JP6269217B2 - Slot antenna and slot antenna device - Google Patents

Description

  The present invention relates to a slot antenna and a slot antenna device.

  As a slot antenna using a waveguide, a plurality of waveguides in which a plurality of slot elements are formed in the longitudinal direction are arranged in a rectangular shape as a whole, and power is supplied to the slot elements by each waveguide. Yes. Such a slot antenna may be used as an antenna for a radar such as an aircraft (see, for example, Non-Patent Documents 1 and 2).

  14A and 14B show a slot antenna device used as a conventional radar antenna. FIG. 14A is a sectional perspective view, and FIG. 14B is a sectional front view. The slot antenna device includes a radome 201 formed in a curved surface (in the illustrated example, a cylindrical cross section) to reduce wind receiving load during flight of an aircraft, and a rectangular slot antenna housed in the radome 201. 203. The slot antenna 203 is formed in a rectangular shape by arranging a plurality of waveguides 202 in which a plurality of slot elements 202a that radiate radio waves are formed. The slot antenna 203 is supported, for example, so as to be able to rotate and move about the axis Py ′ and the axis Pz ′ passing through the central portion of the slot antenna 203 with respect to the radome 201 so that the radio wave radiation direction can be changed.

“Airborne Synthetic Aperture Radar (Pi-SAR2)”, [online], National Institute of Information and Communications Technology, [February 24, 2014 search], Internet <URL: http: //aer.nict.go. jp / institute / pdf / PiSAR2_J_Hi.pdf> Kiyomi Uratsuka, 9 others, “Research and development of visualization technology of the earth's surface using radio waves”, [online], 2007, National Institute of Information and Communications Technology, [Search February 24, 2014] Internet <URL: http://www.nict.go.jp/publication/shuppan/nenpou/nenpou_19/nenpou_19data/030801.pdf>

  However, in the slot antenna device configured as described above, the radome 201 is formed in a curved shape, whereas the slot antenna 203 is formed in a rectangular shape. As shown in b), when the slot antenna 203 is rotated about the axis Py ′ and the axis Pz ′ in order to change the radiation direction of the radio wave, the corner 203a of the antenna body 203 is placed on the inner peripheral surface of the radome 201. There was a risk of contact and damage.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a slot antenna and a slot antenna device that can prevent the corners from interfering with other members.

  The present invention is a slot antenna comprising an antenna body formed in a rectangular shape by a waveguide, and a plurality of slot elements that are formed on one surface of the antenna body and radiate radio waves, the antenna body comprising: A slot antenna having a chamfered portion formed in at least one of the four corners viewed from the one surface side.

  Another aspect of the present invention is a slot antenna device including a storage container, and the slot antenna that is stored in the storage container and supported to be movable with respect to the storage container.

  According to this invention, it can suppress that the corner | angular part of a slot antenna interferes with another member.

BRIEF DESCRIPTION OF THE DRAWINGS The slot antenna apparatus provided with the slot antenna which concerns on 1st Embodiment of this invention is shown, (a) is a cross-sectional perspective view, (b) is a cross-sectional front view. It is a front view of a slot antenna. FIG. 3 is a cross-sectional view taken along the arrow I-I in FIG. 2. It is a principal part expansion perspective view which shows a chamfering part. It is a figure which shows VSWR when the chamfer dimension of a chamfer part is changed in the slot antenna of 1st Embodiment. It is a figure which shows E surface directivity at the time of changing the chamfer dimension of a chamfering part in the slot antenna of 1st Embodiment. It is a figure which shows the H surface directivity at the time of changing the chamfer dimension of a chamfer part in the slot antenna of 1st Embodiment. It is a front view which shows the antenna main body of the slot antenna which concerns on 2nd Embodiment of this invention. It is a principal part expansion perspective view which shows the chamfering part of the antenna main body of 2nd Embodiment. It is a figure which shows VSWR when the chamfer dimension of a chamfer part is changed in the slot antenna of 2nd Embodiment. It is a figure which shows E surface directivity at the time of changing the chamfer dimension of a chamfering part in the slot antenna of 2nd Embodiment. It is a figure which shows the H surface directivity at the time of changing the chamfer dimension of a chamfering part in the slot antenna of 2nd Embodiment. It is a cross-sectional perspective view which shows the slot antenna apparatus provided with the slot antenna which concerns on 3rd Embodiment of this invention. The conventional slot antenna apparatus is shown, (a) is a cross-sectional perspective view, (b) is a cross-sectional front view. The state which moved the conventional slot antenna is shown, (a) is a cross-sectional perspective view, (b) is a cross-sectional front view.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
(1) A slot antenna according to an embodiment of the present invention includes an antenna body formed in a rectangular shape by a waveguide, and a plurality of slot elements that are formed on one surface of the antenna body and radiate radio waves. In the slot antenna, the antenna main body has a chamfered portion formed at at least one corner portion of four corner portions viewed from the one surface side.
Here, the “chamfered portion” means not only a chamfered portion formed in a straight line when viewed from the one surface side but also a chamfered portion formed in a curved shape when viewed from the one surface side.
In addition, the term “formed chamfered portion” includes not only the case where the chamfered portion is formed by cutting off the corner portion of the antenna body, but also the case where the antenna body is manufactured in a shape in which the chamfered portion is formed at the corner portion. It is.

  According to the slot antenna, since the chamfered portion is formed in at least one corner of the four corners of the antenna body, the corner of the antenna body can be prevented from interfering with other members. .

(2) The antenna body according to (1) includes a plurality of the waveguides arranged in a direction orthogonal to the tube axis, and the chamfered portion includes two or more chamfered portions at the one corner portion. The two or more waveguides are formed across the waveguide from the center of the slot element closest to the chamfered portion by a length of ¼ of the wavelength λ of the operating frequency. It is preferable to have a short-circuit wall provided in the vicinity of a position distant from the end side.
Here, “near the position” means not only the position but also a position slightly deviated from the position.
In this case, even if the chamfered portion is formed across two or more waveguides, a short-circuit wall is formed on the end side of each of these waveguides, so that it is orthogonal to the radio wave radiated from the slot element. The short-circuit wall can suppress unnecessary radio waves that become the electric field in the direction from leaking from the end of the waveguide. As a result, it is possible to suppress a decrease in antenna performance due to the leakage of unnecessary radio waves.

(3) The antenna body according to (1) or (2) includes a plurality of the waveguides arranged side by side in a direction orthogonal to the tube axis, and one or more of the waveguides are provided at the one corner. An end portion of the waveguide is missing, and the chamfered portion of the one waveguide is a first chamfer formed at a first corner that appears due to the lack of the end portion; In another waveguide adjacent to the waveguide, it is preferable to have a second chamfer formed at a second corner portion that appears by the missing portion at the end.
Here, “the end portion is missing” means not only the case where the end portion of the waveguide is cut off, but also the case where the waveguide is manufactured in a shape where the end portion is missing. It is.
If the end of the waveguide is missing at the corner of the antenna body, a chamfered portion is formed at the corner that appears due to the loss. Compared with the case of loss, it is possible to suppress a decrease in the area of one surface of the antenna body, that is, the area for forming the slot element. As a result, it is possible to suppress a decrease in antenna performance.

(4) It is preferable that the antenna body according to any one of (1) to (3) is housed in a storage container and supported so as to be movable with respect to the storage container.
In this case, when the antenna body is moved relative to the storage container in a state where the antenna body is stored in the storage container, it is possible to suppress the corner portion of the antenna body from interfering with the storage container.

(5) It is preferable that the storage container of (4) has an inner peripheral surface formed in a curved shape.
In this case, when the antenna body is moved with respect to the storage container in a state of being stored in the storage container, the corner portion of the antenna body is prevented from interfering with the inner peripheral surface formed in the curved shape of the storage container. be able to.

(6) It is preferable that the chamfered surface of the chamfered portion of any one of (1) to (5) is open, and the opening of the chamfered surface is open.
In this case, since a lid member that covers the opening of the chamfered surface is not necessary, interference between the corner portion of the antenna body and the other member can be suppressed with an inexpensive configuration.

(7) The antenna body according to (6) includes a plurality of the waveguides arranged in a direction perpendicular to the tube axis, and the chamfered portion is disposed at the one corner. The chamfer dimension C of the chamfered portion formed in the waveguide is C / A ≦ 1 when the length dimension in the orthogonal direction in the waveguide in which the chamfered portion is formed is A. It is preferable to set so as to satisfy the relationship of / 3.
In this case, even if the opening of the chamfered surface is opened, good VSWR characteristics and directivity can be obtained.

(8) The chamfered surface of the chamfered portion of (1) to (5) may be open, and the antenna body may include a lid portion that covers the opening of the chamfered surface.
In this case, the end of the waveguide in which the chamfered portion is formed can be reliably short-circuited by the lid that covers the opening of the chamfered surface.

(9) The antenna body according to (8) includes a plurality of the waveguides arranged in a direction orthogonal to the tube axis, and the chamfered portion is disposed at the one corner. The chamfer dimension C of the chamfered portion formed in the waveguide is C / A ≦ 1 when the length dimension in the orthogonal direction in the waveguide in which the chamfered portion is formed is A. It is preferably set so as to satisfy the relationship of / 2.
In this case, better VSWR characteristics and directivity can be obtained even if the chamfered portion of the chamfered portion is made larger than when the chamfered surface is opened.

(10) A slot antenna device according to an embodiment of the present invention relating to another aspect is stored in the storage container and the storage container, and is supported movably with respect to the storage container. (9) any one of the slot antennas.
According to the slot antenna device, it is possible to suppress the corner portion of the slot antenna from interfering with the storage container when the slot antenna is moved with respect to the storage container in a state of being stored in the storage container.

[Details of the embodiment of the present invention]
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
<Overall configuration>
1A and 1B show a slot antenna device including a slot antenna according to a first embodiment of the present invention, in which FIG. 1A is a sectional perspective view, and FIG. 1B is a sectional front view. The slot antenna device 1 is used as an antenna for aircraft radar, for example. The slot antenna device 1 includes a radome (storage container) 2 and a slot antenna 3 stored in the radome 2.

  The radome 2 is attached to the wing portion of the aircraft. For this reason, the outer shape of the radome 2 is formed in a curved surface so as to reduce the wind receiving load during the flight of the aircraft. The radome 2 of this embodiment is formed in a cylindrical shape in cross section, and its inner peripheral surface 2a is also formed in a curved surface shape.

  The slot antenna 3 is disposed at a position offset with respect to the center line of the radome 2 (center line B in the Z-axis direction in the illustrated example) in the front view of FIG. The central portion of the slot antenna 3 is supported by the radome 2 via a support device (not shown). In order to change the radiation direction of the radio wave radiated from the slot antenna 3, the support device can rotate the slot antenna 3 with respect to, for example, the axis Py and the axis Pz passing through the center of the slot antenna 3. I support it.

  The slot antenna 3 may be supported so as to be rotatable with respect to at least one of the two axes. The slot antenna 3 is supported so as to be rotatable about its central portion, but is supported so as to be rotatable about a point other than the central portion, or supported so as to be swingable. It is only necessary to be supported so as to be movable so that the radiation direction of radio waves can be changed.

<Slot antenna>
FIG. 2 is a front view of the slot antenna 3. 3 is a cross-sectional view taken along the line II in FIG.
As shown in FIG. 2, the slot antenna 3 includes an antenna body 11 and a plurality of slot elements 12 that radiate radio waves.
The antenna body 11 is formed in a rectangular shape when viewed from the front by a plurality (six in the illustrated example) of the waveguides 14A to 14F arranged side by side in a direction orthogonal to the tube axis K (the left-right direction in FIG. 2). Has been. The waveguides 14B to 14E except for the waveguides 14A and 14F disposed at both ends in the orthogonal direction are short-circuited by termination walls 147 provided at both ends in the tube axis K direction. The waveguides 14A and 14F will be described later.

  As shown in FIG. 3, each of the waveguides 14 </ b> A to 14 </ b> F is formed in a rectangular shape in cross section, and a plurality of the slot elements 12 are formed on the wide wall surface 141 on the upper side in the drawing, which is one surface thereof. . Specifically, as shown in FIG. 2, a plurality of slot elements 12 are formed in a staggered manner over the entire length in the tube axis K direction on the wide wall surface 141 of the waveguides 14A to 14F. The distances L1 between the centers of the slot elements 12 adjacent to each other in the tube axis K direction are each set to a length of λ / 2. Here, λ is the wavelength within the waveguides 14A to 14F at the operating frequency.

As shown in FIG. 3, feed slot elements 15 </ b> A to 15 </ b> F for feeding power to the slot elements 12 are formed on the lower wide wall surface 142 in the figure, which is the other face of each of the waveguides 14 </ b> A to 14 </ b> F. . As shown in FIG. 2, each of the power supply slot elements 15A to 15F is formed at a central portion of each of the waveguides 14A to 14F in the tube axis K direction.
A pair of power feeding slot elements 15C and 15D adjacent to each other with a power feeding point 13a, which will be described later, are formed to be inclined in the same direction with respect to the tube axis K. Further, among the power supply slot elements 15 </ b> A to 15 </ b> C, adjacent power supply slot elements are inclined with respect to the tube axis K in opposite directions. Similarly, among the power supply slot elements 15D to 15F, adjacent power supply slot elements are inclined with respect to the tube axis K in opposite directions.

  The slot antenna 3 further includes a feeding path 13 for feeding power to the feeding slot elements 15A to 15F of the respective waveguides 14A to 14F. The feed path 13 is formed by, for example, a waveguide, and is orthogonal to the tube axis K direction along the wide wall surface 142 of each of the waveguides 14A to 14F so as to cover the feed slot elements 15A to 15F. It extends in the direction (left-right direction in FIG. 2). The power supply path 13 has a power supply point 13a to which power is supplied at the center in the longitudinal direction.

As shown in FIG. 2, the waveguides 14 </ b> A and 14 </ b> F disposed at both ends in the left-right direction in the drawing of the antenna main body 11 lack both ends 143 (hatched portions in the drawing) in the tube axis K direction. . In the present embodiment, each of the end portions 143 is missing in a rectangular shape when viewed from the front, and the size of the end portions 143 is such that one slot element 12 is cut off.
In this embodiment, the waveguides 14A and 14F are cut off at the end portions 143, but the waveguides 14A and 14F may be manufactured in a shape in which the end portions 143 are missing. .
Further, in this embodiment, the end portions 143 of the waveguides 14A and 14F are missing, but two or more waveguides such as the waveguides 14B and 14E adjacent to the waveguides 14A and 14F are present. It may be missing continuously.
Further, the antenna main body 11 lacks the end portions 143 of the waveguides 14A and 14F arranged at the corners thereof, but does not necessarily need to be missing.

<Chamfered part>
The antenna main body 11 has a plurality of chamfered portions 20 respectively formed at corners of four corners as viewed from the front side (one surface side). Each chamfered portion 20 is formed across the end portions of the two waveguides 14A and 14B (14E and 14F).
Specifically, the chamfered portion 20 cuts off the first corner portion 144 (the cross-hatched portion in the waveguide 14A (14F) in the figure) that appears due to the loss of the both ends 143 in the waveguide 14A (14F). The first chamfer 21 formed in FIG. 5 and the second corner portion 145 (cross-hatched portion in the waveguide 14B (14E) in the figure) that appears due to the defect in the waveguide 14B (14E) are cut off. And a second chamfer 22.

  The first and second chamfers 21 and 22 are formed so as to cut off the first and second corner portions 144 and 145 linearly along the chamfer line M in a front view. The chamfer dimension C of the first chamfer 21 (second chamfer 22) is the tube axis K in the waveguides 14A and 14F (14B and 14E) in which the first chamfer 21 (second chamfer 22) is formed. When the length dimension in the orthogonal direction is A, it is set so as to satisfy the relationship of C / A ≦ 1/3.

In addition, although the chamfered portion 20 is formed by cutting off a corner portion of the antenna body 11, the antenna body 11 may be manufactured in a shape in which the chamfered portion 20 is formed at the corner portion.
In addition, the chamfered portion 20 is formed at the corners of the four corners of the antenna body 11, but may be formed at least at the corner of the corner. In addition, the chamfered portion 20 is formed across two waveguides, but may be formed only on one waveguide, or may be formed across three or more waveguides. good. The first and second chamfers 21 and 22 are formed in a straight line shape, but may be formed in a curved surface shape. In that case, the first and second chamfers 21 and 22 are preferably formed in a concave curved surface along the inner peripheral surface 2 a of the radome 2.

  FIG. 4 is an enlarged perspective view of a main part showing the chamfered portion 20. As shown in FIG. 4, in this embodiment, the chamfered surface 21a of the first chamfer 21 is open, and these openings are opened without being covered with a lid or the like. Similarly, the chamfered surface 22a of the second chamfer 22 is open, and the opening is opened without being covered with a lid or the like.

  The waveguide 14F (14A) has a defect at both ends 143 (see FIG. 2) and a defect end face 146 that appears due to the formation of the first chamfer 21. The defect end face 146 is open, and this opening is covered with a short-circuit wall 148. As shown in FIG. 2, the short-circuit wall 148 of each waveguide 14F (14A) is provided in the vicinity of a position away from the slot element 12 closest to the first chamfer 21 by a predetermined distance L2 in the tube axis K direction. . Here, “near the position” means not only the position but also a position slightly deviated from the position.

The distance L2 is set to a length of ¼ of the wavelength λ of the operating frequency from the center of the slot element 12 closest to the first chamfer 21. Thereby, both ends of the waveguide 14F (14A) in the tube axis K direction are short-circuited by the short-circuit wall 148.
Note that the second chamfer 22 is formed so that only the second corner 145 that is a part of the both ends in the tube axis K direction of the waveguide 14E (14B) adjacent to the waveguide 14F (14A) is cut off. Therefore, the end wall 147 provided at the other part of the both end portions exists even if the second chamfer 22 is formed. For this reason, the termination wall 147 functions as the short-circuit wall 148 at both ends of the waveguide 14E (14B) in the tube axis K direction.

<About antenna performance>
FIG. 5 is a diagram showing the VSWR when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, the chamfer dimension C is changed to five lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 5, the slot antenna 3 of the present embodiment has a chamfer dimension C of 0 to A / 3, generally 1.5 over the entire operating frequency range (6.4 GHz to 7.1 GHz). Although the following good values are shown, when the chamfer dimension C is A / 2, the value of VSWR exceeds 1.5, and the chamfer dimension C is 0 to A / 3. It is worse than that. That is, it can be seen that the slot antenna 3 of the present embodiment can obtain good VSWR characteristics if the chamfer dimension C of the chamfered portion 20 is set so as to satisfy the relationship of C / A ≦ 1/3.

FIG. 6 is a diagram showing the E plane directivity when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, as in the case of FIG. 5, the chamfer dimension C is changed to five lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 6, the slot antenna 3 of the present embodiment has a chamfer dimension C of 0 to A / 3, and the gain in the 0 degree direction is in the range of 21 dB to 22 dB. When the length is A / 2, the gain in the 0 degree direction is reduced to less than 20 dB. That is, the slot antenna 3 of the present embodiment can obtain good E-plane directivity if the chamfer dimension C of the chamfered portion 20 is set so as to satisfy the relationship of C / A ≦ 1/3. I understand.

FIG. 7 is a diagram illustrating the H-plane directivity when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, as in the case of FIG. 5, the chamfer dimension C is changed to five lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 7, the slot antenna 3 of the present embodiment has a chamfer dimension C of 0 to A / 3, and the gain in the 0 degree direction is in the range of 21 dB to 22 dB. When the length is A / 2, the gain in the 0 degree direction is reduced to less than 20 dB. That is, the slot antenna 3 of the present embodiment can obtain good H-plane directivity by setting the chamfer dimension C of the chamfered portion 20 so as to satisfy the relationship of C / A ≦ 1/3. I understand.

<Operational effects of this embodiment>
As described above, according to the slot antenna device 1 and the slot antenna 3 according to the present embodiment, since the chamfered portions 20 are formed at the corners of the four corners of the antenna body 11, the antenna body 11 is stored in the radome 2. When the antenna body 11 is moved, the corner portion of the antenna body 11 can be prevented from interfering with the inner peripheral surface 2 a formed in the curved shape of the radome 2.

  Further, even if the chamfered portion 20 is formed across the end portions of the two waveguides 14A and 14B (14E and 14F), the end portions of the respective waveguides 14A and 14B (14E and 14F) are short-circuited. Since the wall 148 is formed, the short-circuit wall 148 prevents unnecessary radio waves that become an electric field perpendicular to the radio waves radiated from the slot element 12 from leaking from the ends of the waveguides 14A and 14B (14E and 14F). Can be suppressed. As a result, it is possible to suppress a decrease in antenna performance due to the leakage of unnecessary radio waves.

  Further, when the end portion 143 of the waveguide 14A (14F) is missing at the corner portion of the antenna body 11, the chamfered portion 20 is formed at the first and second corner portions 144 and 155 that appear due to the loss. Therefore, the area of the wide wall surface 141 of the antenna body 11, that is, the area for forming the slot element 12 is reduced as compared with the case where the entire end including the first and second corners 144 and 155 is newly lost. Can be suppressed. As a result, it is possible to suppress a decrease in antenna performance.

  Moreover, since the opening of the chamfered surfaces 21a and 22a of the chamfered portion 20 is open, a lid member that covers these openings is unnecessary. Therefore, interference between the corners of the antenna body 11 and the radome 2 can be suppressed with an inexpensive configuration.

  Further, the chamfer dimension C of the chamfered portion 20 has a relationship of C / A ≦ 1/3, where A is the length dimension in the direction perpendicular to the tube axis K in the waveguide in which the chamfered portion 20 is formed. Since they are set so as to satisfy the requirements, even if the openings of the chamfered surfaces 21a and 22a of the chamfered portion 20 are opened, good VSWR characteristics and directivity can be obtained.

[Second Embodiment]
FIG. 8 is a front view showing the antenna body 11 of the slot antenna 3 according to the second embodiment of the present invention. FIG. 9 is an enlarged perspective view of a main part showing the chamfered portion 20 of the antenna body 11.
As shown in FIGS. 8 and 9, the antenna main body 11 of the present embodiment covers the first lid portion 23 covering the opening of the chamfered surface 21 a of the first chamfer 21 and the opening of the chamfered surface 22 a of the second chamfer 22. And a second lid 24.

As shown in FIG. 8, the chamfer dimension C of the first chamfer 21 (second chamfer 22) of the present embodiment is the waveguides 14A and 14F (14B) in which the first chamfer 21 (second chamfer 22) is formed. , 14E) where the length dimension in the orthogonal direction of the tube axis K is A, the relationship C / A ≦ 1/2 is set.
In addition, the point which abbreviate | omitted description in 2nd Embodiment is the same as that of 1st Embodiment.

FIG. 10 is a diagram showing VSWR when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, the chamfer dimension C is changed to five lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 10, the slot antenna 3 of the present embodiment is approximately 1 over the entire operating frequency (6.4 GHz to 7.1 GHz) in all the lengths of the chamfer dimension C from 0 to A / 3. As shown in FIG. 5, the VSWR does not deteriorate when the chamfer dimension C is increased to A / 2 as in the VSWR characteristic (see FIG. 5) of the first embodiment. . That is, the slot antenna 3 of the present embodiment has a good VSWR characteristic even when the chamfer dimension C is increased by setting the chamfer dimension C of the chamfered portion 20 to satisfy the relationship of C / A ≦ 1/2. You can get that.

FIG. 11 is a diagram illustrating the E-plane directivity when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, as in the case of FIG. 10, the chamfer dimension C is changed to five types of lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 11, the slot antenna 3 of the present embodiment has a gain in the 0-degree direction around 22 dB for all the lengths of the chamfer dimension C from 0 to A / 2. Like the E-plane directivity of the form (see FIG. 6), when the chamfer dimension C is increased to A / 2, the gain in the 0 degree direction does not show a value less than 20 dB. That is, the slot antenna 3 according to the present embodiment has a good E surface even when the chamfer dimension C is increased by setting the chamfer dimension C of the chamfered portion 20 to satisfy the relationship of C / A ≦ 1/2. It can be seen that directivity can be obtained.

FIG. 12 is a diagram showing the H-plane directivity when the chamfer dimension C of the chamfered portion 20 is changed with respect to the length dimension A in the waveguide in the slot antenna 3 of the present embodiment. Here, as in the case of FIG. 10, the chamfer dimension C is changed to five types of lengths of 0, A / 5, A / 4, A / 3, and A / 2.
As shown in FIG. 12, the slot antenna 3 of this embodiment shows a value in the vicinity of 22 dB of gain in the 0 degree direction for all the lengths of the chamfer dimension C from 0 to A / 2. Like the H-plane directivity (see FIG. 7), when the chamfer dimension C is increased to A / 2, the gain in the 0 degree direction does not show a value less than 20 dB. In other words, the slot antenna 3 of the present embodiment has a good H surface even when the chamfer dimension C is increased by setting the chamfer dimension C of the chamfered portion 20 to satisfy the relationship of C / A ≦ 1/2. It can be seen that directivity can be obtained.

  As described above, according to the slot antenna 3 according to the present embodiment, since the openings of the chamfered surfaces 21a and 22a of the chamfered portion 20 are covered with the first and second lid portions 23 and 24, the chamfered portion 20 is formed. It is possible to reliably short-circuit the ends of the waveguides.

  Further, the chamfer dimension C of the chamfered portion 20 has a relationship of C / A ≦ 1/2, where A is the length dimension in the direction perpendicular to the tube axis K in the waveguide in which the chamfered portion 20 is formed. Since VSWR characteristics and directivity are good even when the chamfer dimension C of the chamfered portion 20 is increased, the chamfered portion 20 has a larger chamfer dimension C than the case where the openings of the chamfered surfaces 21a and 22a of the chamfered portion 20 are opened. Can be obtained.

[Third Embodiment]
FIG. 13 is a cross-sectional perspective view showing the slot antenna device 1 including the slot antenna 3 according to the third embodiment of the present invention. As shown in FIG. 13, the slot antenna device 1 of this embodiment includes a radome 2 formed in a bottomed cylindrical shape, and a slot antenna 3 housed in the radome 2. The slot antenna 3 has the same configuration as the slot antenna 3 of the first embodiment, and is housed in the radome 2 in a state where the wide wall surface 141 of the antenna body 11 is arranged in parallel with the bottom surface 2b of the radome 2. Has been. The inner peripheral surface 2a of the side wall of the radome 2 is formed in a curved surface shape. Note that points that are not described in the third embodiment are the same as in the first embodiment.

  Also in the slot antenna device 1 and the slot antenna 3 of the present embodiment, the chamfered portions 20 are formed at the corners of the four corners of the antenna body 11, and therefore the corners of the antenna body 11 housed in the radome 2 are the radomes. 2 can be prevented from interfering with the inner peripheral surface 2a formed in the curved surface shape.

[Other variations]
The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 slot antenna device 2 radome (storage container)
2a Inner peripheral surface 2b Bottom surface 3 Slot antenna 11 Antenna body 12 Slot element 13 Feed path 13a Feed point 14A-14F Waveguide 15A-15F Feed slot element 20 Chamfer 21 First chamfer 21a Chamfer 22 Second chamfer 22a Chamfer 23 1st cover part 24 2nd cover part 141 Wide wall surface (one side)
142 Wide wall surface 143 End portion 144 First corner portion 145 Second corner portion 146 Defect end surface 147 Termination wall 148 Short-circuit wall A Length dimension B Center line C Chamfer dimension K Pipe axis L1 Distance L2 Distance M Chamfering line Py Axis line Pz Axis line λ wavelength

Claims (9)

An antenna body formed in a rectangular shape by a waveguide;
A slot antenna comprising a plurality of slot elements formed on one surface of the antenna body and radiating radio waves,
The antenna body includes a chamfered portion formed at at least one of the four corners viewed from the one surface side, and a plurality of the waveguides arranged side by side in a direction perpendicular to the tube axis. , have a,
The chamfered portion is formed across the two or more waveguides at the one corner,
Each of the two or more waveguides is provided in the vicinity of a position away from the center of the slot element closest to the chamfered portion toward the end portion by a length of ¼ of the wavelength λ of the operating frequency. A slot antenna having a short-circuit wall . An antenna body formed in a rectangular shape by a waveguide;
A slot antenna comprising a plurality of slot elements formed on one surface of the antenna body and radiating radio waves,
The antenna body has a chamfered portion formed on at least one corner of the four corners as viewed from the one side, and a plurality of the waveguides arranged side by side in a direction orthogonal to the tube axis , has a,
One or more of the waveguides at the one corner are missing at their ends,
The chamfered portion is
In the one waveguide, a first chamfer formed at a first corner that appears due to a defect in the end;
In addition to the waveguide adjacent to the waveguide of the one, away lots antenna having a, a second chamfer formed on a second corner portion which appeared by defect of the edge. The slot antenna according to claim 1 , wherein the antenna main body is accommodated in a storage container and supported so as to be movable with respect to the storage container. The slot antenna according to claim 3 , wherein the storage container has an inner peripheral surface formed in a curved shape. An antenna body formed in a rectangular shape by a waveguide;
A slot antenna comprising a plurality of slot elements formed on one surface of the antenna body and radiating radio waves,
The antenna body has a chamfered portion formed in at least one of the four corners seen from the one surface side,
The chamfered surface of the chamfered portion is open,
Luz lot antenna aperture of the chamfered surfaces are open. The antenna body has a plurality of the waveguides arranged in a direction perpendicular to the tube axis,
The chamfered portion is formed in the waveguide disposed at the one corner,
The chamfer dimension C of the chamfered portion is set so as to satisfy the relationship of C / A ≦ 1/3, where A is the length dimension in the orthogonal direction in the waveguide where the chamfered portion is formed. The slot antenna according to claim 5 . The chamfered surface of the chamfered portion is open,
The slot antenna according to any one of claims 1 to 4 , wherein the antenna body has a lid portion that covers an opening of the chamfered surface. An antenna body formed in a rectangular shape by a waveguide;
A slot antenna comprising a plurality of slot elements formed on one surface of the antenna body and radiating radio waves,
The antenna body has a chamfered portion formed in at least one of the four corners seen from the one surface side,
The chamfered surface of the chamfered portion is open,
The antenna main body has a lid covering the opening of the chamfered surface, and a plurality of the waveguides arranged side by side in a direction orthogonal to the tube axis, a,
The chamfered portion is formed in the waveguide disposed at the one corner,
The chamfer dimension C of the chamfered part is set so as to satisfy the relationship of C / A ≦ 1/2, where A is the length dimension in the orthogonal direction in the waveguide where the chamfered part is formed. Tei Luz lot antenna. A storage container;
Wherein while being accommodated in the container, and the slot antenna apparatus and a slot antenna according to any one of claims 1 to claim 8 which is movably supported with respect to the container.