JP6585440B2 - Substrate side horn antenna - Google Patents

Description

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

  Techniques for detecting the presence of a target at a wide angle are disclosed in Patent Documents 1 to 3. In Patent Document 1, the presence of a target in the front direction is detected using a planar antenna formed on the substrate plane, and the presence of the target in the side direction is detected using an electromagnetic wave reflection surface formed on the side surface of the substrate. To do. In Patent Document 2, the presence of a target in the front direction is detected using a planar antenna formed on the substrate plane, and the side surface direction is detected using an antenna pattern formed on the end of the substrate plane near the substrate side surface. Detect the presence of the target. In Patent Document 3, the presence of a target in the front direction is detected using a planar antenna formed on the substrate plane, and the side direction is determined using a dipole antenna formed at the end of the substrate plane near the substrate side surface. Detect the presence of the target.

Japanese Unexamined Patent Publication No. 2007-049791 Japanese Patent No. 5464152 Japanese Patent No. 5609772

  Incidentally, in Patent Documents 1 and 3, detection of the presence of the target at a wide angle is considered, but detection of the orientation of the target at a wide angle is not considered. However, in Patent Document 2, it is considered that the presence of the target is detected at a wide angle in the direction of the front of the substrate, and that the direction of the target is detected at a wide angle in the direction of the front of the substrate. Yes. Still, 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 at a wide angle in the direction of the substrate side surface, but also targets at a wide angle in the direction of the substrate side surface. In order to detect the orientation of an object, it was impossible to know whether the wide-angle orientation detection system could be reduced in size, manufactured easily, and reduced in cost.

  Therefore, in order to solve the above problems, the present invention devised a method of forming spatially separated antennas on the side surface of the substrate, and not only detects the presence of the target at a wide angle in the direction of the substrate side surface, In addition to detecting the azimuth of the target at a wide angle in the direction of the side surface of the substrate, it is an object to reduce the size of the wide-angle azimuth detection system, facilitate manufacturing, and reduce costs.

  In order to achieve the above object, a monopulse angle measurement method is adopted using two horn antennas, and the antenna directivity can be easily adjusted. Here, in order to reduce the size of the wide-angle azimuth detection system, facilitate manufacturing, and reduce the cost, each waveguide connected to each horn structure should be placed in the same position in the thickness direction of the dielectric substrate as much as possible. It is desirable to form.

  However, if the opening direction of the two horn structures is the same in the direction parallel to the thickness direction of the dielectric substrate, the interval between the two horn antennas is effectively zero. It cannot be adopted. Therefore, if the opening directions of the two horn structures are different from each other in the direction parallel to the thickness direction of the dielectric substrate, the distance between the two horn antennas is effectively a finite value. Can be adopted.

  Specifically, the present invention provides a dielectric substrate in which a waveguide portion of two waveguides is formed in the substrate in a direction parallel to the substrate plane, and an opening portion of the two waveguides is 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 are connected to the connecting portions of the two receiving horn structures. The openings of the two receiving horn structures are arranged so as to be separated from each other in the direction parallel to the thickness direction of the dielectric substrate, and the opening direction of each receiving horn structure is It is set in the same direction as the direction away from the opening of the receiving horn structure, and the two receiving horn structures can measure a target angle parallel to the thickness direction of the dielectric substrate. 2 in the thickness direction and the vertical direction The opening of the receiving horn structure is disposed so as to be separated from each other, and the two receiving horn structures can measure a target angle in a direction perpendicular to the thickness direction of the dielectric substrate. Side horn antenna.

  According to this configuration, the waveguide portions 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. Therefore, not only the horn antenna is formed on the side of the substrate but also the planar antenna is formed on the substrate plane, so that the presence of the target is detected at a wide angle, and the orientation of the target is detected at a wide angle. The detection system can be reduced in size, manufactured easily, and reduced in cost.

  Further, the present invention is the substrate side horn antenna, wherein the waveguide portion and the opening portion of the two waveguides are formed at the same position in the thickness direction of the dielectric substrate.

  According to this configuration, the waveguide portion of each waveguide connected to each horn structure can be formed at the same position in the thickness direction of the dielectric substrate. Therefore, not only to form a horn antenna on the side of the substrate, but also to form a planar antenna on the substrate plane, not only to detect the presence of the target at a wide angle, but also to detect the orientation of the target at a wide angle, The wide-angle azimuth detection system can be further reduced in size, manufactured easily, and reduced in cost.

  According to the present invention, the dielectric substrate has a waveguide portion of a separate waveguide formed in a direction parallel to the substrate plane inside the substrate, and an opening portion of the separate waveguide is formed on a side surface of the substrate. The member is formed with a transmission horn structure, and is connected to the dielectric substrate so that an opening of the separate waveguide and a connection portion of the transmission horn structure are connected, and the two and separate waveguides are connected to each other. The substrate side horn antenna is characterized in that the waveguide and the opening are formed at the same position in the thickness direction of the dielectric substrate.

  According to this configuration, when the transmission / reception horn antenna is formed on the side surface of the substrate, the wide-angle azimuth detection system can be further reduced in size, manufactured easily, and reduced in cost.

  As described above, the present invention devised a method of forming spatially separated antennas on the substrate side surface to detect not only the presence of the target at a wide angle in the direction of the substrate side surface but also a wide angle in the direction of the substrate side surface. In addition to detecting the orientation of the target, the wide-angle orientation detection system can be reduced in size, manufactured easily, and reduced in cost.

It is a figure which shows the structure of the wide angle azimuth | direction detection system of this invention. It is a figure which shows the principle of the monopulse angle measuring system of this invention. It is a figure which shows the shape and position of a horn antenna of the board | substrate side surface of this invention. It is a figure which shows the shape and position of a horn antenna of the board | substrate side surface of this invention. It is a figure which shows the horizontal direction angle measurement possibility of the horn antenna of the board | substrate side surface of this invention. It is a figure which shows the horizontal / vertical direction directivity of the horn antenna of the board | substrate side surface of this invention. It is a figure which shows the structure of the array antenna of the board | substrate plane of this invention. It is a figure which shows the structure of the planar antenna of the board | substrate plane of this invention.

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

(Configuration of wide-angle azimuth detection system)
The configuration of the wide-angle azimuth detection system of the present invention is shown in FIG. The wide-angle azimuth detection system S of the present invention includes a dielectric substrate 1 and a metal member 2. In the dielectric substrate 1, waveguide portions (see FIG. 3) of the waveguides 11, 12, and 13 are formed in a direction parallel to the substrate plane inside the substrate, 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 planar antenna 14 is formed in 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 to each other. In addition, the dielectric substrate 1 is connected.

  The horn structures 21 and 22 are for reception, and the horn structure 23 is for transmission. Details of the horn structures 21, 22, and 23 will be described with reference to FIGS. The substrate planar antenna 14 is arranged with a high degree of freedom for reception and transmission according to various monitoring methods. The substrate planar antenna 14 will be described with reference to FIGS. In the following description, the direction parallel to the thickness direction of the dielectric substrate 1 is defined as “horizontal direction”, and the direction perpendicular to the thickness direction of the dielectric substrate 1 is defined as “vertical direction”.

(Configuration of horn antenna on the side of the board)
The principle of the monopulse angle measurement system of the present invention is shown in FIG. In the monopulse angle measurement method, the phase difference 2π (d sin θ / λ) (λ is the vacuum wavelength of the electromagnetic wave) of the received signal is measured by using an antenna spatially separated by a distance d, and the arrival angle of the reflected wave is measured. Measure θ.

  The shape and position of the horn antenna on the side surface of the substrate of the present invention are shown in FIGS. The most preferred embodiment of the shape and position of the horn antenna on the side surface of the substrate will be described with reference to FIG. The reason why the embodiment of FIG. 3 is selected as the most desirable embodiment regarding the shape and position of the horn antenna on the side surface of the substrate will be described with reference to FIG.

  First, FIG. 3 will be described. The waveguides and the openings of the waveguides 11, 12, and 13 are formed at the same position in the horizontal direction. Of the waveguides 11, 12, and 13, the wide wall surface parallel to the substrate plane is formed using, for example, a conductive foil, and the narrow wall surface perpendicular to the substrate plane is formed using, for example, a metal column. . The metal pillar that narrows the openings of the waveguides 11, 12, 13 in the direction of the wide wall surface of the waveguides 11, 12, 13 functions as an impedance matching device, and the openings of the waveguides 11, 12, 13 are connected to the waveguide 11. , 12, 13 function as reflectors. A method of forming the waveguides 11, 12, and 13 is 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 shifted to the right in the drawing on the basis of the opening of the waveguide 11, and the opening of the horn structure 22 is on the left in the drawing on the basis of the opening of the waveguide 12. Sneak away. The horizontal component in the opening direction of the horn structures 21 and 22 is set in the same direction as the above-described 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 in the drawing with respect to the waveguide direction of the waveguide 11, and the horizontal component in the opening direction of the horn structure 22 is guided in the waveguide 12. Shifts to the left side of the page with respect to the direction. The horn structures 21 and 22 can measure the target angle in the horizontal direction.

  The openings of the horn structures 21 and 22 are arranged so as to be separated from each other in the vertical direction. In FIG. 3, the opening of the horn structure 21 is positioned upward in the drawing according to the position of the opening of the waveguide 11, and the opening of the horn structure 22 is positioned below the drawing according to the position of the opening of the waveguide 12. Located in the direction. The horn structures 21 and 22 can measure the target angle in the vertical direction.

  Next, FIG. 4 will be described. In the present invention, using the two horn structures 21 and 22, the monopulse angle measurement method is adopted, and the antenna directivity can be easily adjusted. Here, in order to reduce the size of the wide-angle azimuth detection system S, facilitate manufacturing, and reduce the cost, 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 it at the same position in the thickness direction (see the upper left column in 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 distance d in the horizontal direction of the horn structures 21 and 22 is set to 0. The horizontal monopulse angle measurement method cannot be adopted, and this is a problem before the wide-angle azimuth detection system S is reduced in size, manufactured easily, and reduced in cost. Then, as shown in the upper right column of FIG. 4, if the waveguides 11 and 12 are formed at positions that are greatly different in the thickness direction of the dielectric substrate 1 (separation distance h in the thickness direction of the dielectric substrate 1), Since the effective distance d in the horizontal direction 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 azimuth detection system S can be downsized, easily manufactured, and low in cost. Cannot be achieved.

  Therefore, as shown in the lower left column of FIG. 4, if the horizontal components in the opening direction of the horn structures 21 and 22 are set in different directions, the waveguides 11 and 12 are positioned not significantly different in the thickness direction of the dielectric substrate 1 ( Even when the dielectric substrate 1 is formed at the separation distance h ′ (<h) in the thickness direction, the effective distance d in the horizontal direction of the horn structures 21 and 22 is finitely about the same as the upper right column in FIG. Value. Therefore, it is possible to adopt a horizontal monopulse angle measurement system, and it is possible to reduce the size, ease of manufacture, and cost reduction of the wide-angle azimuth detection system S.

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

  FIG. 5 shows the possibility of angle measurement in the horizontal direction of the horn antenna (see FIG. 3) on the side surface of the substrate of the present invention. When the arrival angle of the reflected wave is larger than −45 ° and smaller than + 45 °, the phase difference of the received signal changes monotonously according to the arrival angle of the reflected wave, so that the angle can be measured in the horizontal direction. When the angle of arrival of the reflected wave is smaller than −45 ° or larger than + 45 °, the phase difference of the received signal does not substantially change regardless of the angle of arrival of the reflected wave, and thus horizontal angle measurement is impossible. This is because the opening angle in the horizontal direction of the horn structures 21 and 22 is finite.

  FIG. 6 shows the horizontal / vertical direction directivity of the horn antenna (see FIG. 3) on the side surface of the substrate of the present invention. The horizontal directionality of the horn antenna comprising the horn structure 21 is slightly biased in the negative direction (approximately -15 °) in the horizontal direction from the vertical direction to the side surface of the substrate. The horizontal directionality of the horn antenna formed of the horn structure 22 is slightly biased in the positive direction (approximately + 15 °) in the horizontal direction from the vertical direction to the side surface of the substrate. This is because the horizontal component in the opening direction of the horn structures 21 and 22 is deviated from the direction perpendicular to the substrate side surface. The vertical directionality of the horn antenna composed of the horn structures 21 and 22 has a substantially equal gain.

  If the opening angle in the horizontal direction of the horn structures 21 and 22 is large, the effective distance d in the horizontal direction of the horn structures 21 and 22 is widened, the phase center shift of the horn structures 21 and 22 is large, and the horizontal measurement is performed. The angular range is narrowed, and the bias of the horizontal directivity gain is increased. If the opening angle in the horizontal direction of the horn structures 21 and 22 is small, the effective distance d in the horizontal direction of the horn structures 21 and 22 is narrowed, the phase center shift of the horn structures 21 and 22 is reduced, and the horizontal measurement is performed. The angular range is widened, and the horizontal directivity gain bias is reduced.

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

(Platform array / Planar antenna configuration)
FIG. 7 shows the configuration of an array antenna on a substrate plane according to the present invention. In the array antenna 3 of the present invention, the antenna elements 31 are arranged linearly, and a single dielectric substrate 1, a single ground plane conductor (not shown), and a single dielectric layer (not shown and described later) Shared by a plurality of antenna elements 31 arranged in a straight line. The array antenna 3 described in FIG. 7 is a center-fed traveling wave type array antenna. The horizontal direction of the array antenna 3 is defined as a direction perpendicular to the extending direction of the array antenna 3. The vertical direction of the array antenna 3 is defined as a direction parallel to the extending direction of the array antenna 3. The vertical direction of the array antenna 3 coincides with the vertical direction of the side surface of the substrate.

  FIG. 8 shows the configuration of a planar antenna having a substrate plane according to the present invention. In the planar antenna 4 of the present invention, the antenna elements 31 are arranged in a lattice pattern, and a single dielectric substrate 1, a single ground plane conductor (not shown), and a single dielectric layer (not shown and described later) Shared by a plurality of antenna elements 31 arranged in a grid. The planar antenna 4 described in FIG. 8 is a centrally fed traveling wave planar antenna. The horizontal direction of the planar antenna 4 is defined as a direction perpendicular to the extending direction of the array antenna 3. The vertical direction of the planar antenna 4 is defined as a direction parallel to the extending direction of the array antenna 3. The vertical direction of the array antenna 3 coincides with the vertical direction of the side surface of the substrate.

  While the resonant wave type array antenna has a narrow band characteristic, the traveling wave type array antenna has a wide band characteristic. Therefore, the traveling wave type array antenna is used in a wide band application. The inventor of the present application has identified the following problems regarding traveling wave type array antennas.

  That is, when all the antenna elements of the traveling wave array antenna are excited in the same phase, reflection occurs in the same phase from all the antenna elements, so that the reflection loss increases at this frequency and the radiation efficiency decreases. On the other hand, when each antenna element of a traveling wave array antenna is excited in a different phase, reflection occurs in a different phase from each antenna element, so that radiation occurs in a direction tilted from the front direction, but reflection loss is reduced in a wide band. Increases radiation efficiency.

  When the traveling wave array antenna is fed at one end, the angle of the radial direction with respect to the front direction changes when the operating frequency changes. On the other hand, when the traveling wave array antenna is fed at the center, the angle of the radial direction with respect to the front direction does not change even if the operating frequency changes. Therefore, when the traveling wave type array antenna is used in a wide band, it is aimed to feed power at the center of the array.

  When power is supplied at the center of the array, it is necessary to maintain the vertical size of the array (ie, the number of antenna elements), as in the case of power supply at one end of the array. In other words, when feeding at the center of the array, two arrays, each of which has half the vertical size (ie, the number of antenna elements) compared to feeding at one end of the array, sandwiching the feed section Will form.

  Here, the traveling wave type array antenna radiates a part of the feed power at the antenna element close to the power feeding part, and radiates a part of the remaining power at the antenna element far from the power feeding part. The remaining power is dissipated. Therefore, when power is supplied at the center of the array, the radiation efficiency is lower than when power is supplied at one end of the array.

  In the case of feeding at the center of the array, as in the case of feeding at one end of the array, it is conceivable to increase the radiation amount of each antenna element in order to increase the radiation efficiency, that is, widen the width of each antenna element. It is possible. However, if the width of each antenna element is increased, the horizontal directivity of the array is reduced. The inventor of the present application has found that this becomes a problem in applications such as radar that wants to expand the monitoring area.

  Therefore, as shown in FIG. 7, an antenna element 31 having a dielectric layer formed on the element surface is applied. Then, since the effective dielectric constant in the environment around the antenna element conductor is increased, the antenna element conductor can be reduced in the width direction while maintaining high radiation efficiency. Since the propagation distance inside the dielectric layer and the phase delay due to the dielectric layer change according to the incident angle to the inside of the dielectric layer, the antenna element 31 can have a wide-angle directivity in the horizontal direction.

  As shown in FIG. 7, by arranging the stub 33 on the path of the transmission line 32, even when all the antenna elements 31 of the array antenna 3 are excited in the same phase, the in-phase from all the antenna elements 31 can be obtained. Therefore, reflection loss is reduced at this frequency, radiation efficiency is increased, and radiation occurs in the front direction.

  Further, as shown in FIG. 7, by arranging the termination element 34 at the end portion of the transmission line 32, the array antenna 3 radiates the power originally dissipated in the termination resistance in the termination element 34. Radiation efficiency can be further improved.

  As shown in FIG. 7, the transmission line / waveguide converter 35 is disposed at the center of the array antenna 3, so that the array antenna 3 is subjected to central feeding.

  Further, in FIG. 8, the transmission line / waveguide converters 35 are arranged in a staggered manner in the horizontal direction of the planar antenna 4. Here, as a modification, the transmission line / waveguide converter 35 may be linearly arranged in the horizontal direction of the planar antenna 4.

  The substrate side surface horn antenna of the present invention is combined with the substrate planar antenna to detect not only the presence of the target at a wide angle, but also to detect the orientation of the target at a wide angle, and to reduce the size and manufacture of the wide angle direction detection system. It can be applied to facilitate and reduce costs.

S: Wide-angle azimuth detection system 1: Dielectric substrate 2: Metal members 11, 12, 13: Waveguide 14: Substrate planar antennas 21, 22, 23: Horn structure 3: Array antenna 31: Antenna element 32: Transmission line 33: Stub 34: Termination element 35: Transmission line / waveguide converter 4: Planar antenna

Claims (3)

A dielectric substrate in which a waveguide portion of two waveguides is formed in a direction parallel to the substrate plane inside the substrate, and an opening of the two waveguides is formed on the side surface of the substrate, and two receiving horn structures are provided. A metal member formed and connected to the dielectric substrate so that the openings of the two waveguides and the connection portions of the two receiving horn structures are connected,
With respect to 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, and the opening direction of each receiving horn structure is the same as that of each receiving horn structure. It is set in the same direction as the separation direction of the opening, and the target object angle in the direction parallel to the thickness direction of the dielectric substrate is possible by the phase difference of the reception signals in the two reception horn structures,
In the direction perpendicular 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, and the dielectric is determined by the phase difference of the received signals in the two receiving horn structures. A substrate-side horn antenna characterized by being capable of measuring a target angle in a direction perpendicular to a thickness direction of a body substrate.   The substrate side surface horn antenna according to claim 1, wherein the waveguide portion and the opening portion of the two waveguides are formed at the same position in the thickness direction of the dielectric substrate. The dielectric substrate is formed with a waveguide portion of a separate waveguide in a direction parallel to the substrate plane inside the substrate, and an opening portion of the separate waveguide is formed on a side surface of the substrate,
The metal member is connected to the dielectric substrate so that a transmission horn structure is formed, and an opening of the separate waveguide and a connection portion of the transmission horn structure are connected.
The substrate side surface horn antenna according to claim 1 or 2, wherein the waveguide portions and the openings of the two and separate waveguides are formed at the same position in the thickness direction of the dielectric substrate. .

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