1. A phased array antenna calibration method based on a grouping rotation vector method is characterized by comprising the following steps;

step S1: dividing a phased array antenna with N radiating elements into N groups, wherein N is less than or equal to N; the grouping principle is that the synthetic field vectors diagnosed among groups are kept consistent as much as possible by means of different numbers of units of each group, and the ratio of each component in each group is as close as possible;

step S2: calculating K of each group of radiation units_iAnd X_i；K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the excitation coefficient phase of the ith group of radiation units and the phase of the initial synthetic field vector is indicated, and the value range of i is 1 to n; knowing K_iI.e. know E_iAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_iThe relationship between the groups, namely the diagnosis between the groups is completed;

step S3: calculating K of each radiation unit in each group of radiation units_jAnd X_j；K_jRefers to the ratio of the amplitude of the excitation coefficient of the j-th radiation element in the group of radiation elements to the amplitude of the initial resultant field vector, X_jThe difference between the excitation coefficient phase of the jth radiation unit in the group of radiation units and the phase of the initial synthetic field vector is referred, and the value range of j is 1 to the number of the radiation units contained in the group of radiation units; knowing K_jI.e. know E_jAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_jThe relationship between them, i.e. the in-group diagnosis is completed.

2. The method of claim 1, wherein the grouped rotation vector method phased array antenna calibration method is based on Hadamard matrix or not.

3. The method of claim 1, wherein in step S2, the initial resultant field vector of the phased array antenna is set toChanging the phase of the i-th group of radiating elements toThe resultant field vector at this time is calculated by formula one；

Formula one is(ii) a Wherein the content of the first and second substances,refers to the magnitude of the initial resultant field vector,refers to the phase of the initial resultant field vector,refers to the amplitude of the i-th group of radiating elements,refers to the initial phase of the i-th group of radiating elements.

4. The method for calibrating a phased array antenna based on the grouped rotation vector method according to claim 3, wherein in the step S2, let K_i＝E_i/E₀，Obtaining a formula II and a formula III;

the second formula is(ii) a Formula III is(ii) a Wherein, T is (r-1)/(r + 1); r is the maximum E in the resultant field vector when the phase is changed_maxAnd the minimum value E_minIs equal to E_max/E_min(ii) a Calculating K corresponding to each group of radiation units by using a formula II and a formula III_iAnd X_i。

5. The method for calibrating a phased array antenna according to claim 3 or 4, wherein in step S3, the specific calculation process of step S2 is repeated, the symbols and the subscript in the formula are changed from i to j, and K for each radiation element in each group of radiation elements is calculated_jAnd X_j。

6. A phased array antenna calibration device based on a grouping rotation vector method is characterized by comprising a grouping unit, an inter-group diagnosis unit and an intra-group diagnosis unit;

the grouping unit is used for dividing the phased array antenna with N radiating elements into N groups, wherein N is less than or equal to N; the grouping principle is that the synthetic field vectors diagnosed among groups are kept consistent as much as possible by means of different numbers of units of each group, and the ratio of each component in each group is as close as possible;

the inter-group diagnosis unit is used for calculating K of each group of radiation units_iAnd X_i，K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the excitation coefficient phase of the ith group of radiation units and the phase of the initial synthetic field vector is indicated, and the value range of i is 1 to n; knowing K_iI.e. know E_iAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_iThe relationship between the groups, namely the diagnosis between the groups is completed;

the in-group diagnosis unit is used for calculating K of each radiation unit in each group of radiation units_jAnd X_j；K_jRefers to the ratio of the amplitude of the excitation coefficient of the j-th radiation element in the group of radiation elements to the amplitude of the initial resultant field vector, X_jThe difference between the excitation coefficient phase of the jth radiation unit in the group of radiation units and the phase of the initial synthetic field vector is referred, and the value range of j is 1 to the number of the radiation units contained in the group of radiation units; knowing K_jI.e. know E_jAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_jThe relationship between them, i.e. the in-group diagnosis is completed.

Background

A phased array antenna (phased array antenna) refers to an antenna that changes the shape of a radiation pattern by controlling the feeding phase of a radiation element (radiation element) in an array antenna (array antenna). Phased array antennas are increasingly widely used in radio systems such as military radars and civil radars, and therefore calibration of phased array antennas is a hot point of research.

After a general phased array antenna is processed, measurement needs to be performed and measurement data needs to be calibrated. The purpose of calibration is to eliminate the related errors as much as possible, such as amplitude and phase distribution errors, phase shifter and position errors caused by structural asymmetry, so that the performance of the array antenna can reach the required technical conditions or the optimal state.

Rotation-element field vector (REV) is a classical phased array antenna calibration method. In a small-scale array antenna, the size of the synthetic vector is sensitive to phase change of a single radiation unit, so that the reading precision is high, and the calibration precision is high. However, in a large-scale array antenna, the magnitude of the resultant vector is not sensitive to single radiating element commutation, and the reading accuracy, and thus the calibration accuracy, is degraded.

In section 3, "grouped rotation-electric field vector" is introduced, which states "due to the superiority of Hadamard matrix, the grouped matrix is based on Hadamard matrix". The Hadamard matrix is called Hadamard matrix or Hadamard matrix.

Disclosure of Invention

The method is suitable for diagnosis of large-scale phased array antennas, and can solve the problems that the size of a synthetic vector in the large-scale phased array antennas is insensitive to phase change of a single antenna unit, reading accuracy is poor, and calibration accuracy is also poor.

In order to solve the technical problem, the application provides a phased array antenna calibration method based on a grouping rotation vector method, which comprises the following steps. Step S1: dividing a phased array antenna with N radiating elements into N groups, wherein N is less than or equal to N; the grouping principle is that the number of units in each group is different, so that the synthesized field vectors diagnosed among groups are kept consistent as much as possible, and the ratio of each component in the group is close as much as possible. Step S2:calculating K of each group of radiation units_iAnd X_i；K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the excitation coefficient phase of the ith group of radiation units and the phase of the initial synthetic field vector is indicated, and the value range of i is 1 to n; knowing K_iI.e. know E_iAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_iThe relationship between them, i.e. the diagnosis between groups is completed. Step S3: calculating K of each radiation unit in each group of radiation units_jAnd X_j；K_jRefers to the ratio of the amplitude of the excitation coefficient of the j-th radiation element in the group of radiation elements to the amplitude of the initial resultant field vector, X_jThe difference between the excitation coefficient phase of the jth radiation unit in the group of radiation units and the phase of the initial synthetic field vector is referred, and the value range of j is 1 to the number of the radiation units contained in the group of radiation units; knowing K_jI.e. know E_jAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_jThe relationship between them, i.e. the in-group diagnosis is completed.

Further, the grouping matrix of the grouping rotation vector method is either a Hadamard matrix or is not a Hadamard matrix. This shows that the packet rotation vector method of the present application breaks through the limitation of the first document.

Further, in step S2, the initial resultant field vector of the phased array antenna isChanging the phase of the i-th group of radiating elements toBy the formula 1Computing the composite field vector at that time. Wherein the content of the first and second substances,refers to the magnitude of the initial resultant field vector,refers to the phase of the initial resultant field vector,refers to the amplitude of the i-th group of radiating elements,refers to the initial phase of the i-th group of radiating elements.

Further, in the step S2, let K_i＝E_i/E₀，And obtaining a formula two and a formula three. The second formula is(ii) a Formula III is(ii) a Wherein, T is (r-1)/(r + 1); r is the maximum E in the resultant field vector when the phase is changed_maxAnd the minimum value E_minIs equal to E_max/E_min(ii) a Calculating K corresponding to each group of radiation units by using a formula II and a formula III_iAnd X_i。

Further, in step S3, the specific calculation process of step S2 is repeated, i is changed to j for each symbol and the index in the formula, and K of each radiation unit in each group of radiation units is calculated_jAnd X_j. This indicates that the in-group diagnostic algorithm is the same as the inter-group diagnostic algorithm in this application.

The application also provides a phased array antenna calibration device based on the grouping rotation vector method, which comprises a grouping unitAn inter-group diagnosis unit and an intra-group diagnosis unit. The grouping unit is used for dividing the phased array antenna with N radiating elements into N groups, wherein N is less than or equal to N; the grouping principle is that the number of units in each group is different, so that the synthesized field vectors diagnosed among groups are kept consistent as much as possible, and the ratio of each component in the group is close as much as possible. The inter-group diagnosis unit is used for calculating K of each group of radiation units_iAnd X_i，K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the excitation coefficient phase of the ith group of radiation units and the phase of the initial synthetic field vector is indicated, and the value range of i is 1 to n; knowing K_iI.e. know E_iAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_iThe relationship between them, i.e. the diagnosis between groups is completed. The in-group diagnosis unit is used for calculating K of each radiation unit in each group of radiation units_jAnd X_j；K_jRefers to the ratio of the amplitude of the excitation coefficient of the j-th radiation element in the group of radiation elements to the amplitude of the initial resultant field vector, X_jThe difference between the excitation coefficient phase of the jth radiation unit in the group of radiation units and the phase of the initial synthetic field vector is referred, and the value range of j is 1 to the number of the radiation units contained in the group of radiation units; knowing K_jI.e. know E_jAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_jThe relationship between them, i.e. the in-group diagnosis is completed.

The technical effect that this application obtained is: the grouping rotation vector method of the application adopts a grouping principle that the synthetic field vectors diagnosed among groups are kept consistent as much as possible and the ratio of each component in the group is as close as possible by means of different numbers of units in each group, so that the amplitude of the synthetic field vectors changes greatly and the diagnosis error is small when each group of radiation units respectively moves phase.

Drawings

Fig. 1 is a schematic diagram of the variation of the resultant field vector with unit phase.

Fig. 2 is a schematic flow chart of a phased array antenna calibration method based on a grouped rotation vector method according to the present application.

FIG. 3 is a graphical illustration of the magnitude of the resultant field vector versus phase of the center cell for inter-group diagnostics.

FIG. 4 is a graphical illustration of the magnitude of the resultant field vector versus phase of the edge cells for inter-group diagnostics.

FIG. 5 is a graph of raw amplitude for inter-group diagnostics.

FIG. 6 is a graphical illustration of diagnostic magnitude for inter-group diagnostics.

FIG. 7 is a diagram of the raw phase of inter-group diagnostics.

FIG. 8 is a schematic of the calibration phase for inter-group diagnostics.

FIG. 9 is a graph of raw amplitude of intra-group cell diagnostics.

FIG. 10 is a diagnostic magnitude graph of intra-group cell diagnostics.

FIG. 11 is a raw phase diagram of intra-group cell diagnostics.

FIG. 12 is a calibration phase diagram of intra-group cell diagnostics.

Fig. 13 is a schematic diagram comparing a calibration pattern estimated using the diagnostic amplitude phase with a theoretical pattern.

Fig. 14 is a schematic structural diagram of a phased array antenna calibration apparatus based on a grouped rotation vector method according to the present application.

The reference numbers in the figures illustrate: grouping unit 1, inter-group diagnosis unit 2, and intra-group diagnosis unit 3.

Detailed Description

Fig. 1 shows the resultant field vector as a function of cell phase. In FIG. 1, the upper dotted lineFor synthesizing field vectors, the lower dotted lineFor the initial composite field vector, each field component is represented by the solid line with arrows, whereFor the first field vector to be used,for the i-th field vector, the field vector,is the phase shift of the ith field vector.

Referring to fig. 2, the method for calibrating a phased array antenna based on a grouped rotation vector method provided by the present application includes the following steps.

Step S1: a phased array antenna with N radiating elements is divided into N groups, N ≦ N. The grouping principle is that the number of units in each group is different, so that the synthesized field vectors diagnosed among groups are kept consistent as much as possible, and the ratio of each component in the group is close as much as possible. The meaning of the grouping rotation vector method in the application is as follows: the "grouping rotation vector method" of the present application is obtained by canceling the limitation of using the Hadamard matrix based on the "grouping rotation vector method" of the document one and using the grouping principle described in step S1.

Step S2: calculating K of each group of radiation units_iAnd X_i。K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the phase of the excitation coefficient of the ith group of radiating elements and the phase of the initial composite field vector is referred, and the value range of i is 1 to n. Therefore, the relative amplitude-phase relationship of each group of radiation elements is known, and the diagnosis between groups is completed.

The initial resultant field vector of the phased array antenna isChanging the phase of the i-th group of radiating elements toThe resultant field vector can be obtained asAnd the calculation is shown in formula one. The initial synthesized field vector indicates the superimposed vector of each unit before phase conversionAnd, the composite field vector refers to the sum of the superimposed vectors of the units after commutation.

Formula one is. Wherein the content of the first and second substances,refers to the magnitude of the initial resultant field vector,refers to the phase of the initial resultant field vector,refers to the amplitude of the i-th group of radiating elements,is the initial phase of the i-th group of radiating elements.

Defining the relative amplitude K of the i-th group of radiating elements_i＝E_i/E₀Relative phase of the i-th group of radiating elementsThen the combined power Q of the i-th group of radiating elements can be expressed as. Wherein the content of the first and second substances,y and K_i、X_iIt is related.Is the initial phase of the i-th group of radiating elements,is the phase shift amount of the i-th group of radiation units.. It can be seen that the combined power Q follows the relative phase X of the i-th group of radiating elements_iIs varied in a cosine situation, the relative phase X of the i-th group of radiation elements_iChange to-QUOTE The Q is maximized. The ratio of the maximum value Qmax to the minimum value Qmin of the composite power Q is. Let T be (r-1)/(r + 1). r is the maximum E in the resultant field vector when the phase is changed_maxAnd the minimum value E_minIs equal to E_max/E_minCan obtain whenThe second and third equations hold. The second formula is. Formula III is. Knowing K_iI.e. know E_iAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_iThe inter-group amplitude diagnosis is completed. Wherein T is (r-1)/(r + 1). r is the maximum E in the resultant field vector when the phase is changed_maxAnd the minimum value E_minIs equal to E_max/E_min. Calculating K corresponding to each i (i.e. each of the n groups of radiation units) by using a formula two and a formula three_iAnd X_i。

Step S3: repeating the specific calculation process of step S2, changing the index in each symbol and formula from i to j, and calculating K for each radiation element in each group of radiation elements_jAnd X_j。K_jRefer to the groupRatio of amplitude of excitation coefficient of j-th radiation element in radiation element to amplitude of initial resultant field vector, X_jRefers to the difference between the phase of the excitation coefficient of the j-th radiation element in the group of radiation elements and the phase of the initial resultant field vector, E_jRefers to the amplitude, phi, of the jth radiation element in the set of radiation elements_jThe initial phase of the jth radiation unit in the group of radiation units, and the value range of j is 1 to the number of radiation units contained in the group of radiation units, so that the diagnosis of the group of radiation units can be completed, and therefore, the diagnosis of all the units is completed. The calculation method of the intra-group diagnosis and the inter-group diagnosis is the same, the inter-group diagnosis is carried out by grouping, then the intra-group diagnosis is carried out in each group, and the algorithm is completely the same. Knowing K_jI.e. know E_jAnd E₀Due to the relationship of E₀Is an initial composite vector whose value does not change during each test, so that E can be known_jThe relationship between the two groups is completed, and the intra-group amplitude diagnosis is completed.

Taking an example of a phased array antenna having 16 radiating elements, the amplitude distribution is-25 dB Taylor (Taylor) distribution, the grouped rotation vector method of the present application is employed. Let 1 to 6 radiation elements be denoted as group 1, 7 to 10 radiation elements as group 2, and 11 to 16 radiation elements as group 3. At this point, ± 0.1dB random reading error was introduced, and a look was first made at the diagnosis between groups, as shown in fig. 3 to 8. Referring to fig. 3, the resultant field vector magnitude is plotted against the edge cell phase. Referring to fig. 4, the resultant field vector magnitude is plotted against the phase of the center cell. As can be seen from fig. 3 and 4, the resultant field vector magnitude is sensitive to cell phase variations. Referring to fig. 5, this is the original amplitude. Referring to fig. 6, this is the diagnostic amplitude. Referring to fig. 7, this is the original phase. Referring to fig. 8, this is the calibration phase. As can be seen from fig. 5 to 8, the interclass diagnosis is highly accurate at this time. The intra-group unit diagnostics still employ the above-described method, as shown in fig. 9-13. Referring to fig. 9, this is the original amplitude. Referring to fig. 10, this is the diagnostic amplitude. Referring to fig. 11, this is the original phase. Referring to fig. 12, this is the calibration phase. It can be seen from fig. 9 to 12 that, when a random reading error of ± 0.1dB is introduced, the amplitude calibration accuracy is high, and the phase has an error of ± 8 °. Fig. 13 is a comparison of the calibration pattern (dashed line) and the theoretical pattern (solid line) estimated using the amplitude phase diagnostic of the present application, and it can be seen that the error of the present application is small.

Referring to fig. 14, the phased array antenna calibration apparatus based on the grouped rotation vector method proposed by the present application includes a grouping unit 1, an inter-group diagnosis unit 2, and an intra-group diagnosis unit 3. The apparatus shown in fig. 14 corresponds to the method shown in fig. 2.

The grouping unit 1 serves to group a phased array antenna with N radiating elements into N groups, N ≦ N. The grouping principle is that the number of units in each group is different, so that the synthesized field vectors diagnosed among groups are kept consistent as much as possible, and the ratio of each component in the group is close as much as possible.

The inter-group diagnosis unit 2 is used for calculating K of each group of radiation units_iAnd X_i，K_iRefers to the ratio of the amplitude of the excitation coefficient of the i-th group of radiating elements to the amplitude of the initial resultant field vector, X_iThe difference between the phase of the excitation coefficient of the ith group of radiating elements and the phase of the initial composite field vector is referred, and the value range of i is 1 to n. Therefore, the relative amplitude-phase relationship of each group of radiation elements is known, and the diagnosis between groups is completed.

The in-group diagnostic unit 3 is used to calculate K for each radiation element in each group of radiation elements_jAnd X_j。K_jRefers to the ratio of the amplitude of the excitation coefficient of the j-th radiation element in the group of radiation elements to the amplitude of the initial resultant field vector, X_jThe difference between the excitation coefficient phase of the jth radiation unit in the group of radiation units and the phase of the initial composite field vector is referred, and the value range of j is 1 to the number of radiation units contained in the group of radiation units, namely the diagnosis of the units in the group is completed.

In summary, in a large-scale phased array antenna, if the amplitude of the synthesized vector field does not change obviously with the phase of the radiating element, the maximum value and the minimum value of the read curve (the curve of the amplitude of the synthesized vector field changing with the phase) and the corresponding angles (the angle corresponding to the maximum value and the minimum value) are not accurate, which results in poor diagnosis precision. At this time, by adopting the grouping rotation vector method of the application, the principle of grouping is to ensure that the vectors of the synthesized fields diagnosed among groups are kept consistent as much as possible and the ratio of each component in the groups is as close as possible by means of different numbers of units in each group. When the group is diagnosed, the amplitude of the synthetic vector field can be ensured to be sensitive along with the phase change of the radiation unit.

The above are merely preferred embodiments of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.