broadband dipole antenna comprises: a first radiating array 1, a second radiating array 2, a first impedance transformer 3, a second impedance transformer 4, a dielectric substrate 5 and an antenna interface 6;

[0039] The first radiation array 1 and the first impedance transformer 3 are both arranged on the top layer of the dielectric substrate 5;

[0040] A first end of the first impedance converter 3 is connected to a signal end of the antenna interface 6, and a second end of the first impedance converter 3 is connected to a feeder end of the first radiating element 1;

[0041] The second radiation array 2 and the second impedance transformer 4 are both arranged on the bottom layer of the dielectric substrate 5;

[0042] A first end of the second impedance converter 4 is connected to a ground end of the antenna interface 6, and a second end of the second impedance converter 4 is connected to a feeder end of the second radiating element 2;

[0043] The first radiation array 1 and the second radiation array 2 are arranged symmetrically about the left and right axes, and both the first radiation array 1 and the second radiation array 2 are gradient structures.

[0044] In the embodiment of the utility model, a dipole antenna with a planar structure is designed, in which the first radiating array 1 and the second radiating array 2 are respectively arranged on two layers of a dielectric substrate 5, so as to facilitate interconnection with an impedance converter (a first impedance converter 3 and a second impedance converter 4); the first radiating array 1 and the second radiating array 2 are symmetrically arranged about the left and right axes to form a dipole together, and the first radiating array 1 and the second radiating array 2 are both of a gradient structure, so that they can resonate within a wide frequency range to form a pure input resistance, thereby effectively broadening the working frequency range of the antenna, broadening the working bandwidth of the antenna, and further developing radar technology.

[0045] At the same time, the radiation arrays (the first radiation array 1 and the second radiation array 2) and the impedance converters (the first impedance converter 3 and the second impedance converter 4) are all designed on a dielectric substrate 5, which has a simple structure, reduces costs, and improves product consistency.

[0046] Exemplarily, the dielectric substrate 5 is a PCB board.

[0047] The PCB board has a high dielectric constant, which can effectively reduce the length of the first radiation array 1 and the second radiation array 2, and the height of the first impedance transformer 3 and the second impedance transformer 4, which is conducive to miniaturization of the antenna.

[0048] Specifically, the PCB board can be a FR4 board with a thickness of 1.6 mm, a dielectric constant of 4.4, and a loss tangent of 0.011.

[0049] In a possible implementation manner, the first impedance converter 3 and the second impedance converter 4 are both implemented using a microstrip circuit structure.

[0050] In one possible implementation, reference Figure 1 , the first radiation array 1 and the second radiation array 2 may both be trapezoidal structures;

[0051] The feeder end of the first radiating array 1 and the feeder end of the second radiating array 2 are both the upper bottom sides of the trapezoidal structure.

[0052] In the present utility model embodiment, reference Figure 1 The first radiating array 1 and the second radiating array 2 can both be trapezoidal structures, with widths increasing linearly from the feeder end to the end, and the width at the end being the largest, thereby widening the working bandwidth of the antenna.

[0053] Furthermore, the shapes of the first radiating array 1 and the second radiating array 2 are not limited to a trapezoidal structure, and the widths may also be nonlinear gradients such as various quadratic function curves, which can achieve the widening of the antenna bandwidth, and are not specifically limited.

[0054] In a possible implementation manner, the length of the upper bottom side of the trapezoidal structure of the first radiation array 1 and the upper bottom side of the trapezoidal structure of the second radiation array 2 may both be the width of a 150-ohm impedance line;

[0055] The lengths of the lower bottom sides of the trapezoidal structure of the first radiation array 1 and the lower bottom sides of the trapezoidal structure of the second radiation array 2 are both equal to the thickness of the dielectric substrate 5;

[0056] The height of the trapezoidal structure of the first radiation array 1 and the height of the trapezoidal structure of the second radiation array 2 are both

[0057] The embodiment of the utility model can meet the working requirements of the dipole antenna based on the above size settings.

[0058] In one possible implementation, reference Figure 1 , the first impedance converter 3 and the second impedance converter 4 can both be of a trapezoidal structure;

[0059] The second end of the first impedance converter 3 and the second end of the second impedance converter 4 are both the upper bottom side of the trapezoidal structure; the first end of the first impedance converter 3 and the first end of the second impedance converter 4 are both the lower bottom side of the trapezoidal structure;

[0060] The upper bottom side of the trapezoidal structure of the first impedance transformer 3 is the same length as that of the first radiating array 1 ; the upper bottom side of the trapezoidal structure of the second impedance transformer 4 is the same length as that of the second radiating array 2 .

[0061] In the embodiment of the utility model, the first impedance transformer 3 and the second impedance transformer 4 are also trapezoidal structures, and the working bandwidth of the antenna is also widened by linear gradient. The upper bottom side of the trapezoidal structure of the first impedance transformer 3 is connected to the upper bottom side of the trapezoidal structure of the first radiating array 1, and the lengths can be the same, and they are adaptively connected. Similarly, the upper bottom side of the trapezoidal structure of the second impedance transformer 4 is also the same length as the upper bottom side of the trapezoidal structure of the second radiating array 2, and they are adaptively connected.

[0062] In a possible implementation manner, the upper bottom side of the trapezoidal structure of the first impedance transformer 3 is the same length as the upper bottom side of the trapezoidal structure of the first radiation array 1, both being the width of a 150-ohm impedance line;

[0063] The length of the lower base of the trapezoidal structure of the first impedance transformer 3 is equal to the width of the 50-ohm impedance line; the length of the lower base of the trapezoidal structure of the second impedance transformer 4 is three times the width of the 50-ohm impedance line.

[0064] Based on the above size settings in the embodiment of the utility model, the working requirements of the dipole antenna can be met.

[0065] In one possible implementation, reference Figure 2 , the above broadband dipole antenna may further include: a metal reflector 7;

[0066] The metal reflector 7 is arranged vertically to the dielectric substrate 5, and the first end of the second impedance converter 4 is connected to the ground end of the antenna interface 6 through the metal reflector 7;

[0067] The first end of the second impedance transformer 4 , the metal reflector 7 and the grounding end of the antenna interface 6 are connected to a common ground.

[0068] In the embodiment of the utility model, a metal reflector 7 is provided, and the electromagnetic waves radiated downward by the radiating element are reflected to the upper part by the metal reflector 7, thereby improving the antenna gain.

[0069] In a possible implementation manner, the metal reflective plate 7 is circular, and the diameter of the metal reflective plate 7 is

[0070] The vertical distances between the metal reflector 7 and the first radiation array 1 and the second radiation array 2 are

[0071] In the embodiment of the utility model, the metal reflector 7 is circular and the distance from the radiation array is The electromagnetic waves radiated downward by the radiation array produce a phase shift of 180° at the interface of the circular metal reflector 7, and finally form an in-phase synthesis in the upper half of the radiation array, thereby improving the antenna gain in the upper hemisphere area, achieving an E-plane beam width of 84°, an H-plane beam width of 70°, and an antenna gain greater than 8dB.

[0072] The diameter of the metal reflector 7 is This allows multiple antennas to form an array when combined.

[0073] In one possible implementation, reference Figure 2 , the above broadband dipole antenna may further include: a cylindrical antenna cover 8;

[0074] The antenna cover 8 and the metal reflector 7 form a closed cavity, and the dielectric substrate 5 is arranged inside the closed cavity.

[0075] In the embodiment of the utility model, a cylindrical antenna cover 8 is provided, and the cylindrical antenna cover 8 and the metal reflector plate 7 form a closed cavity, which can effectively prevent the performance degradation caused by oxidation of the antenna due to outdoor wind and rain, realize integrated protection of the antenna, and improve the protection capability of the antenna.

[0076] Considering the influence of the radome 8 on the indexes of the broadband dipole antenna, the radome 8 can be made of polytetrafluoroethylene with a dielectric constant of 2.55 and a loss tangent of 2×10 -4 , the thickness of the antenna cover 8 is 3 mm.

[0077] In one possible implementation, reference Figure 2 The closed cavity can be filled with polyurethane foam material 9.

[0078] In the embodiment of the utility model, polyurethane foam material 9 is used to tightly fill the dielectric substrate 5, the cylindrical antenna cover 8 and the metal reflector 7, thereby improving the vibration resistance of the antenna and ensuring that the antenna can meet various application scenarios such as vehicle transportation, airborne transportation and flight vibration.

[0079] Specifically, the filling density of the polyurethane foam material 9 can be 35 kg / m 3 , the equivalent dielectric constant is about 2.2.

[0080] In a possible implementation manner, the antenna interface 6 may be an SMA interface.

[0081] Exemplarily, the SMA interface is mounted on one side of the metal reflector 7 by four fixing screws, and is grounded with the first end of the second impedance transformer 4 through the metal reflector 7. The SMA core wire is connected to the wide side of the first impedance transformer 3 through the metal reflector 7 by welding, referring to Figure 2 .

[0082] The metal reflective plate 7 may also be provided with fixing holes to facilitate the formation of the array.

[0083] The polarity is described below in conjunction with specific embodiments.

[0084] The thickness H of the dielectric substrate 5 is selected to be 1.6 mm, and the dielectric constant ε of the dielectric substrate 5 is selected to be r The copper foil thickness T is 4.4 mm, the center frequency is 5.5 GHz, and the wavelength λ is 54.5 mm.

[0085] Specifically, the width of the 50 ohm impedance line and the width of the 150 ohm impedance line can be calculated based on the following formula:

[0086]

[0087] Where, H is the thickness of the dielectric substrate 5, ε r is the dielectric constant of the dielectric substrate 5, T is the thickness of the copper foil, and W is the line width.

[0088] Based on the above formula, the width W of the 50 ohm impedance line is calculated 50Ω =2.95mm, 150 ohm impedance line width W 150Ω =0.14mm.

[0089] Since the wavelength λ = 54.5 mm, the length of the first radiation array 1 in the ideal space is Since the first radiation array 1 is implemented on the dielectric substrate 5, the length is reduced to 13.6ε due to the influence of the dielectric constant of the dielectric substrate 5. r =6.5mm.

[0090] From this we can get, reference Figure 3 The upper base length of the trapezoidal structure of the first radiation array 1 is 0.14 mm, the lower base length is 1.6 mm, and the height is 6.5 mm. The upper base length of the trapezoidal structure of the second radiation array 2 is 0.14 mm, the lower base length is 1.6 mm, and the height is 6.5 mm.

[0091] The upper base of the trapezoidal structure of the first impedance transformer 3 is 0.14 mm, the lower base is 2.95 mm long, and the two waists are 8.4 mm long.

[0092] The upper base of the trapezoidal structure of the first impedance transformer 3 is 0.14 mm, the lower base is 8.85 mm long, and the two waists are 9.3 mm long.

[0093] The vertical distance between the first impedance converter 3 and the second impedance converter 4 and the reflector is 8.25 mm according to simulation.

[0094] The percentage bandwidth of the broadband dipole antenna provided by the embodiment of the utility model is effectively broadened, and the percentage bandwidth of the antenna reaches more than 25%.

[0095] Corresponding to the above embodiment, the embodiment of the utility model further provides a radar system, including the broadband dipole antenna provided in the above embodiment, and having the advantages of the above broadband dipole antenna, which will not be described in detail here.

[0096] 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 aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A broadband dipole antenna, characterized in that: include: A first radiating array, a second radiating array, a first impedance transformer, a second impedance transformer, a dielectric substrate and an antenna interface; The first radiation array and the first impedance transformer are both arranged on the top layer of the dielectric substrate; The first end of the first impedance converter is connected to the signal end of the antenna interface, and the second end of the first impedance converter is connected to the feeder end of the first radiating array; The second radiation array and the second impedance transformer are both arranged on the bottom layer of the dielectric substrate; The first end of the second impedance transformer is connected to the ground end of the antenna interface, and the second end of the second impedance transformer is connected to the feeder end of the second radiating array; The first radiation array and the second radiation array are arranged symmetrically about the left and right axes, and both the first radiation array and the second radiation array are gradient structures.

2. The broadband dipole antenna according to claim 1, characterized in that: The first radiation array and the second radiation array are both trapezoidal structures; Wherein, the feeder end of the first radiating array and the feeder end of the second radiating array are both the upper and lower sides of the trapezoidal structure.

3. The broadband dipole antenna according to claim 2, characterized in that: The length of the upper bottom side of the trapezoidal structure of the first radiation array and the upper bottom side of the trapezoidal structure of the second radiation array are both equal to the width of a 150-ohm impedance line; The lengths of the lower base of the trapezoidal structure of the first radiation array and the lower base of the trapezoidal structure of the second radiation array are both equal to the thickness of the dielectric substrate; The height of the trapezoidal structure of the first radiation array and the height of the trapezoidal structure of the second radiation array are both λ is 4.

4. The broadband dipole antenna according to claim 2 or 3, characterized in that: The first impedance converter and the second impedance converter are both of ladder structure; The second end of the first impedance converter and the second end of the second impedance converter are both upper bases of the trapezoidal structure; the first end of the first impedance converter and the first end of the second impedance converter are both lower bases of the trapezoidal structure; Among them, the upper base of the trapezoidal structure of the first impedance transformer is the same length as the upper base of the trapezoidal structure of the first radiation array; the upper base of the trapezoidal structure of the second impedance transformer is the same length as the upper base of the trapezoidal structure of the second radiation array.

5. The broadband dipole antenna according to claim 4, characterized in that: The upper bottom side of the trapezoidal structure of the first impedance transformer is the same as the upper bottom side of the trapezoidal structure of the first radiation array, both being the width of a 150-ohm impedance line; The length of the lower bottom side of the trapezoidal structure of the first impedance transformer is equal to the width of a 50-ohm impedance line; the length of the lower bottom side of the topographic structure of the second impedance transformer is three times the width of a 50-ohm impedance line.

6. The broadband dipole antenna according to claim 1, characterized in that: Also includes: Metal reflective panels; The metal reflector is arranged vertically to the dielectric substrate, and the first end of the second impedance converter is connected to the ground terminal of the antenna interface through the metal reflector; The first end of the second impedance converter, the metal reflector and the grounding end of the antenna interface are connected to a common ground.

7. The broadband dipole antenna according to claim 6, characterized in that: The metal reflector is circular, and the diameter of the metal reflector is The vertical distances between the metal reflector and the first radiation array and the second radiation array are 8. The broadband dipole antenna according to claim 7, characterized in that: Also includes: Cylindrical radome; The radome and the metal reflector form a closed cavity, and the first radiation array, the second radiation array, the first impedance converter, the second impedance converter and the dielectric substrate are all arranged inside the closed cavity.

9. The broadband dipole antenna according to claim 8, characterized in that: The closed cavity is filled with polyurethane foaming material.

10. A radar system, characterized in that: Comprising the broadband dipole antenna as claimed in any one of claims 1 to 9.

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