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

Abstract

The application discloses a kind of millimeter wave radar antennas and array based on ground coplanar strip line differential in-phase series feed, the antenna includes sequentially arranged from top to bottom radiator, dielectric plate and floor, radiator includes multiple pairs of dipole units and multiple pairs of transmission lines, multiple pairs of dipole units and multiple pairs of transmission lines one-to-one correspondence, and along axial arrangement, each pair of dipole units has two radiation arms of butterfly structure formed by opposite arrangement, multiple pairs of transmission lines are sequentially connected, each pair of transmission lines has two transmission lines parallel to each other, and two transmission lines are connected with corresponding two dipole units respectively.The antenna of the application utilizes differential in-phase series feed technical scheme, realizes side shooting beam in millimeter wave band, and also has the advantages of wide bandwidth, high gain, simple and compact structure, etc., and the array composed of the antenna has wide bandwidth angle scanning characteristics, and has significant application potential in wideband communication and radar system.

Description

TECHNICAL FIELD

[0001] The application relates to a millimeter wave radar antenna based on ground coplanar strip line differential in-phase series feed, and belongs to the technical field of wireless communication. BACKGROUND

[0002] In the rapid development of wireless communication technology, the antenna as the key component of signal transmission and reception, its performance has a decisive influence on the overall efficiency of the communication system, especially in the millimeter wave frequency band, the design of the antenna faces higher technical challenges, wide bandwidth and high gain become important indicators to measure the performance of the antenna. In the prior art, such as patent CN114447594B proposes an improved design method of wideband capacitively coupled comb series feed antenna, which realizes a bandwidth of 6.25% (76-81GHz), which is a significant progress at that time, but with the demand of wireless communication system for wider bandwidth, this bandwidth is still limited, Chinese invention patent CN109786985B shows a rectangular microstrip series feed antenna based on ground coplanar waveguide, its bandwidth is 4.2% (23.5-24.5GHz), although it has its value in specific applications, but for wideband communication system, this bandwidth is not enough to meet the wider application requirements; In addition, Chinese utility model patent CN218569225U proposes an ultra-wideband antenna and communication equipment, the bandwidth of the antenna is 9.68% (7.5-8.25GHz) when the S parameter reaches-5dB, although this index reflects the wideband performance of the antenna to some extent, but it does not meet the performance requirements in the optimal working state. SUMMARY

[0003] The first object of the application is to overcome the shortcomings and deficiencies of the prior art, and to provide a millimeter wave radar antenna based on ground coplanar strip line differential in-phase series feed, which can realize precise control of performance by controlling the width of the transmission line and the phase difference of the radiator, not only improve the working efficiency of the antenna, but also help to reduce the manufacturing cost, and show high gain, wide bandwidth and good impedance matching performance in Ka band. These characteristics work together and have significant application potential in wideband communication and radar systems.

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

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

[0006] The fourth object of the application is to provide a wireless communication device containing the above-mentioned millimeter wave radar.

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

[0008] A millimeter wave radar antenna based on grounded coplanar strip line differential in-phase series feed comprises a radiator, a dielectric plate and a ground plate arranged in sequence 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 one-to-one corresponding and arranged along an axial direction, each pair of dipole units has two radiation arms arranged oppositely to form a butterfly structure, and the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines has two transmission line segments parallel to each other, and the two transmission line segments are connected with the corresponding two radiation arms respectively.

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

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

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

[0012] Further, the width of each transmission line segment of the first pair of transmission lines along the axial direction is 0.038 lambda, and the width of each transmission line segment of the last pair of transmission lines along the axial direction is 0.02 lambda.

[0013] Further, the length of each transmission line segment of each pair of transmission lines is 0.59 lambda-0.62 lambda.

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

[0015] Further, the radiator is made of metal copper material.

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

[0017] A millimeter wave radar antenna array based on grounded coplanar strip line differential in-phase series feed comprises a radiator, a dielectric plate and a ground plate 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 and the N pairs of transmission lines are one-to-one corresponding and arranged along an axial direction, each pair of dipole units has two radiation arms arranged oppositely to form a butterfly structure, and the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines has two transmission line segments parallel to each other, and the two transmission line segments are connected with the corresponding two radiation arms respectively.

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

[0019] A millimeter wave radar comprising the millimeter wave radar antenna described above, or comprising the millimeter wave radar antenna array described above.

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

[0021] A wireless communication device comprising the millimeter wave radar described above.

[0022] The present application has the following beneficial effects relative to the prior art:

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

[0024] 2、The antenna of the present application operates in a frequency range of 26.60GHz-29.49GHz with a center frequency of 28GHz, realizing a fractional bandwidth of 10.32%, which provides abundant frequency resources for wideband communication systems and significantly improves the flexibility and adaptability of the system, and in particular in the 21.4% range of the Ka band, it shows its potential for widespread application in modern wireless communication systems; in addition, the maximum gain of the antenna of the present application reaches 12.03dB, which significantly improves the signal radiation and reception capability of the antenna and plays an important role in improving the communication distance and signal quality, especially in environments with poor signal propagation conditions. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below, and obviously, the drawings in the following description can only be some embodiments of the present application, and those skilled in the art can obtain other drawings from the structures shown in these drawings without creative labor.

[0026] Figure 1 A perspective view of the millimeter wave radar antenna based on the grounded coplanar strip differential in-phase series feeding of the present application embodiment 1.

[0027] Figure 2A planar structure diagram of a radiator in a millimeter wave radar antenna based on grounded coplanar strip line differential in-phase series feed of embodiment 1 of the present application.

[0028] Figure 3 A S parameter simulation result diagram of a millimeter wave radar antenna based on grounded coplanar strip line differential in-phase series feed of embodiment 1 of the present application.

[0029] Figure 4 A frequency gain diagram of a millimeter wave radar antenna based on grounded coplanar strip line differential in-phase series feed of embodiment 1 of the present application.

[0030] Figure 5 A perspective structure diagram of a millimeter wave radar antenna array based on grounded coplanar strip line differential in-phase series feed of embodiment 2 of the present application.

[0031] Wherein, 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 plate, 3-ground plate. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] Embodiment 1:

[0034] As Figure 1 and Figure 2As shown, the embodiment provides a millimeter wave radar antenna based on grounded coplanar strip line differential in-phase series feed, which comprises a radiator 1, a dielectric plate 2 and a ground plate 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 ground plate 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 comprises 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 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 104, and the four pairs of transmission lines along the axial direction (from left to right along the y-axis direction) 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, each pair of dipole units has two radiation arms arranged oppositely 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 feed lines, which has two transmission lines parallel to each other, that is, one of the four pairs of transmission lines is connected in sequence, the other of the four pairs of transmission lines is connected in sequence, and the two transmission lines of each pair of transmission lines are connected with the corresponding two radiation arms, the cascade design of the antenna enhances the overall gain and directional radiation performance, while maintaining the simplicity and miniaturization of the structure, facilitating integration into modern wireless communication devices.

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

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

[0037] In one embodiment, the width of each segment of the first pair of transmission lines 105 is 0.038λ, the width of each segment of the fourth pair of transmission lines 108 is 0.02λ, and the length of each segment of the four pairs of transmission lines is 0.59λ-0.62λ, which does not change much. This fine size adjustment ensures the efficiency and stability of the signal during transmission, while achieving high gain and broadside characteristics of the antenna in a wide bandwidth range. The step-by-step thinning design of the transmission lines helps to optimize signal transmission and matching, and improves the overall performance of the antenna.

[0038] The millimeter wave radar antenna of the embodiment adopts a three-layer structure, and in combination with material selection and size control, the antenna provides high gain, wide bandwidth and good directional radiation characteristics while maintaining miniaturization, is very suitable for the needs of modern wireless communication systems, and adopts a differential series feed technology. Unlike the differential series feed design of a conventional end-fire antenna, the conventional antenna realizes end-fire by realizing a phase difference of 180° between each pair of dipole units, while the embodiment realizes side-fire characteristics by realizing a phase difference of 0° or 360° between each pair of radiators through in-phase series feed, so that side-fire is realized while maintaining wide bandwidth and high gain, which is particularly important for radar systems and communication systems. In the antenna structure, the use of a coplanar strip line simplifies the design and only one layer of dielectric is used. This material is suitable for high-frequency applications due to its excellent electrical properties and mechanical strength, and the radiator is made of metal copper material to ensure efficient electromagnetic wave radiation. In addition, the antenna has a compact structure and uses a single layer of dielectric plate with specific dimensions of 33.8mm x 7mm x 1.07mm. This design optimizes space occupation, making it suitable for applications with strict size requirements.

[0039] As shown in Figure 3 , it is the S parameter simulation result of the millimeter wave radar antenna of the embodiment, specifically an S 11 parameter diagram. The S 11 parameter is a key indicator for measuring the reflection coefficient of the input port of the antenna. The lower the value, the better the impedance matching performance of the antenna, that is, Z antenna = Z feedline reflected loss is smaller. As can be seen from Figure 3 , the millimeter wave radar antenna of the embodiment exhibits excellent impedance matching performance in the frequency range of 26.60GHz-29.49GHz. The value of the S parameter of the antenna in the frequency range of 26.98GHz-29.49GHz is less than -10dB, further confirming the good performance of the antenna at these frequency points. The millimeter wave radar antenna of the embodiment operates in the frequency band of 26.60GHz-29.49GHz, providing a fractional bandwidth of 10.32%. This fractional bandwidth is calculated based on the center frequency of 28GHz, indicating that the antenna can cover a bandwidth of 21.4% in the Ka band. This wide bandwidth characteristic is particularly important for modern wideband communication systems, as it allows the antenna to maintain high performance over 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 characteristics work together to make the antenna have significant application potential in wideband communication and radar systems.

[0040] As shown in Figure 4As shown, the frequency gain plot of the millimeter wave radar antenna of the present embodiment, which depicts in detail the gain characteristics of the antenna within the operating frequency band of 26.60GHz~29.49GHz, achieves its highest gain of 12.03dB at the frequency point of 26.60GHz, which highlights the outstanding radiation capability of the antenna at this frequency; in addition, the 3dB gain bandwidth range of the antenna is between 24.63GHz and 28.61GHz, which 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, as it allows the system to operate effectively within a wider frequency range, enhancing signal coverage and transmission efficiency; the millimeter wave radar antenna of the present 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 operating frequency band, which together make the antenna very suitable for broadband communication, radar monitoring, and advanced applications that require 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] The present embodiment further designs a millimeter wave radar antenna array based on grounded coplanar strip line differential in-phase series feed, as shown in Figure 5 The radiator 1 includes 4x4 pairs of dipole units and 4x4 pairs of transmission lines, i.e., composed of 4 rows and 4 columns of butterfly dipole units, each pair of dipole units is connected by differential in-phase series feed lines, realizing in-phase series feed, thereby achieving side shooting characteristics while maintaining wide bandwidth and high gain, and having wide bandwidth angle scanning capability in the xoz plane. This 4x4 array configuration antenna design not only inherits all the advantages of individual antenna units, such as high gain, wide bandwidth, and good directional radiation performance, but also has beam scanning capability and ease of arraying characteristics. Through array configuration, the antenna can achieve wider coverage and more flexible beam direction control, which is a significant advantage for radar systems and communication systems.

[0043] In addition, the introduction of array configuration increases the overall gain of the antenna, as multiple radiation arms work together, 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 a new direction for future antenna design, especially in applications that require high gain and precise beam control.

[0044] The marked 1 in the figure indicates each pair of dipole units, which plays a key role in the total radiation characteristics of the antenna, and this design of the antenna allows to increase the overall gain by increasing the number of radiators while maintaining miniaturization, while also providing a structural basis for implementing beam scanning capabilities.

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

[0046] In summary, the antenna of the present application is designed for high frequency applications in the Ka band, significantly expanding the utilization range of this band, with an operating frequency range from 26.60 GHz to 29.49 GHz, occupying 21.4% of the bandwidth of the Ka band, providing wider frequency coverage in the Ka band, not only maintaining high gain within a wide bandwidth, but also having a simple structure, facilitating integration into modern wireless communication devices, providing a high-performance solution for Ka-band radar and other wideband communication applications, and by precisely controlling the size of the feed line, it can adapt to different frequencies and radiation patterns to optimize its performance; In addition, the antenna of the present application also considers the optimization of the manufacturing process, by precisely controlling the feed line width and the phase difference of the radiators, the performance of the antenna is precisely controlled, not only improving the working efficiency of the antenna, but also helping to reduce the manufacturing cost.

[0047] The above is only a preferred embodiment of the present application, but the implementation of the present application is not limited to the above-mentioned embodiment, any change, modification, substitution, combination, simplification made without departing from the spirit and principles of the present application, all should be equivalent replacement method, all are included in the protection scope of the present application.

Claims

1. A millimeter wave radar antenna based on grounded coplanar stripline differential in-phase series feed, characterized by, The antenna comprises a radiator, a dielectric plate and a ground plate arranged in sequence from top to bottom, the radiator comprises a plurality of pairs of dipole units and a plurality of pairs of transmission lines, the pairs of dipole units and the pairs of transmission lines are in one-to-one correspondence and arranged along an axial direction, each pair of dipole units has two radiation arms arranged oppositely to form a butterfly structure, the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines has two transmission lines parallel to each other, the two transmission lines are connected to the corresponding two radiation arms respectively, each pair of transmission lines constitutes a pair of differential in-phase series feed lines, each pair of dipole units is connected through the differential in-phase series feed lines, and in-phase series feed is realized, and a phase difference is 0° or 360°.

2. The millimeter-wave radar antenna according to claim 1, characterized in that The width of each radiation 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 of the plurality of pairs 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 of the first pair of transmission lines along the axial direction is 0.036λ-0.04λ, and the width of each transmission line of the last pair of transmission lines along the axial direction 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 of the first pair of transmission lines along the axial direction is 0.038λ, and the width of each transmission line of the last pair of transmission lines along the axial direction is 0.02λ.

6. The millimeter-wave radar antenna of claim 1, wherein, The length of each transmission line 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 in which the radiator is located.

8. A millimeter wave radar antenna array based on grounded coplanar stripline differential in-phase series feed, characterized in that, The antenna comprises a radiator, a dielectric plate and a ground plate 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 and the N pairs of transmission lines are in one-to-one correspondence and arranged along an axial direction, each pair of dipole units has two radiation arms arranged oppositely to form a butterfly structure, the plurality of pairs of transmission lines are connected in sequence, each pair of transmission lines has two transmission lines parallel to each other, the two transmission lines are connected to the corresponding two radiation arms respectively, each pair of transmission lines constitutes a pair of differential in-phase series feed lines, each pair of dipole units is connected through the differential in-phase series feed lines, and in-phase series feed is realized, and a phase difference is 0° or 360°.

9. A millimeter wave radar, characterized by, The millimeter wave radar antenna comprises the millimeter wave radar antenna array.

10. A wireless communication device, comprising: The millimeter wave radar comprises the millimeter wave radar.

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