Wide-angle scanning lens terminal antenna and scanning mode thereof

Abstract

The application relates to the field of lens antennas, and discloses a wide-angle scanning lens terminal antenna, which comprises a total array composed of a plurality of array elements with the same structure, the array elements comprise corresponding lenses and phased feed source arrays from top to bottom, the phased feed source array is composed of 2N sub-arrays, each of the sub-arrays is composed of N*N antenna units, and N is equal to [2, +infinity]. The application further discloses a scanning mode of the wide-angle scanning lens terminal antenna. The high-gain and large-angle scanning performance of the terminal antenna are realized through the flat-convex lens antenna structure based on the phased feed source; compared with the traditional phased array antenna and the traditional lens antenna, the application has the effects of high flexibility, high gain and large scanning angle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lens antennas, in particular to a wide-angle scanning lens terminal antenna and a scanning method thereof. BACKGROUND

[0002] Terminal antennas with tracking capability are one of the key components of satellite communication systems, and the wide-angle scanning capability of terminal antennas is required to achieve good automatic tracking capability of the antennas to satellites. Phased array antennas installed on mobile terminals on land, sea and air are currently commonly used terminal system designs to complete tracking and communication of satellites. Using traditional phased array technology with scanning capability, the wide-angle scanning function can be realized by controlling the phase information of each unit channel. However, when considering high-gain design, the number of units in the antenna array will increase, and the corresponding feed network will become complex and large. More importantly, the insertion loss of the feed network will also increase, which will reduce the gain of the antenna. If a point source feed lens structure is used alone to achieve high gain, the scanning flexibility and scanning capability of the terminal antenna system will be reduced. SUMMARY

[0003] The technical problem to be solved by the present application is the cost problem caused by the large volume and large number of channels of existing high-gain antenna arrays, and the problem that existing single-feed lens antenna arrays cannot perform fast beam scanning. A new type of wide-angle scanning lens terminal antenna based on a loaded phased feed is proposed. The lens unit and the traditional phased array are effectively fused together in the lens antenna, and the scanning function of the lens can be realized by changing the phase of the phased feed. Not only can the gain of the antenna be effectively improved, but also the wide-angle scanning of the lens antenna can be realized.

[0004] The present application is implemented by the following technical solutions:

[0005] A wide-angle scanning lens terminal antenna, comprising a total array composed of a plurality of array elements, the array elements comprising a one-to-one corresponding lens and a phased feed array from top to bottom, the phased feed array being composed of 2N sub-arrays, each of the sub-arrays being composed of N*N antenna elements, N∈[2, +∞].

[0006] As an optimization, the lens is a plano-convex lens, and the convex surface of the lens faces the phased feed, and the plane of the lens radiates outward.

[0007] As an optimization, the antenna element is sequentially connected with a top layer, a middle layer and a bottom layer, the top layer being a first square corner piece with a pair of corner angles, the middle layer being a second square corner piece with a pair of corner angles, and a gap being provided on the second square corner piece, and the bottom layer being a ground plate, and the pair of corner angles of the first square corner piece and the second square corner piece being in the same direction.

[0008] As an optimization, the antenna elements in the same subarray are rotated 90° clockwise in sequence.

[0009] As an optimization, several array elements are selected as dummy elements based on the principle of sparse array arrangement.

[0010] This invention also discloses a scanning method for a wide-angle scanning lens terminal antenna, comprising the following steps:

[0011] S1. Each antenna element in each phased feed array is fed with equal amplitude, and the phases of the antenna elements in each subarray are successively 90° apart. The phase settings of each subarray are the same, thus obtaining the normal pattern of the total array.

[0012] S2. By combining the normal pattern of the overall array with the grating lobe suppression technology of the reconfigurable lens antenna array based on the differential evolution algorithm, the phase information ψ of each lens element (array element) at the scanning position of the target is obtained through array synthesis analysis. i ;

[0013] S3. Based on the phase information ψ of the lens unit (array element) i The radiation characteristics of each phased feed array are obtained by relating it to the phase center of the phased feed array, thereby obtaining the phase of the antenna element in each phased feed array.

[0014] S4. Based on the obtained phase of the antenna element Configure the feed phase of the antenna element.

[0015] As an optimization, step S2 involves using the phase information ψ of the lens unit (array element). i The optimal decision variable X for each lens unit (array element) is calculated based on the differential evolution algorithm. best，G To suppress the grid lobes.

[0016] As an optimization, the phase information ψ of the lens unit (array element) i Equivalent scan pattern angle including the overall array pattern distribution And the feed phase α.

[0017] As an optimization, the optimal decision variable X is calculated. best，G The steps are as follows:

[0018] Step 1: Initialize the decision variables of the overall array, where the decision variables of the overall array are X. i，G ;

[0019] Step 2: Initialize the decision variable X i，GThe evaluation function Fit is substituted into the calculation, if the evaluation function Fit is greater than the set threshold value, step 3 is entered, otherwise, the decision variable is the optimal decision variable X best，G The value of the optimal decision variable X best，G is outputted.

[0020] Step 3, the decision variable is subjected to differential, crossover, selection iteration operation, a new decision variable is calculated, and step 2 is returned.

[0021] As optimization, in S3, the phase information ψ i of the array element is one-to-one mapped to the phase of the antenna element in the phased feed array.

[0022] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0023] The present application realizes high gain and large angle scanning performance of the terminal antenna through the plano-convex lens antenna structure based on the phased feed, and has high flexibility, high gain and large scanning angle compared with the conventional phased array antenna and the conventional lens antenna. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0025] Figure 1 It is a layout schematic diagram of the total array of the wide-angle scanning lens terminal antenna according to the present application.

[0026] Figure 2 It is a dummy element layout schematic diagram of the total array of the wide-angle scanning lens terminal antenna according to the present application.

[0027] Figure 3 It is a structure schematic diagram of the array element of the wide-angle scanning lens terminal antenna according to the present application.

[0028] Figure 4 It is a structure schematic diagram of the lens of the wide-angle scanning lens terminal antenna according to the present application.

[0029] Figure 5 It is a layout schematic diagram of the phased feed array of the wide-angle scanning lens terminal antenna according to the present application.

[0030] Figure 6 ​A subarray layout diagram of a phased feed array of a wide-angle scanning lens terminal antenna according to the present application;

[0031] Figure 7 A structure diagram of an antenna unit of a phased feed array of a wide-angle scanning lens terminal antenna according to the present application;

[0032] Figure 8 A left and right circular direction diagram of an array element of a wide-angle scanning lens terminal antenna according to the present application;

[0033] Figure 9 An axial ratio diagram of an array element of a wide-angle scanning lens terminal antenna according to the present application;

[0034] Figure 10 An overall array normal direction diagram of a wide-angle scanning lens terminal antenna according to the present application;

[0035] Figure 11 An overall array scanning direction diagram of a wide-angle scanning lens terminal antenna according to the present application;

[0036] Figure 12 A scanning direction diagram of a 45° target scanning position of a wide-angle scanning lens terminal antenna according to the present application;

[0037] Figure 13 A top view diagram of a linear arrangement of an array element in an embodiment;

[0038] Figure 14 A side view diagram of a linear arrangement of an array element in an embodiment. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be given to the present application in combination with embodiments and drawings, and the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application.

[0040] Embodiment 1

[0041] The present application discloses a wide-angle scanning lens terminal antenna, which comprises an overall array composed of a plurality of array elements with the same structure, wherein the array elements comprise corresponding lenses and phased feed arrays from top to bottom, the phased feed array is composed of 2N subarrays, each of the subarrays is composed of N*N antenna units, and N is an element in [2, +∞]. The lenses and the phased feed array are spaced apart and supported by respective support mechanisms, which can be existing support plates and the like, and the distance between the phased feed array and the lenses is generally equal to the focal length of the lenses, and can be adjusted according to actual conditions.

[0042] In the embodiment, the lens is a plano-convex lens, and the convex surface of the lens faces the phased feed source, and the plane of the lens radiates outward.

[0043] In the embodiment, the antenna unit package sequentially connects a top layer, a middle layer and a bottom layer, the top layer is a first square corner cutting piece with a pair of cutting corners, the middle layer is a second square corner cutting piece with a pair of cutting corners, and a gap is arranged on the second square corner cutting piece, and the bottom layer is a ground plate, and the pair of cutting corners of the first square corner cutting piece and the second square corner cutting piece are in the same direction.

[0044] In the embodiment, the antenna units in the same subarray sequentially rotate 90 degrees in a clockwise direction.

[0045] In the embodiment, a plurality of array elements are selected as dummy elements according to the principle of sparse array arrangement.

[0046] Specifically, the application can be applied to different working frequency bands, and a lens terminal transmitting antenna array (total array) working in a Ka frequency band is taken as an example, as shown in FIG. Figures 1-2 The total array adopts a triangular grid array, and there are 91 array elements. Each array element in the array has the same structure, as shown in FIG. Figure 3 The lens and the phased feed source are arranged from top to bottom. As shown in FIG. Figure 4 The lens adopts a plano-convex lens structure, and the phased feed source is a microstrip form phased array antenna array.

[0047] Further, in the design of the 91 array elements, 10 lens elements (array elements) are selected as dummy elements according to the optimization design requirements of component channel arrangement and combined with the idea of sparse array arrangement, so as to realize array layout setting, as shown in FIG. Figure 2 The sparse array layout antenna can be performed according to actual conditions, which will not be described here. The above lens array layout structure, combined with the idea of sparse array arrangement, realizes the optimization design of channel arrangement through dummy element design, and further reduces the number of system channels.

[0048] Further, the plano-convex lens is a hyperbolic lens, the convex surface faces the phased feed source, the plane radiates outward, and the aperture of the plano-convex lens is 35 mm. The focal length corresponding to the plano-convex lens is 38 mm, Figure 3 The phased feed source array shown in FIG.

[0049] Further, as shown in FIG. Figures 5-7As shown, the phased-array feed is 4×4 in size, consisting of four 2×2 subarrays. Each antenna element in the subarray has a square chamfered top layer, a square chamfered middle layer radiating patch with slots, and a ground plane at the bottom. That is, the antenna element includes two dielectric substrates, a top parasitic patch, a middle radiating patch, and a bottom antenna GND structure. The top parasitic patch and the middle radiating patch are attached to the dielectric substrate, both of which are 0.254mm thick Taconic TLY material. The top parasitic patch is square chamfered, the middle radiating patch is a square chamfered patch with lateral slots, and the bottom layer is the antenna GND. This square chamfered patch structure, by adding a top parasitic patch design and etching lateral slots at the center of the middle radiating patch, achieves a wider circular polarization bandwidth and better impedance matching.

[0050] The 2×2 subarray antenna is obtained by rotating each individual antenna element 90° clockwise in space. The four antenna elements have a phase difference of 90°.

[0051] The present invention also includes an embodiment 2, a scanning method for a wide-angle scanning lens terminal antenna, comprising the following steps:

[0052] S1. Each antenna element in each phased feed array is fed with equal amplitude, and the phases of the antenna elements in each subarray are successively 90° apart. The phase settings of each subarray are the same, thus obtaining the normal pattern of the total array.

[0053] S2. By combining the normal pattern of the overall array with the grating lobe suppression technology of the reconfigurable lens antenna array based on the differential evolution algorithm, the phase information ψ of each lens element (array element) at the scanning position of the target is obtained through array synthesis analysis. i ;

[0054] S3. Based on the phase information ψ of the lens unit (array element) i The radiation characteristics of each phased feed array are obtained by relating it to the phase center of the phased feed array, thereby obtaining the phase of the antenna element in each phased feed array.

[0055] S4. Based on the obtained phase of the antenna element Configure the feed phase of the antenna element.

[0056] In this embodiment, step S2 is to determine the phase information ψ of the lens unit (array element). i The optimal decision variable X for each lens unit (array element) is calculated based on the differential evolution algorithm. best，G To suppress the grid lobes.

[0057] In this embodiment, the phase information ψ i The equivalent scan pattern angle of the array pattern distribution And the feed phase α.

[0058] In this embodiment, the optimal decision variable X best，G The steps are:

[0059] Step 1, initialize the decision variable of the total array, the decision variable of the lens (total) array is X i，G .

[0060] Step 2, substitute the initialized decision variable X i，c into the evaluation function Fit for calculation, if the evaluation function Fit is greater than the set threshold, go to step 3, otherwise, the decision variable is the optimal decision variable X best，G , output the value of the optimal decision variable X best，G .

[0061] Step 3, perform differential, crossover, and selection iteration operations on the decision variable to calculate a new decision variable, and return to step 2.

[0062] In this embodiment, in S3, the phase information ψ i of the lens unit (array element) is one-to-one mapped to the phase of the antenna unit in the phased feed array.

[0063] For the total lens array, the normal pattern can be represented as:

[0064]

[0065] Where E (p) is the pth reconfigurable pattern of the lens unit (array element), and the grating lobe is suppressed by selecting different reconfigurable patterns of the lens unit (array element) in a non-periodic manner, and Q is the number of lens units (array elements). The final purpose of optimization is to find a set of reconfigurable pattern distributions of the lens antenna (array element), that is:

[0066] The equivalent optimization target is to find a set of scan pattern angles of the subarray, that is:

[0067]

[0068] The new grating lobe algorithm provided by the application comprises the following steps, and the algorithm flow is shown in Figure 12 .

[0069] Step A: input the total array parameters, step B: based on the differential evolution algorithm.

[0070] Specifically:​

[0071] In step A, the parameters of the total array include, operating frequency, scale, topology of the lens (total) array, selectable pattern of the lens element (array element), i.e. the maximum scanning range of the lens element (array element), target scanning position.

[0072] In step B, the selection of the reconfigurable lens element pattern and the array feeding phase are optimized based on the differential evolution algorithm.

[0073] In step B, the following steps are included:

[0074] Step B1----Step B2----Step B3----Step B4----Step B5.

[0075] In step B1, the lens array population (array element population) is initialized, and the equivalent scanning pattern angle of the lens element reconfigurable pattern distribution is selected and the feeding phase ∝ is initialized as the initial variable q :

[0076]

[0077] wherein is the target scanning position to be scanned by the pattern, x q and y q are the horizontal and vertical coordinates of the position of the lens element, respectively.

[0078] In step B2, the selection of the evaluation function is evaluated, and the target is the suppression of the grating lobe. The optimization problem can be written as

[0079]

[0080] Then, the evaluation function is expressed as

[0081] Fit = PSLL - kG + C;

[0082] wherein k is a positive weight coefficient, and C is a constant, which ensures that Fit > 0, so as to avoid the termination of the iteration of steps B3-B5 below, resulting in the inability to find the optimal decision variable X best，G .

[0083] When the evaluation function Fit meets the threshold value, PSLL can be regarded as the minimum value of the grating lobe value, and the gain is the gain value when the target scanning position is scanned, and the value of is the maximum when the target scanning position is scanned.

[0084] In step A, the lens array (total array) parameters are input, such as Figures 13-14As shown, 8 lens units are linearly arranged, the unit spacing is 3.8λ, the maximum scanning range of the lens unit is ±40°, and the target scanning positions are (45°, 0°) and (40°, 0°).

[0085] In step B, the selection of the reconfigurable lens unit directional pattern and the array feed phase are optimized based on the differential evolution algorithm.

[0086] Step B also includes the following steps:

[0087] Step B1----Step B2----Step B3----Step B4----Step B5.

[0088] In step B1, the population is initialized, and the evaluation function of the optimization problem is calculated, and the decision variable is the optimization target X i,G which can be expressed as

[0089]

[0090] In the formula, i represents the ith individual in the population, D represents the dimension of the vector, here D=3Q, Q is the number of lens units, the population size NP is set, and the maximum number of iterations G max The equivalent scanning directional pattern angle of the reconfigurable directional pattern distribution of the lens unit is selected and the feed phase α is initialized as the initial variable q The decision variable is constrained in the search space by the target problem, which can be expressed as the lower bound x min =-θ max and the upper bound x max =θ max Therefore, the initial population can be expressed as

[0091]

[0092] In the formula, rand(0,1) represents a uniformly distributed random number in the interval [0,1], and j is the vector dimension.

[0093] In step B2, the parameter selection of the evaluation function is k=0.2 and C=20.

[0094] Fit=PSLL-kG+C;

[0095] In step B3, differential mutation operation is performed:

[0096]

[0097] X best，G is the individual with the optimal fitness value in the Gth iteration. F is a positive parameter, ranging from 0 to 1, called the scaling factor, used to control the degree of differential disturbance.

[0098] Step B4 performs the crossover operation, and binomial crossover operation is used to enhance the diversity of the population, and the binomial crossover operation is used to obtain new individuals.

[0099]

[0100] rand j rand is an integer randomly generated in the range of [1, D], CR is a crossover factor in the range of [0, 1], and F is the same as F, which is a parameter for controlling the DE algorithm.

[0101] Step B5 performs the selection operation, and the individual with better fitness is greedily selected from the parent individual and the trial individual as the parent individual of the next generation.

[0102]

[0103] Through the above three steps of difference, mutation and selection, the process is repeated generation after generation until the condition is met.

[0104] The above-mentioned reconfigurable lens antenna array sidelobe suppression technology based on the differential evolution algorithm is applied to the design of the lens array loaded with the phased feed, and the sidelobe suppression under the large array spacing is realized.

[0105] The simulation analysis is performed on the lens unit, and the left and right circular polarization gain of the antenna is as shown in Figure 8 The simulation result shows that the normal gain of the lens unit is 20.18dBi. It can be seen that the transmitting lens unit antenna is a right circularly polarized antenna.

[0106] By setting the phased array unit to work at different frequency points, the axial ratio information of the lens unit (array element) can be obtained, and the result is shown in the figure. It can be seen from Figure 9 that the axial ratio of the transmitting lens unit is less than 3dB in the working frequency band.

[0107] The array spacing is set to 38mm, and the normal pattern is as shown in Figure 10 The simulation shows that the normal gain is 39.26dBi.

[0108] Combined with the reconfigurable lens antenna array sidelobe suppression technology based on the differential evolution algorithm, the scanning angle of the transmitting lens array is realized to 45°, and the scanning pattern is as shown in Figure 11 It can be seen that the maximum gain is 34.99dBi when scanning to 45°, and the sidelobe suppression is 9.55dB.

[0109] In summary, first, each unit in the phased feed source below the lens is fed with equal amplitude and in-phase to obtain its normal radiation performance; in order to realize the wide-angle scanning function of the lens such as ±45°, while meeting the low sidelobe design of the lens array under the large spacing arrangement, the array synthesis analysis needs to be carried out by combining the total array normal pattern with the reconfigurable lens antenna array sidelobe suppression technology based on the differential evolution algorithm to obtain the phase information ψ of each lens unit when scanning ±45° i ; then the radiation characteristics of each phased feed source are obtained according to the relationship between the lens unit phase and the phase center of the phased feed source, that is, the phase of the unit in each phased feed source is obtained After setting , the wide-angle scanning function of the lens can be realized.

[0110] Working principle: in order to realize wide-angle scanning, first, the phased feed source needs to be provided with a certain amplitude and phase, and by changing the amplitude and phase of the phased feed source, the radiation characteristics of the phased feed source can be changed, thereby affecting the phase center. When the phase center of the feed source changes, the radiation characteristics of the lens will change, thereby realizing wide-angle scanning; and combined with the large spacing arrangement sidelobe suppression algorithm, the suppression of the sidelobe of the lens array under the large spacing arrangement is realized.

[0111] Therefore, the wide-angle scanning lens terminal antenna design realized by the present application avoids the problems of low gain, complex feed network, high cost of traditional phased array antennas, low scanning flexibility, poor scanning ability and the like of traditional lens antennas, and adopts the sparse array design of the lens antenna based on the phased feed source to realize the wide-angle scanning function, thereby having the advantages of high gain, fast beam scanning, few channels and low cost, and the design advantage of large spacing sidelobe suppression can be realized by the reconfigurable lens antenna array sidelobe suppression technology based on the differential evolution algorithm.

[0112] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application, and any modification, equivalent replacement, improvement and the like within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A scanning method of a wide-angle scanning lens terminal antenna, characterized by, The wide-angle scanning lens terminal antenna comprises a total array composed of a plurality of structural identical array elements, the array elements comprise corresponding lenses and phased feed source arrays from top to bottom, the phased feed source array is composed of 2N sub-arrays, each of the sub-arrays is composed of N*N antenna units, N [2, + ∞], and the method comprises the following steps: S1, each of the antenna units in each of the phased feed source arrays is fed with equal amplitude, and the antenna units in each of the sub-arrays are sequentially 90° out of phase, the phase of each of the sub-arrays is set to be the same, and the normal direction pattern of the total array is obtained; S2, through the normal direction diagram of the total array, combining with the reconfigurable lens antenna array grating lobe suppression technology based on differential evolution algorithm, array synthesis analysis is carried out to obtain the phase information of each array element when the scanning target scans the position i ; the phase information of the array element i The equivalent scanning direction diagram angle including the total array direction diagram distribution And the feeding phase α; Step S2 is to calculate the optimal decision variable X of each array element based on the parameters of the total array according to the differential evolution algorithm best,G to suppress the grating lobes; The step of calculating the optimal decision variable X best,G is: Step 1, initialize the decision variables for the total array, X i,G ; Step 2, the initialized decision variable X i,G is substituted into the evaluation function Fit for calculation. If the evaluation function Fit is greater than the set threshold value, step 3 is entered, otherwise, the decision variable is the optimal decision variable X best,G , and the value of the optimal decision variable X best,G is output. Step 3, the iterative operation of difference, crossover and selection is performed on the decision variable to calculate a new decision variable, and step 2 is returned; The evaluation function is: Fit = PSLL - kG + C; k is a positive weight coefficient, C is a constant, G is the gain of the target position, PSLL is the optimization problem, and S3. The phase information ψ of the array element i The radiation characteristics of each phased feed array are obtained from the relationship between the phase center of the phased feed array and the phase of the antenna element in each phased feed array S4, setting the phase of the antenna element based on the obtained phase The feeding phase of the antenna element is set.

2. The scanning method of a wide-angle scanning lens terminal antenna according to claim 1, wherein The lens is a plano-convex lens, and the convex surface of the lens faces the phased feed source, and the plane of the lens radiates outward.

3. The scanning method of a wide-angle scanning lens terminal antenna according to claim 1, wherein The antenna unit comprises a top layer, a middle layer and a bottom layer connected in sequence, the top layer is a first square corner piece with opposite corner angles; the middle layer is a second square corner piece with opposite corner angles, and a gap is arranged on the second square corner piece; the bottom layer is a ground plate, and the opposite corner angles of the first square corner piece and the second square corner piece are in the same direction.

4. The scanning method of a wide-angle scanning lens terminal antenna according to claim 3, wherein The antenna units in the same sub-array are sequentially rotated by 90° in the clockwise direction.

5. The scanning method of a wide-angle scanning lens terminal antenna according to claim 1, wherein A plurality of array elements are selected as dummy elements according to the principle of sparse array.

6. The scanning method of a wide-angle scanning lens terminal antenna according to claim 1, wherein In S3, the phase information ψ of the array element i with the phase of the antenna elements in the phased feed array One-to-one mapping corresponds.

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