Millimeter wave radar antenna and array based on grounding coplanar strip line differential in-phase series feed

Abstract

The invention discloses a millimeter wave radar antenna and array based on grounding coplanar strip line differential in-phase series feed, the antenna comprises a radiator, a dielectric plate and a floor which are sequentially arranged from top to bottom, the radiator comprises a plurality of pairs of dipole units and a plurality of pairs of transmission lines, the plurality of pairs of dipole units and the plurality of pairs of transmission lines are in one-to-one correspondence and are arranged along the axial direction, and the plurality of pairs of transmission lines are in one-to-one correspondence. Each pair of dipole units is provided with two radiation arms which are oppositely arranged to form a butterfly-shaped structure, the multiple pairs of transmission lines are connected in sequence, each pair of transmission lines is provided with two transmission lines which are parallel to each other, and the two transmission lines are connected with the two corresponding dipole units respectively. According to the antenna, a differential in-phase series feed technical scheme is utilized, side-emission wave beams are achieved in a millimeter wave band, meanwhile, the antenna has the advantages of being wide in broadband, high in gain, simple and compact in structure and the like, and an array formed by the antenna has the broadband wide-angle scanning characteristic and has remarkable application potential in broadband communication and radar systems.

Description

Technical Field

[0001] The invention relates to a millimeter wave radar antenna and an array based on grounded coplanar strip line differential in-phase series feeding, belonging to the technical field of wireless communication. Background Art

[0002] With the rapid development of wireless communication technology, antennas are key components for signal transmission and reception, and their performance has a decisive impact on the overall efficiency of the communication system. Especially in the millimeter wave frequency band, the design of antennas faces higher technical challenges, and wide bandwidth and high gain have become important indicators for measuring antenna performance. In the prior art, for example, patent CN114447594B proposed an improved design method for a broadband capacitively coupled comb-type series-fed antenna, which achieved a bandwidth of 6.25% (76-81 GHz), which was a significant improvement at the time. However, with the demand for wider bandwidth in wireless communication systems, this bandwidth is still limited. Chinese invention patent CN109786985B shows a rectangular microstrip series-fed antenna based on a grounded coplanar waveguide, which has a bandwidth of 4.2% (23.5-24.5 GHz). Although it has its value in specific applications, for broadband communication systems, this bandwidth is not enough to meet the needs of a wider range of applications; in addition, Chinese utility model patent CN218569225U proposes an ultra-wideband antenna and communication equipment, which has a bandwidth of 9.68% (7.5-8.25 GHz) when the S parameter reaches -5 dB. Although this indicator reflects the broadband performance of the antenna to a certain extent, it does not meet the performance requirements under the optimal working state. Summary of the invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a millimeter-wave radar antenna based on grounded coplanar stripline differential in-phase series feeding. The antenna can achieve precise control of performance by controlling the width of the transmission line and the phase difference of the radiator, which not only improves the working efficiency of the antenna, but also helps to reduce manufacturing costs. It exhibits high gain, wide bandwidth and good impedance matching performance in the Ka band. These characteristics work together and have significant application potential in broadband communications and radar systems.

[0004] The second object of the present invention is to provide a millimeter wave radar antenna array based on grounded coplanar strip line differential in-phase series feeding.

[0005] The third object of the present invention is to provide a millimeter wave radar comprising the above-mentioned millimeter wave radar antenna or antenna array.

[0006] A fourth object of the present invention is to provide a wireless communication device including the above-mentioned millimeter wave radar.

[0007] The first object of the present invention can be achieved by adopting the following technical solutions:

[0008] A millimeter wave radar antenna based on grounded coplanar stripline differential in-phase series feeding comprises a radiator, a dielectric plate and a floor arranged in sequence from top to bottom, wherein the radiator comprises a plurality of pairs of dipole units and a plurality of pairs of transmission lines, the plurality of pairs of dipole units and the plurality of pairs of transmission lines correspond to each other one by one and are arranged in an axial direction, each pair of dipole units comprises two radiating arms arranged opposite to each other to form a butterfly structure, the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines comprises two sections of transmission lines parallel to each other, and the two sections of transmission lines are respectively connected to the corresponding two radiating arms.

[0009] Furthermore, the width of each radiation arm gradually decreases from an end away from the transmission line to an end connected to the transmission line.

[0010] Furthermore, the width of each transmission line segment of the plurality of pairs of transmission lines gradually decreases along the axial direction.

[0011] Furthermore, the width of each transmission line segment of the first pair of transmission lines in the axial direction is 0.036λ-0.04λ, and the width of each transmission line segment of the last pair of transmission lines is 0.01λ~0.03λ, wherein λ is the wavelength of the antenna.

[0012] Furthermore, the width of each transmission line segment of the first pair of transmission lines in the axial direction is 0.038λ, and the width of each transmission line segment of the last pair of transmission lines is 0.02λ.

[0013] Furthermore, the length of each transmission line segment of each pair of transmission lines is 0.59λ to 0.62λ.

[0014] Furthermore, the radiation direction of the radiator is perpendicular to the plane where the radiator is located.

[0015] Furthermore, the radiator is made of metallic copper material.

[0016] The second object of the present invention can be achieved by adopting the following technical solutions:

[0017] A millimeter wave radar antenna array based on grounded coplanar stripline differential in-phase series feeding comprises a radiator, a dielectric plate and a floor arranged in sequence from top to bottom, wherein the radiator comprises N×N pairs of dipole units and N×N pairs of transmission lines, the N pairs of dipole units and the N pairs of transmission lines correspond to each other one by one and are arranged in an axial direction, each pair of dipole units has two radiating arms arranged opposite to each other to form a butterfly structure, a plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines has two sections of transmission lines parallel to each other, and the two sections of transmission lines are respectively connected to the corresponding two radiating arms.

[0018] The third object of the present invention can be achieved by adopting the following technical solutions:

[0019] A millimeter wave radar comprises the above-mentioned millimeter wave radar antenna, or comprises the above-mentioned millimeter wave radar antenna array.

[0020] The third object of the present invention can be achieved by adopting the following technical solutions:

[0021] A wireless communication device comprises the above-mentioned millimeter wave radar.

[0022] The present invention has the following beneficial effects compared with the prior art:

[0023] 1. The antenna of the present invention realizes the side-firing characteristic through the in-phase series feeding design between each pair of dipole units, so that the antenna has a stronger radiation capability in a specific direction, which is particularly important in application scenarios that require directional radiation, such as radar monitoring and satellite communications. Unlike traditional end-fire antennas, the antenna of the present invention adopts differential in-phase series feeding technology. Each pair of radiators is in-phase series fed with a phase difference of 0° or 360°, thereby realizing the side-firing characteristic and significantly improving the integrity of the signal. This design reduces the phase error and amplitude fluctuation of the signal during transmission. Due to the opposite phases of the differential signals on the two lines, the electromagnetic fields they generate cancel each other out in space. The differential series feeding design helps to achieve good impedance matching between the antenna and the feeding network.

[0024] 2. The antenna of the present invention operates in the frequency range of 26.60 GHz to 29.49 GHz, with a center frequency of 28 GHz, achieving a fractional bandwidth of 10.32%. This wide bandwidth characteristic provides abundant frequency resources for broadband communication systems, significantly improving the flexibility and adaptability of the system, especially within the 21.4% range of the Ka band, showing its potential for wide application in modern wireless communication systems; in addition, the maximum gain of the antenna of the present invention reaches 12.03 dB. This high gain characteristic significantly improves the signal radiation and receiving capabilities of the antenna, which plays an important role in improving the communication distance and signal quality, especially in environments with poor signal propagation conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 the structures shown in these drawings without paying creative work.

[0026] Figure 1 This is a three-dimensional structural diagram of a millimeter-wave radar antenna based on grounded coplanar stripline differential in-phase series feeding according to Example 1 of the present invention.

[0027] Figure 2This is a planar structural diagram of a radiator in a millimeter-wave radar antenna based on grounded coplanar stripline differential in-phase series feeding according to Embodiment 1 of the present invention.

[0028] Figure 3 This is a diagram of S-parameter simulation results of the millimeter-wave radar antenna based on grounded coplanar stripline differential in-phase series feeding according to Example 1 of the present invention.

[0029] Figure 4 This is a frequency gain diagram of the millimeter wave radar antenna based on grounded coplanar stripline differential in-phase series feeding according to Example 1 of the present invention.

[0030] Figure 5 This is a three-dimensional structural diagram of a millimeter-wave radar antenna array based on grounded coplanar stripline differential in-phase series feeding according to Example 2 of the present invention.

[0031] Among them, 1-radiator, 101-first pair of dipole units, 102-second pair of dipole units, 103-third pair of dipole units, 104-fourth pair of dipole units, 105-first pair of transmission lines, 106-second pair of transmission lines, 107-third pair of transmission lines, 108-fourth pair of transmission lines, 2-dielectric board, 3-floor. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Embodiment 1:

[0034] like Figure 1 and Figure 2As shown, this embodiment provides a millimeter wave radar antenna based on grounded coplanar stripline differential in-phase series feeding, the antenna includes a radiator 1, a dielectric plate 2 and a floor 3 arranged in sequence from top to bottom, that is, the radiator 1 is arranged on the upper surface of the dielectric plate 2, and the floor 3 is arranged on the lower surface of the dielectric plate 2. The radiator 1 radiates along the z-axis direction, that is, the radiation direction of the radiator 1 is perpendicular to the plane where the radiator 1 is located. The radiator 1 includes four pairs of dipole units and four pairs of transmission lines. The four pairs of dipole units and the four pairs of transmission lines correspond to each other one by one and are arranged along the axial direction. The four pairs of dipole units along the axial direction (from left to right) are respectively a first pair of dipole units 101, a second pair of dipole units 102, a third pair of dipole units 103 and a fourth pair of dipole units 10 4. The four pairs of transmission lines are respectively a first pair of transmission lines 105, a second pair of transmission lines 106, a third pair of transmission lines 107 and a fourth pair of transmission lines 108 along the axial direction (from left to right along the y-axis direction). Each pair of dipole units has two radiating arms that are relatively arranged to form a butterfly structure. The four pairs of transmission lines are connected in sequence. Each pair of transmission lines constitutes a pair of differential feeders, which have two sections of transmission lines parallel to each other, that is, one section of the four pairs of transmission lines is connected in sequence, and the other section of the four pairs of transmission lines is connected in sequence. The two sections of each pair of transmission lines are respectively connected to the corresponding two radiating arms. The cascade design of the antenna enhances the overall gain and directional radiation performance, while maintaining the simplicity and miniaturization of the structure, which is easy to integrate into modern wireless communication equipment.

[0035] In one embodiment, the width of each radiating arm gradually decreases from an end away from the transmission line to an end connected to the transmission line, and each radiating arm is disposed on the upper surface of the dielectric plate 2 by printing.

[0036] In one embodiment, the width of each transmission line segment of the four pairs of transmission lines gradually decreases along the axial direction, that is, the width of each transmission line segment of the first pair of transmission lines 105 is greater than the width of each transmission line segment of the second pair of transmission lines 106, the width of each transmission line segment of the second pair of transmission lines 106 is greater than the width of each transmission line segment of the third pair of transmission lines 107, and the width of each transmission line segment of the third pair of transmission lines 107 is greater than the width of each transmission line segment of the fourth pair of transmission lines 108.

[0037] In one embodiment, the width of each transmission line segment of the first pair of transmission lines 105 is 0.038λ, the width of each transmission line segment of the fourth pair of transmission lines 108 is 0.02λ, and the length of each transmission line segment of the four pairs of transmission lines is 0.59λ~0.62λ, with little change. This fine size adjustment ensures the efficiency and stability of the signal during transmission, while achieving high gain and side-shooting characteristics of the antenna within a wide bandwidth. The step-by-step tapering design of the transmission line helps to optimize signal transmission and matching, and improve the overall performance of the antenna.

[0038] The millimeter wave radar antenna of this embodiment adopts a three-layer structure, combined with material selection and size control, so that the antenna provides high gain, wide bandwidth and good directional radiation characteristics while maintaining miniaturization, which is very suitable for the needs of modern wireless communication systems, and adopts differential series feeding technology, which is different from the differential series feeding design of the traditional end-fire antenna. The traditional antenna achieves end-fire by realizing a phase difference of 180° between each pair of dipole units, while this embodiment achieves side-fire characteristics by realizing in-phase series feeding between each pair of radiators with a phase difference of 0° or 360°. This design allows the antenna to achieve side-fire while maintaining wide bandwidth and high gain, which is particularly important for radar systems and communication systems. In the antenna structure, the use of coplanar strip lines simplifies the design and only uses one layer of dielectric. This material is suitable for high-frequency applications due to its excellent electrical properties and mechanical strength. The radiator uses metal copper material to ensure efficient electromagnetic wave radiation. In addition, the antenna has a compact structure and uses a single-layer dielectric board. The specific size of the dielectric board is 33.8 mm×7 mm×1.07 mm. This design optimizes space occupancy, making it suitable for application scenarios with strict size requirements.

[0039] like Figure 3 As shown in the figure, the S parameter simulation result of the millimeter wave radar antenna of this embodiment is shown in the figure. 11 Parameter diagram, S 11 The parameter is a key indicator to measure the reflection coefficient of the antenna input port. The lower its value, the better the impedance matching performance of the antenna. antenna =Z feedline The smaller the reflection loss, the Figure 3 It can be seen that the millimeter-wave radar antenna of this embodiment exhibits excellent impedance matching performance in the frequency range of 26.60GHz to 29.49GHz. The value of the S parameter of the antenna in the frequency range of 26.98GHz to 29.49GHz is less than -10dB, which further confirms the good performance of the antenna at these frequency points. The millimeter-wave radar antenna of this embodiment enables it to work in the frequency band of 26.60GHz to 29.49GHz, providing a fractional bandwidth of 10.32%. The calculation of this fractional bandwidth is based on the center frequency of 28GHz, indicating that the antenna can cover 21.4% of the bandwidth in the Ka band. This wide bandwidth feature is particularly important for modern broadband communication systems because it allows the antenna to maintain high performance in a wider frequency range; it can be seen that the millimeter-wave radar antenna exhibits high gain, wide bandwidth and good impedance matching performance in the Ka band. These features work together to make the antenna have significant application potential in broadband communication and radar systems.

[0040] like Figure 4As shown, it is a frequency gain diagram of the millimeter-wave radar antenna of this embodiment, which details the gain characteristics of the antenna in the operating frequency band of 26.60 GHz to 29.49 GHz. At the frequency point of 26.60 GHz, the antenna achieves its highest gain, reaching 12.03 dB. This significant gain value highlights the excellent radiation capability of the antenna at this frequency. In addition, the 3 dB gain bandwidth range of the antenna is between 24.63 GHz and 28.61 GHz. This wider bandwidth range ensures that the antenna can maintain high gain at multiple frequency points, thereby providing greater flexibility and reliability for broadband communication systems. This wide bandwidth characteristic is particularly important for modern wireless communication systems because it allows the system to operate effectively over a wider frequency range, enhancing signal coverage and transmission efficiency. The millimeter-wave radar antenna of this embodiment exhibits excellent frequency gain characteristics in the Ka band, not only providing high gain near the center frequency, but also maintaining stable performance throughout the entire operating frequency band. These characteristics work together to make the antenna very suitable for broadband communications, radar monitoring, and advanced applications requiring high resolution and precise detection. Through this design, the antenna exhibits significant advantages in improving signal transmission efficiency and reducing interference, providing a high-performance solution for millimeter-wave radar and other broadband communication applications.

[0041] Embodiment 2:

[0042] This embodiment further designs a millimeter wave radar antenna array based on grounded coplanar strip line differential in-phase series feeding, such as Figure 5 As shown, the radiator 1 includes 4×4 pairs of dipole units and 4×4 pairs of transmission lines, that is, it is composed of 4 rows and 4 columns of butterfly dipole units. Each pair of dipole units is connected by a differential in-phase series feed line to achieve in-phase series feeding, thereby achieving side-firing characteristics while maintaining wide bandwidth and high gain, and has wide bandwidth angle scanning capability in the xoz plane. This 4×4 array configuration antenna design not only inherits all the advantages of a single antenna unit, such as high gain, wide bandwidth and good directional radiation performance, but also has beam scanning capability and easy array formation. Through the array configuration, the antenna can achieve a wider coverage range and more flexible beam direction control, which is a significant advantage for radar systems and communication systems.

[0043] In addition, the introduction of the array configuration increases the overall gain of the antenna. Due to the collaborative work of multiple radiating arms, the antenna array can concentrate more energy to radiate in a specific direction, thereby further improving the gain of the antenna. This design not only improves the performance of the antenna, but also provides new directions for future antenna design, especially in applications that require high gain and precise beam control.

[0044] The 1 marked in the figure indicates each pair of dipole units, which play a key role in the overall radiation characteristics of the antenna. This design of the antenna allows the overall gain to be improved by increasing the number of radiators while maintaining miniaturization, and also provides a structural basis for achieving beam scanning capabilities.

[0045] In summary, the antenna array design of this embodiment demonstrates the potential of the millimeter-wave radar antenna based on the grounded coplanar stripline differential in-phase series feeding technology in practical applications. Its beam scanning capability, easy array formation characteristics and further increased gain make it a promising technical choice in future wireless communications and radar systems.

[0046] In summary, the antenna of the present invention is designed for high-frequency applications in the Ka band, which significantly expands the utilization range of this band. The working frequency band of the antenna extends from 26.60 GHz to 29.49 GHz, occupying 21.4% of the bandwidth of the Ka band, providing a wider frequency coverage in the Ka band, not only maintaining high gain in a wide bandwidth, but also having a simple structure, which is easy to integrate into modern wireless communication equipment, and providing a high-performance solution for Ka-band radar and other broadband communication applications. By precisely controlling the size of the feeder, it can adapt to different frequencies and radiation modes, thereby optimizing its performance; in addition, the antenna of the present invention also takes into account the optimization of the manufacturing process, and by precisely controlling the feeder width and the phase difference of the radiator, it achieves precise control of the antenna performance, which not only improves the working efficiency of the antenna, but also helps to reduce manufacturing costs.

[0047] The above is only a preferred embodiment of the present invention, but the implementation of the present invention is not limited to the above embodiment. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A millimeter wave radar antenna based on grounded coplanar stripline differential in-phase series feeding, characterized in that: The invention comprises a radiator, a dielectric plate and a floor arranged in sequence from top to bottom, wherein the radiator comprises a plurality of pairs of dipole units and a plurality of pairs of transmission lines, the plurality of pairs of dipole units and the plurality of pairs of transmission lines correspond to each other one by one and are arranged along the axial direction, each pair of dipole units comprises two radiating arms arranged opposite to each other to form a butterfly structure, the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines comprises two sections of transmission lines parallel to each other, and the two sections of transmission lines are respectively connected to the corresponding two radiating arms.

2. The millimeter wave radar antenna according to claim 1, characterized in that: The width of each radiating arm gradually decreases from an end away from the transmission line to an end connected to the transmission line.

3. The millimeter wave radar antenna according to claim 1, characterized in that: The width of each transmission line segment of the plurality of transmission lines gradually decreases along the axial direction.

4. The millimeter wave radar antenna according to claim 3, characterized in that: The width of each transmission line segment of the first pair of transmission lines in the axial direction is 0.036λ-0.04λ, and the width of each transmission line segment of the last pair of transmission lines is 0.01λ~0.03λ, wherein λ is the wavelength of the antenna.

5. The millimeter wave radar antenna according to claim 4, characterized in that: The width of each transmission line segment of the first pair of transmission lines in the axial direction is 0.038λ, and the width of each transmission line segment of the last pair of transmission lines is 0.02λ.

6. The millimeter wave radar antenna according to claim 1, characterized in that: The length of each transmission line segment of each pair of transmission lines is 0.59λ~0.62λ.

7. The millimeter wave radar antenna according to any one of claims 1 to 6, characterized in that: The radiation direction of the radiator is perpendicular to the plane where the radiator is located.

8. A millimeter wave radar antenna array based on grounded coplanar stripline differential in-phase series feeding, characterized in that: The invention comprises a radiator, a dielectric plate and a floor which are arranged in sequence from top to bottom. The radiator comprises N×N pairs of dipole units and N×N pairs of transmission lines. The N pairs of dipole units correspond to the N pairs of transmission lines one by one and are arranged in the axial direction. Each pair of dipole units has two radiating arms which are arranged opposite to each other to form a butterfly structure. The multiple pairs of transmission lines are connected in sequence. Each pair of transmission lines has two sections of transmission lines which are parallel to each other. The two sections of transmission lines are respectively connected to the corresponding two radiating arms.

9. A millimeter wave radar, characterized in that: The invention comprises the millimeter wave radar antenna as described in any one of claims 1 to 7, or comprises the millimeter wave radar antenna array as described in claim 8.

10. A wireless communication device, characterized in that: Including the millimeter wave radar as described in claim 9.

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