A design method for flat shoulder beam array antenna

Abstract

The present invention relates to a flat shoulder beam array antenna design method, comprising the following steps: step 1: establishing an array element pattern of a target antenna; step 2: establishing an antenna array in simulation software, and placing the antenna array in a tightly coupled state; step 3: performing full-wave simulation, extracting array element pattern data of each antenna array, wherein the array element pattern data includes the influence of tight coupling; step 4: using a beamforming algorithm based on an adaptive Tent chaotic artificial bee colony algorithm, performing flat shoulder beamforming using the array element pattern, and calculating initial amplitude and phase weights; step 5: fine-tuning according to the calculated initial amplitude and phase weights to obtain the amplitude and phase weights; step 6: designing a power divider based on the obtained amplitude and phase weights; step 7: using the designed power divider, establishing an overall antenna array of a tightly coupled array and simulating and optimizing, and obtaining a desired result. The present invention can improve antenna design efficiency and effectively reduce antenna volume.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a design method for a flat-shoulder beam array antenna. Background Art

[0002] With the development of modern science and technology, military radar technology has begun to be applied to civilian systems, and the application of radar technology in the automotive industry has received great attention.

[0003] Vehicle-mounted anti-collision radar is a key sensor in ADAS (Advanced Driver Assistance System). Compared with passive protection measures such as car airbags, vehicle-mounted anti-collision radar is an active preventive measure. The use of vehicle-mounted anti-collision radar can warn the driver when a dangerous target appears, thereby gaining precious reaction time and greatly reducing the probability of traffic accidents.

[0004] At present, automotive radar is evolving towards low cost, miniaturization, high integration and intelligence. The evolution of miniaturization has brought challenges to the design and layout of antennas. Traditional front radars generally adopt a strategy of one array covering short distances and one array covering long distances to achieve simultaneous coverage of short and long distances. However, this strategy requires the use of two arrays, which results in a large antenna size and cannot meet the needs of miniaturization. Summary of the invention

[0005] The purpose of the present invention is to provide a design method for a flat shoulder beam array antenna. The design method designs a power divider network of the antenna by a beamforming algorithm based on an adaptive Tent chaotic artificial bee colony algorithm, which can achieve medium and long-range integration and effectively reduce the size of the antenna.

[0006] A method for designing a flat shoulder beam array antenna comprises the following steps:

[0007] Step 1: Establish the element pattern of the target antenna;

[0008] Step 2: Create an antenna array in the simulation software and put the antenna array in a tightly coupled state;

[0009] Step 3: Perform full-wave simulation to extract array element pattern data of each antenna array, wherein the array element pattern data includes the influence of tight coupling;

[0010] Step 4: Use the beamforming algorithm based on the adaptive Tent chaotic artificial bee colony algorithm to perform flat-shoulder beamforming using the array element pattern and calculate the initial amplitude and phase weights;

[0011] Step 5: Fine-tune the initial amplitude and phase weights calculated to obtain amplitude and phase weights;

[0012] Step 6: Design a power divider based on the obtained amplitude and phase weights;

[0013] Step 7: Use the designed power divider to build a tightly coupled overall antenna array and perform simulation optimization to obtain the desired results.

[0014] Further, the step 4 comprises the following steps:

[0015] Step 41: Set relevant parameters;

[0016] Step 42: Import the array element directivity diagram, amplitude and phase weight encoding, the tent chaos reverse learning initialization population, and the fitness value to calculate the initial nectar source;

[0017] Step 43: The leader bee searches near the nectar source to generate a new solution, calculates the fitness value of the new solution and updates the nectar source, and records the number of times the leader bee stays at the same nectar source;

[0018] Step 44: Calculate the selection probability P, the follower bee selects a nectar source based on P and searches near the nectar source to generate a new solution, calculate the fitness value of the new solution and update the nectar source, and record the number of times the follower bee stays at the same nectar source;

[0019] Step 45: store the best global honey source location;

[0020] Step 46: Determine whether the sum of the number of times the leading bee and the following bee stay at the same nectar source is greater than the limited number of nectar collection times L of the same nectar source. If so, enter the scout bee stage; otherwise, enter the iteration number judgment;

[0021] Step 47: The leading bee abandons the current nectar source and becomes a scout bee. The scout bee generates a new solution to replace the nectar source based on the Tent chaotic search. If the maximum number of iterations is reached, the amplitude and phase weights are obtained by reverse encoding. If not, jump to step 43.

[0022] Furthermore, the relevant parameters of step 41 include population size N, number of nectar sources SN, dimension of nectar sources D, and maximum number of evolution times G.

[0023] Furthermore, in step 41, the swarm (N, T) is encoded by real number encoding:

[0024] ;

[0025] ;

[0026] Î[-1,1], rand∈[-1,1];

[0027] Among them, N is the number of linear arrays of the target antenna, and T is the population size of the swarm.

[0028] Furthermore, in step 6, the phase difference of the power divider is calculated by the following method: :

[0029] ;

[0030] ;

[0031] ;

[0032] in, L is the length of the phase shifter in the power divider, f is the frequency, is the phase velocity on the dielectric plate, is the effective dielectric constant, is the dielectric constant of the dielectric plate, h is the thickness of the dielectric plate, and w is the width of the microstrip line.

[0033] Furthermore, the power divider in step 6 is a microstrip T-type power distribution power divider, the power divider is an axisymmetric structure with the central axis as the symmetry axis, the number of output paths is an even number, and each output path is connected to a radiation subarray.

[0034] Furthermore, in step 1, the spacing d of the antenna arrays is equal, and d<λ / 2, where λ is the wavelength in air.

[0035] Furthermore, in step 5, the fine-tuning amplitude is ±10% of the initial amplitude and phase weights.

[0036] Compared with the prior art, the beneficial effects of the present invention are: the design method of the present invention can perform flat-shoulder beamforming according to the array element radiation pattern of the target antenna, thereby achieving medium and long-range integrated coverage of a single antenna, effectively reducing the antenna volume and improving design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The flowchart of the flat shoulder beam array antenna design method of the present invention is shown in FIG.

[0038] Figure 2 The present invention is a flow chart of the beamforming algorithm based on the adaptive Tent chaotic artificial bee colony algorithm.

[0039] Figure 3 It is a logic diagram of the beamforming algorithm based on the adaptive Tent chaotic artificial bee colony algorithm of the present invention.

[0040] Figure 4 It is the radiation pattern of the target antenna of the flat shoulder beam array antenna design method of the present invention.

[0041] Figure 5The antenna structure diagram is formed by adopting the flat shoulder beam array antenna design method of the present invention.

[0042] Figure 6 This is a structural diagram of a power divider formed by adopting the design method of the flat shoulder beam array antenna of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] like Figures 1 to 4 As shown, in a preferred embodiment, the flat shoulder beam array antenna design method of the present invention comprises the following steps:

[0045] Step 1: Establish an array element pattern of the target antenna; the array element pattern of the target antenna has the characteristics of simultaneously satisfying the coverage of the medium-range and long-range field of view angles. Specifically, the array element pattern of the target antenna can be calculated by the radar equation based on the size of the area covering the medium and long distances.

[0046] Step 2: Create an antenna array in the simulation software and put the antenna array in a tightly coupled state;

[0047] Among them, the antenna array can adopt the six-unit, eight-unit, ten-unit, and twelve-unit linear series-fed microstrip antenna commonly used in vehicle-mounted radars. The spacing d of the antenna array is equal, and d<λ / 2, where λ is the wavelength in air.

[0048] Step 3: Perform full-wave simulation to extract the element pattern data of each antenna array. The element pattern data includes the influence of tight coupling.

[0049] The full-wave simulation may be performed using commercial software such as HFSS or CST, and the pattern data is the simulated electric field vector of the antenna.

[0050] Step 4: Use the beamforming algorithm based on the adaptive Tent chaotic artificial bee colony algorithm to perform flat-shoulder beamforming using the array element pattern and calculate the initial amplitude and phase weights;

[0051] In this step, the preset flat shoulder beam pattern is used as the target, the array element pattern obtained in step 2 is input, and then the initial amplitude and phase weights are calculated based on the antenna array integrated beam synthesis principle and the adaptive Tent chaotic artificial bee colony algorithm.

[0052] Please refer to Figure 2 and Figure 3 , step 3 specifically includes the following steps:

[0053] Step 41: Set relevant parameters; the relevant parameters include population size N, number of nectar sources SN, nectar source dimension D, and maximum number of evolutions G. In specific implementation, the population size N is the number of linear arrays of the target antenna, the number of nectar sources SN can be set to a larger value, including but not limited to 1000, the nectar source dimension D is the number of variables of the directional pattern, and the maximum number of evolutions G can be defined by oneself.

[0054] Step 42: Import the array element directivity diagram, amplitude and phase weight encoding, the tent chaos reverse learning initialization population, and the fitness value to calculate the initial nectar source;

[0055] Step 43: The leader bee searches near the nectar source to generate a new solution, calculates the fitness value of the new solution and updates the nectar source, and records the number of times the leader bee stays at the same nectar source;

[0056] Step 44: Calculate the selection probability P, the follower bee selects a nectar source based on P and searches near the nectar source to generate a new solution, calculate the fitness value of the new solution and update the nectar source, and record the number of times the follower bee stays at the same nectar source;

[0057] Step 45: store the best global honey source location;

[0058] Step 46: Determine whether the sum of the number of times the leading bee and the following bee stay at the same nectar source is greater than the limited number of nectar collection times L of the same nectar source. If so, enter the scout bee stage; otherwise, enter the iteration number judgment;

[0059] Step 47: The leading bee abandons the current nectar source and becomes a scout bee. The scout bee generates a new solution to replace the nectar source based on the Tent chaotic search. If the maximum number of iterations is reached, the amplitude and phase weights are obtained by reverse encoding. If not, jump to step 33.

[0060] Through the above method, the amplitude and phase weights can be obtained.

[0061] In specific implementation, in step 41, the swarm (N, T) is encoded by real number encoding, and the encoding method is as follows:

[0062] ;

[0063] Where N is the number of target antennas, T is the size of the swarm, and each individual in the swarm contains the amplitude and phase weight information of the array element. The complex form of (a+ib) is used to represent the amplitude and phase information of the array element. The array element uses the normalized amplitude, and the phase is between 0 and That is, the range of a and b is [-1, 1], so ∈[-1,1]. In real number coding, The specific calculation method is:

[0064] ;

[0065] Among them, rand∈[-1,1], its value conforms to the uniform distribution.

[0066] Step 5: Fine-tune the initial amplitude and phase weights calculated to obtain amplitude and phase weights;

[0067] It should be understood that the adaptive Tent chaos artificial bee colony algorithm is based on a relatively ideal calculation process, which ignores the effects of the dielectric board and copper cladding on the antenna radiation, as well as the details of tight coupling. In order to make the antenna radiation pattern closer to the flat shoulder effect, the amplitude and phase weight data needs to be fine-tuned. The fine-tuning amplitude is ±10% of the initial amplitude and phase weight, and then the actual value of the final amplitude weight is determined based on the shaping effect.

[0068] Step 6: Design a power divider based on the obtained amplitude and phase weights;

[0069] Specifically, the phase difference of the power divider is calculated as follows: :

[0070] ;

[0071] ;

[0072] ;

[0073] in, L is the length of the phase shifter in the power divider, f is the frequency, is the phase velocity on the dielectric plate, is the effective dielectric constant, is the dielectric constant of the dielectric plate, h is the thickness of the dielectric plate, and w is the width of the microstrip line.

[0074] It should be understood that the power divider described herein is preferably a microstrip T-type power distribution power divider, which has an axisymmetric structure with the central axis as the axis of symmetry, an even number of output paths, and each output path is connected to a radiation subarray.

[0075] Step 7: Use the designed power divider to build a tightly coupled antenna array and perform simulation optimization to obtain the desired results. In this step, the shape of the microstrip patch of the antenna array, the distance between the patch centers of the connected microstrip antennas, and the width of the microstrip line length can be adjusted to meet the requirements of the array antenna amplitude distribution.

[0076] Please refer to Figures 4 to 6In a specific embodiment, the antenna and the antenna power divider formed by the flat shoulder beam array antenna design method of the present invention are a six-element linear series-fed microstrip antenna, which can achieve medium and long-range integrated coverage and effectively reduce the antenna volume. It can be understood that in other embodiments, the shaped antenna can be an eight-element, ten-element, or twelve-element linear series-fed microstrip antenna.

[0077] Although the present invention is described in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.

Claims

1. A flat shoulder beam array antenna design method, characterized in that: The following steps are involved: Step 1: Establish the element pattern of the target antenna; Step 2: Create an antenna array in the simulation software and put the antenna array in a tightly coupled state; Step 3: Perform full-wave simulation to extract array element pattern data of each antenna array, wherein the array element pattern data includes the influence of tight coupling; Step 4: Use the beamforming algorithm based on the adaptive Tent chaotic artificial bee colony algorithm to perform flat-shoulder beamforming using the array element pattern and calculate the initial amplitude and phase weights; Step 5: Fine-tune the initial amplitude and phase weights calculated to obtain amplitude and phase weights; Step 6: Design a power divider based on the obtained amplitude and phase weights; Step 7: Use the designed power divider to build a tightly coupled antenna array and perform simulation optimization to obtain the desired results. The step 4 comprises the following steps: Step 41: setting relevant parameters, including the number of nectar sources SN, the nectar source dimension D and the maximum number of evolution times G, wherein the nectar source dimension D is the number of variables of the directional graph; Step 42: Import the array element pattern, amplitude and phase weight encoding, the tent chaos reverse learning initialization population and fitness value, and calculate the initial nectar source; Step 43: The leader bee searches near the nectar source to generate a new solution, calculates the fitness value of the new solution and updates the nectar source, and records the number of times the leader bee stays at the same nectar source; Step 44: Calculate the selection probability P, the follower bee selects a nectar source based on P and searches near the nectar source to generate a new solution, calculate the fitness value of the new solution and update the nectar source, and record the number of times the follower bee stays at the same nectar source; Step 45: Store the best global honey source location; Step 46: Determine whether the sum of the number of times the leading bee and the following bee stay at the same nectar source is greater than the limited number of nectar collection times L of the same nectar source. If so, enter the scout bee stage; otherwise, enter the iteration number judgment; Step 47: The leading bee abandons the current nectar source and becomes a scout bee. The scout bee generates a new solution to replace the nectar source based on the Tent chaotic search. If the maximum number of iterations is reached, the amplitude and phase weights are obtained by reverse encoding. If not, jump to step 43. In step 41, the swarm (N, T) is encoded by real number encoding: X nt =X min +(X max -X min )·rand; X nt ∈[-1,1],rand∈[-1,1]; Where N is the number of linear arrays of the target antenna, and T is the population size of the swarm; In step 6, the phase difference of the power divider is calculated as follows: in, is the length of the phase shifter in the power divider, f is the frequency, v p is the phase velocity on the dielectric plate, ε e is the effective dielectric constant, ε r is the dielectric constant of the dielectric plate, h is the thickness of the dielectric plate, w is the width of the microstrip line, and λ is the wavelength in air.

2. The flat shoulder beam array antenna design method according to claim 1, characterized in that: The power divider in step 6 is a microstrip T-type power distribution power divider, which has an axisymmetric structure with the central axis as the symmetry axis, an even number of output paths, and each output path is connected to a radiation subarray.

3. The design method of flat shoulder beam array antenna according to claim 1, characterized in that: In step 2, the spacing d of the antenna arrays is equal, and d<λ / 2, where λ is the wavelength in air.

4. The design method of flat shoulder beam array antenna according to claim 1, characterized in that: In step 5, the fine-tuning amplitude is ±10% of the initial amplitude and phase weights.

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