Log-periodic antenna linear array design method considering grating lobe suppression and application

Abstract

The application discloses a log-periodic antenna linear array design method considering grating lobe suppression, and comprises the following steps: acquiring a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna units changing with a feed phase; acquiring a second direction function of a main lobe direction of the uniform linear array composed of a plurality of antenna units under the influence of a beam width of the antenna units; constructing a normalized direction function of the linear array according to the first direction function and the second direction function; obtaining antenna array direction patterns under different intervals of the antenna units according to the normalized direction function by controlling the intervals between the antenna units, so as to acquire an interval range of the antenna units without grating lobes; and constructing a linear array of a plurality of linearly arranged antenna units according to the interval range. The method can solve the problem that the traditional antenna array uses the mode of changing the intervals, feed amplitudes and phases of the antenna units to control the side lobe level, thereby increasing the complexity and cost of the feed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, and in particular to a log-periodic antenna linear array design method considering grating lobe suppression, a log-periodic antenna linear array design device considering grating lobe suppression, an electronic device, and a computer readable storage medium. BACKGROUND

[0002] A log-periodic dipole antenna is usually composed of several dipole antennas, and the physical structure of each dipole antenna and the spacing between them change according to a certain scale factor. Although the log-periodic dipole antenna is composed of multiple symmetrical oscillators, not all oscillators contribute to radiation at any operating frequency. Only the oscillators in the radiation zone (those oscillators with a length of about half the operating wavelength) play a major role in radiation, so its directivity cannot be very strong. The directivity coefficient or gain is usually only about 10 dBi, which belongs to the category of medium gain antennas. By selecting appropriate scale factors and spacing factors, a log-periodic dipole antenna can cover a relatively wide frequency band, and it usually has a horizontal plane beam width of several tens of degrees to cover a certain sector. However, when the log-periodic dipole antenna is fixed, its beam coverage range is also fixed. In order to achieve longer distance communication and detection of different direction targets, multiple antenna units are usually used to form a phased array, and a linear array is the simplest array form. Arranging several log-periodic dipole antennas in a straight line at equal intervals forms a uniform linear array. By changing the feeding phase of the antenna units, beam scanning can be achieved, so it is widely used in radio systems.

[0003] For the design of a uniform linear array composed of horizontally mounted log-periodic dipole antennas, the selection of the spacing is particularly important. When the spacing is too small, due to the wide operating bandwidth of the log-periodic dipole antenna, there will be structural overlap between the horizontally mounted antenna units. When the spacing is too large, it will cause grating lobes in the scanning process of the antenna array beam. Most current designs of log-periodic dipole linear arrays use a spacing of half the center operating wavelength to control grating lobes. However, this arrangement is only suitable for linear arrays with narrow bandwidth. The use of a wider bandwidth may cause structural overlap between the array elements, so it will inevitably limit the bandwidth. At the same time, the spacing range determined by the existing antenna theory only considers the conditions for grating lobes when point source antennas are arrayed, and does not consider the influence of different antenna units on the generation of grating lobes. Therefore, it is impossible to obtain the accurate spacing range that does not produce grating lobes, and it is impossible to maximize the bandwidth of the linear array. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a log-periodic antenna linear array design method with controllable sidelobe level and application, which can solve the problem of increasing the complexity and cost of feeding caused by the traditional antenna array using the method of changing the interval, feeding amplitude and phase of the antenna unit to control the sidelobe level.

[0005] In one aspect, the first embodiment of the present application provides a log-periodic antenna linear array design method considering grating lobe suppression, comprising: obtaining a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna units varying with a feeding phase; obtaining a second direction function of a main lobe direction of a uniform linear array composed of a plurality of log-periodic dipole antenna units under the influence of a beam width of the antenna unit itself; constructing a normalized direction function of a log-periodic dipole antenna linear array according to the first direction function and the second direction function; obtaining an antenna array directional diagram under different intervals between the antenna units according to the normalized direction function by controlling the interval between the antenna units, and obtaining an antenna unit interval range without grating lobe according to the antenna array directional diagram; and constructing a log-periodic dipole antenna linear array by arranging a plurality of log-periodic dipole antennas in a straight line according to the interval range.

[0006] In one embodiment of the present application, the first direction function is: wherein M is the number of antenna units, ψ = ξ + kdsinθ is the total phase; wherein ξ is the feeding phase, is the wave constant, d is the interval between the antenna units, and θ is the included angle between the main lobe and the normal.

[0007] In one embodiment of the present application, the second direction function is: F1(θ) = cos m (θ / 2); wherein θ is the included angle between the main lobe and the normal, m is defined as a beam width factor, and has wherein 2θ 0.5E is the 3db beam width of the log-periodic dipole antenna in the horizontal plane.

[0008] In one embodiment of the present application, the normalized direction function of the log-periodic dipole antenna linear array is constructed according to the first direction function and the second direction function, comprising: representing the normalized direction function as the product of the first direction function and the second direction function, i.e. wherein ψ = kd(sinθ-sinθ0), θ0 is the main lobe direction, i.e. ξ =-kdsinθ0.

[0009] In one embodiment of the present application, the antenna unit interval range of the log-periodic dipole antenna linear array without grating lobe is:

[0010] In an embodiment of the present application, the log-periodic antenna linear array design method considering grating lobe suppression further comprises: obtaining the range of the antenna element spacing of the log-periodic dipole antenna linear array without overlapping between the antenna elements, which is: d > K1λ L ; wherein K1 is the low frequency truncation coefficient of the antenna, and λ L is the lowest working frequency of the antenna.

[0011] In an embodiment of the present application, the log-periodic antenna linear array design method considering grating lobe suppression further comprises: obtaining the restriction of the beam scanning bandwidth of the log-periodic dipole antenna linear array without grating lobe and without overlapping of the antenna elements, which is: wherein λ H is the highest working frequency, and τ is the proportional factor.

[0012] In another aspect, an embodiment of the present application provides a log-periodic antenna design device considering grating lobe suppression, comprising: a first direction function obtaining module, configured to obtain a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna elements varying with a feed phase; a second direction function obtaining module, configured to obtain a second direction function of a main lobe direction of a uniform linear array composed of a plurality of log-periodic dipole antenna elements under the influence of a beam width of the antenna elements; a normalized direction function obtaining module, configured to construct a normalized direction function of the log-periodic dipole antenna linear array according to the first direction function and the second direction function; an antenna element spacing range obtaining module, configured to obtain a range of antenna element spacing without grating lobe by controlling the spacing between the antenna elements and obtaining an antenna array pattern under different spacing according to the normalized direction function, and obtaining the range of the antenna element spacing without grating lobe according to the antenna array pattern; and a linear array constructing module, configured to construct a log-periodic dipole antenna linear array by arranging a plurality of log-periodic dipole antennas in a straight line according to the range of the spacing.

[0013] In still another aspect, an embodiment of the present application provides an electronic device, comprising: a memory and one or more processors connected to the memory, the memory storing a computer program, and the processor being configured to execute the computer program to implement the log-periodic antenna design method considering grating lobe suppression according to any one of the above embodiments.

[0014] In yet another aspect, an embodiment of the present application provides a computer readable storage medium, which stores computer executable instructions, and the computer executable instructions are used to execute the log-periodic antenna design method considering grating lobe suppression according to any one of the above embodiments.

[0015] As can be seen from the above, compared with the prior art, the above-mentioned scheme conceived by the present application can have one or more of the following beneficial effects:

[0016] (1) By simultaneously analyzing the condition of grating lobe produced by the array of antenna element groups and the influence of different antenna elements on the production of grating lobe, a more accurate antenna element spacing satisfying the condition of no grating lobe is calculated, which can effectively avoid the occurrence of main lobe deviation and grating lobe;

[0017] (2) By considering the relationship between different antenna elements and beam scanning bandwidth, the limitation of beam scanning bandwidth of the uniform linear array of non-overlapping logarithmic periodic dipole antenna elements without grating lobe is obtained, which can maximize the bandwidth of the linear array under the premise of no grating lobe and no overlapping of antenna elements.

[0018] Other aspects of the application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the application. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the application, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise specified, they are merely intended to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application. In the drawings:

[0020] Figure 1 A flow chart of a logarithmic periodic antenna design method considering grating lobe suppression provided for an embodiment of the application;

[0021] Figure 2 A schematic diagram of a logarithmic periodic dipole antenna provided for an embodiment of the application;

[0022] Figure 3 A normalized pattern of a 16-element uniform linear array at different spacings and different scanning angles provided for an embodiment of the application;

[0023] Figure 4 A schematic diagram of a logarithmic periodic dipole antenna forming a uniform linear array provided for an embodiment of the application;

[0024] Figure 5 A horizontal plane normalized pattern of a logarithmic periodic dipole antenna at different beam width factors provided for an embodiment of the application;

[0025] Figure 6 A normalized pattern of a 16-element logarithmic periodic dipole linear array (d=0.645λ) when the beam is scanned to 30° provided for an embodiment of the application;

[0026] Figure 7A normalized pattern when a 16-element log-periodic dipole linear array (d=0.75 lambda) provided by the embodiment of the present application is scanned to 30 degrees;

[0027] Figure 8 A normalized pattern when a 16-element log-periodic dipole linear array (d=0.85 lambda) provided by the embodiment of the present application is scanned to 30 degrees;

[0028] Figure 9 A normalized pattern when a 16-element log-periodic dipole linear array (d=1.15 lambda) provided by the embodiment of the present application is scanned to 30 degrees

[0029] Figure 10 A normalized pattern when a 16-element log-periodic dipole linear array (d=1.15 lambda) provided by the embodiment of the present application is scanned to 30 degrees

[0030] Figure 11 An angle diagram corresponding to grating lobes under different intervals provided by the embodiment of the present application

[0031] Figure 12 A structure diagram of a log-periodic antenna design device considering grating lobe suppression provided by the embodiment of the present application;

[0032] Figure 13 A structure diagram of an electronic device provided by the embodiment of the present application;

[0033] Figure 14 A structure diagram of a computer readable storage medium provided by the embodiment of the present application.

[0034] Explanation of reference signs

[0035] S1 to S5: steps of the log-periodic antenna design method considering grating lobe suppression;

[0036] 20: a log-periodic antenna design device considering grating lobe suppression; 201: a first direction function acquisition module; 202: a second direction function acquisition module; 203: a normalized direction function acquisition module; 204: an antenna element interval range acquisition module; 205: a linear array construction module;

[0037] 30: an electronic device; 31: a processor; 32: a memory;

[0038] 40: a computer readable storage medium. DETAILED DESCRIPTION

[0039] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described below with reference to the accompanying drawings and in combination with the embodiments.

[0040] In order to make ordinary skilled in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments of the present application, which should all belong to the protection scope of the present application.

[0041] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are applicable to distinguish similar objects, and do not have to be used to describe a particular order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0042] It should also be noted that the division of the plurality of embodiments in the present application is only for the convenience of description, and should not constitute a special limitation. The features in various embodiments can be combined with each other without contradiction, and can be mutually quoted.

[0043] As shown in Figure 1 The embodiments of the present application propose a log-periodic antenna linear array design method considering grating lobe suppression, for example, comprising: step S1, obtaining a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna units varying with a feed phase; step S2, obtaining a second direction function of a main lobe direction of a uniform linear array composed of a plurality of log-periodic dipole antenna units under the influence of a beam width of the antenna units; step S3, constructing a normalized direction function of a log-periodic dipole antenna linear array according to the first direction function and the second direction function; step S4, obtaining an antenna array directional diagram under different intervals between the antenna units according to the normalized direction function by controlling the intervals between the antenna units, and obtaining an antenna unit interval range in which no grating lobe appears according to the antenna array directional diagram; and step S5, arranging a plurality of log-periodic dipole antennas in a straight line to construct a log-periodic dipole antenna linear array according to the interval range.

[0044] Specifically, a Log-Periodic Dipole Antenna (LPDA) consists of several parallel symmetrical dipoles, all with their structures varying proportionally. Each dipole is connected to a pair of transmission lines called the feed lines, and is fed through these feed lines. To achieve coaxial cable feeding, a balun is typically used connected at the center of the shortest dipole. To achieve directivity of radiation (from the longest dipole to the shortest dipole), the arms of adjacent dipoles are cross-fed. By short-circuiting the feed line terminals or adding a matching load, terminal reflections can be reduced, thereby improving its low-frequency VSWR characteristics.

[0045] The schematic diagram of the log-periodic dipole antenna is shown below. Figure 2 As shown, it consists of N parallel oscillators. The length of the i-th oscillator is l. i (i = 1, ..., N), (radius of the oscillator cross section) is a i Its distance from the (virtual) vertex O is R. i ,d i This represents the distance between the i-th element and the (i+1)-th element. Typically, the structure of a log-periodic dipole antenna satisfies the following relationship:

[0046]

[0047]

[0048]

[0049] τ, σ, and α are called the scaling factor, the interval factor, and the imaginary vertex angle, respectively. They satisfy the following relationship:

[0050]

[0051] The number of elements in a log-periodic dipole antenna is related to the required operating bandwidth and gain factor. Higher gain necessitates a greater number of elements, resulting in a larger scaling factor. It is typically determined by the following formula:

[0052] N = 1 + log(B) s ) / log(1 / τ) (5)

[0053] B s =B(1.1+7.7*(1-τ)) 2 cot(α)), B=f H / f L (6)

[0054] f H f L These represent the antenna's highest and lowest operating frequencies, respectively.

[0055] The length of the elements in a log-periodic dipole antenna is also related to the designed frequency range of the antenna. In engineering, the truncation factors K1 and K2 are often used to determine the length of the longest and shortest elements. Wherein, l1 = K1 λ L , l N = K2 λ H . K1 and K2 are called low-frequency truncation coefficient and high-frequency truncation coefficient, whose size depends on the scale factor and interval factor, and the specific calculation formula is as follows:

[0056] K1 = 1.01 - 0.519 τ (7)

[0057] K2 = 7.1 τ 3 -21.3 τ 2 +21.98 τ -7.3 + σ (21.82 - 66 τ + 61.12 τ 2 -18.29 τ 3 ) (8)

[0058] In step S1, a uniform linear array composed of M point source antennas has a spacing d, and the phase difference of the feeding current between the antenna elements is ξ. According to the antenna array theory, the first directional function of the main lobe direction changing with the feeding phase can be expressed as:

[0059]

[0060] Wherein, ψ = ξ + k d sin θ, ψ is the total phase, is the wave constant, and θ is the included angle between the main lobe and the normal.

[0061] When the array elements are fed in phase (ξ = 0), due to the symmetry of the structure, the uniform linear array will form the maximum radiation (main lobe) in the 0° direction and 180°. When the feeding is changed to ξ = -k d sin θ0, the main lobe is directed to θ0. This is also the working principle of the phased array antenna, which realizes the change of the maximum radiation direction by changing the feeding phase of the antenna elements.

[0062] According to formula (9), the normalized directional diagram of the uniform linear array can be drawn. Figure 2 The normalized directional diagram of a 16-element uniform linear array at different scanning angles and spacings is given. It is obvious that when the spacing of the array elements is too large, there will be an area with the same size as the main lobe in other directions, which is called grating lobe. The appearance of the grating lobe means that the antenna radiation energy is not concentrated, which will lead to the decrease of the directivity. Therefore, the appearance of the grating lobe should be avoided in the design of the antenna array. According to the antenna array theory, the condition for the point source antenna array directional diagram not to appear the grating lobe is:

[0063]

[0064] Figure 3 The normalized radiation patterns of a 16-element uniform linear array under different spacings and scanning angles are shown below. The maximum spacing values ​​corresponding to different scanning angles can be calculated according to formula (10), as shown in Table 1 below:

[0065] Table 1 shows the maximum spacing values ​​corresponding to different scanning angles.

[0066] scan angle (θ0) 0 10 20 30 40 50 60 70 80 90 Maximum spacing (λ) 1 0.852 0.745 0.667 0.609 0.566 0.536 0.516 0.504 0.5

[0067] Table 1 shows that when the scanning angle θ0 = 30°, d < 0.667λ. Figure 3 The normalized radiation patterns of the 16-element uniform linear array at different maximum scan angles of 30° and different spacings clearly show that grating lobes appear when d ≥ 0.667λ. From... Figure 3 It can be observed that when d = 0.6λ, a grating lobe will appear in the 150° direction, mainly due to the symmetry of the linear array and the non-directionality of the point source antenna.

[0068] Based on the working principle of log-periodic antennas, they are classified as medium-gain antennas. To improve the directivity of the system, an antenna array composed of log-periodic antennas can be used, and the beam can be scanned by changing the feed phase of each antenna element. A uniform linear array is the simplest type of array to feed and has wide applications. For horizontally mounted log-periodic dipole antennas as antenna elements, as shown... Figure 4 The diagram shows a uniform linear array. Horizontal beam scanning capability is achieved by changing the feed phase of the antenna elements.

[0069] According to the pattern product theorem, the direction function of a uniform linear array composed of M log-periodic dipole antennas can be expressed as:

[0070] F(θ)=F1(θ)×F a (θ) (11)

[0071] In the formula, F1(θ) is the direction function of the log-periodic dipole antenna, called the self-factor, which depends only on the antenna element. a F1(θ) is from formula (1) and is called the array factor. It depends only on the array configuration and is independent of the antenna elements. Since it is necessary to achieve beam scanning of the log-periodic dipole antenna array on the horizontal plane (called the beamforming surface), F1(θ) in formula (11) can be chosen as the horizontal plane direction function.

[0072] In step S2, for example, cos mθ0) is the second direction function of the log-periodic dipole antenna in the horizontal plane. m is defined as the beam width factor, which is related to the horizontal beam width of the log-periodic dipole antenna, and there is a relationship as follows:

[0073]

[0074] wherein 2θ 0.5E represents the 3dB beam width of the log-periodic dipole antenna in the horizontal plane.

[0075] Figure 5 The horizontal normalized pattern of the log-periodic dipole antenna with different m values is given. It can be found from the figure that the greater the beam width factor, the narrower the horizontal beam width.

[0076] In step S3, according to the pattern multiplication theorem, the horizontal normalized direction function of the linear array of the log-periodic dipole antenna can be expressed as:

[0077]

[0078] wherein ψ = kd(sinθ - sinθ0).

[0079] In step S4, as Figures 5 to 9 The normalized pattern of the linear array composed of 16 log-periodic dipoles with a beam scanning angle of 30° at different beam widths is given.

[0080] Figure 6 The normalized pattern of the linear array composed of 16 log-periodic dipoles with a beam scanning angle of 30° at different beam widths is given. Since the distance d = 0.645λ satisfies the requirement of not appearing grating lobes, when the log-periodic dipole antenna takes different m values, the pattern of the antenna array does not appear grating lobes. At the same time, due to the directivity of the log-periodic dipole antenna, the grating lobes caused by the symmetry of the linear array itself are also suppressed.

[0081] Figure 7 The pattern of the 16-element linear array with a scanning angle of 30° when the distance d = 0.75λ is given. It can be found from the figure that since d = 0.75λ has exceeded the limit of not appearing grating lobes in Table 1, the array factor appears three grating lobes. When the direction function of the log-periodic dipole antenna is multiplied by the direction function of the array factor, it can be found that due to the directivity of the log-periodic dipole antenna, the grating lobes of the linear array are well suppressed.

[0082] Figure 8 、 Figure 9 、 Figure 10Normalized radiation patterns of a 16-element log-periodic dipole antenna linear array beam scanning to 30° are given for d = 0.85λ, d = λ, and d = 1.15λ. The figures show that the sidelobe level of the antenna array increases with increasing spacing. Furthermore, it is observed that when the spacing becomes sufficiently large (e.g., d = 1.15λ), the maximum beam pointing direction is not at 30° regardless of the beamwidth factor m of the log-periodic dipole antenna elements. Therefore, for a uniform linear array, the angle corresponding to the generation of grating lobes due to excessive spacing is:

[0083] θ s =arcsin(sin(θ0)-λ / d) (14)

[0084] Figure 11 The angles corresponding to different grating lobe spacings are given. When the array normal of a linear array is 0°, its beam scanning range is usually described by ±θ0. The sign of θ0 only represents the scanning direction; due to structural symmetry, usually only one direction needs to be analyzed. For the scanning angle described in this paper, θ is positive. s Then it is negative; conversely, when the scanning angle is negative, then θ is negative. s Then it is positive. From Figure 10 It can be observed that as the spacing gradually increases, the uniform linear array will develop grating lobes, and the positions of the grating lobes gradually move towards the 0° direction. When |θ s When |<θ0, due to the self-factor direction function (cos m Symmetry of (θ / 2)), cos m (θ s / 2)>cos m (θ0 / 2), and the values ​​of the matrix factor direction functions are the same (both are 1). According to the pattern product theorem, F(θ) s If )>F(θ0), it will inevitably lead to a shift in the main lobe.

[0085] Therefore, to avoid main lobe shift and grating lobe formation, it is required that |θ s |>θ0, which means the following condition should be satisfied:

[0086]

[0087] According to formula (16), the spacing constraint condition for a uniform linear array composed of log-periodic dipole antennas when θ0 = 30° without grating lobes can be calculated as d < λ. Figures 6 to 9 This condition can also be verified by the normalized directional patterns of log-periodic dipole linear arrays with different spacings.

[0088] In addition, the log-periodic dipole antenna is composed of several dipoles, and a very wide operating bandwidth can be achieved by selecting appropriate scale factors and interval factors. Assuming that the operating frequency range of the log-periodic dipole antenna is [f L ,f H ], f L , f H represent the lowest operating frequency and the highest operating frequency, respectively. Correspondingly, λ L , λ H represent the wavelengths corresponding to the lowest operating frequency and the highest operating frequency, respectively.

[0089] Further, when the log-periodic dipole antenna with a wide operating frequency range is horizontally erected, according to the operating principle of the log-periodic antenna, the length of the longest dipole may exceed , which will cause structural overlap between adjacent elements. In order to avoid structural overlap of the log-periodic dipole antenna when the elements are arranged, the distance d between the antenna elements should be greater than K1λ L . In summary of the above conditions of no grating lobe and no structural overlap, the time distance of the log-periodic dipole antenna to form a uniform linear array should satisfy the following relationship:

[0090]

[0091] Further, the restriction of the beam scanning bandwidth of the log-periodic dipole uniform linear array without grating lobe and structural overlap is:

[0092]

[0093] As can be seen from the above formula (18), when the maximum beam scanning angle θ0 is fixed, the greater the scale factor is selected, the greater the bandwidth of the antenna element can be achieved.

[0094] In step S5, a plurality of log-periodic dipole antennas are arranged in a uniform linear array according to the above distance range, for example, to form a log-periodic dipole linear array that meets the requirements.

[0095] In summary, the log-periodic antenna linear array design method considering grating lobe suppression proposed in the embodiments of the present application can obtain more accurate antenna element distance without grating lobe by simultaneously analyzing the conditions of grating lobe generated when the antenna elements are arranged and the influence of different antenna elements on the generation of grating lobe, which can effectively avoid the shift of the main lobe and the generation of grating lobe. By considering the relationship between different antenna elements and the beam scanning bandwidth, the restriction of the beam scanning bandwidth of the log-periodic dipole uniform linear array without grating lobe and structural overlap is obtained, which can maximize the bandwidth of the linear array under the premise of no grating lobe and no overlap between the antenna elements.

[0096] As shown in Figure 12 The second embodiment of the present application also proposes a design device 20 for a linear array of log-periodic antennas considering grating lobe suppression, for example, comprising: a first directional function obtaining module 201, a second directional function obtaining module 202, a normalized directional function obtaining module 203, an antenna element spacing range obtaining module 204, and a linear array constructing module 205.

[0097] The first directional function obtaining module 201 is configured to obtain a first directional function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna elements varying with a feed phase. The second directional function obtaining module 202 is configured to obtain a second directional function of a main lobe direction of a uniform linear array composed of a plurality of log-periodic dipole antenna elements under the influence of a beam width of the antenna elements. The normalized directional function obtaining module 203 is configured to construct a normalized directional function of a linear array of log-periodic dipole antennas according to the first directional function and the second directional function. The antenna element spacing range obtaining module 204 is configured to obtain an antenna array directional diagram under different spacings between the antenna elements according to the normalized directional function by controlling the spacings, and obtain a spacing range of the antenna elements without grating lobes according to the antenna array directional diagram. The linear array constructing module 205 is configured to construct a linear array of log-periodic dipole antennas by arranging a plurality of log-periodic dipole antennas in a straight line according to the spacing range.

[0098] The design method of a linear array of log-periodic antennas considering grating lobe suppression realized by the design device 20 for a linear array of log-periodic antennas considering grating lobe suppression disclosed in the second embodiment of the present application is as described in the first embodiment, and will not be described in detail here. Alternatively, each module in the second embodiment and the other operations or functions described above are respectively configured to realize the method described in the first embodiment, and the beneficial effects of the present embodiment are the same as those of the first embodiment, which will not be described here for the sake of brevity.

[0099] As shown in Figure 13 The third embodiment of the present application proposes an electronic device 30, for example, comprising: a memory 32 and one or more processors 31 connected to the memory 32. The memory 32 stores a computer program, and the processor 31 is configured to execute the computer program to realize the design method of a linear array of log-periodic antennas considering grating lobe suppression as described in the first embodiment. The specific design method of a linear array of log-periodic antennas considering grating lobe suppression can refer to the method described in the first embodiment, which will not be described here for the sake of brevity, and the beneficial effects of the electronic device 30 provided by the present embodiment are the same as those of the design method of a linear array of log-periodic antennas considering grating lobe suppression provided by the first embodiment.

[0100] As shown in Figure 14As shown, the fourth embodiment of the present application provides a computer readable storage medium 40, which is a non-volatile memory and stores computer readable instructions. When the computer readable instructions are executed by one or more processors, the one or more processors are caused to perform the method for designing a log-periodic antenna linear array considering grating lobe suppression as described in the first embodiment. The specific method can refer to the method described in the first embodiment, which is not repeated here for brevity, and the computer readable storage medium 40 provided by the present embodiment has the same beneficial effects as the method for designing a log-periodic antenna linear array considering grating lobe suppression provided by the first embodiment.

[0101] In addition, it can be understood that the foregoing embodiments are only exemplary descriptions of the present application, and the technical solutions of the embodiments can be combined and used as long as the technical features do not conflict, the structures do not contradict, and the purposes of the present application are not violated.

[0102] In the several embodiments of the present application, it should be understood that the disclosed system, device and / or method can be implemented in other ways. For example, the device embodiments described above are only schematic. The division of the units / modules is only a logical function division. There can be another division manner in actual implementation. For example, a plurality of units / modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units / modules shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0103] The units / modules described as separate components can or can not be physically separate, and the components shown as units / modules can or can not be physical units. That is, they can be located in one place, or distributed on a plurality of network units. Some or all of the units / modules can be selected according to actual needs to achieve the purpose of the present embodiment.

[0104] In addition, each functional unit / module in each embodiment of the present application can be integrated into a processing unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated into one unit / module. The integrated unit / module can be realized in the form of hardware or in the form of hardware plus software functional unit / module.

[0105] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A design method of a linear array of log-periodic antennas considering the inhibition of grating lobes, characterized in that, The method comprises the following steps: obtaining a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna units varying with a feed phase; obtaining a second direction function of a main lobe direction of a uniform linear array composed of a plurality of pairs of log-periodic dipole antenna units under the influence of a beam width of the antenna units themselves; constructing a normalized direction function of the log-periodic dipole antenna linear array according to the first direction function and the second direction function; obtaining an antenna array directional diagram under different spacings between the antenna units according to the normalized direction function by controlling the spacings between the antenna units, and obtaining a spacing range between the antenna units without grating lobes according to the antenna array directional diagram; constructing a required log-periodic dipole antenna linear array by arranging a plurality of log-periodic dipole antennas in a straight line according to the spacing range; Wherein, the first direction function is: ; wherein, is the total phase; wherein, is the total phase; wherein, is the total phase; wherein, is the wave constant, d is the antenna unit spacing, is the angle between the main lobe and the normal. wherein the second direction function is: ; wherein, is the angle between the main lobe and the normal, is defined as the beam width factor, and has ; wherein, is the 3db beam width of the log-periodic dipole antenna in the horizontal plane; wherein the step of constructing the normalized direction function of the log-periodic dipole antenna linear array according to the first direction function and the second direction function comprises: The normalized directional function is expressed as the product of the first directional function and the second directional function, i.e. ; wherein, , is the main lobe direction, i.e. there is .

2. The design method of linear array of log-periodic antennas considering the inhibition of grating lobes according to claim 1, characterized in that, The range of the antenna element spacing in which the log-periodic dipole antenna linear array does not exhibit grating lobes is: .

3. The design method of a log-periodic antenna linear array considering the suppression of grating lobes according to claim 2, characterized in that, The method further comprises the following steps: The range of antenna element spacing in which no overlap between the antenna elements of the log-periodic dipole antenna linear array is obtained is: ; wherein is a low frequency cutoff factor of the antenna, is a lowest operating frequency of the antenna.

4. The design method of a log-periodic antenna linear array considering the suppression of grating lobes according to claim 3, characterized in that, The method further comprises the following steps: The bandwidth limitation for the log-periodic dipole antenna linear array not to appear grating lobes and the antenna units not to overlap is: ; wherein, is the highest operating frequency, is the scale factor.

5. A device for designing a linear array of log-periodic antennas taking into account the inhibition of grating lobes, characterized in that, The method comprises the following steps: The first direction function obtaining module is configured to obtain a first direction function of a main lobe direction of a uniform linear array composed of a plurality of point source antenna units varying with a feed phase; The second direction function obtaining module is configured to obtain a second direction function of a main lobe direction of a uniform linear array composed of a plurality of pairs of log-periodic dipole antenna units under the influence of a beam width of the antenna units themselves; The normalized direction function obtaining module is configured to construct a normalized direction function of the log-periodic dipole antenna linear array according to the first direction function and the second direction function; The antenna unit spacing range obtaining module is configured to obtain an antenna array directional diagram under different spacings between the antenna units according to the normalized direction function by controlling the spacings between the antenna units, and obtain a spacing range between the antenna units without grating lobes according to the antenna array directional diagram; The linear array constructing module is configured to construct a log-periodic dipole antenna linear array by arranging a plurality of log-periodic dipole antennas in a straight line according to the spacing range; wherein the first direction function is: ; wherein, is the number of antenna elements, is the total phase; wherein, is the feed phase, is the wave constant, d is the antenna element spacing, is the angle between the main lobe and the normal. wherein the second direction function is: ; wherein, is the angle between the main lobe and the normal, is defined as the beam width factor, and has ; wherein, is the 3db beam width of the log-periodic dipole antenna in the horizontal plane; wherein the step of constructing the normalized direction function of the log-periodic dipole antenna linear array according to the first direction function and the second direction function comprises: The normalized directional function is expressed as the product of the first directional function and the second directional function, i.e. ; wherein, , is the main lobe direction, i.e. there is .

6. An electronic device, comprising: The method comprises the following steps: The memory stores a computer program, and the one or more processors are configured to execute the computer program to implement the log-periodic antenna design method considering grating lobe suppression.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores computer executable instructions for executing the log-periodic antenna design method considering grating lobe suppression.

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