JP6789086B2 - Board side horn antenna - Google Patents

Description

The present disclosure relates to a technique for detecting the presence and orientation of a target object at a wide angle.

Patent Documents 1 to 3 disclose techniques for detecting the presence of a target object in a wide angle. In Patent Document 1, the presence of a target object in the front direction is detected by using a flat antenna formed on the plane of the substrate, and the presence of the target object in the side surface direction is detected by using the electromagnetic wave reflecting surface formed on the side surface of the substrate. To do. In Patent Document 2, a planar antenna formed on a substrate plane is used to detect the presence of a target object in the front direction, and an antenna pattern formed at an end of the substrate plane near the side surface of the substrate is used in the side surface direction. Detects the presence of the target. In Patent Document 3, the presence of a target object in the front direction is detected by using a plane antenna formed on a substrate plane, and a dipole antenna formed at an end of the substrate plane near the side surface of the substrate is used in the side surface direction. Detects the presence of the target.

Japanese Unexamined Patent Publication No. 2007-049691 Japanese Patent No. 5464152 Japanese Patent No. 56097772

By the way, in Patent Documents 1 and 3, detecting the presence of a target object at a wide angle is considered, but detecting the orientation of the target object at a wide angle is not considered. However, in Patent Document 2, it is considered that the presence of the target object is detected at a wide angle in the direction of the front surface of the substrate, and that the orientation of the target object is detected at a wide angle in the direction of the front surface of the substrate. There is. Nevertheless, in Patent Document 2, how to form spatially separated antennas on the side surface of the substrate not only detects the presence of the target object at a wide angle in the direction of the side surface of the substrate, but also targets the wide angle in the direction of the side surface of the substrate. In addition to detecting the orientation of an object, it was not possible to know whether the wide-angle orientation detection system could be made smaller, easier to manufacture, and lower in cost.

Therefore, in order to solve the above-mentioned problems, the present disclosure not only detects the presence of a target object at a wide angle in the direction of the side surface of the substrate by devising a method of forming spatially separated antennas on the side surface of the substrate. The purpose is to detect the orientation of the target object at a wide angle in the direction of the side surface of the substrate, and to reduce the size, manufacture, and cost of the wide-angle orientation detection system.

In order to achieve the above object, a monopulse angle measurement method is adopted by using two horn antennas, and the antenna directivity can be easily adjusted. Here, in order to reduce the size, manufacture, and cost of the wide-angle orientation detection system, the waveguides connected to the respective horn structures should be positioned at the same position as possible in the thickness direction of the dielectric substrate. It is desirable to form.

However, if the opening directions of the two horn structures are the same in the direction parallel to the thickness direction of the dielectric substrate, the distance between the two horn antennas is effectively set to 0, so a monopulse angle measurement method is used. Cannot be adopted. Therefore, if the opening directions of the two horn structures are different in the direction parallel to the thickness direction of the dielectric substrate, the distance between the two horn antennas is effectively set to a finite value. Therefore, a monopulse angle measurement method is used. Can be adopted.

Specifically, for a dielectric substrate, two waveguides are formed inside the substrate in a direction parallel to the plane of the substrate, and openings of two waveguides are formed on the side surface of the substrate. Then, the metal member is connected to the dielectric substrate so that two receiving horn structures are formed and the openings of the two waveguides and the connecting portion of the two receiving horn structures are connected.

Here, with respect to the metal member, a planar structure is not formed but a staircase structure is formed on at least one of the four pipe walls of each receiving horn structure. Therefore, while facilitating the manufacture and reducing the cost of the wide-angle directional detection system, the normal horn structure itself is not realized, but a structure close to the normal horn structure can be realized.

Specifically, the present disclosure is a dielectric substrate in which two waveguides are formed inside the substrate in a direction parallel to the plane of the substrate, and openings of the two waveguides are formed on the side surface of the substrate. And a metal member connected to the dielectric substrate so that two receiving horn structures are formed and the openings of the two waveguides and the connecting portion of the two receiving horn structures are connected. , And the openings of the two receiving horn structures are arranged so as to be separated from each other in a direction parallel to the thickness direction of the dielectric substrate, and the opening direction of each of the receiving horn structures is It is set in the same direction as the separation direction of the opening of the receiving horn structure, and the two receiving horn structures enable the target angle measurement in the direction parallel to the thickness direction of the dielectric substrate, and the dielectric substrate can be measured. The openings of the two receiving horn structures are arranged so as to be separated from each other in the thickness direction and the vertical direction of the above, and the target in the thickness direction and the direction perpendicular to the thickness direction of the dielectric substrate is provided by the two receiving horn structures. The substrate side surface horn antenna is capable of measuring an object angle, and has a stepped structure formed on at least one of the four tube walls of each of the receiving horn structures.

According to this configuration, the waveguides of the respective waveguides connected to the respective horn structures can be formed at the same position as possible in the thickness direction of the dielectric substrate. Then, by forming a staircase structure in at least one of the four tube walls of each receiving horn structure, a structure close to a normal horn structure can be realized. Therefore, not only by forming a horn antenna on the side surface of the substrate, but also by forming a planar antenna on the plane of the substrate, the presence of the target object can be detected at a wide angle, and the orientation of the target object can be detected at a wide angle. The detection system can be miniaturized, easy to manufacture, and low in cost.

Further, in the present disclosure, among the sizes of each step of the staircase structure of each of the receiving horn structures, the size in the direction parallel to the thickness direction of the dielectric substrate is half or less of the band center wavelength of the substrate side horn antenna. It is a substrate side horn antenna characterized by being.

According to this configuration, since the discontinuity of the staircase structure is small, the directivity of the horn structure can be easily designed without generating unnecessary modes due to the staircase structure. It should be noted that the staircase structure may be formed over the entire pipe wall of the horn structure, or the staircase structure may be formed only in a part thereof. Further, the band center wavelength of the substrate side horn antenna represents the wavelength in vacuum when the radome member described later is not embedded, and when the radome member described later is embedded, the wavelength or vacuum inside the radome member described later. Represents the wavelength inside.

Further, the present disclosure is further provided with a radome member whose embedding depth is adjusted by using the staircase structure of each of the receiving horn structures when it is embedded in the opening of each of the receiving horn structures. It is a board side horn antenna.

According to this configuration, the radome member is "embedded" by using the staircase structure of each receiving horn structure as a stopper without adopting the structure of "pasting" the radome member so as to close the opening surface of each receiving horn structure. "The structure is adopted. Therefore, it is possible to reduce the size of the wide-angle directional detection system, facilitate manufacturing, reduce the cost, and increase the resistance to wind and rain.

Then, in the attached radome member, the influence of the repeatedly reflected wave inside leaking from the end portion can be eliminated. Therefore, it may be considered that the phase difference of the received signal changes almost monotonously with respect to the arrival angle of the reflected wave with almost no ripple. That is, it may be considered that the arrival angles of the plurality of reflected waves rarely correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method can be improved.

Here, the openings of the two horn structures are formed on a housing surface having a finite spread of the wide-angle directional detection system. Then, the two horn antennas are affected by the diffracted wave whose diffraction source is the housing angle of the wide-angle directional detection system. Therefore, the phase difference of the received signal does not change monotonically with respect to the arrival angle of the reflected wave and causes ripple. That is, the arrival angles of the plurality of reflected waves correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method becomes low.

Therefore, the inventor referred to Japanese Patent Application Laid-Open No. 2015-061231 of the in-house application, and the influence of the diffracted wave whose diffraction source is the housing angle of the wide-angle directional detection system is the same as the housing angle of the wide-angle azimuth detection system. It was noted that the difference depends on the distance between the openings of the individual horn structures.

When the distance between the housing angle of the wide-angle orientation detection system and the openings of the two horn structures is "short distance", the wavelength of the diffracted wave is the housing angle of the wide-angle orientation detection system and the openings of the two horn structures. Since it is sufficiently long compared to the distance between the parts, the phase difference of the received signal only produces a ripple having a long period with respect to the arrival angle of the reflected wave, and it may be considered that the phase difference changes almost monotonously. ..

When the distance between the housing angle of the wide-angle orientation detection system and the openings of the two horn structures is "long distance", the amplitude of the diffracted wave is the housing angle of the wide-angle orientation detection system and the openings of the two horn structures. Since it is sufficiently attenuated in the distance between the parts, the phase difference of the received signal only produces a ripple having a small amplitude with respect to the arrival angle of the reflected wave, and it may be considered that the phase difference changes almost monotonously.

When the distance between the housing angle of the wide-angle orientation detection system and the openings of the two horn structures is "medium distance", the phase difference of the received signal has a moderate period with respect to the arrival angle of the reflected wave. Since it produces ripples with a finite amplitude, it cannot be considered to change almost monotonously.

Therefore, when the distance between the housing angle of the wide-angle directional detection system and the openings of the two horn structures is "medium distance", the following means are used to improve the angle measurement accuracy of the monopulse angle measurement method. It is desirable to apply. Of course, even when the distance between the housing angle of the wide-angle directional detection system and the openings of the two horn structures is "short distance" or "long distance", the angle measurement accuracy of the monopulse angle measurement method is high to some extent. , There is no problem in applying the means shown below.

The means is that the diffraction structure that is the diffraction source for the received wave between the housing angle of the wide-angle directional detection system and the openings of the two horn structures is set separately from the housing angle of the wide-angle directional detection system. , To form. Here, the distance between the diffraction structure that is the diffraction source for the received wave and the openings of the two horn structures is the above-mentioned "short distance". Therefore, the diffracted wave from the diffracted structure which is the diffraction source with respect to the received wave does not lower the angle measurement accuracy of the monopulse angle measurement method. The diffracted wave from the housing angle of the wide-angle orientation detection system is attenuated as a result of interfering with the diffracted wave from the diffracted structure that is the diffraction source with respect to the received wave, and therefore does not affect the angle measurement accuracy of the monopulse angle measurement method. ..

Specifically, in the present disclosure, the diffraction structure that serves as a diffraction source for the received wave is on the housing surface of the metal member on which the openings of the two receiving horn structures are formed, and the dielectric substrate. Between the housing angle of the metal member and the openings of the two receiving horn structures in a direction parallel to the thickness direction of the dielectric substrate, the dielectric substrate is formed by being stretched in a direction perpendicular to the thickness direction of the dielectric substrate. It is a featured substrate side horn antenna.

According to this configuration, the phase difference of the received signal only causes a ripple having a long period with respect to the arrival angle of the reflected wave, and it may be considered that the phase difference changes almost monotonously. That is, it may be considered that the arrival angles of the plurality of reflected waves rarely correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method can be improved.

As described above, the present disclosure devises a method of forming spatially separated antennas on the side surface of the substrate, and not only detects the presence of a target at a wide angle in the direction of the side surface of the substrate, but also wide-angle in the direction of the side surface of the substrate. In addition to detecting the orientation of the target object, the wide-angle orientation detection system can be miniaturized, easy to manufacture, and low in cost.

It is a figure which shows the structure of the wide-angle directional detection system of this disclosure. It is a figure which shows the principle of the monopulse angle measurement system of this disclosure. It is a figure which shows the shape and position of the horn antenna on the side surface of the substrate of this disclosure. It is a figure which shows the shape and position of the horn antenna on the side surface of the substrate of this disclosure. It is a figure which shows the shape of the horn antenna on the side surface of the substrate of this disclosure when the opening angle in the angle measuring direction is large. It is a figure which shows the shape of the horn antenna on the side surface of the substrate of this disclosure when the opening angle in the angle measuring direction is small. It is a figure which shows the shape of the horn antenna on the side surface of the substrate of the modification. It is a figure which shows the arrangement method of the radome member of the horn antenna on the side surface of the substrate of this disclosure. It is a figure which shows the monopulse angle measurement system of the antenna element of the substrate plane of the prior art. It is a figure which shows the position of the diffraction structure in the vicinity of the horn antenna on the side surface of the substrate of the modification. It is a figure which shows the structure of the diffraction structure in the vicinity of the horn antenna on the side surface of the substrate of this disclosure. It is a figure which shows the structure of the diffraction structure in the vicinity of the horn antenna on the side surface of the substrate of this disclosure. It is a figure which shows the monopulse angle measurement accuracy of the horn antenna on the side surface of the substrate of the comparative example. It is a figure which shows the monopulse angle measurement accuracy of the horn antenna on the side surface of the substrate of this disclosure.

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.

(Structure of wide-angle directional detection system)
The configuration of the wide-angle directional detection system of the present disclosure is shown in FIG. The wide-angle orientation detection system S of the present disclosure is composed of a dielectric substrate 1 and a metal member 2. In the dielectric substrate 1, waveguides 11, 12, and 13 are formed inside the substrate in a direction parallel to the plane of the substrate (see FIG. 3), and openings of the waveguides 11, 12, and 13 are formed on the side surface of the substrate. (See FIG. 3) is formed, and the substrate plane antenna 14 is formed on the substrate plane. The metal member 2 is formed with horn structures 21, 22 and 23 so that the openings of the waveguides 11, 12 and 13 (see FIG. 3) and the connection portions of the horn structures 21, 22 and 23 are connected, respectively. Is connected to the dielectric substrate 1.

The horn structures 21 and 22 are for reception, and the horn structure 23 is for transmission. As the substrate flat antenna 14, the one for reception and the one for transmission are arranged with a high degree of freedom according to various monitoring methods. In the following description, the direction parallel to the thickness direction of the dielectric substrate 1 is defined as the "horizontal direction", and the direction perpendicular to the thickness direction of the dielectric substrate 1 is defined as the "vertical direction".

(Structure of horn antenna on the side of the board)
The principle of the monopulse angle measurement method of the present disclosure is shown in FIG. In the monopulse angle measurement method, the phase difference of the received signal is measured by 2π (dsinθ / λ ₀ ) (λ ₀ is the vacuum wavelength of the electromagnetic wave) using antennas spatially separated by the distance d, and the reflected wave is measured. The arrival angle θ is measured.

The shape and position of the horn antenna on the side surface of the substrate of the present disclosure are shown in FIGS. 3 and 4. The most desirable embodiment of the shape and position of the horn antenna on the side surface of the substrate will be described with reference to FIG. Regarding the shape and position of the horn antenna on the side surface of the substrate, the reason for selecting the embodiment of FIG. 3 as the most desirable embodiment will be described with reference to FIG.

First, FIG. 3 will be described. The waveguides and openings of the waveguides 11, 12, and 13 are formed at the same positions in the horizontal direction. Of the waveguides 11, 12, and 13, the wide wall surface in the direction parallel to the substrate plane is formed by using, for example, a conductor foil, and the narrow wall surface in the direction perpendicular to the substrate plane is formed by, for example, using a metal column. .. The metal column that narrows the openings of the waveguides 11, 12, and 13 in the direction of the wide wall surface of the waveguides 11, 12, and 13 functions as an impedance matching box, and the openings of the waveguides 11, 12, and 13 are closed to the waveguide 11. , 12, 13 metal columns extending in the direction of the wide wall surface function as a reflector. Methods for forming the waveguides 11, 12, and 13 are disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-109438 and Japanese Patent No. 5669043.

The openings of the horn structures 21 and 22 are arranged so as to be separated from each other in the horizontal direction. In FIG. 3, the opening of the horn structure 21 is displaced to the right of the paper surface with reference to the opening of the waveguide 11, and the opening of the horn structure 22 is to the left of the paper surface with reference to the opening of the waveguide 12. It shifts. The horizontal component in the opening direction of the horn structures 21 and 22 is set in the same direction as the above-mentioned separation direction of the openings of the horn structures 21 and 22. In FIG. 3, the horizontal component in the opening direction of the horn structure 21 is shifted to the right on the paper surface with reference to the waveguide direction of the waveguide 11, and the horizontal component in the opening direction of the horn structure 22 is the waveguide of the waveguide 12. It shifts to the left of the page with respect to the direction. The horn structures 21 and 22 enable horizontal target angle measurement.

The openings of the horn structures 21 and 22 are arranged so as to be vertically separated from each other. In FIG. 3, the opening of the horn structure 21 is located on the paper surface according to the position of the opening of the waveguide 11, and the opening of the horn structure 22 is located below the paper surface according to the position of the opening of the waveguide 12. Located in the direction. The horn structures 21 and 22 enable vertical target angle measurement.

Next, FIG. 4 will be described. In the present disclosure, the monopulse angle measurement method is adopted by using the two horn structures 21 and 22, and the antenna directivity can be easily adjusted. Here, in order to reduce the size, manufacture, and cost of the wide-angle directional detection system S, the waveguides 11 and 12 connected to the horn structures 21 and 22 are connected to the dielectric substrate 1. It is desirable to form them at the same position as possible in the thickness direction (see the upper left column of FIG. 4).

However, as shown in the upper left column of FIG. 4, if the horizontal components in the opening direction of the horn structures 21 and 22 are the same direction, the effective horizontal distance d of the horn structures 21 and 22 is 0. It is not possible to adopt the monopulse angle measurement method in the horizontal direction, which is a problem before the miniaturization, manufacturing simplification, and cost reduction of the wide-angle directional detection system S. Then, as shown in the upper right column of FIG. 4, if the waveguides 11 and 12 are formed at positions significantly different in the thickness direction of the dielectric substrate 1 (separation distance l in the thickness direction of the dielectric substrate 1), the horn Since the effective horizontal distance d of the structures 21 and 22 is set to a finite value, a horizontal monopulse angle measurement method can be adopted, but the wide-angle direction detection system S is miniaturized, easy to manufacture, and low in cost. It cannot be converted.

Therefore, as shown in the lower left column of FIG. 4, if the horizontal components in the opening directions of the horn structures 21 and 22 are different, the waveguides 11 and 12 are located at positions that are not so different in the thickness direction of the dielectric substrate 1 ( Even if the dielectric substrate 1 is formed at an isolation distance l'(<l) in the thickness direction, the effective horizontal spacing d of the horn structures 21 and 22 is as finite as in the upper right column of FIG. Use as a value. Therefore, in addition to being able to adopt the horizontal monopulse angle measurement method, it is possible to reduce the size, manufacture, and cost of the wide-angle direction detection system S.

Then, as shown in the lower right column of FIG. 4, if the horizontal components in the opening directions of the horn structures 21 and 22 are different, the waveguides 11 and 12 are formed at the same positions in the thickness direction of the dielectric substrate 1. Even so, the effective horizontal spacing d of the horn structures 21 and 22 is set to a finite value, though not as much as in the lower left column of FIG. Therefore, in addition to being able to adopt the horizontal monopulse angle measurement method, it is possible to further reduce the size, manufacture, and cost of the wide-angle direction detection system S.

(Shape of horn antenna on the side of the board)
In FIGS. 3 and 4, the horn structures 21, 22, and 23 are not ordinary horn structures. The shapes of the horn structures 21, 22 and 23 will be described with reference to FIGS. 5 to 7.

FIG. 5 shows the shape of the horn antenna on the side surface of the substrate of the present disclosure when the opening angle in the angle measurement direction is “large”. In FIG. 5, the horizontal shape of the horn structure 21 will be described after adopting the horizontal direction as the angle measurement direction. The horizontal shape of the horn structures 22 and 23 and the vertical direction of the horn structures 21, 22 and 23 will be described. The shape of is almost the same.

As shown in the left column of FIG. 5, in the pipe wall that opens the horn structure 21 in the horizontal direction, when the number of steps of the staircase structure is small (in the left column of FIG. 5, the two-step staircase structure), the discontinuity of the staircase structure Is large, and the horn structure 21 is far from the normal horn structure. Therefore, it becomes difficult to design the directivity of the horn structure 21 due to the generation of unnecessary modes due to the staircase structure.

As shown in the right column of FIG. 5, in the pipe wall that opens the horn structure 21 in the horizontal direction, when the number of steps of the staircase structure is large (in the right column of FIG. 5, the four-step staircase structure), the discontinuity of the staircase structure Is small, and the horn structure 21 is close to the normal horn structure. Therefore, the directivity of the horn structure 21 can be easily designed without generating an unnecessary mode due to the staircase structure.

FIG. 6 shows the shape of the horn antenna on the side surface of the substrate of the present disclosure when the opening angle in the angle measurement direction is “small”. In FIG. 6, the horizontal shape of the horn structure 21 will be described after adopting the horizontal direction as the angle measurement direction. However, the horizontal shape of the horn structures 22 and 23 and the vertical direction of the horn structures 21, 22 and 23 will be described. The shape of is almost the same.

As shown in FIG. 6, in the pipe wall that opens the horn structure 21 in the horizontal direction, even when the number of steps of the staircase structure is small (in FIG. 6, the two-step staircase structure), the discontinuity of the staircase structure is small, which is normal. The horn structure 21 is similar to the horn structure. Therefore, the directivity of the horn structure 21 can be easily designed without generating an unnecessary mode due to the staircase structure.

Specifically, of the sizes of each step of the staircase structure of the horn structure 21, the size in the direction parallel to the thickness direction of the dielectric substrate 1 is half λ _g / of the band center wavelength λ _g of the wide-angle orientation detection system S. It is 2 or less. Then, in the pipe wall that opens the horn structure 21 in the horizontal direction, the discontinuity of the staircase structure is small, and the horn structure 21 is close to the normal horn structure. Therefore, the directivity of the horn structure 21 can be easily designed without generating an unnecessary mode due to the staircase structure.

Then, while facilitating the manufacture and reducing the cost of the wide-angle directional detection system S, the normal horn structure itself is not realized, but the horn structure 21 close to the normal horn structure can be realized. For example, tapered square hole processing can be used.

As will be described later in FIG. 7, a staircase structure may be formed over the entire pipe wall of the horn structure 21, or a staircase structure may be formed only in a part thereof. Further, the band center wavelength λ _g of the wide-angle orientation detection system S represents the wavelength λ ₀ in vacuum when the radome member 31 described later is not embedded in FIG. 8, and the radome member 31 described later is embedded in FIG. Occasionally, FIG. 8 represents the wavelength λ _g inside the radome member 31, which will be described later, or the wavelength λ ₀ in vacuum.

The horn structures 21 and 22 of the present embodiment shown in FIGS. 3 and 4 will be described. A two-step staircase structure is formed on a single pipe wall that opens the horn structures 21 and 22 in the horizontal direction. A two-step staircase structure is formed on the two-sided pipe wall that opens the horn structures 21 and 22 in the vertical direction. In order to form the waveguides 11 and 12 at the same position in the thickness direction of the dielectric substrate 1, the horn structures 21 and 22 are opened horizontally in the remaining one tube wall of the horn structures 21 and 22. No, no staircase structure is formed.

The horn structure 23 of the present embodiment shown in FIGS. 3 and 4 will be described. A staircase structure may be formed on the pipe wall of each surface that opens the horn structure 23 in the horizontal direction and the vertical direction, or a planar structure such as a normal horn structure may be formed.

The horn structure 21 of the first modification shown in the upper left column of FIG. 7 will be described. In the one-sided pipe wall that opens the horn structure 21 in the horizontal direction, a one-step staircase structure is formed on the opening surface side, and a planar structure like a normal horn structure is formed on the waveguide 11 side. A two-step staircase structure is formed on the two-sided pipe wall that opens the horn structure 21 in the vertical direction. In order to form the waveguides 11 and 12 at the same position in the thickness direction of the dielectric substrate 1, the horn structure 21 is not opened in the horizontal direction in the tube wall on the remaining one surface of the horn structure 21, and the horn. The staircase structure or the horizontal structure that opens the structure 21 is not formed.

The horn structure 21 of the second modification shown in the upper right column of FIG. 7 will be described. A planar structure similar to a normal horn structure is formed on one pipe wall that opens the horn structure 21 in the horizontal direction. A two-step staircase structure is formed on the two-sided pipe wall that opens the horn structure 21 in the vertical direction. In order to form the waveguides 11 and 12 at the same position in the thickness direction of the dielectric substrate 1, the horn structure 21 is not opened in the horizontal direction in the tube wall on the remaining one surface of the horn structure 21, and the horn. The staircase structure or the horizontal structure that opens the structure 21 is not formed.

The horn structure 21 of the third modification shown in the lower left column of FIG. 7 will be described. A two-step staircase structure is formed on one pipe wall that opens the horn structure 21 in the horizontal direction. A planar structure like a normal horn structure is formed on the two-sided pipe wall that opens the horn structure 21 in the vertical direction. In order to form the waveguides 11 and 12 at the same position in the thickness direction of the dielectric substrate 1, the horn structure 21 is not opened in the horizontal direction in the tube wall on the remaining one surface of the horn structure 21, and the horn. The staircase structure or the horizontal structure that opens the structure 21 is not formed.

The horn structure 21 of the fourth modified example shown in the lower right column of FIG. 7 will be described. In the one-sided pipe wall that opens the horn structure 21 in the horizontal direction, a one-step staircase structure is formed on the opening surface side, and a planar structure like a normal horn structure is formed on the waveguide 11 side. A planar structure like a normal horn structure is formed on the two-sided pipe wall that opens the horn structure 21 in the vertical direction. In order to form the waveguides 11 and 12 at the same position in the thickness direction of the dielectric substrate 1, the horn structure 21 is not opened in the horizontal direction in the tube wall on the remaining one surface of the horn structure 21, and the horn. The staircase structure or the horizontal structure that opens the structure 21 is not formed.

(Arrangement method of radome member)
In FIGS. 3 and 4, in the horn structures 21, 22, 23, the radome members 31, 32, 33 are embedded in the opening, and the film members 31', 32', 33'are attached to the opening surface. The arrangement method of the radome members 31, 32, 33 and the film members 31', 32', 33'of the horn structures 21, 22, and 23 will be described with reference to FIG.

FIG. 8 shows a method of arranging the radome member of the horn antenna on the side surface of the substrate of the present disclosure. In FIG. 8, a method of arranging the radome member 31 and the film member 31'of the horn structure 21 in the horizontal direction after adopting the horizontal direction as the angle measurement direction will be described. However, the radome members 32 and 33 of the horn structures 22 and 23 will be described. Also, the horizontal arrangement method of the film members 32'and 33'and the vertical arrangement method of the radome members 31, 32, 33 and the film members 31', 32', 33'of the horn structures 21, 22, 23 are almost the same. The same is true.

As shown in the left column of FIG. 8, a case where a structure in which the radome member 31 (for example, a half-wave radome) is “attached” is adopted so as to close the opening surface of the horn structure 21 will be described. Then, even if the wide-angle directional detection system S can be easily manufactured, the cost can be reduced, and the resistance to wind and rain can be increased, the wide-angle directional detection system S cannot be miniaturized.

Then, in the attached thick radome member 31 (for example, about half a wavelength), the influence of the repeatedly reflected wave inside leaking from the end portion cannot be eliminated. Therefore, the phase difference of the received signal may cause a large ripple (see FIG. 13) with respect to the arrival angle of the reflected wave, and cannot be considered to change monotonically. That is, it cannot be considered that the arrival angles of the plurality of reflected waves do not correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method cannot be improved.

As shown in the right column of FIG. 8, a case where a structure in which the radome member 31 (for example, a half-wave radome) is “embedded” is adopted by using the step structure of the horn structure 21 as a stopper will be described. Here, the film member 31'(for example, a film having a thickness of less than half a wavelength) may be attached so as to close the opening surface of the horn structure 21. Then, the wide-angle directional detection system S can be miniaturized, easy to manufacture, low cost, and highly resistant to wind and rain.

Then, in the film member 31'with no thickness (for example, less than half a wavelength) attached, it is possible to eliminate the influence of the repeatedly reflected wave inside leaking from the end portion. Therefore, it may be considered that the phase difference of the received signal changes almost monotonously with respect to the arrival angle of the reflected wave with almost no ripple (see FIG. 14). That is, it may be considered that the arrival angles of the plurality of reflected waves rarely correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method can be improved.

The horn structures 21 and 22 of the present embodiment shown in FIGS. 3 and 4 will be described. First, a two-step staircase structure formed on one tube wall that opens the horn structures 21 and 22 in the horizontal direction and a two-step structure formed on the two-sided tube wall that opens the horn structures 21 and 22 in the vertical direction. The rectangular parallelepiped radome members 31 and 32 are embedded using the staircase structure as a stopper. Next, the film members 31'and 32'may be attached so as to close the opening surfaces of the horn structures 21 and 22.

The horn structure 23 of the present embodiment shown in FIGS. 3 and 4 will be described. First, when a staircase structure formed on two pipe walls that open the horn structure 23 in the horizontal direction and a staircase structure formed on the two pipe walls that open the horn structure 23 in the vertical direction are formed. With these staircase structures as stoppers, a rectangular parallelepiped radome member 33 is embedded. Next, the film member 33'may be attached so as to close the opening surface of the horn structure 23.

The horn structure 21 of the first modification shown in the upper left column of FIG. 7 will be described. First, a one-step staircase structure formed on a one-sided pipe wall that opens the horn structure 21 in the horizontal direction, and a two-step staircase structure formed on the two-sided pipe wall that opens the horn structure 21 in the vertical direction. Is used as a stopper to embed a rectangular parallelepiped radome member 31. Next, the film member 31'may be attached so as to close the opening surface of the horn structure 21.

The horn structure 21 of the second modification shown in the upper right column of FIG. 7 will be described. First, the radome member 31 having a shape along the four pipe walls is embedded by using the two-step staircase structure formed on the two pipe walls that open the horn structure 21 in the vertical direction as a stopper. Next, the film member 31'may be attached so as to close the opening surface of the horn structure 21.

The horn structure 21 of the third modification shown in the lower left column of FIG. 7 will be described. First, the radome member 31 having a shape along the four pipe walls is embedded by using the two-step staircase structure formed on the one pipe wall that opens the horn structure 21 in the horizontal direction as a stopper. Next, the film member 31'may be attached so as to close the opening surface of the horn structure 21.

The horn structure 21 of the fourth modified example shown in the lower right column of FIG. 7 will be described. First, the radome member 31 having a shape along the four pipe walls is embedded by using the one-step staircase structure formed on the one-sided pipe wall that opens the horn structure 21 in the horizontal direction as a stopper. Next, the film member 31'may be attached so as to close the opening surface of the horn structure 21.

(Principle of diffraction source for received wave)
FIG. 9 shows a diagram showing a monopulse angle measurement method of an antenna element on a substrate plane according to a prior art (Japanese Patent Application Laid-Open No. 2015-061231) in relation to the principle of a diffraction source for a received wave.

Here, the openings of the horn structures 21 and 22 are formed on the housing surface 24 where the spread of the metal member 2 is finite. Then, the horn structures 21 and 22 are affected by the diffracted wave having the housing angles 25 and 26 of the metal member 2 as the diffraction source. Therefore, the phase difference of the received signal does not change monotonically with respect to the arrival angle of the reflected wave and causes ripple. That is, the arrival angles of the plurality of reflected waves correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method becomes low.

Therefore, the inventor refers to Japanese Patent Application Laid-Open No. 2015-061231 of the in-house application, and the influence of the diffracted wave having the housing angles 25 and 26 of the metal member 2 as the diffraction source affects the housing angle 25 of the metal member 2. , 26 and the openings of the horn structures 21 and 22 are different depending on the distance.

In the prior art, as shown in the upper part of FIG. 9, when the distance between the flat antenna element and the flat end of the substrate is "short distance", the wavelength of the diffracted wave is between the flat antenna element and the flat end of the substrate. Since it is sufficiently long compared to the distance, the phase difference of the received signal only produces a ripple having a long period with respect to the arrival angle of the reflected wave, and it may be considered that the phase difference changes almost monotonously.

In the present disclosure, referring to the prior art shown in the upper part of FIG. 9, diffraction occurs when the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is "short distance". Since the wavelength of the wave is sufficiently long compared to the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22, the phase difference of the received signal is relative to the arrival angle of the reflected wave. Therefore, it only produces ripples with a long period, and it may be considered that the change is almost monotonous.

In the prior art, as shown in the lower part of FIG. 9, when the distance between the flat antenna element and the flat end of the substrate is "long distance", the amplitude of the diffracted wave is between the flat antenna element and the flat end of the substrate. Since it is sufficiently attenuated at a distance, the phase difference of the received signal only produces a ripple having a small amplitude with respect to the arrival angle of the reflected wave, and it may be considered that the phase difference changes almost monotonously.

In the present disclosure, referring to the prior art shown in the lower part of FIG. 9, diffraction occurs when the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is “long distance”. Since the wave amplitude is sufficiently attenuated at the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22, the phase difference of the received signal is relative to the arrival angle of the reflected wave. It only produces ripples with small amplitudes and may be considered to vary almost monotonically.

In the prior art, as shown in the middle part of FIG. 9, when the distance between the flat antenna element and the flat end of the substrate is "medium distance", the phase difference of the received signal is relative to the arrival angle of the reflected wave. It cannot be considered to change almost monotonically because it produces ripples with moderate period and finite amplitude.

In the present disclosure, referring to the prior art shown in the middle part of FIG. 9, when the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is "medium distance", reception is performed. The phase difference of the signal cannot be considered to change almost monotonically because it produces ripples with a moderate period and finite amplitude with respect to the arrival angle of the reflected wave.

Therefore, when the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is "medium distance", in order to improve the angle measurement accuracy of the monopulse angle measurement method, the following It is desirable to apply the means shown. Of course, even when the distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is "short distance" or "long distance", the angle measurement accuracy of the monopulse angle measurement method is to some extent. Although expensive, it is okay to apply the means shown below.

As already shown in FIGS. 1, 3 and 4, the means is a diffraction source for the received wave between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22. The diffraction structure 27 is formed separately from the housing angles 25 and 26 of the metal member 2. Here, the distance between the diffraction structure 27, which is the diffraction source for the received wave, and the openings of the horn structures 21 and 22, is the “short distance” referred to in FIG. Therefore, the diffracted wave from the diffracted structure 27 which is the diffracted source with respect to the received wave does not lower the angle measurement accuracy of the monopulse angle measurement method. Then, the diffracted waves from the housing angles 25 and 26 of the metal member 2 are attenuated as a result of interfering with the diffracted waves from the diffractive structure 27 which is the diffraction source with respect to the received waves. Does not affect.

Therefore, it may be considered that the phase difference of the received signal only causes a ripple having a long period with respect to the arrival angle of the reflected wave, and changes almost monotonously. That is, it may be considered that the arrival angles of the plurality of reflected waves rarely correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method can be improved.

Here, a signal processing circuit (not shown) is connected to one plane of the dielectric substrate 1 on which the substrate plane antenna 14 is not formed, and a monopulse angle measurement method is applied to process the received signal.

Then, the diffraction structure 27, which is a diffraction source for the received wave, is on the housing surface 24 of the metal member 2 on which the openings of the horn structures 21, 22, and 23 are formed, and the “signal” of the metal member 2 in the horizontal direction. It is desirable that the housing angle 25 on the "processing circuit side" and the openings of the horn structures 21, 22 and 23 can be formed so as to extend in the vertical direction.

On the other hand, the diffraction structure 27, which serves as a diffraction source for the received wave, is formed on the housing surface 24 of the metal member 2 on which the openings of the horn structures 21, 22, and 23 are formed, and in the horizontal direction, the metal member 2 is " It is not always required to be formed by extending in the vertical direction between the housing angle 26 on the "dielectric substrate 1 side" and the openings of the horn structures 21, 22, and 23.

(Modification example provided with a diffraction source for the received wave)
FIG. 10 shows the position of the diffraction structure in the vicinity of the horn antenna on the side surface of the substrate of the modified example. The diffraction structures 27 shown in the first and second modifications have different formation locations.

The distance between the housing angles 25 and 26 of the metal member 2 and the openings of the horn structures 21 and 22 is determined according to the thickness of the dielectric substrate 1 and the signal processing circuit.

Here, the distance between the housing angle 25 on the “signal processing circuit side” of the metal member 2 and the openings of the horn structures 21 and 22 is referred to in FIG. 9 in consideration of the thickness of the signal processing circuit. It is often "medium distance". Therefore, between the housing angle 25 on the “signal processing device side” of the metal member 2 and the openings of the horn structures 21 and 22, the diffraction structure 27 that serves as a diffraction source for the received wave is transferred to the “signal” of the metal member 2. It is desirable to form it separately from the housing angle 25 on the "processing device side".

In the first modification, a diffraction structure 27 that serves as a diffraction source for received waves is formed between the housing angle 25 on the “signal processing device side” of the metal member 2 and the openings of the horn structures 21, 22, and 23. , The metal member 2 is formed separately from the housing angle 25 on the “signal processing device side”. When the openings of the horn structures 21 and 22 are largely separated in the horizontal direction, the distance between the opening of the horn structure 21 and the diffraction structure 27 and the opening of the horn structure 22 and the diffraction structure 27 It is desirable to bend the diffraction structure 27 in the vicinity of the boundary between the openings of the horn structures 21 and 22 so that the distances between them are almost equal to each other as referred to in FIG.

On the other hand, the distance between the housing angle 26 on the “dielectric substrate 1 side” of the metal member 2 and the openings of the horn structures 21 and 22 is shown in the figure in consideration of the substrate plane antenna 14 of the dielectric substrate 1. It is often the "short distance" referred to in 9. Therefore, between the housing angle 26 on the “dielectric substrate 1 side” of the metal member 2 and the openings of the horn structures 21 and 22, the diffraction structure 27 that serves as a diffraction source for the received wave is set on the metal member 2. It is not necessary to form it separately from the housing angle 26 on the "dielectric substrate 1 side".

In the second modification, the diffraction structure 27 that serves as a diffraction source for the received wave between the housing angle 26 of the “dielectric substrate 1 side” of the metal member 2 and the openings of the horn structures 21, 22, and 23. Is formed separately from the housing angle 26 of the “dielectric substrate 1 side” of the metal member 2. When the openings of the horn structures 21 and 22 are largely separated in the horizontal direction, the distance between the opening of the horn structure 21 and the diffraction structure 27 and the opening of the horn structure 22 and the housing angle 26 It is desirable to extend the diffraction structure 27 in the horizontal direction on the housing angle 26 side of the opening of the opening of the horn structure 21 so that the distances between the two are substantially equal to each other as referred to in FIG.

(Composition of diffraction source for received wave)
The structure of the diffraction structure in the vicinity of the horn antenna on the side surface of the substrate of the present disclosure is shown in FIGS. 11 and 12. The components of the diffraction structure 27 shown in FIGS. 11 and 12 are different from each other.

In FIGS. 1, 3, 4 and 10, the diffraction structure 27 has an unspecified structure as long as it serves as a diffraction source for the received wave. In FIGS. 11 and 12, the diffraction structure 27 not only serves as a diffraction source for the received wave, but also has a choke structure.

Here, the choke structure is formed along the housing surface 24 of the metal member 2 on which the openings of the horn structures 21 and 22 are formed, and the housing angles 25 and 26 of the metal member 2 and the horn structure 21 in the horizontal direction. It reduces the propagation of electromagnetic waves between the 22 openings.

Therefore, due to the weakening interference between the electromagnetic waves passing through / passing through the choke structure, the diffracted waves from the housing angles 25 and 26 of the metal member 2 are attenuated at the openings of the horn structures 21 and 22, so that the monopulse angle measurement is performed. The angle measurement accuracy of the method can be improved.

In the present disclosure shown in FIG. 11, the choke structure has a depth of housing surface 24 in the vertical direction h = λ _0/4 of the metal member 2, the width w ≦ a direction parallel to the housing surface 24 of the metal member 2 It has a λ _0/2. Therefore, the diffracted wave from the housing angles 25 and 26 of the metal member 2 having an electric field in the direction perpendicular to the housing surface 24 of the metal member 2 can be attenuated at the openings of the horn structures 21 and 22.

In the present disclosure shown in FIG. 12, the choke structure has a housing surface 24 and the direction parallel to the depth h = λ _0/4 of the metal member 2, the width w ≦ vertical and housing surface 24 of the metal member 2 It has a λ _0/2. Therefore, the diffracted wave from the housing angles 25 and 26 of the metal member 2 having an electric field in the direction parallel to the housing surface 24 of the metal member 2 can be attenuated at the openings of the horn structures 21 and 22.

(Comparative example without a diffraction source for the received wave)
FIG. 13 shows the monopulse angle measurement accuracy of the horn antenna on the side surface of the substrate of the comparative example.

In the comparative example shown in FIG. 13, the diffraction structure 27, which is a diffraction source for the received wave, is on the housing surface 24 of the metal member 2 in which the openings of the horn structures 21, 22, and 23 are formed, and in the horizontal direction. Between the housing angle 25 on the "signal processing circuit side" of the metal member 2 and the openings of the horn structures 21, 22 and 23, the metal member 2 is not formed so as to extend in the vertical direction. However, in the horn structures 21, 22, 23, the radome members 31, 32, 33 are embedded in the opening, and the film members 31', 32', 33'are attached to the opening surface.

Then, in the comparative example, the phase difference of the received signal does not change monotonically with respect to the arrival angle of the reflected wave, and ripple occurs. That is, in the comparative example, the arrival angles of the plurality of reflected waves correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method becomes low.

This is because, in the comparative example, the horizontal directivity of the horn structures 21, 22, and 23 causes a large ripple with respect to the horizontal angle of the wide-angle directional detection system S. That is, in the comparative example, the signal-to-noise ratio of the horn structures 21, 22, and 23 can be extremely low at a specific horizontal angle of the wide-angle directional detection system S, and the angle measurement accuracy of the monopulse angle measurement method is low. Become.

(The present disclosure including a diffraction source for received waves)
FIG. 14 shows the monopulse angle measurement accuracy of the horn antenna on the side surface of the substrate of the present disclosure.

In the present disclosure shown in FIG. 14, the diffraction structure 27, which is a diffraction source for the received wave, is on the housing surface 24 of the metal member 2 in which the openings of the horn structures 21, 22, and 23 are formed, and in the horizontal direction. It is formed so as to extend in the vertical direction between the housing angle 25 on the “signal processing circuit side” of the metal member 2 and the openings of the horn structures 21, 22 and 23. In the horn structures 21, 22 and 23, the radome members 31, 32 and 33 are embedded in the opening, and the film members 31', 32' and 33'are attached to the opening surface.

Then, in the present disclosure, the phase difference of the received signal changes monotonically with respect to the arrival angle of the reflected wave without causing ripple. That is, in the present disclosure, the arrival angles of the plurality of reflected waves do not correspond to the phase difference of a single received signal, and the angle measurement accuracy of the monopulse angle measurement method is improved.

This is because, in the present disclosure, the horizontal directivity of the horn structures 21, 22, and 23 does not cause a large ripple with respect to the horizontal angle of the wide-angle directional detection system S. That is, in the present disclosure, the signal-to-noise ratio of the horn structures 21, 22, and 23 cannot be extremely low at a specific horizontal angle of the wide-angle directional detection system S, and the angle measurement accuracy of the monopulse angle measurement method is high. Become.

Here, when the arrival angle of the reflected wave is larger than -60 ° and smaller than + 60 °, the phase difference of the received signal changes monotonically according to the arrival angle of the reflected wave, so that the angle can be measured in the horizontal direction. Is. When the arrival angle of the reflected wave is smaller than -60 ° or larger than + 60 °, the phase difference of the received signal hardly changes regardless of the arrival angle of the reflected wave, so that the horizontal angle cannot be measured. .. This is because the opening angles of the horn structures 21 and 22 in the horizontal direction are finite.

Further, the horizontal directivity of the horn antenna composed of the horn structures 21 and 22 is slightly biased in the opposite directions from the vertical direction to the horizontal direction with respect to the side surface of the substrate. This is because the horizontal component in the opening direction of the horn structures 21 and 22 deviates from the direction perpendicular to the side surface of the substrate.

If the horizontal opening angle of the horn structures 21 and 22 is large, the effective horizontal distance d of the horn structures 21 and 22 becomes wide, the phase center shift of the horn structures 21 and 22 becomes large, and the horizontal measurement is performed. The angular range becomes narrower, and the horizontal directivity gain bias increases. If the horizontal opening angle of the horn structures 21 and 22 is small, the effective horizontal distance d of the horn structures 21 and 22 is narrowed, the phase center shift of the horn structures 21 and 22 is small, and the horizontal measurement is performed. The angular range becomes wider and the bias of the horizontal directivity gain becomes smaller.

However, if the horizontal opening angle of the horn structures 21 and 22 becomes too small, the effective horizontal distance d of the horn structures 21 and 22 also becomes too small, so that the monopulse angle measurement method cannot be adopted. The horizontal opening angles of the horn structures 21 and 22 can be set with a high degree of freedom according to the monitoring range and monitoring accuracy.

The substrate side surface horn antenna of the present disclosure not only detects the presence of a target object at a wide angle, but also detects the orientation of the target object at a wide angle in combination with the substrate plane antenna, and miniaturizes and manufactures a wide-angle orientation detection system. It can be applied for facilitation and cost reduction.

S: Wide-angle orientation detection system 1: Dielectric substrate 2: Metal members 11, 12, 13: Waveguide 14: Substrate plane antenna 21, 22, 23: Horn structure 24: Housing surface 25, 26: Housing angle 27: Diffraction Structures 31, 32, 33: Radome members 31', 32', 33': Film members

Claims (4)

A dielectric substrate in which two waveguides are formed inside the substrate in a direction parallel to the substrate plane and openings of the two waveguides are formed on the side surface of the substrate, and two receiving horn structures. A metal member which is formed and connected to the dielectric substrate so as to connect the openings of the two waveguides and the connecting portions of the two receiving horn structures is provided.
The openings of the two receiving horn structures are arranged so as to be separated from each other in a direction parallel to the thickness direction of the dielectric substrate, and the opening direction of each receiving horn structure is the opening direction of each receiving horn structure. It is set in the same direction as the separation direction of the opening, and the two receiving horn structures enable target angle measurement in the direction parallel to the thickness direction of the dielectric substrate.
The openings of the two receiving horn structures are arranged so as to be separated from each other in the direction perpendicular to the thickness direction of the dielectric substrate, and the two receiving horn structures are arranged in the thickness direction of the dielectric substrate. Vertical target angle measurement is possible,
A substrate side surface horn antenna characterized in that a staircase structure is formed on at least one of the four tube walls of each of the receiving horn structures. Among the sizes of each step of the staircase structure of each of the receiving horn structures, the size in the direction parallel to the thickness direction of the dielectric substrate is not more than half of the band center wavelength of the substrate side horn antenna. The substrate side surface horn antenna according to claim 1. Claim 1 or 2 further comprises a radome member whose embedding depth is adjusted by using the staircase structure of each of the receiving horn structures when it is embedded in the opening of each of the receiving horn structures. Board side horn antenna described in. The diffraction structure that serves as a diffraction source for the received wave is on the housing surface of the metal member in which the openings of the two receiving horn structures are formed, and in the direction parallel to the thickness direction of the dielectric substrate. Claims 1 to 3 are characterized in that they are formed by extending in a direction perpendicular to the thickness direction of the dielectric substrate between the housing angle of the metal member and the openings of the two receiving horn structures. Board side horn antenna described in any of.

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