JP6910028B2 - Direction finder antenna - Google Patents

Description

The present disclosure relates to a technique for calculating a radio wave arrival angle from a radio wave radiation source.

Conventionally, there are technologies for calculating the direction of another vehicle as seen from the own vehicle in order to avoid a vehicle collision, and technology for calculating the direction of another vehicle as seen from the own ship for docking a spacecraft. do.

In order to calculate the direction of the other device as seen from the own device, the other device has a radio wave radiation source, and the own device calculates the radio wave arrival angle. Here, when the own device has a single antenna, the own device can calculate an absolute value but not a code for the deviation angle in the direction of arrival of radio waves from the front direction of the antenna. On the other hand, when the own device uses a phase monopulse, the own device can calculate an absolute value and a code for the deviation angle in the direction of arrival of radio waves from the front direction of the antenna (for example, Patent Documents). See 1st grade.).

Japanese Unexamined Patent Publication No. 2012-137447

However, when the own device uses a phase monopulse, the own device needs to have a phase discrimination circuit, so that the circuit configuration of the own device becomes complicated and the cost of the own device increases.

Therefore, in order to solve the above-mentioned problems, the present disclosure discloses that the other device has a radio wave radiation source and the own device calculates the radio wave arrival angle in order to calculate the direction of the other device as seen from the own device. The purpose is to simplify the circuit configuration of the own device and reduce the cost of the own device.

In order to solve the above problem, after arranging a plurality of antenna elements in the one-dimensional direction, the radio wave arrival angle in the one-dimensional direction is calculated based on the power difference of the received power of the plurality of antenna elements. Therefore, it is not necessary to have a phase discrimination circuit, and it is sufficient to have a power calculation circuit.

Specifically, the present disclosure includes a plurality of antenna elements arranged in a one-dimensional direction, a reception power difference calculation unit that calculates a power difference between the reception powers of the plurality of antenna elements, and reception of the plurality of antenna elements. The direction-finding antenna is provided with a radio wave arrival angle calculation unit that calculates the radio wave arrival angle in the one-dimensional direction based on the power difference of electric power.

According to this configuration, when the own device calculates the radio wave arrival angle in the one-dimensional direction, the circuit configuration of the own device can be simplified and the cost of the own device can be reduced.

Specifically, conventionally, a down converter and a high-speed A / D have been required to obtain digital information. In the present disclosure, for example, microwaves are directly analog-processed and a DC signal is output, so that the microwaves can be processed at low speed A / D.

In the present disclosure, further, since the direction finding signal can be directly output by analog and microwave, if the Rat-Race can be made compact by CMOS, if it is an X-band active integrated antenna, it can be placed on the back side of each patch antenna. A direction finder, amplifier and regulator will be installed. Since this integrated antenna is a planar circuit, it is convenient for stacking.

Further, in the present disclosure, the received power difference calculation unit calculates the power difference of the received power of the plurality of antenna elements without further shifting the phase difference of the receiving phases of the plurality of antenna elements. It is a characteristic direction finding antenna.

According to this configuration, the power difference between the received powers of the plurality of antenna elements becomes the minimum at a deviation angle of 0 ° with respect to the deviation angle change in the radio wave arrival direction from the front direction of the antenna, and is symmetrical with respect to the deviation angle of 0 °. It changes a lot. For example, in the difference directivity in the middle stage of FIG. 8, the power difference between the received powers of the plurality of antenna elements becomes the minimum at a deviation angle of 0 ° within the applicable range of the direction finding antenna, and changes significantly symmetrically with respect to the deviation angle of 0 °. do. Therefore, although the sign of the radio wave arrival angle in the one-dimensional direction cannot be calculated, the absolute value of the radio wave arrival angle in the one-dimensional direction can be calculated with high accuracy.

Further, in the present disclosure, the received power difference calculation unit calculates the power difference of the received power of the plurality of antenna elements after the phase difference of the receiving phases of the plurality of antenna elements is further shifted. It is a characteristic direction finding antenna.

According to this configuration, the power difference between the received powers of the plurality of antenna elements is minimized at a finite deviation angle with respect to the deviation angle change in the radio wave arrival direction from the front direction of the antenna, and in the vicinity of the deviation angle 0 °. It changes monotonously. For example, in the difference directivity in the middle stage of FIG. 9, the power difference between the received powers of the plurality of antenna elements becomes the minimum at a finite deviation angle within the applicable range of the direction finding antenna, and becomes monotonous near the deviation angle of 0 °. Change. Therefore, the absolute value of the radio wave arrival angle in the one-dimensional direction can be calculated, and the sign of the radio wave arrival angle in the one-dimensional direction can be calculated.

Further, in the present disclosure, the radio wave arrival angle calculation unit is based on the ratio of the power difference between the received powers of the plurality of antenna elements and the sum of the received powers of the plurality of antenna elements in the one-dimensional direction. It is a direction-finding antenna characterized by calculating the radio wave arrival angle of.

Here, the power difference between the received powers of the plurality of antenna elements and the sum of the received powers of the plurality of antenna elements depend on the radiated power of the radio wave radiation source and the distance between the direction detection antenna and the radio wave radiation source. However, these ratios do not depend on the radiated power of the radio source and the distance between the directional detection antenna and the radio source. Therefore, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna and the radio wave radiation source are unknown, the radio wave arrival angle in the one-dimensional direction can be calculated. For example, in the specific directivity in the lower part of FIGS. 8 and 9, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna and the radio wave radiation source are unknown, the radio wave arrival angle in the one-dimensional direction can be calculated. ..

In order to solve the above problem, after arranging a plurality of antenna elements in a two-dimensional plane, the row direction / row direction / based on the row-to-column difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column. Calculate the radio wave arrival angle in the column direction. Therefore, it is not necessary to have a phase discrimination circuit, and it is sufficient to have a power calculation circuit.

Specifically, in the present disclosure, the difference between the rows of the sum of the received powers of the antenna elements of each row and the plurality of antenna elements arranged in the two-dimensional plane is calculated, and the received power of the antenna elements of each column is calculated. Based on the difference between the rows of the received power difference calculation unit that calculates the difference between the columns of the sum of power and the difference between the rows of the sum of the received power of the antenna elements of the antenna elements in each row, the radio wave arrival angle in the row direction is calculated and the antenna in each row. The azimuth detection antenna is characterized by including a radio wave arrival angle calculation unit that calculates a radio wave arrival angle in the column direction based on the difference between rows of the sum of the received powers of the elements.

According to this configuration, when the own device calculates the radio wave arrival angle in the two-dimensional plane, the circuit configuration of the own device can be simplified and the cost of the own device can be reduced.

Specifically, conventionally, a down converter and a high-speed A / D have been required to obtain digital information. In the present disclosure, for example, microwaves are directly analog-processed and a DC signal is output, so that the microwaves can be processed at low speed A / D.

In the present disclosure, further, since the direction finding signal can be directly output by analog and microwave, if the Rat-Race can be made compact by CMOS, if it is an X-band active integrated antenna, it can be placed on the back side of each patch antenna. A direction finder, amplifier and regulator will be installed. Since this integrated antenna is a planar circuit, it is convenient for stacking.

Further, in the present disclosure, the received power difference calculation unit determines the sum of the received powers of the antenna elements of each row without further shifting the phase difference between the rows of the received powers of the antenna elements of each row. The difference between the rows is calculated, and the difference between the columns of the sum of the received powers of the antenna elements in each column is calculated without further shifting the phase difference between the columns. It is an azimuth detection antenna characterized by calculating.

According to this configuration, the row-to-row difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column is at a deviation angle of 0 ° with respect to the deviation angle change in the radio wave arrival direction from the front direction of the antenna. It becomes a minimum and changes greatly symmetrically with respect to a deviation angle of 0 °. For example, in the difference directivity in the middle row of FIG. 8, the row-to-row difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column becomes the minimum at a deviation angle of 0 ° in the applicable range of the direction finding antenna. , The deviation angle changes greatly symmetrically with respect to 0 °. Therefore, although the sign of the radio wave arrival angle in the two-dimensional plane cannot be calculated, the absolute value of the radio wave arrival angle in the two-dimensional plane can be calculated with high accuracy.

Further, in the present disclosure, the received power difference calculation unit further shifts the phase difference between the lines of the power sum of the received powers of the antenna elements of each line, and then the power sum of the received powers of the antenna elements of each line. The difference between the rows is calculated, and the phase difference between the columns of the sum of the received powers of the antenna elements in each column is further shifted, and then the difference between the columns of the sum of the received powers of the antenna elements in each column is calculated. It is an azimuth detection antenna characterized by calculating.

According to this configuration, the row-to-row difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column is at a finite deviation angle with respect to the deviation angle change in the radio wave arrival direction from the front direction of the antenna. It becomes extremely small and changes monotonically near a deviation angle of 0 °. For example, in the difference directivity in the middle row of FIG. 9, the row-to-row difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column becomes the minimum at a finite deviation angle within the applicable range of the direction-finding antenna. , It changes monotonically near the deviation angle of 0 °. Therefore, the absolute value of the radio wave arrival angle in the two-dimensional plane can be calculated, and the sign of the radio wave arrival angle in the two-dimensional plane can be calculated.

Further, in the present disclosure, the radio wave arrival angle calculation unit is based on the ratio of the line-to-line difference of the sum of the received powers of the antenna elements of each line and the sum of the received powers of the plurality of antenna elements. While calculating the radio wave arrival angle in the row direction, the column is based on the ratio of the difference between the columns of the sum of the received powers of the antenna elements in each column and the sum of the received powers of the plurality of antenna elements. It is a direction-finding antenna characterized by calculating the arrival angle of radio waves in a direction.

Here, the row-to-row difference / column-to-column difference of the sum of the received powers of the antenna elements in each row / column and the sum of the received powers of the plurality of antenna elements are the radiated power of the radio wave radiation source and the direction finder antenna and the radio wave radiation. Depends on the distance to the source. However, these ratios do not depend on the radiated power of the radio source and the distance between the directional detection antenna and the radio source. Therefore, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna and the radio wave radiation source are unknown, the radio wave arrival angle in the two-dimensional plane can be calculated. For example, in the specific directivity in the lower part of FIGS. 8 and 9, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna and the radio wave radiation source are unknown, the radio wave arrival angle in the two-dimensional plane can be calculated. can.

Further, when the plurality of antenna elements are arranged in the one-dimensional direction and when the plurality of antenna elements are arranged in the two-dimensional plane, the following configurations may be provided.

Specifically, the present disclosure calculates the distance between the direction finding antenna and the radio wave radiation source based on the sum of the received powers of the plurality of antenna elements and the radiation power of the radio wave radiation source. It is a direction finding antenna characterized by further including a radiation source distance calculation unit.

According to this configuration, the sum of the received powers of the plurality of antenna elements hardly changes in the vicinity of the deviation angle of 0 ° with respect to the deviation angle change in the radio wave arrival direction from the front direction of the antenna. For example, in the sum directivity in the upper part of FIGS. 8 and 9, the sum of the received powers of the plurality of antenna elements does not change substantially in the vicinity of the deviation angle of 0 ° in the applicable range of the direction finding antenna. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna is near the front direction of the antenna, the distance between the direction finding antenna and the radio wave radiation source can be calculated with high accuracy.

Further, the present disclosure is a direction finding antenna further comprising a data transmission / reception unit that transmits / receives data by the sum of the output powers of the plurality of antenna elements.

According to this configuration, the sum of the output powers of the plurality of antenna elements hardly changes in the vicinity of the deviation angle of 0 ° with respect to the deviation angle change in the radio wave radiation / arrival direction from the front direction of the antenna. For example, in the sum directivity in the upper part of FIGS. 8 and 9, the sum of the output powers of the plurality of antenna elements does not change substantially in the vicinity of the deviation angle of 0 ° in the applicable range of the direction finding antenna. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna is near the front direction of the antenna, data transmission / reception between the direction finding antenna and the radio wave radiation source can be executed.

As described above, in the present disclosure, in order to calculate the orientation of the other device as seen from the own device, the other device has a radio wave radiation source, and when the own device calculates the radio wave arrival angle, the circuit configuration of the own device is described. It can be simplified and the cost of the own device can be reduced.

It is a figure which shows the structure of the power receiving circuit of the direction finding antenna of 1st Embodiment. It is a figure which shows the structure of the power receiving circuit of the direction finding antenna of 1st Embodiment. It is a figure which shows the structure of the signal processing circuit of the direction finding antenna of 1st Embodiment. It is a figure which shows the structure of the power receiving circuit of the direction finding antenna of 2nd Embodiment. It is a figure which shows the structure of the power receiving circuit of the direction finding antenna of 2nd Embodiment. It is a figure which shows the structure of the power receiving circuit of the direction finding antenna of 2nd Embodiment. It is a figure which shows the structure of the signal processing circuit of the direction finding antenna of 2nd Embodiment. It is a figure which shows the direction finding performance of the direction finding antenna of 2nd Embodiment. It is a figure which shows the direction finding performance of the direction finding antenna of 2nd Embodiment.

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

(Direction Detecting Antenna of the First Embodiment)
The configuration of the power receiving circuit of the direction finding antenna of the first embodiment is shown in FIGS. 1 and 2. The configuration of the signal processing circuit of the direction finding antenna of the first embodiment is shown in FIG.

The power receiving circuit of the direction finding antenna A1 shown in FIG. 1 includes a plurality of antenna elements 11-1 and 11-2 and a received power combining unit 12. The power receiving circuit of the direction finding antenna A1 shown in FIG. 2 further includes a phase shifting unit 17 in addition to the power receiving circuit of the direction finding antenna A1 shown in FIG. The signal processing circuit of the direction-finding antenna A1 shown in FIG. 3 can be applied in common to the power receiving circuit of the direction-finding antenna A1 shown in FIGS. 1 and 2, and the radio wave arrival angle calculation unit 13 and the radiation source distance can be applied in common. It includes a calculation unit 14, a data reception unit 15, and a data transmission unit 16.

The plurality of antenna elements 11-1 and 11-2 shown in FIGS. 1 and 2 are arranged in the one-dimensional direction (y direction). As shown in the right column of FIGS. 1 and 2, assuming that the radio wave arrival angle α _y in the one-dimensional direction (y direction) is closer to the antenna element 11-1 than to the antenna element 11-2. _{The lead angle Δθ y} of the reception phase of the antenna element 11-1 with respect to the reception phase of the antenna element 11-2 is expressed as in Equation 1. Incidentally, d is an element spacing between the antenna elements 11-1 and the antenna elements 11-2, lambda is the wavelength of the radio wave in vacuum, l _y the antenna elements with respect to the optical path length of the antenna elements 11-1 It is the surplus length of the optical path length to 11-2.

1 and reception power combiner 12 shown in FIG. 2, the output terminal indicated by "180 °", the power difference of the received power _Y 1, _{Y 2} of the plurality of antenna elements 11 - 1 and 11 - 2 _{Y dif} Is calculated.

Here, the received power combining unit 12 shown in FIG. 1 has a plurality of antenna elements 11-1 without further _{phase difference Δθ y of the receiving phases of the plurality of antenna elements 11-1 and 11-2.} , 11-2, and the power difference Y _div of the received powers Y ₁ and Y ₂ is calculated. Then, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2 is represented as the number 2. Assuming that the approximation of the distant field is established, Y ₁ = P ₁ = _Pr and Y ₂ = P ₂ = _Pr are established.

That is, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, with respect to a change in radio wave arrival direction offset angle alpha _y from the front direction of the antenna, the deviation angle It becomes the minimum when α _y = 0 °, and changes significantly symmetrically with respect to _{the deviation angle α y = 0 °.}

Therefore, the radio wave arrival angle calculating unit 13 shown in FIG. 3, based on the received power of the plurality of antenna elements 11 - 1 and 11 - 2 _Y 1, _{Y 2} power difference _{Y dif,} the one-dimensional direction (y-direction) Calculate the radio wave arrival angle α _y. Therefore, although the sign of the radio wave arrival angle α _{y in} the one-dimensional direction (y direction) cannot be calculated, _{the absolute value of the radio wave arrival angle α y in} the one-dimensional direction (y direction) can be calculated with high accuracy. Note that not only calculates the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, the received power _Y 1 of a plurality of antenna elements 11-1 and 11-2, It _{is necessary to calculate the sum} of power Y _{sum of Y 2} , which will be described in detail later.

On the other hand, in the received power combining unit 12 shown in FIG. 2, the phase difference Δθ _y of the receiving phases of the plurality of antenna elements 11-1 and 11-2 is further shifted, and then the plurality of antenna elements 11-1 , 11-2, and the power difference Y _div of the received powers Y ₁ and Y ₂ is calculated. However, the arrangement position of the phase shift portion 17 having the phase shift amount θ> 0 ° is set to the antenna element 11-1 side. Then, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2 is represented as Equation 3. Assuming that the approximation of the distant field is established, Y ₁ = P ₁ = _Pr and Y ₂ = P ₂ = _Pr are established.

That is, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, with respect to a change in radio wave arrival direction offset angle alpha _y from the front direction of the antenna, finite It becomes the minimum when the deviation angle α _y ≠ 0 °, and changes monotonically near the _{deviation angle α y = 0 °.}

Therefore, the radio wave arrival angle calculating unit 13 shown in FIG. 3, based on the received power of the plurality of antenna elements 11 - 1 and 11 - 2 _Y 1, _{Y 2} power difference _{Y dif,} the one-dimensional direction (y-direction) Calculate the radio wave arrival angle α _y. Therefore, the absolute value of the radio wave arrival angle α _{y in} the one-dimensional direction (y direction) can be calculated, and the sign _{of the radio wave arrival angle α y in the one-dimensional direction (y direction) can be calculated.} Note that not only calculates the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, the received power _Y 1 of a plurality of antenna elements 11-1 and 11-2, It _{is necessary to calculate the sum} of power Y _{sum of Y 2} , which will be described in detail later.

In the received power combining unit 12 shown in FIGS. 1 and 2, at the output terminal indicated as “0 °”, the sum of the received powers Y ₁ and Y ₂ of _{the plurality of antenna elements 11-1 and 11-2 is Y sum.} Is calculated.

Here, the received power combining unit 12 shown in FIG. 1 has a plurality of antenna elements 11-1 without further _{phase difference Δθ y of the receiving phases of the plurality of antenna elements 11-1 and 11-2.} , and calculates the reception power _Y 1, _{Y 2} power sum _{Y sum} of 11-2. _{Then, the sum of the powers Y 1} and Y ₂ of the received powers Y 1 and Y 2 of the plurality of antenna elements 11-1 and 11-2 is expressed as the equation 4.

On the other hand, in the received power combining unit 12 shown in FIG. 2, the phase difference Δθ _y of the receiving phases of the plurality of antenna elements 11-1 and 11-2 is further shifted, and then the plurality of antenna elements 11-1 , and calculates the reception power _Y 1, _{Y 2} power sum _{Y sum} of 11-2. _{Then, the sum of the powers Y 1} and Y ₂ of the received powers Y 1 and Y 2 of the plurality of antenna elements 11-1 and 11-2 is expressed as the equation 5.

That is, the sum of the received powers Y ₁ and Y ₂ of _{the plurality of antenna elements 11-1 and 11-2 Y sum} is the deviation angle with respect to the change _{of the deviation angle α y in} the radio wave arrival direction from the front direction of the antenna. There is almost no change near _{α y = 0 °.} This is true regardless of whether or not _{the phase difference Δθ y} of the reception phases of the plurality of antenna elements 11-1 and 11-2 is further phase-shifted.

Therefore, the radiation source distance calculation unit 14 shown in FIG. 3 includes the _{sum of the powers Y 1} and Y ₂ of the received powers Y 1 and Y 2 of the plurality of antenna elements 11-1 and 11-2 and the known radiation power of the radio wave radiation source. , The distance between the azimuth detection antenna A1 and the radio wave radiation source is calculated. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna A1 is near the front direction of the antenna, the distance between the direction finding antenna A1 and the radio wave radiation source can be calculated with high accuracy.

Then, the radio wave arrival angle calculating unit 13 shown in FIG. 3, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, and azimuth detection antenna A1 and radio source Based on the distance between the two, the radio wave arrival angle α _y in the one-dimensional direction (y direction) is calculated.

Alternatively, the radio wave arrival angle calculating unit 13 shown in FIG. 3, the power difference _{Y dif} received power _Y 1, _{Y 2} of the plurality of antenna elements 11-1 and 11-2, a plurality of antenna elements 11-1,11 _{The radio wave arrival angle α y} in the one-dimensional direction (y direction) is calculated based on the ratio Y _dif / Y _sum of the received powers Y ₁ and Y _{2 of -2 and the sum} of the power Y sum. The reason is as shown below.

Since the received power _Y 1, _{Y 2} power difference _{Y dif} plurality of antenna elements 11-1 and 11-2, a plurality of antenna elements 11-1 and 11-2 of the received power _Y 1, _{Y 2} The sum of electric power Y _sum depends on the radiated power of the radio wave radiation source and the distance between the direction finding antenna A1 and the radio wave radiation source. However, these ratios Y _dim / Y _sum do not depend on the radiated power of the radio wave source and the distance between the directional detection antenna A1 and the radio wave source. As a result, even if the radiated power of the radio wave radiation source and the distance between the direction finding antenna A1 and the radio wave radiation source are unknown, the radio wave arrival angle in the one-dimensional direction (y direction) is based on _{these ratios Y dim} / Y _sum. α _y can be calculated.

The data receiving unit 15 shown in FIG. 3 receives data by the power sum Y _{sum of the received powers Y 1} and Y _{2 of the plurality of antenna elements 11-1 and 11-2.} The data transmission unit 16 shown in FIG. 3 transmits data by the sum of the transmission powers of the plurality of antenna elements 11-1 and 11-2.

Here, the sum of the received powers Y ₁ and Y ₂ of _{the plurality of antenna elements 11-1 and 11-2 Y sum} is deviated with respect to a change in _{the deviating angle α y in} the radio wave arrival direction from the front direction of the antenna. There is almost no change near the angle α _{y = 0 °.} The sum of the transmission powers of the plurality of antenna elements 11-1 and 11-2 is also in the vicinity of the _{deviation angle α y} = 0 ° with respect to the change in _{the deviation angle α y in the radio wave radiation direction from the front direction of the antenna.} There is almost no change in. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna A1 is near the front direction of the antenna, data reception and data transmission between the direction finding antenna A1 and the radio wave radiation source can be executed.

In this way, when the radio wave arrival angle calculation unit 13 calculates the radio wave arrival angle α _y in the one-dimensional direction (y direction), the direction finder antenna A1 does not need to have a phase discrimination circuit in the phase monopulse, and receives power. It suffices to have the synthesis unit 12. Therefore, the circuit configuration of the direction-finding antenna A1 can be simplified and the cost of the direction-finding antenna A1 can be reduced.

(Direction Detecting Antenna of the Second Embodiment)
The configuration of the power receiving circuit of the direction finding antenna of the second embodiment is shown in FIGS. 4 to 6. The configuration of the signal processing circuit of the direction finding antenna of the second embodiment is shown in FIG.

The power receiving circuit of the direction finding antenna A2 shown in FIG. 4 includes a plurality of antenna elements 21-1, 21-2, 21-3, 21-4 and received power combining units 22-X and 22-Y. The power receiving circuit of the direction finding antenna A2 shown in FIG. 5 further includes phase shifting units 27-X and 27-Y in addition to the power receiving circuit of the direction finding antenna A2 shown in FIG. The power receiving circuit of the direction finding antenna A2 shown in FIG. 6 further includes phase shifting units 27-1, 27-3, and 27-4 in addition to the power receiving circuit of the direction finding antenna A2 shown in FIG. The signal processing circuit of the direction-finding antenna A2 shown in FIG. 7 can be applied in common to the power receiving circuit of the direction-finding antenna A2 shown in FIGS. 4 to 6, and the radio wave arrival angle calculation unit 23 and the radiation source can be applied in common. It includes a distance calculation unit 24, a data reception unit 25, and a data transmission unit 26.

The plurality of antenna elements 21-1, 21-2, 21-3, and 21-4 shown in FIGS. 4 to 6 are arranged in a two-dimensional plane (in the xy plane) in a square grid pattern.

As shown in the right column of FIGS. 4 to 6, the radio wave arrival angle α _y in the row direction (y direction) is set by the antenna elements 21-1 and 21-3 rather than the antenna elements 21-2 and 21-4. _{Assuming that the antenna elements are closer to each other, the lead angle Δθ y} of the reception phase of the antenna elements 21-1 and 21-3 with respect to the reception phase of the antenna elements 21-2 and 21-4 is expressed as in Equation 6. Incidentally, d is an element spacing between the antenna elements 21-1 and 21-3 and the antenna elements 21-2,21-4, λ is the wavelength of the radio wave in vacuum, _{l y} the antenna elements 21- It is the surplus length of the optical path length to the antenna elements 21-2 and 21-4 with respect to the optical path length to 1 and 21-3.

As shown in the upper column of FIGS. 4 to 6, the radio wave arrival angle α _x in the column direction (x direction) is set by the antenna elements 21-3 and 21-4 rather than the antenna elements 21-1 and 21-2. _{Assuming that the antenna elements are closer to each other, the lead angle Δθ x} of the reception phase of the antenna elements 21-3 and 21-4 with respect to the reception phase of the antenna elements 21-1 and 21-2 is expressed as in Equation 7. Incidentally, d is an element spacing between the antenna elements 21-1 and 21-2 and the antenna elements 21-3,21-4, λ is the wavelength of the radio wave in vacuum, _{l y} the antenna elements 21- It is the surplus length of the optical path length to the antenna elements 21-1 and 21-2 with respect to the optical path length to 3 and 21-4.

Receiving power combiner 22-Y shown in FIGS. 4 to 6, the output terminal indicated by "180 °", the received power _P 1, _{P 3} of the antenna elements 21-1 and 21-3 in the ascending power The sum Y ₁ = (P ₁ + P ₃ ) / 2 and the sum Y ₂ = (P ₂ + P ₄ ) / 2 _{of the received powers P 2} and P ₄ of the descending antenna elements 21-2 and 21-4. The line spacing difference Y _dif = | Y ₁ −Y ₂ | is calculated.

Here, the reception power combiner 22-Y shown in FIG. 4, without line spacing phase difference [Delta] [theta] _y of power sum of the ascending and descending Y _1, Y ₂ is further phase, the ascending and descending force sum Y _1. Calculate the line spacing Y _div of Y _2. Then, the line-to-line difference Y _{div of the sum of electric powers Y 1} and Y ₂ between the ascending line and the descending line is expressed as the equation 8. Assuming that the approximation of the far field holds, P ₁ = P ₂ = P ₃ = P ₄ = _Pr holds. Then, the radio wave arrival angle calculation unit 23 shown in FIG. 7 calculates _{the radio wave arrival angle α y} in the row direction (y direction) based on the line-to-line difference Y _{div of the sum of the powers Y 1} and Y _{2 of the ascending and descending lines.} ..

On the other hand, the reception power combiner 22-Y shown in FIGS. 5 and 6, in terms of rows phase difference [Delta] [theta] _y of power sum of the ascending and descending Y _1, Y ₂ is further phase shift, ascending and descending The line spacing difference Y _div of the sum of power Y ₁ and Y ₂ is calculated. However, the arrangement positions of the phase shift portions 27-Y, 27-1, 27-3 with the phase shift amount θ> 0 ° are set to the antenna elements 21-1, 21-3 side. In FIG. 5, after synthesizing the received power P _1, P ₃ of the ascending, and phase shifting the power sum Y ₁ ascending. Then, in FIG. 6, the received power P _1, P ₃ in ascending in terms of the phase, and calculates the power sum Y ₁ ascending. Then, the line-to-line difference Y _{div of the sum of the electric powers Y 1} and Y _{2 in} the ascending line and the descending line is expressed as the number 9 and the number 10 in FIGS. 5 and 6, respectively. Assuming that the approximation of the far field holds, P ₁ = P ₂ = P ₃ = P ₄ = _Pr holds. Then, the radio wave arrival angle calculation unit 23 shown in FIG. 7 calculates _{the radio wave arrival angle α y} in the row direction (y direction) based on the line-to-line difference Y _{div of the sum of the powers Y 1} and Y _{2 of the ascending and descending lines.} ..

Receiving power combiner 22-X shown in FIGS. 4 to 6, the output terminal indicated by "180 °", the antenna elements 21-1 and 21-2 in the left column of the received power _P 1, _{P 2} The sum of power X ₁ = (P ₁ + P ₂ ) / 2 and the sum of the received powers P ₃ and P ₄ of _{the antenna elements 21-3 and 21-4 in the right column X 2} = (P ₃ + P ₄ ) / 2. , The difference between columns X _dif = | X ₁ −X ₂ | is calculated.

Here, the received power combining unit 22-X shown in FIG. 4 has the left column and the right column without further phase shift of the inter-column phase difference Δθ _{x of the power sum X 1} and X _{2 in} the left column and the right column. Calculate the _{difference X dim} between the columns of the sum of the power of the columns X ₁ and X _{2. Then, the difference X dim} between the columns of the _{sum of power X 1} and X _{2 in} the left column and the right column is expressed as the equation 11. Assuming that the approximation of the far field holds, P ₁ = P ₂ = P ₃ = P ₄ = _Pr holds. Then, the radio wave arrival angle calculation unit 23 shown in FIG. 7 has a radio _{wave arrival angle α x in the} column direction (x direction) based on the inter-row difference X _{div of the sum of power X 1} and X _{2 in the left column and the right column.} Is calculated.

On the other hand, the received power combining unit 22-X shown in FIGS. 5 and 6 is left after the _{phase difference Δθ x} between the columns of the _{sum of powers X 1} and X _{2 in the left and right columns is further shifted.} Calculate the _{difference X dim} between the columns of the _{sum of power X 1} and X ₂ between the columns and the right column. However, the arrangement positions of the phase shift portions 27-X, 27-3, 27-4 with the phase shift amount θ> 0 ° are set to the antenna elements 21-3, 21-4 side. In FIG. 5, after synthesizing the received power P _3, P ₄ in the right column, are phase-shifted in the right column force sum X _2. Then, in FIG. 6, in terms of the phase shift of the received power P _3, P ₄ in the right column, and calculates the right column force sum X _{2. Then, the difference X dim} between the columns of the _{sum of power X 1} and X _{2 in} the left column and the right column is represented by the equation 12 and the equation 13 in FIGS. 5 and 6, respectively. Assuming that the approximation of the far field holds, P ₁ = P ₂ = P ₃ = P ₄ = _Pr holds. Then, the radio wave arrival angle calculation unit 23 shown in FIG. 7 has a radio _{wave arrival angle α x in the} column direction (x direction) based on the inter-row difference X _{div of the sum of power X 1} and X _{2 in the left column and the right column.} Is calculated.

Receiving power combiner 22-Y shown in FIGS. 4 to 6, the output terminal indicated as "0 °", the received power _P 1, _{P 3} of the antenna elements 21-1 and 21-3 in the ascending power The sum Y ₁ = (P ₁ + P ₃ ) / 2 and the sum Y ₂ = (P ₂ + P ₄ ) / 2 _{of the received powers P 2} and P ₄ of the descending antenna elements 21-2 and 21-4. Calculate the _{sum of} lines Y sum = Y ₁ + Y _2.

Here, the reception power combiner 22-Y shown in FIG. 4, without line spacing phase difference [Delta] [theta] _y of power sum of the ascending and descending Y _1, Y ₂ is further phase, the ascending and descending force sum Y Calculate the _sum of lines Y _{sum of 1} and Y _2. Then, the sum of the powers Y ₁ and Y ₂ of the _{ascending and descending lines, Y sum,} is expressed as the equation 14.

On the other hand, the reception power combiner 22-Y shown in FIGS. 5 and 6, in terms of rows phase difference [Delta] [theta] _y of power sum of the ascending and descending Y _1, Y ₂ is further phase shift, ascending and descending Calculate the line spacing Y _sum of the power sums Y ₁ and Y _2. Then, the sums of power Y ₁ and Y _{2 in} the _{ascending and descending lines, Y sum,} are represented by the equations 15 and 16, respectively, in FIGS. 5 and 6, respectively.

Receiving power combiner 22-X shown in FIGS. 4 to 6, the output terminal indicated as "0 °", the antenna elements 21-1 and 21-2 in the left column of the received power _P 1, _{P 2} The sum of power X ₁ = (P ₁ + P ₂ ) / 2 and the sum of the received powers P ₃ and P ₄ of _{the antenna elements 21-3 and 21-4 in the right column X 2} = (P ₃ + P ₄ ) / 2. , The sum of columns X _sum = X ₁ + X ₂ is calculated.

Here, the received power combining unit 22-X shown in FIG. 4 has the left column and the right column without further phase shift of the inter-column phase difference Δθ _{x of the power sum X 1} and X _{2 in} the left column and the right column. Calculate the inter-column sum X _sum of the column power sum X ₁ and X _2. Then, the inter-column sum X _{sum of the power sum X 1} and X _{2 in} the left column and the right column is expressed as the equation 17.

On the other hand, the received power combining unit 22-X shown in FIGS. 5 and 6 is left after the phase difference Δθ _{x between the rows of the power sums X 1} and X _{2 in the left and right columns is further shifted.} Calculate the inter-column sum X _{sum of the power sum X 1} and X ₂ of the column and the right column. Then, the inter-column sum X _{sum of the power sums X 1} and X _{2 in} the left column and the right column is represented as the equation 18 and the equation 19 in FIGS. 5 and 6, respectively.

Then, the radiation source distance calculation unit 24 shown in FIG. 7 has received powers P ₁ , P ₂ , P ₃ , and P ₄ of the plurality of antenna elements 21-1, 21-2, 21-3, and 21-4. The distance between the directional detection antenna A2 and the radio wave radiation source is calculated based on the sum | P ₁ + P ₂ + P ₃ + P ₄ | = X _sum + Y _{sum and the known radiated power of the radio wave radiation source.}

Further, the radio wave arrival angle calculation unit 23 shown in FIG. 7 is based on the line-to-line difference Y _{div of the sum of the ascending and descending powers Y 1} and Y ₂ and the distance between the direction finder antenna A2 and the radio wave radiation source. Then, the radio wave arrival angle α _y in the row direction (y direction) is calculated. On the other hand, in the radio wave arrival angle calculation unit 23 shown in FIG. 7, the distance between the row difference X _{div of the sum of power X 1} and X _{2 in} the left column and the right column, and the direction finder antenna A2 and the radio wave radiation source. Based on the above, the radio wave arrival angle α _x in the column direction (x direction) is calculated.

Alternatively, the radio wave arrival angle calculating unit 23 shown in FIG. 7, the upper row and the power sum _Y 1 of the descending line spacing difference Y _{2 Y dif,} the total power sum _{X sum + Y} sum and, the ratio _Y dif _{/ (X sum} + Y _sum ) is used to calculate _{the radio wave arrival angle α y} in the row direction (y direction). On the other hand, the radio wave arrival angle calculation unit 23 shown in FIG. 7 has a ratio X _{dim of the} difference X _{dim between the rows of the power sum X 1} and X _{2 in} the left column and the right column and the total power sum X _sum + Y _sum. Based on / (X _sum + Y _sum ), the radio wave arrival angle α _x in the column direction (x direction) is calculated.

The data receiving unit 25 shown in FIG. 7 receives data by the _{sum of all powers X sum} + Y sum. The data transmission unit 26 shown in FIG. 7 transmits data by the total power sum.

Of the direction-finding antennas of the second embodiment, the direction-finding performance of the direction-finding antenna A2 (when there is no phase shift θ) shown in FIG. 4 is shown in FIG. The power values shown in Equations 8, 11, 14, and 17 were calculated in consideration of the actual directivity of each antenna element. _{For example, -15 ° <α x} , α _y <15 ° is the applicable range for collision avoidance of automobiles and docking of spacecraft.

The upper part of FIG. 8 shows the directivity of the _{total power sum X sum} + Y _sum. The total power sum X _sum + Y _sum hardly changes in the vicinity of _{the deviation angles α x} and α _y = 0 ° with respect to the changes in _{the deviation angles α x} and α _{y in} the direction of arrival of radio waves from the front direction of the antenna. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna A2 is near the front direction of the antenna, the distance between the direction finding antenna A2 and the radio wave radiation source can be calculated with high accuracy. Then, if the direction of the radio wave radiation source seen from the direction finding antenna A2 is near the front direction of the antenna, data reception and data transmission between the direction finding antenna A2 and the radio wave radiation source can be executed.

The middle row of FIG. 8 shows the directivity of the column-to-column difference X- _dim and the row-to-row difference Y- _dif. The difference between columns X _dim and the _{difference between rows Y dim} are minimized at the deviation angles α _x and α _y = 0 ° with _{respect to changes in the deviation angles α x} and α _{y in} the direction of arrival of radio waves from the front direction of the antenna. It changes greatly symmetrically with respect to the angles α _x and α _{y = 0 °.} Therefore, it is not possible to calculate the sign of the radio wave arrival angles α _x and α _{y in} the column / row direction (x / y direction), but the radio wave arrival angles α _x and α _{y in the column / row direction (x / y direction).} The absolute value of can be calculated with high accuracy.

The lower part of FIG. 8 shows the directivity of _{X dif} / (X _sum + Y _sum ) and Y _dif / (X _sum + Y _sum). X _dif / (X _sum + Y _sum ) and Y _dif / (X _sum + Y _sum ) do not depend on the radiated power of the radio source and the distance between the directional detection antenna A2 and the radio source. Therefore, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna A2 and the radio wave radiation source are unknown, _{the codes of the radio wave arrival angles α x} and α _{y in} the column / row direction (x / y direction) are calculated. _{Although this is not possible, the absolute values of the radio wave arrival angles α x} and α _{y in} the column / row direction (x / y direction) can be calculated with high accuracy.

Of the direction-finding antennas of the second embodiment, the direction-finding performance of the direction-finding antenna A2 (when there is a phase shift θ) shown in FIGS. 5 and 6 is shown in FIG. The power values shown in Equations 9, 10, 12, 13, 15, 16, 18, and 19 were calculated in consideration of the directivity of each of the actual antenna elements. _{For example, -15 ° <α x} , α _y <15 ° is the applicable range for collision avoidance of automobiles and docking of spacecraft.

The upper part of FIG. 9 shows the directivity of the _{total power sum X sum} + Y _sum. The total power sum X _sum + Y _sum hardly changes in the vicinity of _{the deviation angles α x} and α _y = 0 ° with respect to the changes in _{the deviation angles α x} and α _{y in} the direction of arrival of radio waves from the front direction of the antenna. Therefore, if the direction of the radio wave radiation source seen from the direction finding antenna A2 is near the front direction of the antenna, the distance between the direction finding antenna A2 and the radio wave radiation source can be calculated with high accuracy. Then, if the direction of the radio wave radiation source seen from the direction finding antenna A2 is near the front direction of the antenna, data reception and data transmission between the direction finding antenna A2 and the radio wave radiation source can be executed.

The middle row of FIG. 9 shows the directivity of the column-to-column difference X- _dim and the row-to-row difference Y- _dif. The inter-column difference X _dif and the inter-row difference Y _dif are minimized at finite deviation angles α _x and α _y ≠ 0 ° with _{respect to changes in the deviation angles α x} and α _{y in} the direction of arrival of radio waves from the front direction of the antenna. , The deviation angle _{changes monotonically near α x} and α _y = 0 °. Therefore, the radio wave arrival angle alpha _x column / row direction (x / _{y-direction),} alpha code it is possible to calculate the _y, the radio wave arrival angle alpha _x column / row direction (x / _{y-direction),} alpha _y The absolute value of can be calculated.

The lower part of FIG. 9 shows the directivity of _{X dif} / (X _sum + Y _sum ) and Y _dif / (X _sum + Y _sum). X _dif / (X _sum + Y _sum ) and Y _dif / (X _sum + Y _sum ) do not depend on the radiated power of the radio source and the distance between the directional detection antenna A2 and the radio source. Therefore, even if the radiated power of the radio wave radiation source and the distance between the direction detection antenna A2 and the radio wave radiation source are unknown, _{the codes of the radio wave arrival angles α x} and α _{y in} the column / row direction (x / y direction) are calculated. In addition, the absolute values of _{the radio wave arrival angles α x} and α _{y in} the column / row direction (x / y direction) can be calculated.

In this way, when the radio wave arrival angle calculation unit 23 calculates the radio wave arrival angles α _x and α _y in the column / row direction (x / y direction), the direction finding antenna A2 has a phase discrimination circuit in the phase monopulse. It is not necessary, and it is sufficient to have the received power combining unit 22-X and 22-Y. Therefore, the circuit configuration of the direction-finding antenna A2 can be simplified and the cost of the direction-finding antenna A2 can be reduced.

Even if only three antenna elements 21-1, 21-2, and 21-3 are arranged as a plurality of antenna elements, the radio wave arrival angles α _x and α _y in the column / row direction (x / y direction) can be set. Although it can be calculated, the circuit scale is only 3/4 times smaller than the reception efficiency is 1/2 times lower. On the other hand, when four antenna elements 21-1, 21-2, 21-3, and 21-4 are arranged as a plurality of antenna elements, the circuit scale becomes large, but the reception efficiency becomes high, and then the rows are arranged. _{The radio wave arrival angles α x} and α _y in the / row direction (x / y direction) can be calculated.

(Modified example direction finding antenna)
In the second embodiment, the plurality of antenna elements are arranged in 2 rows and 2 columns. As a modification, the plurality of antenna elements may be arranged in m rows and n columns (m and n are arbitrary integers of 2 or more). At this time, the phase shift θ may be applied between adjacent rows / columns, _{and the row-to-row difference Y dif} and the column-to-column difference X _dif may be calculated at any row-to-column spacing.

In the second embodiment, the plurality of antenna elements are arranged in a square grid pattern. As a modification, the plurality of antenna elements may be arranged in a triangular lattice pattern or the like. At this time, one arrangement direction may be the row direction, and the arrangement direction separated by 60 ° may be the column direction.

In the first and second embodiments, the process of not performing the phase shift θ and the process of performing the phase shift θ are realized by using separate power receiving circuits. As a modification, the process of not performing the phase shift θ and the process of performing the phase shift θ may be switched in a single power receiving circuit. In the process without phase shift θ, the absolute value of the radio wave arrival angle can be calculated with high accuracy, and in the process with phase shift θ, the sign of the radio wave arrival angle can be calculated. You can have it together.

The directional detection antenna of the present disclosure calculates the direction of another vehicle as seen from the own vehicle for avoiding a collision of a vehicle, and calculates the direction of another ship as seen from the own ship for docking a spacecraft. It can be applied to the technology to be used.

A1, A2: Direction finder antennas 11-1, 11-2, 21-1, 21-2, 21-3, 21-4: Antenna elements 12, 22-X, 22-Y: Received power synthesizers 13, 23 : Radio wave arrival angle calculation unit 14, 24: Radiation source distance calculation unit 15, 25: Data reception unit 16, 26: Data transmission unit 17, 27-X, 27-Y, 27-1, 27-3, 27-4 : Phase transfer section

Claims (10)

Multiple antenna elements arranged in one-dimensional direction,
A reception power difference calculation unit that calculates the power difference between the reception powers of the plurality of antenna elements, and a reception power difference calculation unit.
A radio wave arrival angle calculation unit that calculates the radio wave arrival angle in the one-dimensional direction based on the power difference between the received powers of the plurality of antenna elements.
A direction finder antenna characterized by being equipped with. The claim is characterized in that the received power difference calculation unit calculates the power difference of the received power of the plurality of antenna elements without further shifting the phase difference of the reception phases of the plurality of antenna elements. The direction finding antenna according to 1. The claim is characterized in that the received power difference calculation unit calculates the power difference of the received power of the plurality of antenna elements after the phase difference of the receiving phases of the plurality of antenna elements is further shifted. The direction-finding antenna according to 1 or 2. The radio wave arrival angle calculation unit calculates the radio wave arrival angle in the one-dimensional direction based on the ratio of the power difference between the received powers of the plurality of antenna elements and the sum of the received powers of the plurality of antenna elements. The direction-finding antenna according to any one of claims 1 to 3, wherein the antenna is provided. Multiple antenna elements arranged in a two-dimensional plane,
A reception power difference calculation unit that calculates the difference between the rows of the sum of the received powers of the antenna elements in each row and the sum of the received powers of the antenna elements in each column.
The radio wave arrival angle in the row direction is calculated based on the difference between the rows of the sum of the received powers of the antenna elements in each row, and the columns are based on the difference between the rows of the sum of the received powers of the antenna elements in each row. A radio wave arrival angle calculation unit that calculates the direction radio wave arrival angle, and
A direction finder antenna characterized by being equipped with. The received power difference calculation unit calculates the line-to-line difference of the power sum of the received powers of the antenna elements of each line without further shifting the phase difference of the power sum of the received powers of the antenna elements of each line. The feature is that the difference between the rows of the sum of the received powers of the antenna elements in each row is calculated without further shifting the phase difference between the rows of the sum of the received powers of the antenna elements in each row. The orientation detection antenna according to claim 5. The received power difference calculation unit further shifts the phase difference between the lines of the sum of the received powers of the antenna elements of each line, and then calculates the difference between the lines of the sum of the received powers of the antenna elements of each line. The phase difference between the rows of the sum of the received powers of the antenna elements in each row is further transferred, and then the difference between the rows of the sum of the received powers of the antenna elements in each row is calculated. The orientation detection antenna according to claim 5 or 6. The radio wave arrival angle calculation unit is based on the ratio of the line-to-line difference in the sum of the received powers of the antenna elements in each row and the sum of the received powers of the plurality of antenna elements, and the radio wave arrival angle in the row direction. Is calculated, and the radio wave arrival angle in the column direction is determined based on the ratio of the difference between the rows of the sum of the received powers of the antenna elements in each row and the sum of the received powers of the plurality of antenna elements. The azimuth detection antenna according to any one of claims 5 to 7, characterized in that it is calculated. Further, a radiation source distance calculation unit that calculates the distance between the direction finding antenna and the radio wave radiation source based on the sum of the received powers of the plurality of antenna elements and the radiation power of the radio wave radiation source. The direction-finding antenna according to any one of claims 1 to 8, further comprising. The direction-finding antenna according to any one of claims 1 to 9, further comprising a data transmission / reception unit that transmits / receives data by the sum of the output powers of the plurality of antenna elements.

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