JP2023047695A - Array antenna calibration device and array antenna calibration program - Google Patents

Abstract

Kind Code: A1 In calibrating each antenna element using the REV method (element electric field vector rotation method) so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element, the relative We can find out the cause of the abnormality, such as whether the wrong solution was selected as the amplitude and phase of the radiated electric field, whether there was an abnormal operation of each antenna element, whether the S/N at the time of measurement was low, etc. The purpose is to separate. Kind Code: A1 The present disclosure provides a sum vector over all antenna elements 11-1 to 11-N and an initial synthesis of all antenna elements 11-1 to 11-N regarding the relative radiated electric field vector of each antenna element 11-n. A calibration accuracy evaluation unit 24 is provided for evaluating the calibration accuracy of all the antenna elements 11-1 to 11-N based on the magnitude of the difference between the radiated electric field vector and . [Selection drawing] Fig. 1

Description

The present disclosure relates to a technique of calibrating each antenna element by using the REV method (Rotating element electric field vector method) so that the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element are aligned.

Techniques for calibrating each antenna element using the REV method so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element are disclosed in Patent Documents 1 and 2, Non-Patent Document 1, and the like.

First, while rotating the phase of the radiated electric field of each antenna element from the phase of the initial radiated electric field, the amplitude of the combined radiated electric field of all the antenna elements is measured. Next, the amplitude and phase of the relative radiated electric field of each antenna element are calculated based on the amplitude and phase of the initial synthesized radiated electric field of all the antenna elements, based on the amplitude of the synthesized radiated electric field of all the antenna elements. Next, each antenna element is calibrated based on the amplitude and phase of the relative radiated electric field of each antenna element so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element.

In this way, the amplitude characteristics and phase characteristics of the radiated electric field of each element of the phased array antenna can be determined only by measuring the amplitude of the synthesized radiated electric field of all the antenna elements without measuring the phase of the synthesized radiated electric field of all the antenna elements. can be calibrated.

Japanese Patent Publication No. 03-038548 Japanese Patent Application Laid-Open No. 2001-201526

Kiyoshi Mano, Takashi Katagi, "Method for measuring element amplitude and phase of phased array antenna - Element electric field vector rotation method", Transactions of the Institute of Electronics, Information and Communication Engineers, The Institute of Electronics, Information and Communication Engineers, May 1982, Vol. B65, No. 5 , pp. 555-560.

Here, the amplitude of the relative radiated electric field of each antenna element and the As a phase, one of two types of solutions (K1 solution and K2 solution) should be selected.

Then, in order to determine whether or not the correct solution has been selected as the amplitude and phase of the relative radiated electric field of each antenna element, the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements need to confirm.

In addition, by only checking the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements, did you choose the wrong solution as the amplitude and phase of the relative radiated electric field of each antenna element? It is difficult to isolate the cause of the abnormality, such as whether there was an abnormal operation of each antenna element or whether the S/N at the time of measurement was low.

Moreover, a great deal of cost and know-how are required to confirm the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements.

Therefore, in order to solve the above problems, the present disclosure uses the REV method (element electric field vector rotation method) to align each antenna element so that the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element are calibrated. In doing so, the cause of the abnormality, such as whether the wrong solution was selected as the amplitude and phase of the relative radiated electric field of each antenna element, whether there was an abnormal operation of each antenna element, whether the S/N at the time of measurement was low, etc. The purpose is to cut without great cost and know-how.

In order to solve the above-mentioned problems, based on the magnitude of the difference between the total vector over all antenna elements of the relative radiated electric field vectors of each antenna element and the initial synthesized radiated electric field vector of all antenna elements, all antennas Evaluate the calibration accuracy across the elements. When the difference is large, there is a high possibility that an erroneous solution has been selected as the amplitude and phase of the relative radiated electric field of each antenna element.

Specifically, the present disclosure includes a radiated electric field measurement unit that measures the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field. an amplitude and phase calculator for calculating the amplitude and phase of the relative radiated electric field of each of the elements based on the amplitude and phase of the initial synthesized radiated electric field of all the elements, based on the amplitude of the synthesized radiated electric field of all the elements; an amplitude/phase calibrator for calibrating each of the elements so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each of the elements based on the amplitude and phase of the relative radiation electric field of each of the elements; A sum vector over all the elements with respect to the relative radiated electric field vector of each element, composed of the amplitude and phase of the electric field; and a calibration accuracy evaluation unit that evaluates the calibration accuracy over all the elements based on the magnitude of the difference between the initial synthesized radiation electric field vector and the array antenna calibration device.

Further, the present disclosure includes a radiated electric field measurement step of measuring the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field; an amplitude and phase calculation step of calculating the amplitude and phase of the relative radiated electric field of each of the elements based on the amplitude of the synthesized radiated electric field of the elements, with reference to the amplitude and phase of the initial synthesized radiated electric field of all the elements; an amplitude and phase calibration step of calibrating each element so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each element based on the amplitude and phase of the relative radiated electric field of each element; and the phase of the relative radiated electric field vector of each element, the sum vector over all the elements, and the initial synthesized radiation of all the elements, consisting of the amplitude and phase of the initial synthesized radiated electric field of all the elements. and a calibration accuracy evaluation step of evaluating the calibration accuracy over all the elements based on the magnitude of the difference between the electric field vectors.

According to these configurations, it is possible to investigate the cause of an abnormality such as selecting an erroneous solution as the amplitude and phase of the relative radiated electric field of each antenna element, without significant cost and know-how. In other words, it is only necessary to calculate the difference without checking the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the extracted pulse waveform of all antenna elements.

Further, in the present disclosure, the calibration accuracy evaluation unit calculates the measurement result of the amplitude of the synthetic radiated electric field of all the elements with respect to the rotation phase of the radiated electric field from the phase of the initial radiated electric field of each element, and an arbitrary amplitude and phase. and a sine function or cosine function of the array antenna.

According to this configuration, it is possible to investigate the cause of the abnormality, such as whether there was an abnormal operation of each antenna element, whether the S/N at the time of measurement was low, etc., without a great deal of cost and know-how. That is, it is only necessary to calculate the determination coefficient without checking the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements.

Further, according to the present disclosure, the calibration accuracy evaluation unit determines abnormal operation of each element when the coefficient of determination is smaller than a predetermined value, When it is larger than a predetermined value, the normal operation of each element and the spurious solution of the amplitude/phase calculator are determined, and when the coefficient of determination is larger than the predetermined value and the difference is smaller than the predetermined value, The array antenna calibrating apparatus is characterized in that a normal operation of each element and a normal solution of the amplitude/phase calculator are determined.

According to this configuration, by using the difference and the coefficient of determination together, it is possible to determine whether the cause of the abnormality is an algorithm problem of the REV method or a problem of the hardware of the array antenna transmitting/receiving device. and can be cut without know-how. In other words, it is only necessary to calculate the difference and the determination coefficient without checking the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements.

In order to solve the above-mentioned problem, a determination between a measurement result of the amplitude of the combined radiated electric field of all antenna elements with respect to the rotational phase of the radiated electric field from the phase of the initial radiated electric field of each antenna element and a sine function or a cosine function. The calibration accuracy of each antenna element is evaluated based on the magnitude of the coefficient. When the coefficient of determination is small, there is a high possibility that each antenna element malfunctioned or that the S/N at the time of measurement was low.

Specifically, the present disclosure includes a radiated electric field measurement unit that measures the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field. an amplitude and phase calculator for calculating the amplitude and phase of the relative radiated electric field of each of the elements based on the amplitude and phase of the initial synthesized radiated electric field of all the elements, based on the amplitude of the synthesized radiated electric field of all the elements; an amplitude/phase calibrator for calibrating each of the elements so as to match the amplitude and phase characteristics of the radiated electric field of each of the elements based on the amplitude and phase of the relative radiated electric field of each of the elements; and an initial radiation of each of the elements. Based on the magnitude of the coefficient of determination between the measurement of the amplitude of the combined radiated electric field of all the elements with respect to the rotational phase of the radiated electric field from the phase of the electric field and a sine or cosine function with arbitrary amplitude and phase and a calibration accuracy evaluation unit for evaluating the calibration accuracy of each element.

According to this configuration, it is possible to investigate the cause of the abnormality, such as whether there was an abnormal operation of each antenna element, whether the S/N at the time of measurement was low, etc., without a great deal of cost and know-how. That is, it is only necessary to calculate the determination coefficient without checking the calibration coefficient of each antenna element, the radiation pattern of all antenna elements, or the pulse extraction waveform of all antenna elements.

In this way, the present disclosure uses the REV method (element electric field vector rotation method) to calibrate each antenna element so that the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element are aligned. Whether the wrong solution was selected as the amplitude and phase of the relative radiated electric field, whether there was an abnormal operation of each antenna element, whether the S/N at the time of measurement was low, etc. can be separated into

1 is a diagram showing the configuration of an array antenna system of the present disclosure; FIG. It is a figure which shows the procedure of the array antenna calibration process of this indication. FIG. 4 is a diagram showing an overview of array antenna calibration processing of the present disclosure; FIG. 5 is a diagram illustrating details of the K1 solution or K2 solution selection process of the present disclosure; It is a figure which shows the procedure of the calibration accuracy evaluation process of this indication. FIG. 5 is a diagram illustrating an overview of first calibration accuracy evaluation processing of the present disclosure; FIG. 10 is a diagram illustrating an overview of second calibration accuracy evaluation processing of the present disclosure;

Embodiments of the present disclosure will be described with reference to the accompanying drawings. The embodiments described below are examples of implementing the present disclosure, and the present disclosure is not limited to the following embodiments.

(Array antenna calibration process of the present disclosure)
FIG. 1 shows the configuration of the array antenna system of the present disclosure. An array antenna system A includes an array antenna transmission/reception device 1 and an array antenna calibration device 2 . The array antenna transmitting/receiving apparatus 1 includes antenna elements 11-n (n=1 to N), attenuators 12-n (n=1 to N), phase shifters 13-n (n=1 to N), splitter/synthesizer. It includes a device 14, a transmitter/receiver 15 and a control unit 16, and any of an all-analog system, an all-digital system, and an analog/digital mixed system can be adopted. The array antenna calibration device 2 includes a radiation electric field measurement unit 21, an amplitude phase calculation unit 22, an amplitude phase calibration unit 23, and a calibration accuracy evaluation unit 24. The array antenna calibration program shown in FIG. 2 and the calibration accuracy evaluation program shown in FIG. can be installed on the computer.

FIG. 2 shows the procedure of array antenna calibration processing according to the present disclosure. An overview of the array antenna calibration process of the present disclosure is shown in FIG. Details of the K1 solution or K2 solution selection process of the present disclosure are shown in FIG.

The radiated electric field measurement unit 21 uses each phase shifter 12-n to rotate the phase of the radiated electric field of each antenna element 11-n from the phase of the initial radiated electric field, while all the antenna elements 11-1 to 11-N is measured (step S1). In the first stage of FIG ^. 3, power |E ₀ | ₂ ( An initial composite radiated electric field vector E ₀ ) is measured _, and all antenna elements 11-1 to 11-N ^is _{measured .}

In the first stage of FIG. 3, since the circuit characteristics and the like of each antenna element 11-n vary, the amplitude |E _0,n | and phase φ _0,n of the initial radiation electric field of each antenna element 11-n are uniform. , and the lengths and directions of the initial radiated electric field vectors E0 _,n of the antenna elements 11-n are not aligned.

The amplitude-phase calculator 22 calculates the amplitude and phase of the initial synthetic radiated electric field of all the antenna elements 11-1 to 11-N based on the amplitude of the synthetic radiated electric field of all the antenna elements 11-1 to 11-N, The amplitude and phase of the relative radiated electric field of each antenna element 11-n are calculated (step S2). In the second stage of FIG. 3, the power ratio |E _{m ,n '} of the composite radiated electric field of all the antenna elements 11-1 to 11-N to the phase Δm,n of the radiated electric field of each antenna element 11-n. | ² /|E ₀ | ² is calculated. In the third stage of FIG. 3, the amplitude ratio of the relative radiated electric field of each antenna element 11-n based on the amplitude |E _{0 |} k _n =|E _0,n |/|E ₀ | and phase X _n =φ _0,n −φ ₀ are calculated. Details of the second and third stages in FIG. 3 will be described later with reference to FIG.

The amplitude and phase calibration unit 23 uses the control unit 16 to match the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element 11-n based on the amplitude and phase of the relative radiated electric field of each antenna element 11-n. to calibrate each antenna element 11-n (step S3). In the fourth stage _of FIG. 3, _each attenuator 12-n and each phase shifter 13 -n calibration coefficients (correction amounts of the amplitude and phase of the radiated electric field) are calculated.

The radiation field measuring unit 21, the amplitude phase calculating unit 22, and the amplitude phase correcting unit 23 repeat steps S1 to S3 for all the antenna elements 11-1 to 11-N (step S4).

In the fourth stage of FIG. 3, the amplitude |E _0,n ″| and phase φ _{0, n} ″ are aligned, and the lengths and directions of the radiated electric field vectors E _0,n ″ of the antenna elements 11-n are aligned.

In this way, without measuring the phase arg(E _{m, n} ') of the synthetic radiated electric field of all the antenna elements 11-1 to 11-N, the power of the synthetic radiated electric field of all the antenna elements 11-1 to 11-N Only by measuring |E _m,n ' ^|

In the first stage of FIG. 4, the amplitude |Y _n |=|E _0,1 + _{. N} −E _0,n | is larger than the amplitude |E _m,n | of the radiated electric field of each antenna element 11-n. Therefore, it is necessary to select the K1 solution by setting the amplitude ratio k _n =|E _0,n |/|E ₀ | of the relative radiated electric field of each antenna element 11-n and the phase X _n =φ _0,n −φ ₀ . be.

Here, the amplitude ratio _kn of the relative radiated electric field of each antenna element 11-n is calculated as shown in Equations 1 and 2, and the phase _Xn of the relative radiated electric field of each antenna element 11-n is calculated as shown in Equations 1 and 3. is calculated as Q _{n, max} and Q _{n, min} in Equation 1 are the maximum and minimum values of |E _{m, n} ′| ² /|E ₀ | ² , and Δ _{m_max, n} in Equations 2 and 3 are Δ _{m, n that} ^{gives the maximum of |E m,n′| 2 / |} _E ⁰ _| approximating the relationship between _{m and n} with a sine or cosine function).

In the second stage of FIG. 4, the amplitude |Y _n |=|E _0,1 + _{. N} −E _0,n | is smaller than the amplitude |E _m,n | of the radiated electric field of each antenna element 11-n. Therefore, it is necessary to select the K2 solution by setting the amplitude ratio k _n =|E _0,n |/|E ₀ | of the relative radiated electric field of each antenna element 11-n and the phase X _n =φ _0,n −φ ₀ . be.

Here, the amplitude ratio _kn of the relative radiated electric field of each antenna element 11-n is calculated as shown in Equations 4 and 5, and the phase _Xn of the relative radiated electric field of each antenna element 11-n is calculated as shown in Equations 4 and 6. is calculated as Q _n,max and Q _n,min in Equation 4 are the maximum and minimum values of |E _m,n ′| ² /|E ₀ | ² , and Δ _{m_max,n} in Equations 5 and 6 are Δ _{m, n that} ^{gives the maximum of |E m,n′| 2 / |} _E ⁰ _| approximating the relationship between _{m and n} with a sine or cosine function).

However, the amplitude |Y _n |=|E _0,1 + . . . +E _0,N −E _0,n is larger or smaller than the amplitude |E _m,n | of the radiated electric field of each antenna element 11-n. Therefore, given the amplitude ratio k _n =|E _0,n |/|E ₀ | and phase X _n =φ _0,n −φ ₀ of the relative radiated electric field of each antenna element 11-n, out of the K1 solution and the K2 solution, It is not obvious which solution should be selected. Therefore, the following first to third selection methods are executed.

In the first selection method, a plurality of different states are set as the amplitude |E ₀ | and phase φ ₀ (mainly phase φ ₀ ) of the initial synthetic radiated electric field of all the antenna elements 11-1 to 11-N. , compute K1 and K2 solutions in a plurality of different states, and select solutions that have the same meaning in a plurality of different states.

In the second selection method, not only is the power |E _m,n ^′ | After measuring the phase arg (E _{m, n} ') of the radiated electric field, all the antenna elements 11-1 to 11-N rotate as the phase Δ _{m, n} of the radiated electric field of each antenna element 11-n rotates. Choose the K1 solution when the phase arg(E _m,n ') of the resultant radiated electric field of does not change by more than 180°.

In the third selection method, the amplitude | _Yn | The K1 solution is selected after setting the phase φ _0,n of the initial radiation field of each antenna element 11-n so that it always increases rather than decreases compared to E _m,n |.

In Equations 1 and 4, since Q _n,min is 0 or negative, the calibration coefficient of each antenna element 11-n becomes abnormal when r _n ² is ∞ or negative. Therefore, when the calibration coefficient of each antenna element 11-n is abnormal (YES in step S5), the amplitude/phase calibrator 23 changes the phases φ _0,n of the initial radiated electric field of each antenna element 11-n, and Then (step S6), the radiation field measurement unit 21, the amplitude phase calculation unit 22, and the amplitude phase calibration unit 23 re-execute the REV method. On the other hand, when the calibration coefficient of each antenna element 11-n is normal (NO in step S5), the amplitude phase calibration unit 23 performs the radiation electric field measurement unit 21 and the amplitude phase calculation unit 22 without executing step S6. And the amplitude-phase calibrator 23 terminates the REV method.

(Calibration accuracy evaluation process of the present disclosure)
FIG. 5 shows the procedure of the calibration accuracy evaluation process of the present disclosure. FIG. 6 shows an overview of the first calibration accuracy evaluation process of the present disclosure. FIG. 7 shows an overview of the second calibration accuracy evaluation process of the present disclosure.

As a first calibration accuracy evaluation process, the calibration accuracy evaluation unit 24 performs all antenna The initial sum of all the antenna elements 11-1 to 11-N, which is composed of the sum vector over the elements 11-1 to 11-N and the amplitude and phase of the initial synthesized radiated electric field of all the antenna elements 11-1 to 11-N Based on the magnitude of the difference between the synthesized radiated electric field vector and , the calibration accuracy over all the antenna elements 11-1 to 11-N is evaluated (step S11).

In the first stage of FIG. 6, the phases X _n =φ _{0 and n} −φ ₀ of the relative radiated electric fields of the antenna elements 11-n are not aligned (the circuit characteristics of the antenna elements 11-n vary, etc.). ). Therefore, the amplitude |Y _n |=|E _0,1 + . . . +E _0,N −E _0,n is smaller than the amplitude |E _m,n | of the radiated electric field of each antenna element 11-n, and the probability of occurrence of the K2 solution is high. In the first to third selection methods described above, there is a high probability that the K2 solution will not be selected and the K1 solution will be erroneously selected.

The sum vector over all the antenna elements 11-1 to 11-N regarding the relative radiated electric field vector of each antenna element 11-n can be expressed in complex terms as Σ|E _0,n |/|E ₀ |×exp( j(φ _0,n −φ ₀ ))=Σk _n exp(jX _n ). Under the condition that there is no theoretical error, the initial combined radiation electric field vector of all the antenna elements 11-1 to 11-N is |E ₀ |/|E ₀ |×exp(j(φ ₀ −φ ₀ ))=1+0j. Σk _n exp(jX _n )≠1 when wrong solutions are chosen for k _n and X _n or when some error occurs.

In the second stage of FIG. 6, the phases X _n =φ _{0 and n} −φ ₀ of the relative radiated electric fields of the antenna elements 11-n are aligned to some extent. Therefore, the amplitude |Y _n |=|E _0,1 + . . . +E _0,N −E _0,n is less than the amplitude |E _m,n | of the radiated electric field of each antenna element 11-n, and the probability of occurrence of the K2 solution is low. In the first to third selection methods described above, there is a high probability that the K2 solution will not be selected and the K1 solution will be positively selected.

The sum vector over all the antenna elements 11-1 to 11-N regarding the relative radiated electric field vector of each antenna element 11-n can be expressed in complex terms as Σ|E _0,n |/|E ₀ |×exp( j(φ _0,n −φ ₀ ))=Σk _n exp(jX _n ). Under the condition that there is no theoretical error, the initial combined radiation electric field vector of all the antenna elements 11-1 to 11-N is |E ₀ |/|E ₀ |×exp(j(φ ₀ −φ ₀ ))=1+0j. Σk _n exp(jX _n )≈1 when the correct solution is chosen for k _n and X _n or when no error has occurred.

Thus, it is possible to investigate the cause of an abnormality such as selecting an erroneous solution as the amplitude and phase of the relative radiated electric field of each antenna element 11-n without much cost and know-how. That is, the difference Σk _n exp We only need to calculate (jX _n )−1. In Equations 1 and 4, since Q _{n, min} is 0 or negative, r _n ² being ∞ or negative may also cause an abnormality.

As a second calibration accuracy evaluation process, the calibration accuracy evaluation unit 24 calculates the synthetic radiation electric field of all the antenna elements 11-1 to 11-N with respect to the rotational phase of the radiation electric field from the phase of the initial radiation electric field of each antenna element 11-n. and a sine function or cosine function with arbitrary amplitude and phase, the calibration accuracy of each antenna element 11-n is evaluated (step S12).

In the first stage of FIG. 7, there is an abnormal operation of each antenna element 11-n, or the S/N at the time of measurement is low. Therefore, when the phase _Δm,n of the radiated electric field of each antenna element 11-n rotates from the phase 0° of the initial radiated electric field to 360° after one rotation, all the antenna elements 11-1 to 11-N The power |E _m,n ′| ² of the resultant radiated electric field does not exactly match a sine or cosine function with arbitrary amplitude and phase.

For the phase Δ _m,n of the radiated electric field of each antenna element 11-n, the power |E _m,n ^′ _| '| ² =A+Bcos(Δ _m,n −Δ _{m_max,n} ). Then, the least squares coefficient of determination ^R2 is 0.852. Since A, B and Δ _{m_max, n} are not calculated accurately in the approximate expression, Q _{n, max} , Q _{n, min} and Δ _{m_max, n} are not accurately calculated in Equations 1 to 6, k _n and X _n are also not calculated accurately.

In the second stage of FIG. 7, there is no abnormal operation of each antenna element 11-n, or the S/N at the time of measurement is high. Therefore, when the phase _Δm,n of the radiated electric field of each antenna element 11-n rotates from the phase 0° of the initial radiated electric field to 360° after one rotation, all the antenna elements 11-1 to 11-N The power |E _m,n ′| ² of the resultant radiated electric field is well matched to a sine or cosine function with arbitrary amplitude and phase.

For the phase Δ _m,n of the radiated electric field of each antenna element 11-n, the power |E _m,n ^′ _| '| ² =A+Bcos(Δ _m,n −Δ _{m_max,n} ). Then, the least squares coefficient of determination ^R2 is 0.997. Then, in the approximation formula, A, B and Δ _{m_max, n} are accurately calculated. Therefore, in Equations 1 to 6, Q _{n, max} , Q _{n, min} and Δ _{m_max, n} are accurately calculated, k _n and X _n are also calculated accurately.

In this way, it is possible to investigate the cause of the abnormality, such as whether there was an abnormal operation of each antenna element 11-n, whether the S/N at the time of measurement was low, etc., without much cost and know-how. In other words, the determination coefficient R ² just need to calculate The abnormal operation of each antenna element 11-n includes an abnormal operation of each phase shifter 13-n, an abnormal operation of each attenuator 12-n, or an unnecessary signal from the adjacent antenna element 11-n to each antenna element 11-n. electric field/magnetic field coupling and the like.

Here, when there is an abnormal operation of each antenna element 11-n, or when the S/N at the time of measurement is low, not only does the coefficient of determination R ² decrease, but also the difference Σk _n exp(jX _n )-1 may become large. Therefore, based only on the fact that the difference Σk _n exp(jX _n )−1 is large, whether the wrong solution was selected as the amplitude and phase of the relative radiated electric field of each antenna element 11-n, or whether each antenna element 11-n It is not possible to determine whether there was an abnormal operation or whether the S/N at the time of measurement was low. Therefore, the following processing is executed.

When the coefficient of determination R ² is smaller than the predetermined value (step S13, YES), the calibration accuracy evaluation unit 24 determines abnormal operation of each antenna element 11-n regardless of the difference Σk _n exp(jX _n )−1. Determine (step S14). Then, the radiation field measurement unit 21, the amplitude phase calculation unit 22, and the amplitude phase calibration unit 23 correct the abnormal operation of each antenna element 11-n, or improve the S/N at the time of measurement. , the REV method is re-executed (step S15).

If the coefficient of determination R ² is larger than the predetermined value (step S13, NO), but the difference Σk _n exp(jX _n )−1 is larger than the predetermined value (step S16, YES), the calibration accuracy evaluation unit 24 , the normal operation of each antenna element 11-n and the spurious solution of the amplitude/phase calculator 22 (step S17). Then, the radiation electric field measuring unit 21, the amplitude phase calculating unit 22, and the amplitude phase calibrating unit 23 correct the REV method and re-execute it (step S18).

When the determination coefficient R ² is larger than the predetermined value (step S13, NO) and the difference Σk _n exp(jX _n )−1 is smaller than the predetermined value (step S16, NO), the calibration accuracy evaluation unit 24 , the normal operation of each antenna element 11-n and the normal solution of the amplitude/phase calculator 22 (step S19). Then, the radiation electric field measurement unit 21, the amplitude phase calculation unit 22, and the amplitude phase calibration unit 23 terminate without correcting the REV method (step S20).

In this way, by using the difference Σk _n exp(jX _n )−1 and the coefficient of determination R ² together, it is possible to determine whether it is an algorithm problem of the REV method or a hardware problem of the array antenna transmitting/receiving device 1. , the cause of the anomaly can be isolated without significant cost and know-how. That is, the difference Σk _n exp We only need to calculate (jX _n )−1 and the coefficient of determination R ² .

The array antenna calibration apparatus and array antenna calibration program of the present disclosure use the REV method to calibrate each antenna element so that the amplitude characteristics and phase characteristics of the radiated electric field of each antenna element are aligned. It can be cut without expensive cost and know-how.

A: Array antenna system 1: Array antenna transmitting/receiving device 2: Array antenna calibration devices 11-1, 11-2, 11-3, 11-N: Antenna elements 12-1, 12-2, 12-3, 12-N : Attenuators 13-1, 13-2, 13-3, 13-N: Phase shifter 14: Divider/combiner 15: Transmitting/receiving unit 16: Control unit 21: Radiated electric field measuring unit 22: Amplitude phase calculating unit 23: Amplitude and phase calibration unit 24: calibration accuracy evaluation unit

Claims (5)

a radiated electric field measuring unit that measures the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field;
an amplitude/phase calculator for calculating the amplitude and phase of the relative radiated electric field of each element based on the amplitude and phase of the initial synthesized radiated electric field of all the elements, based on the amplitude of the synthesized radiated electric field of all the elements;
an amplitude and phase calibration unit that calibrates each element based on the amplitude and phase of the relative radiated electric field of each element so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each element;
Constructed from the amplitude and phase of the relative radiated electric field of each element, the sum vector over all the elements regarding the relative radiated electric field vector of each of the elements, and the amplitude and phase of the initial synthetic radiated electric field of all the elements a calibration accuracy evaluation unit that evaluates the calibration accuracy over all the elements based on the magnitude of the difference between the initial synthesized radiated electric field vector of the all elements, and
An array antenna calibration device comprising: The calibration accuracy evaluation unit measures the amplitude of the synthetic radiated electric field of all the elements with respect to the rotational phase of the radiated electric field from the phase of the initial radiated electric field of each element, and a sine function or cosine function having an arbitrary amplitude and phase. 2. The array antenna calibration apparatus according to claim 1, wherein the calibration accuracy of each element is evaluated based on the magnitude of the coefficient of determination between . The calibration accuracy evaluation unit determines abnormal operation of each element when the coefficient of determination is smaller than a predetermined value, and the difference is larger than the predetermined value even though the coefficient of determination is greater than the predetermined value. Sometimes, the normal operation of each element and the spurious solution of the amplitude/phase calculator are determined, and when the coefficient of determination is larger than a predetermined value and the difference is smaller than a predetermined value, the normal operation of each element is determined. 3. The array antenna calibration device according to claim 2, wherein a normal solution of said amplitude-phase calculator is determined. a radiated electric field measuring unit that measures the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field;
an amplitude/phase calculator for calculating the amplitude and phase of the relative radiated electric field of each element based on the amplitude and phase of the initial synthesized radiated electric field of all the elements, based on the amplitude of the synthesized radiated electric field of all the elements;
an amplitude and phase calibration unit that calibrates each element based on the amplitude and phase of the relative radiated electric field of each element so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each element;
Coefficient of determination between the measurement result of the amplitude of the resultant radiated electric field of all the elements with respect to the rotational phase of the radiated electric field from the phase of the initial radiated electric field of each of the elements, and a sine or cosine function with arbitrary amplitude and phase a calibration accuracy evaluation unit that evaluates the calibration accuracy of each element based on the magnitude;
An array antenna calibration device comprising: a radiated electric field measurement step of measuring the amplitude of the combined radiated electric field of all the elements of the array antenna while rotating the phase of the radiated electric field of each element of the array antenna from the phase of the initial radiated electric field;
an amplitude phase calculation step of calculating the amplitude and phase of the relative radiated electric field of each of the elements based on the amplitude and phase of the initial composite radiated electric field of all the elements;
an amplitude and phase calibration step of calibrating each element based on the amplitude and phase of the relative radiated electric field of each element so as to match the amplitude characteristics and phase characteristics of the radiated electric field of each element;
Constructed from the amplitude and phase of the relative radiated electric field of each element, the sum vector over all the elements regarding the relative radiated electric field vector of each of the elements, and the amplitude and phase of the initial synthetic radiated electric field of all the elements a calibration accuracy evaluation step of evaluating the calibration accuracy over all the elements based on the magnitude of the difference between the initial synthesized radiation electric field vector of all the elements, and
Array antenna calibration program for causing the computer to execute in order.

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