Traveling wave array antenna design method and traveling wave array antenna

Abstract

The embodiment of the invention provides a traveling wave array antenna design method and a traveling wave array antenna, and the design method comprises the steps: determining the number and shape of radiation units required by a target traveling wave array antenna, an antenna polarization mode and a series feed mode according to the performance demand index of the target traveling wave array antenna; the radiation current or radiation power of each radiation unit is determined through shaping weighted design; simulating and analyzing the energy loss characteristics on the main feeder line; calculating and determining the radiation conductance of each radiation unit; determining the width and resonance length of each radiation unit; forming an initial linear array; the initial impedance value of the input end of the initial linear array is set in a simulation mode, and a terminal load matched with the initial linear array is designed in a simulation mode based on the initial impedance value; and after the terminal load matching design is completed, performing impedance matching design on the input end of the initial linear array to obtain a target traveling wave array antenna with a target impedance value. According to the embodiment, the working bandwidth of the antenna can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a design method for a traveling wave array antenna and a traveling wave array antenna. Background Technology

[0002] Vehicle-mounted millimeter-wave radar uses microstrip array antennas to transmit and receive millimeter waves. Currently, the microstrip array antennas used in vehicle-mounted millimeter-wave radar are typically standing wave array antennas.

[0003] However, the inventors discovered in practice that using a standing wave antenna results in a relatively narrow impedance bandwidth, typically only 1~2GHz. Moreover, the more radiating elements there are, the narrower the impedance bandwidth becomes. A narrow operating bandwidth leads to low range resolution of the vehicle radar. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a design method for a traveling wave array antenna, which results in a traveling wave array antenna with a wider operating bandwidth.

[0005] A further technical problem to be solved by the embodiments of the present invention is to provide a traveling wave array antenna with a wider operating bandwidth.

[0006] To address the aforementioned technical problems, this invention first provides the following technical solution: a design method for a traveling wave array antenna, comprising the following steps: Based on the performance requirements of the target traveling wave array antenna, determine the number and shape of the radiating elements, antenna polarization, and series feed configuration required for the target traveling wave array antenna; The radiation current or radiation power of each radiation element is determined by shape-weighted design. Simulation analysis of energy loss characteristics on the main feeder; The radiation conductivity of each radiation unit is calculated and determined by combining the energy loss characteristics and the radiation current or radiation power of each radiation unit. The width and resonant length of each radiating element are determined based on the energy loss characteristics and the radiative conductivity. The radiating elements, each with a defined width and resonant length, are connected in series via the main feed line to form an initial linear array. The simulation sets the initial impedance value at the input terminal of the initial linear array, and designs a matching terminating load based on the initial impedance value; and After completing the terminal load matching design, impedance matching design is performed on the input end of the initial linear array to obtain a target traveling wave array antenna with the target impedance value.

[0007] Furthermore, determining the width and resonant length of each radiating element based on the energy loss characteristics and the radiative conductivity specifically includes: firstly, calculating the width of each radiating element based on the energy loss characteristics of the main feeder and the radiative conductivity of each radiating element; and then performing simulation calculations based on the width of each radiating element to obtain the resonant length of each radiating element.

[0008] Furthermore, the terminal load includes a main body, a connecting portion corresponding to the end of the initial linear array and the main body, and a first side branch and a second side branch extending outward from one side of the main body connected to the end of the array. The connecting portion, the first side branch, and the second side branch extend in parallel, and the first side branch and the second side branch are symmetrically located on opposite sides of the connecting portion. The outer edges of the first side branch and the second side branch are flush with the corresponding side edges of the main body. During simulation design, at least one of the following adjustments is made: adjusting the length of the main body, the first side branch, and the second side branch; adjusting the width of the main body, the connecting portion, the first side branch, and the second side branch.

[0009] Furthermore, the series-feed pattern is a comb antenna or a series antenna.

[0010] Furthermore, the shaping weighted design employs the Chebyshev method or the Taylor method to weight each of the radiating elements.

[0011] Furthermore, the performance requirements include at least gain, sidelobe level, azimuth and elevation beamwidth, and impedance bandwidth.

[0012] On the other hand, in order to solve the above-mentioned further technical problems, the embodiments of the present invention provide the following technical solution: a traveling wave array antenna designed based on the traveling wave array antenna design method described above.

[0013] After adopting the above technical solution, the embodiments of the present invention have at least the following beneficial effects: The embodiments of the present invention adopt the above method, firstly determining the number and shape of the radiating elements, antenna polarization and series feed form of the target traveling wave array antenna according to the performance requirements of the target traveling wave array antenna, and determining the radiation current or radiation power of each radiating element through shape-weighted design to form the basic shape model of the target traveling wave array antenna. Then, in further design, the energy loss characteristics on the main feed line are simulated and analyzed, and the radiation conductance of each radiating element is calculated and determined by combining the energy loss characteristics and the radiation current or radiation power of each radiating element, thereby determining the width and resonant length of each radiating element, which can effectively improve the calculation accuracy and is conducive to improving antenna performance. After forming an initial linear array based on the determined width and resonant length, the initial impedance value is input at the input end of the initial linear array by simulating the initial impedance value, and then a matching terminal load is designed on the initial linear array to achieve impedance matching. Finally, the impedance matching design of the input end of the initial linear array can obtain a target traveling wave array antenna with the target impedance value. The design efficiency is high and the antenna bandwidth obtained is wider. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the steps of an optional embodiment of the design method for a traveling wave array antenna of the present invention.

[0015] Figure 2 This is a planar schematic diagram of an optional embodiment of the traveling wave array antenna of the present invention.

[0016] Figure 3 A curve showing the sidelobe level of a traveling wave array antenna as a function of frequency, designed using the traveling wave array antenna design method provided in the embodiments of the invention.

[0017] Figure 4 A graph showing the VSWR of a traveling wave array antenna as a function of frequency, designed using the traveling wave array antenna design method provided in the embodiments of the invention.

[0018] Figure 5 The radiation pattern of a traveling wave array antenna is designed using the design method of the traveling wave array antenna provided in the embodiments of the invention. Detailed Implementation

[0019] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the following illustrative embodiments and descriptions are only used to explain the present invention and are not intended to limit the present invention. Moreover, the embodiments and features in the embodiments of the present application can be combined with each other unless otherwise specified.

[0020] like Figure 1 and Figure 2As shown, an optional embodiment of the present invention provides a design method for a traveling wave array antenna, comprising the following steps: S1: Based on the performance requirements of the target traveling wave array antenna 1, determine the number and shape of the radiating elements 10, antenna polarization, and series feed form required for the target traveling wave array antenna 1; S2: Determine the radiation current or radiation power of each of the radiation elements 10 through shape-weighted design; S3: Simulation analysis of energy loss characteristics on main feeder 12; S4: Calculate and determine the radiation conductivity of each radiation unit 10 by combining the energy loss characteristics and the radiation current or radiation power of each radiation unit 10. S5: Determine the width and resonant length of each radiating element 10 based on the energy loss characteristics and the radiation conductivity; S6: Connect the individual radiating elements 10, each with a defined width and resonant length, in series via the main feed line 12 to form an initial linear array; S7: Simulate and set the initial impedance value of the input terminal of the initial linear array, and simulate and design the terminating load 14 matching the initial linear array based on the initial impedance value; and S8: After completing the terminal load 14 matching design, perform impedance matching design on the input end of the initial linear array to obtain the target traveling wave array antenna 1 with the target impedance value.

[0021] This invention employs the above-described method. First, based on the performance requirements of the target traveling-wave array antenna 1, the number and shape of the radiating elements 10, antenna polarization, and series feed configuration required for the target traveling-wave array antenna 1 are determined. Then, through shape-weighted design, the radiating current or radiating power of each radiating element 10 is determined, forming a basic shape model of the target traveling-wave array antenna 1. Next, during further design, the energy loss characteristics on the main feed line 12 are simulated and analyzed. Combining these energy loss characteristics with the radiating current or radiating power of each radiating element 10, the radiating conductance of each radiating element 10 is calculated, thereby determining the width and resonant length of each radiating element 10. This effectively improves calculation accuracy and enhances antenna performance. After forming an initial linear array based on the determined width and resonant length, the initial impedance value is input at the input end of the initial linear array through simulation. A matching terminal load 14 is then designed on the initial linear array to achieve impedance matching. Finally, impedance matching design is performed on the input end of the initial linear array to obtain a target traveling-wave array antenna with the target impedance value. This design method is highly efficient and yields a wider antenna bandwidth.

[0022] In an optional embodiment of the present invention, determining the width and resonant length of each radiation unit 10 based on the energy loss characteristics and the radiation conductance specifically includes: first calculating the width of each radiation unit 10 corresponding to the energy loss characteristics of the main feeder 12 and the radiation conductance of each radiation unit 10, and then obtaining the resonant length of each radiation unit 10 through simulation calculation based on the width of each radiation unit 10. In this embodiment, since the width of each radiation unit 10 is proportional to the energy loss of the main feeder 12, therefore, the width of the corresponding radiation unit 10 can be calculated based on the energy loss of the main feeder 12 first, and then the resonant length at the width of each radiation unit 10 can be further determined through corresponding simulation, with high calculation efficiency.

[0023] In an optional embodiment of the present invention, as Figure 2 shown, the terminal load 14 includes a main body portion 141, a connecting portion 142 corresponding to connect the tip end 101 of the initial linear array and the main body portion 141, and a first side branch portion 143 and a second side branch portion 145 respectively protruding and extending outward from one side edge of the main body portion 141 to connect the tip end 101. The connecting portion 142, the first side branch portion 143 and the second side branch portion 145 extend in parallel, and the first side branch portion 143 and the second side branch portion 145 are symmetrically located on opposite sides of the connecting portion 142. The outer edges of the first side branch portion 143 and the second side branch portion 145 are flush with the corresponding side edges of the main body portion 141. When performing simulation design, at least one of the following adjustments is made: adjusting the lengths of the main body portion 141, the first side branch portion 143 and the second side branch portion 145; adjusting the widths of the main body portion 141, the connecting portion 142, the first side branch portion 143 and the second side branch portion 143. In this embodiment, the terminal load 14 is in an overall "mountain" shape. When performing specific simulation design, the lengths and widths of its main body portion 141, the first side branch portion 143 and the second side branch portion 145, and the distances between the first side branch portion 143 and the second side branch portion 145 and the connecting portion 142 respectively will all affect the impedance matching. Therefore, reasonably adjusting the above parameters can effectively achieve the impedance matching of the antenna.

[0024] In an optional embodiment of the present invention, the series-feed pattern is a comb antenna or a string antenna. In this embodiment, the comb antenna or the string antenna is a common series-feed linear array antenna, thus providing the design of two different patterns of antennas.

[0025] In an optional embodiment of the present invention, the shaped weighting design is to perform weighting design on each of the radiation units by using the Chebyshev method or the Taylor method. This embodiment uses the Chebyshev method or the Taylor synthesis method as a common beam shaping method for antennas, which can effectively achieve a lower sidelobe level of the traveling wave array antenna, thereby obtaining an antenna pattern with an ultra-low sidelobe level.

[0026] In an optional embodiment of the present invention, the performance requirements include at least gain, sidelobe level, azimuth and elevation beamwidth, and impedance bandwidth. This embodiment considers these parameters when designing the traveling-wave array antenna, resulting in a more targeted design, higher design efficiency, and the ability to meet predetermined operational requirements after design completion.

[0027] On the other hand, one embodiment of the present invention provides a traveling wave array antenna designed based on the traveling wave array antenna design method described in the above embodiments.

[0028] Using the design method provided in the above embodiments, a traveling wave array antenna is designed. The specific process is as follows: Corresponding to step S1: The performance requirement is SLL = -22dB, where, as Figure 2 As shown, the target traveling wave array antenna 1 requires 12 radiating elements N, which are rectangular in shape, linearly polarized, and fed in a comb-shaped manner. The dielectric substrate 3 is of type Ro3003G2. Corresponding step S2: Using Chebyshev amplitude weighting, with SLL set to -25dB, calculate the weighted value of the radiation current for each radiating element 10: I i =[0.4225, 0.4572, 0.6372, 0.8031, 0.9307, 1.0000, 1.0000, 0.9307, 0.8031, 0.6372, 0.4572, 0.4225]; where i = 1~12; Corresponding to step S3: Assuming the attenuation coefficient of the main feeder 12 is a (the attenuation coefficient a is related to the dielectric loss of the main feeder 12 material), the traveling wave propagating on the main feeder 12, after traveling a distance d, decreases to a factor of q. Then: (Formula 1); Where d is the length of the main feed line 12 between two adjacent radiating elements 10, and q is a positive number less than 1. The specific value of q can be obtained through corresponding simulation. Corresponding step S4: Calculate the radiation conductance of each radiation element 10 based on the energy loss of the main feeder 12: (Formula 2); Among them, G i Let U be the radiation conductance of the i-th radiating unit 10. i Let U be the radiation voltage of the i-th radiating unit 10. Since U is normalized... i =I i Therefore, U here i I can be used i By calculating the value of , the radiative conductance is obtained: Gi =[0.1567, 0.1606, 0.2288, 0.3040, 0.3847, 0.4701, 0.5605, 0.6566, 0.7589, 0.8652, 0.9611, 0.9937]; For radiation conductivity G i Normalization yields: G i =[0.0241, 0.0247, 0.0352, 0.0468, 0.0592, 0.0723, 0.0862, 0.1010, 0.1167, 0.1331, 0.1478, 0.1529]; Corresponding to step S5: Due to the width W of each radiating element 10 i Proportional to radiative conductivity G i Therefore, based on the radiation conductance G i The width W of the corresponding radiating element 10 can then be calculated. i Furthermore, the width W of the radiating element 10 was determined. i The resonant length L corresponding to the width of each radiating element 10 can be determined through simulation. i The dimensions of the 12 radiating elements 10 are shown in the table below:

[0029] Corresponding to step S6: Connect the radiating elements 10 of each determined size in series according to the determined shape and shaping method to form an initial linear array; Corresponding to step S7: Simulate and set the initial impedance value Zin at the input terminal of the initial linear array (Zin can be a complex impedance, i.e., the impedance has a real part and an imaginary part; it is usually related to the radiating element 10, and the specific value is obtained through simulation), and design a matching load 14 at the end of the initial linear array to achieve impedance matching; and Corresponding to step S8: perform impedance matching (e.g., 50 ohm impedance matching) on ​​the input end of the initial linear array to obtain the target traveling wave array antenna 1 with the target impedance value.

[0030] like Figure 3 The figure shows the curves of the SLL (Side Lobe Level) and VSWR (Voltage Standing Wave Ratio) of the target traveling wave array antenna 1 as a function of frequency; as shown. Figure 4 The image shows the radiation pattern (normalized) of the target traveling wave array antenna 1. Figure 5As shown in the radiation pattern, the impedance bandwidth of the target traveling wave array antenna 1 is greater than 6GHz, and SLL is about -22dB, which meets the design requirements and can meet the frequency bandwidth range of 76GHz~81GHz for vehicle front corner radar.

[0031] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the scope of protection of the present invention.

Claims

1. A design method for a traveling wave array antenna, characterized in that, The method includes the following steps: Based on the performance requirements of the target traveling wave array antenna, determine the number and shape of the radiating elements, antenna polarization, and series feed configuration required for the target traveling wave array antenna; The radiation current or radiation power of each radiation element is determined by shape-weighted design. Simulation analysis of energy loss characteristics on the main feeder; The radiation conductivity of each radiation unit is calculated and determined by combining the energy loss characteristics and the radiation current or radiation power of each radiation unit. The width and resonant length of each radiating element are determined based on the energy loss characteristics and the radiative conductivity. The radiating elements, each with a defined width and resonant length, are connected in series via the main feed line to form an initial linear array. The simulation sets the initial impedance value at the input terminal of the initial linear array, and designs a matching terminating load based on the initial impedance value; and After completing the terminal load matching design, impedance matching design is performed on the input end of the initial linear array to obtain a target traveling wave array antenna with the target impedance value.

2. The design method of the traveling wave array antenna as described in claim 1, characterized in that, The determination of the width and resonant length of each radiating element based on the energy loss characteristics and the radiative conductance specifically includes: firstly, calculating the width of each radiating element based on the energy loss characteristics of the main feeder and the radiative conductance of each radiating element; and then performing simulation calculations based on the width of each radiating element to obtain the resonant length of each radiating element.

3. The design method of the traveling wave array antenna as described in claim 1, characterized in that, The terminal load includes a main body, a connecting portion corresponding to the end of the initial linear array and the main body, and a first side branch and a second side branch extending outward from one side of the main body connected to the end of the array. The connecting portion, the first side branch and the second side branch extend in parallel, and the first side branch and the second side branch are symmetrically located on opposite sides of the connecting portion. The outer edges of the first side branch and the second side branch are flush with the corresponding side edges of the main body. During simulation design, at least one of the following adjustments is made: adjusting the length of the main body, the first side branch and the second side branch; adjusting the width of the main body, the connecting portion, the first side branch and the second side branch.

4. The design method of the traveling wave array antenna as described in claim 1, characterized in that, The series feed form is either a comb antenna or a series antenna.

5. The design method of the traveling wave array antenna as described in claim 1, characterized in that, The shaping weighted design employs the Chebyshev method or the Taylor method to weight each of the radiating elements.

6. The design method of the traveling wave array antenna as described in claim 1, characterized in that, The performance requirements include at least gain, sidelobe level, azimuth and elevation beamwidth, and impedance bandwidth.

7. A traveling wave array antenna designed based on the traveling wave array antenna design method according to any one of claims 1-6.

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