JP2010210337A - Angle-measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an angle-measuring device capable of measuring an angle effectively by suppressing GL and canceling an influence on angle measuring processing, by laying on each divided region, element arrangement similar to unequal spacing arrangement used as a reference in a one-dimensional or two-dimensional direction. <P>SOLUTION: This device includes: an array antenna 1 wherein a plurality of antenna elements 2 are arranged at unequal intervals; Σ signal calculation means 10, 11 for calculating the sum of each received complex signal as a Σ signal; Δ signal calculation means 10, 12 for dividing an array of the plurality of antenna elements 2 into two regions, and calculating the difference in each sum signal of the complex signal received by each divided region as a Δ signal; and a phase monopulse angle measuring part 13 for estimating the incoming angle of a received incoming wave by the array antenna 1, by using the Σ signal and the Δ signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an angle measuring device including a one-dimensional array antenna or a planar array antenna (hereinafter simply referred to as “array antenna”).

Conventionally, in this type of angle measuring device, monopulse angle measurement is performed by dividing an array antenna in which a plurality of antenna elements are arranged at equal intervals so that gains are equal (for example, Non-patent document 1).
On the other hand, in an array antenna, it is known that it is effective to arrange antenna elements at unequal intervals in order to suppress the generation of grating lobes (GL) (see, for example, Non-Patent Document 2).

  However, the array antennas arranged at unequal intervals, unlike the evenly spaced array antennas, has a problem that the phase center moves according to the arrival angle, so that the angle measuring device using the array antennas at unequal intervals is used. However, there is a problem that the azimuth angle measurement result changes due to a change in the elevation angle in spite of the azimuth (angle of arrival) angle measurement.

Hereinafter, with reference to FIG. 15 to FIG. 17, problems in a conventional angle measuring device using a general equally-spaced array antenna and a non-uniformly-spaced array antenna will be described.
FIG. 15 is a plan view showing a conventional equally spaced array antenna 101, and FIG. 16 is a plan view showing a conventional unequally spaced array antenna 201. As shown in FIG. FIG. 17 is a plan view showing a conventional non-uniformly spaced array antenna 301 obtained by extending the configuration of FIG. 16 to a two-dimensional planar antenna.

In FIG. 15, an equally spaced array antenna 101 is composed of a plurality of antenna elements 102 that are two-dimensionally (planarly) arranged at equal intervals.
An alternate long and short dash line 103 in the equally spaced array antenna 101 shows an example of a two-region division boundary line for elevation angle measurement, and a broken line 104 shows an example of a two-region division boundary line for azimuth angle measurement. Yes.

  When an equally spaced array antenna 101 as shown in FIG. 15 is used, an area division boundary is determined so that the divided area has an equal gain, as indicated by a one-dot chain line 103 and a broken line 104, and two divided areas are divided. One-dimensional or two-dimensional angle measurement processing can be performed using the observation signal by general phase monopulse angle measurement.

  However, in the angle measuring device using the equally spaced array antenna 101 of FIG. 15, when the distance between the antenna elements 102 is large with respect to the wavelength, Since the signals are in the same phase state, the signal has the same gain as the main lobe, so that there is a problem that a so-called grating lobe (GL) is generated.

  Considering the case of receiving radio waves using the equally spaced array antenna 101 that generates such GL, there is a problem that unnecessary radio waves are received from directions other than the main lobe. There is a problem that it becomes an interference source when viewed from other communications.

  In addition, when the equally spaced array antenna 101 of FIG. 15 is applied to an adaptive antenna, a main lobe is suppressed when an interference wave arrives from the GL direction, resulting in a large S / N reduction. is there.

  Furthermore, when the equally spaced array antenna 101 of FIG. 15 is applied to the radio wave arrival direction detection device, there is a problem that the GL direction corresponding to the true direction cannot be identified when there is a GL having the same reception phase state. End up.

  Therefore, conventionally, in order to suppress the occurrence of the GL as described above, it has been proposed to use an unequal interval array antenna 201 in which a plurality of antenna elements 102 are arranged at unequal intervals as shown in FIG. .

  However, as shown in FIG. 17, when the unequally spaced array antenna 201 of FIG. 16 is expanded to a two-dimensional planar antenna, the phase center changes depending on the arrival direction of the received wave, and thus the two-dimensional unequally spaced array antenna. In the case of measuring the angle of arrival in both one-dimensional and two-dimensional directions using the antenna 301, the phase centers of the two divided regions change differently depending on the arrival angles. Therefore, there is a problem that the angle measurement result changes due to the change in the azimuth angle (or vice versa, the azimuth angle measurement result changes depending on the elevation angle) even though the angle measurement is the elevation angle.

Supervised by Takashi Yoshida, “Revised Radar Technology”, edited by the Institute of Electronics, Information and Communication Engineers, October 1, 1996, first edition, pages 262-264 (corona agency sales) Kazufumi Hirata et al., “Distribution method of distributed array antenna to suppress grating lobe”, IEICE, IEICE Technical Report A / P 2005-15, pp. 35-40

The conventional angle measuring device has a problem of generating GL at a high frequency when the equally spaced array antenna 101 as shown in FIG. 15 is used.
Further, even if the non-uniformly spaced array antenna 301 as shown in FIG. 17 is used, in order to ensure a divided region with equal gain when considering the angle measurement processing, the arrangement of the antenna elements 102, As the division boundary line 304 needs to be devised, the phase center cannot be determined, so that there is a problem that one angle change of the two-dimensional arrival angle affects the other angle measurement result.

  The present invention has been made in order to solve the above-described problems, and a space in a direction perpendicular to the angle-measuring direction of the number of antenna elements in two regions after antenna division in one or two-dimensional directions. When the distribution is a constant multiple, and each antenna element array parallel to the angle measurement direction is configured as an antenna that is added together by shifting the reference antenna arrangement (basic pattern) in the angle measurement direction, The antennas are arranged so that the reference antenna arrangement is the same in all the antenna element arrays parallel to the angle measurement direction. Accordingly, an object of the present invention is to obtain an angle measuring device that can effectively measure the angle by suppressing the GL and canceling the influence on the angle measuring process due to the phase center not being determined.

  The angle measuring device according to the present invention includes an array antenna in which a plurality of antenna elements are arranged at unequal intervals, a Σ signal calculating means for calculating a sum of complex signals received by the plurality of antenna elements as a Σ signal, The antenna element array is divided into two regions, Δ signal calculating means for calculating the difference between the sum signals of the complex signals received in each divided region as a Δ signal, and an array using the Σ signal and the Δ signal. Angle measuring means for estimating the angle of arrival of the incoming incoming wave at the antenna.

  According to the present invention, in both the one-dimensional direction or the two-dimensional direction, the spatial distribution in the direction perpendicular to the angle measurement direction of the number of antenna elements in the two areas after the antenna division is multiplied by a constant, and the angle measurement is performed. When each antenna element array parallel to the direction is configured as an antenna obtained by shifting and adding the reference antenna arrangement (basic pattern) in the angle measurement direction, the reference antenna arrangement is parallel to the angle measurement direction. By arranging the antennas so as to be the same in all the antenna element arrays, it is possible to suppress the GL and to cancel the influence on the angle measurement process due to the fact that the phase center is not determined, and to perform the angle measurement effectively.

It is a top view which shows the array antenna used for the angle measuring device which concerns on Embodiment 1 of this invention. It is a top view which shows the array antenna used for the angle measuring device which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the number of antenna elements in each division area of the array antenna of FIG. 2 with a histogram. It is a top view which shows the other example of non-uniform spacing arrangement | positioning of the array antenna used for the angle measuring device which concerns on Embodiment 1 of this invention. It is a block diagram which shows the angle measuring device which concerns on Embodiment 1 of this invention. It is a block diagram which shows the processing function of the phase monopulse angle measuring part by Embodiment 1 of this invention. It is explanatory drawing which shows the angle characteristic of (DELTA) / (Sigma) signal by Embodiment 1 of this invention. It is a block diagram which shows the processing function of the phase monopulse angle measuring part by Embodiment 2 of this invention. It is explanatory drawing which shows the angle characteristic of the imaginary part of (DELTA) / (Sigma) signal by Embodiment 2 of this invention. It is a block diagram which shows the processing function of the phase monopulse angle measuring part by Embodiment 3 of this invention. It is explanatory drawing which shows the angle characteristic of the real part of (DELTA) / (Sigma) signal by Embodiment 3 of this invention. It is a top view which shows the array antenna used for the angle measuring device which concerns on Embodiment 4 of this invention. It is a block diagram which shows the angle measuring apparatus which concerns on Embodiment 4 of this invention. It is a top view which shows the array antenna used for the angle measuring device which concerns on Embodiment 5 of this invention. It is a top view which shows the equidistant array antenna used for the conventional angle measuring device. It is a top view which shows the conventional non-uniformly spaced array antenna. It is a top view which shows the conventional non-uniformly spaced array antenna.

Embodiment 1 FIG.
FIG. 1 is a plan view showing an array antenna 1 used in an angle measuring device according to Embodiment 1 of the present invention.
In FIG. 1, the columns of all antenna elements 2 in the direction parallel to the angle to be measured are the antenna elements 2 obtained by adding the reference common antenna arrangement (basic pattern) by arbitrarily shifting each column. It is a column. In this case, the angle measuring means (described later) estimates only one arbitrary two-dimensional angle.

In FIG. 1, an array antenna 1 has a plurality of antenna elements 2 that are two-dimensionally arranged at unequal intervals. In the array antenna 1 of FIG. 1, an alternate long and short dash line 3 indicates an example of a boundary line in region division for creating two regions in the vertical direction.
The array antenna 1 has an antenna arrangement corresponding only to elevation angle measurement.

In FIG. 1, the number of each antenna element 2 when the antenna arrangement is divided into regions in the vertical direction is indicated by histograms 7 and 8 with respect to space.
Histograms 7 and 8 show the distribution of the number of elements in the horizontal direction in each of the upper and lower regions when the region is divided into two in the vertical direction (z-axis direction) by the alternate long and short dash line 3, and the unequal intervals are shown. The relationships are consistent with each other.
As is apparent from FIG. 1, it can be seen that the histograms of the two regions after the region division have a constant multiple relationship. The relationship shown in FIG. 1 is one of two antenna arrangement conditions for elevation angle measurement in the first embodiment of the present invention.

In FIG. 1, the array of all antenna elements in the vertical direction of the array antenna 1 is obtained by adding and shifting the basic pattern of FIG. 1 in the vertical direction. If it is the leftmost column, it is the basic tone pattern itself, and if it is the third column from the left, it is a combination of two antenna element columns that are shifted from each other in the vertical direction.
As described above, all the antenna element columns in the direction parallel to the angle to be measured are the antenna element columns obtained by adding and shifting the common key pattern. This is the second of the two antenna arrangement conditions for elevation angle measurement in Embodiment 1 of the present invention.

For example, in FIG. 1, when it is considered to divide two regions in the vertical direction using the one-dot chain line 3 and measure the angle of arrival in the vertical direction, the relationship between the phase centers of the two regions is Must be invariant to the direction of arrival.
In the case of FIG. 1, since the array antennas 1 are arranged at unequal intervals, the phase centers of the two regions change as the arrival angle changes in the lateral direction as described above.

  However, as shown in FIG. 1, in the case of the array antenna 1 that is two-dimensionally arranged at unequal intervals, the phase center changes, but if the above two conditions are satisfied, the change in both of the two regions. Since the method is the same, the relative relationship between the phase centers between the two regions does not change.

  Therefore, according to the angle measuring device according to the first embodiment of the present invention using the array antenna 1 of FIG. 1, the GL is suppressed by the array antenna 1 of two-dimensional unequal spacing, It is possible to perform angle measurement independently without being affected by the azimuth angle.

Moreover, although the case of elevation angle measurement was described here, azimuth angle measurement can be similarly considered.
In that case, the histogram of the number of elements in the vertical direction of each area obtained by dividing the antenna into two in the horizontal direction has a constant multiple relationship, and all the columns in the horizontal direction add a common key pattern. It is a condition that it is composed of a combination.

FIG. 2 is a plan view showing the array antenna 1 used in the angle measuring apparatus according to Embodiment 1 of the present invention.
In FIG. 2, the array antenna 1 has a plurality of antenna elements 2 that are two-dimensionally arranged at unequal intervals, and different random unequal intervals are set in the vertical and horizontal directions. Each antenna element 2 constituting the array antenna 1 satisfies the above two antenna arrangement conditions in both the vertical and horizontal directions.

In the array antenna 1 of FIG. 2, an alternate long and short dash line 3 indicates an example of a boundary line in region division for creating two vertical regions, and a broken line 4 indicates region division for creating two horizontal regions. The example of the boundary line in is shown.
In addition, each boundary line 3 and 4 is not limited to the position of the dashed-dotted line and the broken line in FIG. 2, but it is set to any position as long as it is a boundary line perpendicular to the direction divided into two regions. May be.

FIG. 3 is an explanatory diagram showing the number of elements in each divided region. The number of each antenna element 2 when the antenna arrangement is divided into regions as shown in FIG.
In FIG. 3, histograms 5 and 6 indicate the element number distribution in the vertical direction of each of the left and right regions when the region is divided into two in the horizontal direction (y-axis direction) by the broken line 4. The relationships are consistent with each other.

Similarly, histograms 7 and 8 show the distribution of the number of elements in the horizontal direction in each of the upper and lower regions when the region is divided into two in the vertical direction (z-axis direction) by the one-dot chain line 3. The unequal spacing relationship is consistent with each other.
As is apparent from FIG. 3, the histograms of the two regions after the region division are in a constant multiple relationship.

  Further, in the array antenna 1 of FIG. 3, since each column has the same configuration for each of the vertical antenna column and the horizontal antenna column, it is clearly configured with a common key pattern. The antenna arrangement conditions for the basic pattern are also satisfied.

  1 and 2 show examples of random unequal interval arrangement, for example, as shown in FIG. 4, the interval between the antenna elements 2 increases by a certain amount in the upward direction and the right direction. Other unequal spacing arrangements, such as an arrangement, may be used.

The unequal interval arrangement shown in FIG. 4 is obtained by applying the quantitative shift arrangement method shown in the above-mentioned Non-Patent Document 2 in the vertical direction and the horizontal direction as an unequal interval arrangement method capable of effectively suppressing GL.
By applying the quantitative shift arrangement shown in FIG. 4, GL can be effectively suppressed, and an optimum shift amount can be easily designed from the conditions of the number of antennas and the viewing angle (angle that does not cause GL).

FIG. 5 is a block diagram showing the angle measuring device according to the first embodiment of the present invention, and shows a schematic configuration when the array antenna 1 of FIG. 1, FIG. 2 or FIG. 4 is used.
In FIG. 5, the angle measuring device divides the output of the phase shifter 9, the array antenna 1 having an unequal interval configuration composed of a plurality of antenna elements 2, the phase shifter 9 connected to each antenna element 2. Two synthesizers 10 combined for each region, a synthesizer 11 that calculates the sum (Σ signal) of the outputs of the two synthesizers 10, and a difference (Δ signal) of the outputs of the two synthesizers 10 are calculated. And a phase monopulse angle measuring unit 13 for outputting an angle measurement result from the outputs of the combiner 11 and the differencer 12.

  In FIG. 5, a one-dimensional (horizontal direction) angle measuring device is shown. However, when two-dimensional angle measurement is performed, for any other angle of arrival, which antenna element is used for the same angle measuring device. The angle measurement process is performed by changing only the point in which 2 is included in the two regions (which one of the two synthesizers 10 is input).

FIG. 6 is a block diagram showing processing functions of the phase monopulse angle measuring unit 13 in FIG.
In FIG. 6, the phase monopulse angle measurement unit 13 includes a division unit 14, an absolute value calculation unit 15, an imaginary part extraction unit 16, a polarity determination unit 17, and an arrival angle derivation unit 18.

The division unit 14 divides the Δ signal by the Σ signal to generate a Δ / Σ signal, and the absolute value calculation unit 15 calculates the absolute value of the Δ / Σ signal calculated by the division unit 14.
The imaginary part extracting unit 16 extracts the imaginary part of the Δ / Σ signal, and the polarity determining unit 17 uses the imaginary part of the Δ / Σ signal extracted by the imaginary part extracting unit 16 to use the polarity of the Δ / Σ signal. Determine.

The arrival angle deriving unit 18 performs angle measurement using the absolute value of the Δ / Σ signal calculated by the absolute value calculation unit 15 and outputs the arrival angle as an angle measurement result.
At this time, the arrival angle deriving unit 18 uniquely obtains the angle measurement result by using the polarity of the Δ / Σ signal determined by the polarity determining unit 17.

In the conventional phase monopulse angle measurement, the Δ / Σ signal is a pure imaginary number. However, when the array antenna 1 of FIG. 1, FIG. 2 or FIG. Since the gain is different between the regions, the real part appears in the Δ / Σ signal.
Therefore, the arrival angle deriving means 18 takes a method of obtaining the arrival angle from the absolute value of the Δ / Σ signal.

FIG. 7 is an explanatory diagram showing the angle characteristics of the Δ / Σ signal, and shows the relationship between the angle of arrival and the absolute value of the Δ / Σ signal.
In FIG. 7, the horizontal axis represents the angle of arrival (degree), and the vertical axis represents the absolute value of the Δ / Σ signal.

The arrival angle deriving means 18 obtains the arrival angle by referring to the relationship between the absolute value of the Δ / Σ signal and the arrival angle in FIG.
However, as can be seen from FIG. 7, since the absolute value of the Δ / Σ signal has no polarity, the arrival angle cannot be uniquely determined.

  Therefore, as shown in FIG. 6, the phase monopulse angle measuring unit 13 includes polarity determining means 17 for determining the polarity from the imaginary part of the Δ / Σ signal obtained by the imaginary part extracting part 16, and the arrival angle deriving means. The angle measurement result 18 can be obtained uniquely by using the polarity derived by the polarity determination means 17.

  As described above, the angle measuring device according to Embodiment 1 (FIGS. 2 to 7) of the present invention includes the array antenna 1 in which the plurality of antenna elements 2 are arranged at unequal intervals, and the plurality of antenna elements 2. The Σ signal calculating means (synthesizers 10 and 11) for calculating the sum of the received complex signals as a Σ signal and the array of the plurality of antenna elements 2 are divided into two regions, and the complex signals received in each divided region are divided. The arrival angle of the incoming arrival wave at the array antenna 1 is estimated using Δ signal calculation means (the combiner 10 and the difference unit 12) for calculating the difference between the sum signals of the signals as the Δ signal, and the Σ signal and the Δ signal. Angle measuring means (phase monopulse angle measuring unit 13).

The plurality of antenna elements 2 in the array antenna 1 may be arranged at unequal intervals on one dimension (y-axis) as shown in FIG.
In FIG. 5, a plurality of antenna elements 2 are arranged at unequal intervals in each two-dimensional direction (yz direction) in the array antenna 1.

  In this case, as shown in FIG. 3, each histogram of the number of elements of the plurality of antenna elements 2 with respect to the space between the two divided areas has a relationship of one multiple of the other and is parallel to the angle measuring direction. Each antenna array is formed by adding a common key pattern. Thereby, the influence on the angle measurement due to the change of the phase center between the two regions is canceled.

In addition, the Δ signal calculation means calculates the difference between the sum signals of the complex signals received in each divided region obtained by dividing the array of the plurality of antenna elements 2 into two Δ signals in both two-dimensional directions.
The angle measuring means (phase monopulse angle measuring unit 13) performs angle measurement independently for both two-dimensional angles using the Σ signal and two Δ signals.

  The unequal interval arrangement of the plurality of antenna elements 2 may be a random arrangement (FIG. 2) in which the element intervals are set at random, or a quantitative shift arrangement (FIG. 4) in which the element intervals increase by a certain amount. There may be.

  According to the first embodiment of the present invention, by using the array antennas 1 having unequal spacing, it is possible to effectively perform angle measurement while suppressing GL.

  In addition, when a two-dimensional unequal interval arrangement is applied, the histogram of the number of elements with respect to the space between the two divided regions is a constant multiple in both two-dimensional directions, and each of the vertical directions By arranging the antenna elements so that the antenna columns are configured in a common key pattern, and each antenna column in the horizontal direction is also different from the vertical direction, or all columns share the same key pattern, While suppressing GL, it is possible to perform angle measurement independently for each arrival angle in the vertical direction and the horizontal direction without being influenced by the other arrival angle.

Embodiment 2. FIG.
In the first embodiment (FIG. 6), both the absolute value and the imaginary part of the Δ / Σ signal are used in the angle measurement process of the phase monopulse angle measuring unit 13, but only the imaginary part of the Δ / Σ signal is used. It may be used to measure the angle. That is, instead of the phase monopulse angle measurement unit 13 shown in FIG. 6, a phase monopulse angle measurement unit 13A shown in FIG. 8 may be used.

FIG. 8 is a block diagram showing processing functions of the phase monopulse angle measuring unit according to the second embodiment of the present invention.
In FIG. 8, the same components as those described above (see FIG. 6) are denoted by the same reference numerals as those described above, or “A” is appended to the reference numerals and detailed description thereof is omitted.

In this case, the phase monopulse angle measurement unit 13A includes a division unit 14 that generates a Δ / Σ signal, an imaginary part extraction unit 16, and an arrival angle derivation unit 18A.
Unlike the processing function described above (FIG. 6), the arrival angle deriving unit 18A performs angle measurement using only the imaginary part of the Δ / Σ signal extracted by the imaginary part extracting unit 16.

FIG. 9 is an explanatory diagram showing the angle characteristics of the Δ / Σ signal, and shows the relationship between the angle of arrival (horizontal axis) and the imaginary part (vertical axis) of the Δ / Σ signal.
In FIG. 9, it can be seen that the arrival angle and the imaginary part of the Δ / Σ signal have a one-to-one correspondence.
Therefore, in this case, the arrival angle deriving unit 18A can uniquely determine the arrival angle by referring to the relationship between the imaginary part of the Δ / Σ signal and the arrival angle in FIG.

  As described above, according to the angle measuring device according to the second embodiment (FIGS. 8 and 9) of the present invention, as described above, while suppressing GL, for each two-dimensional arrival angle, It becomes possible to perform angle measurement independently without being influenced by the arrival angle.

Embodiment 3 FIG.
In the second embodiment (FIG. 8), only the imaginary part of the Δ / Σ signal is used in the angle measurement process of the phase monopulse angle measuring unit 13A, but both the real part and the imaginary part of the Δ / Σ signal are used. You may measure the angle.
That is, the phase monopulse angle measurement unit 13B of FIG. 10 may be used instead of the phase monopulse angle measurement units 13 and 13A of the first and second embodiments (FIGS. 6 and 8).

FIG. 10 is a block diagram showing processing functions of the phase monopulse angle measuring unit according to the third embodiment of the present invention.
In FIG. 10, the same components as those described above (see FIG. 6) are denoted by the same reference numerals as those described above, or “B” after the reference numerals, and detailed description thereof is omitted.

In this case, the phase monopulse angle measurement unit 13B includes a division unit 14 that generates a Δ / Σ signal, an imaginary part extraction unit 16, a real part extraction unit 16B, and an arrival angle derivation unit 18B.
Unlike the processing function described above (FIG. 8), the arrival angle deriving unit 18B performs measurement using both the real part and the imaginary part of the Δ / Σ signal extracted by the imaginary part extracting unit 16 and the real part extracting unit 16B. Do horns.

FIG. 11 is an explanatory diagram showing the angle characteristics of the Δ / Σ signal, and shows the relationship between the angle of arrival (horizontal axis) and the real part (vertical axis) of the Δ / Σ signal.
In FIG. 11, the arrival angle and the real part of the Δ / Σ signal do not correspond one-to-one due to the lack of polarity, but are uniquely measured by using together with the imaginary part described above (FIG. 9). Angular results can be determined.

  As described above, according to the angle measuring apparatus according to the third embodiment (FIGS. 10 and 11) of the present invention, as described above, while suppressing GL, for each arrival angle in the vertical direction, It becomes possible to perform angle measurement independently without being influenced by the arrival angle.

Embodiment 4 FIG.
In the first, second, and third embodiments (FIGS. 2 to 11), the antenna elements 2 are arranged at unequal intervals in the array antenna 1, but a subarray including a plurality of antenna elements 2 as shown in FIG. The phase center positions of the antennas 20 may be arranged at unequal intervals in the array antenna 1C.

FIG. 12 is a plan view showing an array antenna 1C used in Embodiment 4 of the present invention, and shows the arrangement of subarray antennas 20. FIG. 13 is a block diagram showing processing functions of the angle measuring device according to Embodiment 4 of the present invention.
12 and 13, the same parts as those described above (see FIGS. 2 to 5) are denoted by the same reference numerals as those described above, or “C” after the reference numerals, and detailed description thereof is omitted.

  In FIG. 12, the array antenna 1 </ b> C has a plurality of subarray antennas 20 laid out with the phase center positions of the plurality of subarray antennas 20 arranged at unequal intervals instead of the positions of the antenna elements 2 described above (FIGS. 2 and 3). It is constituted by.

In FIG. 12, the number of antenna elements 2 is different for each subarray, and the arrangement of the plurality of antenna elements in each of the plurality of subarray antennas is not all the same.
However, each histogram of the number of elements of a plurality of antenna elements with respect to the space between two regions has a relationship in which one is a constant multiple of the other and all antenna elements in a direction parallel to the angle to be measured. Is a column of antenna elements in which common keynote patterns are arbitrarily shifted and added for each column.

That is, in this case, for each subarray antenna 20 composed of a plurality of antenna elements 2, the size of the subarray antenna 20 is also set unequal so that the antenna elements 2 are arranged more densely and the gain is increased. ing.
Further, although the subarray antennas 20 are unequal to each other, the histogram for the space of the number of elements of the antenna element 2 in each divided area after the area division in the angle measurement processing is a constant as in the above (FIG. 3). The relationship of maintaining a double relationship and having a common key pattern in each of the vertical and horizontal antenna arrays is also maintained.

A one-dot chain line 3C in FIG. 12 shows an example of the boundary line in the area division for elevation angle measurement, and a broken line 4C shows an example of the boundary line in the area division for azimuth angle measurement.
Each of the boundary lines 3C and 4C is not limited to the positions of the one-dot chain line and the broken line. Like the above, the boundary lines 3C and 4C are perpendicular to the direction divided into two regions, and the histogram for the space of the number of antenna elements is It may be set at any position as long as the condition of a constant multiple is satisfied.

In FIG. 12, the sizes of the subarray antennas 20 are set to be unequal, but all the subarray antennas 20 may have the same structure.
Furthermore, although the quantitative shift arrangement is applied as the arrangement of the phase center positions of the sub-array antennas 20, an irregular arrangement such as another random arrangement may be applied.

FIG. 13 shows a configuration of the angle measuring device using the subarray antenna 20 of FIG. 12, and shows a case where a two-dimensional unequal interval array arrangement is applied.
In FIG. 13, the subarray antenna 20 includes a plurality of antenna elements 2 and a synthesizer 21 that synthesizes the reception signals of the antenna elements 2.

Similarly to the above (FIG. 5), the output of each subarray antenna 20 includes a phase shifter 9C, two synthesizers 10C corresponding to region division, a synthesizer 11C for Σ signal creation, and a Δ signal creation. It becomes a Σ signal and a Δ signal via the difference unit 12C, and is input to the phase monopulse angle measuring unit 13C.
The phase monopulse angle measurement unit 13C outputs two-dimensional arrival angles in both directions as angle measurement results, similarly to the phase monopulse angle measurement unit 13 described above (FIGS. 5 to 8).

  As described above, the angle measuring apparatus according to Embodiment 4 (FIGS. 12 and 13) of the present invention includes an array antenna 1C in which a plurality of subarray antennas 20 including a plurality of antenna elements 2 are arranged, and a plurality of subarrays. The Σ signal calculating means (synthesizers 10C and 11C) for calculating the sum of the complex signals received by the antenna 20 as a Σ signal and the array of the plurality of subarray antennas 20 are divided into two regions, and each divided region is divided into two regions. Δ signal calculation means (synthesizer 10C, difference unit 12C) for calculating a difference between the sum signals of the received complex signals as a Δ signal, and using the Σ signal and the Δ signal, the arrival angle of the received incoming wave at the array antenna 1C is determined. Angle estimation means (phase monopulse angle measurement unit 13C) for estimation.

The phase center positions of the plurality of subarray antennas 20 are arranged at unequal intervals in the array antenna 1C.
The arrangement of the plurality of antenna elements 2 in each of the plurality of subarray antennas 20 may be the same.

The arrangement of the plurality of antenna elements 2 in each of the plurality of subarray antennas 20 may not be the same.
However, in each histogram of the number of elements of the plurality of antenna elements 2 with respect to the space between the two areas after the antenna division, one is set to have a constant multiple of the other.
In addition, each antenna element array parallel to the angle measuring direction is configured by adding a common key pattern.

  The angle measurement means (phase monopulse angle measurement unit 13C) performs region division by setting a straight line perpendicular to the angle measurement direction as a boundary at an arbitrary position, and uses phase monopulse angle measurement in the array antenna 1C. Measures the angle of arrival of the incoming wave.

  Further, the angle measuring means (phase monopulse angle measuring unit 13C), during phase monopulse angle measurement, as described above (FIG. 6), the absolute value of Δ / Σ signal obtained by dividing Δ signal by Σ signal, and Δ The angle is measured using the polarity of the Δ / Σ signal determined from the imaginary part of the / Σ signal, or the Δ / Σ signal obtained by dividing the Δ signal by the Σ signal as described above (FIG. 8). The angle is measured using only the imaginary part of the signal, or the angle is measured using both the real part and the imaginary part of the Δ / Σ signal obtained by dividing the Δ signal by the Σ signal as described above (FIG. 10). Do.

  According to the fourth embodiment of the present invention, a two-dimensional unequal interval arrangement is applied to the phase center position of the subarray antenna 20 in the same manner as described above, and a plurality of subarray antennas 20 are arranged to arrange the array antenna 1C. In addition, since the histogram for the space of the number of antenna elements 2 in each divided region maintains a constant multiple relationship, the relationship that each of the vertical and horizontal antenna arrays has a common key pattern is also maintained. Even when the antenna 20 is used, it is possible to measure the angle independently for each of the vertical and horizontal arrival angles without being influenced by the other arrival angle while suppressing the GL. .

Embodiment 5 FIG.
In the fourth embodiment (FIG. 12), a mounting method of laying down a plurality of subarray antennas 20 is applied. However, as shown in FIG. 14 (see the broken line frame), a plurality of antenna elements 2 are equally spaced. A plurality of subarray antennas 20D may be formed by performing unequal grouping on the array antennas 1D arranged in the array.

  FIG. 14 is a plan view showing an array antenna 1D used in the fifth embodiment of the present invention. Components similar to those described above are denoted by the same reference numerals as those described above, or suffixed with “D”. Detailed description is omitted.

  In FIG. 14, array antennas 1D in which a plurality of antenna elements 2 are originally arranged at equal intervals are grouped in unequal areas, and each grouped area is consequently isolated as a subarray antenna 20D. ing.

In the plurality of subarray antennas 20D mounted in this manner, the histogram of the number of antenna elements 2 in each divided area with respect to the space satisfies the constant multiple relationship as described above (FIG. 12). The relationship of having a common key pattern is also clearly satisfied.
Therefore, even if the array antenna 1D as shown in FIG. 14 is used, the angle can be measured effectively as described above.

  1, 1C, 1D array antenna, 2 antenna elements, 3, 3C, 4, 4C boundary line, 5-8 histogram, 9, 9C phase shifter, 10, 10C, 11, 11C combiner (Σ signal calculation means), 12, 12C Differentiator (Δ signal calculating means), 13, 13A, 13B, 13C Phase monopulse angle measuring part (angle measuring means), 14 Dividing part, 15 Absolute value calculating means, 16, 16B Imaginary part extracting means, 17 Polarity Determination means, 18, 18A, 18B Arrival angle derivation means.

Claims (14)

An array antenna in which a plurality of antenna elements are arranged at unequal intervals;
Σ signal calculating means for calculating a sum of complex signals received by the plurality of antenna elements as a Σ signal;
Δ signal calculation means for dividing the array of the plurality of antenna elements into two regions and calculating a difference between the sum signals of the complex signals received in each divided region as a Δ signal;
An angle measuring device comprising angle measuring means for estimating an angle of arrival of a received incoming wave at the array antenna using the Σ signal and the Δ signal. The plurality of antenna elements are arranged at unequal intervals on one dimension in the array antenna,
2. The angle measuring device according to claim 1, wherein one of the histograms of the number of elements of the plurality of antenna elements with respect to a space between the two regions has a constant multiple of the other. The plurality of antenna elements are arranged at unequal intervals in two-dimensional directions in the array antenna,
Each histogram of the number of elements of the plurality of antenna elements with respect to the space between the two regions is in a relationship of one constant multiple of the other,
All antenna element rows in the direction parallel to the angle to be measured are a row of antenna elements obtained by arbitrarily shifting the common antenna arrangement as a reference for each row,
The angle measuring device according to claim 1, wherein the angle measuring means estimates only one arbitrary angle in two dimensions. The plurality of antenna elements are arranged at unequal intervals in two-dimensional directions in the array antenna,
Each histogram of the number of elements of the plurality of antenna elements with respect to the space between the two regions is in a relationship of one constant multiple of the other,
For both two-dimensional angles, all antenna element rows in a direction parallel to the angle are a row of antenna elements obtained by arbitrarily shifting the reference common antenna arrangement for each row,
The Δ signal calculation means calculates a difference between the sum signals of complex signals received in each divided region obtained by dividing the array of the plurality of antenna elements in two directions in two directions as two Δ signals,
The angle measuring device according to claim 1, wherein the angle measuring unit performs angle measurement independently for both two-dimensional angles using the Σ signal and the two Δ signals.   The arrangement of the plurality of antenna elements in the array antenna at unequal intervals is a quantitative shift arrangement in which the element intervals increase by a certain amount toward a certain direction. The angle measuring device according to any one of the above.   The arrangement of unequal intervals of the plurality of antenna elements in the array antenna is a random arrangement in which element intervals are set at random. 5. Angle measuring device. An array antenna in which a plurality of subarray antennas including a plurality of antenna elements are arranged;
Σ signal calculating means for calculating the sum of each complex signal received by the plurality of subarray antennas as a Σ signal;
A Δ signal calculating means for dividing the array of the plurality of subarray antennas into two regions and calculating a difference between the sum signals of the complex signals received in each divided region as a Δ signal;
Angle measuring means for estimating an arrival angle of a received incoming wave at the array antenna using the Σ signal and the Δ signal;
An angle measuring device, wherein the phase center positions of each of the plurality of subarray antennas are arranged at unequal intervals in the array antenna.   The angle measuring device according to claim 7, wherein the arrangement of the plurality of antenna elements in each of the plurality of subarray antennas is the same. The arrangement of the plurality of antenna elements in each of the plurality of subarray antennas is not all the same,
Each histogram of the number of elements of the plurality of antenna elements with respect to the space between the two regions has a relationship in which one is a constant multiple of the other and all antenna elements in a direction parallel to the angle to be measured are 8. The angle measuring device according to claim 7, wherein the reference common antenna arrangement is a row of antenna elements that are arbitrarily shifted and added for each row.   8. The angle measuring device according to claim 7, wherein the plurality of sub-array antennas are formed by unequally grouping array antennas in which the plurality of antenna elements are arranged at equal intervals.   The angle measurement means divides the region by setting a straight line perpendicular to the angle measurement direction as a boundary at an arbitrary position, and measures the arrival angle of the received arrival wave at the array antenna using phase monopulse angle measurement. The angle measuring device according to any one of claims 1 to 10, wherein an angle is measured.   12. The angle measuring device according to claim 11, wherein angle measurement is performed using only the imaginary part of the Δ / Σ signal obtained by dividing the Δ signal by the Σ signal during the phase monopulse angle measurement.   At the time of phase monopulse angle measurement, the absolute value of the Δ / Σ signal obtained by dividing the Δ signal by the Σ signal and the polarity of the Δ / Σ signal determined from the imaginary part of the Δ / Σ signal are used. The angle measuring device according to claim 11, wherein angle measuring is performed.   12. The angle measuring device according to claim 11, wherein in the phase monopulse angle measurement, angle measurement is performed using both a real part and an imaginary part of a Δ / Σ signal obtained by dividing a Δ signal by a Σ signal. .

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