JP5495955B2 - Waveguide slot array antenna - Google Patents

Description

  The present invention relates to a waveguide slot array antenna, and more particularly to a waveguide slot array antenna used for wireless communication using high frequency waves such as millimeter waves and microwaves.

  A waveguide slot array antenna is configured by providing a plurality of radiation slots (cuts) in a waveguide, and has attracted attention as a low-loss antenna even in millimeter waves. In order to reduce the size of the waveguide slot array antenna, a configuration in which a radiation waveguide and a feeding waveguide are overlapped to feed power from the back surface has been proposed (for example, see Patent Document 1).

  In recent years, a dielectric waveguide formed of a conductor pattern and a conductor via in a dielectric substrate has been reported as a transmission line suitable for millimeter waves, and is provided in series with the dielectric waveguide. For a plurality of slots, a configuration has been proposed in which the amount of coupling to each slot is made uniform by changing the size of each slot (see, for example, Patent Document 2).

JP 2002-223115 A JP 2001-102861 A

  However, in the conventional waveguide slot array antenna disclosed in Patent Document 1, one feed waveguide is arranged so as to be orthogonal to the central portion of the radiation waveguide with respect to the plurality of radiation waveguides. Therefore, in order to construct a slot array antenna having a large antenna opening, it is necessary to feed power to a radiation waveguide long in the tube axis direction provided with a large number of radiation slots at one central portion, and the frequency characteristics are There is a problem that it becomes a narrow band.

  On the other hand, in the array antenna shown in Patent Document 2, in order to adjust the coupling amount to the slot, the impedance of the slot is changed depending on the length of the slot in the longitudinal direction. However, since the slot is provided so as to be orthogonal to the propagation direction of the feed waveguide, and the slot cannot be made longer than the width of the feed waveguide, there is a problem that the range of impedance that can be adjusted is limited. there were.

  The present invention has been made to solve such a problem, and in a waveguide slot array antenna in which a radiating waveguide and a feeding waveguide are stacked one above the other, a frequency characteristic is wideband, and a desired An object of the present invention is to obtain a waveguide slot array antenna capable of easily realizing an excitation distribution.

The present invention provides a first radiating waveguide and a second radiating waveguide, which are arranged in parallel and adjacent to each other with respect to the feeding waveguide, and are fed by the feeding waveguide. A waveguide, a plurality of radiation slots provided in the first radiation waveguide and the second radiation waveguide, the feed waveguide, the first radiation waveguide, and the second A plurality of first coupling slots provided between the first and second radiation waveguides; and a plurality of first coupling slots provided between the first radiation waveguide and the second radiation waveguide. A plurality of second coupling slots, wherein the first coupling slot and the second coupling slot are provided in a direction perpendicular to a tube axis direction of the feed waveguide, coupling slot is a one whose ends are extended toward the tube axis direction of the feed waveguide, wherein 1 of the coupling slot is a slotted waveguide array antenna, characterized in that provided at a position near the center of the feed waveguide than the second coupling slot.

The present invention provides a first radiating waveguide and a second radiating waveguide, which are arranged in parallel and adjacent to each other with respect to the feeding waveguide, and are fed by the feeding waveguide. A waveguide, a plurality of radiation slots provided in the first radiation waveguide and the second radiation waveguide, the feed waveguide, the first radiation waveguide, and the second A plurality of first coupling slots provided between the first and second radiation waveguides; and a plurality of first coupling slots provided between the first radiation waveguide and the second radiation waveguide. A plurality of second coupling slots, wherein the first coupling slot and the second coupling slot are provided in a direction perpendicular to a tube axis direction of the feed waveguide, coupling slot is a one whose ends are extended toward the tube axis direction of the feed waveguide, wherein 1 binding slot, since it is the second waveguide slot array antenna, characterized in that is provided at a position close to the center of the feed waveguide than the coupling slot, the frequency characteristic is broadband, There is an effect that a desired excitation distribution can be easily realized.

1 is an exploded configuration diagram of a waveguide slot array antenna according to Embodiment 1 of the present invention. FIG. It is a top view of the metal plate in the waveguide slot array antenna which concerns on Embodiment 1 of this invention. It is a top view of the other metal plate in the waveguide slot array antenna which concerns on Embodiment 1 of this invention. It is a disassembled block diagram of the waveguide slot array antenna which concerns on Embodiment 2 of this invention. It is a top view of the conductor pattern of the dielectric substrate in the waveguide slot array antenna which concerns on Embodiment 2 of this invention. It is a top view of the other conductor pattern on the dielectric substrate in the waveguide slot array antenna which concerns on Embodiment 2 of this invention. It is a disassembled block diagram of the waveguide slot array antenna which concerns on Embodiment 3 of this invention. It is a top view of the conductor pattern of the dielectric substrate in the waveguide slot array antenna which concerns on Embodiment 3 of this invention. It is a top view of the other conductor pattern of the dielectric substrate in the waveguide slot array antenna which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is an exploded configuration diagram of a waveguide slot array antenna according to Embodiment 1 of the present invention. In the first embodiment, a waveguide slot array antenna is configured by electrically connecting metal plates 1a, 1b, 1c, 1d, and 1e in such a manner that they are stacked one above the other in order. FIG. 2 is a plan view of the metal plate 1a, and FIG. 3 is a plan view of the metal plate 1c. In FIGS. 2 and 3, the structures of slots and the like provided in the other metal plates 1b, 1d, and 1e are indicated by broken lines in order to show the relative positional relationship.

  1 to 3, reference numerals 2a and 2b denote radiating waveguide extraction portions provided on the metal plate 1b, and 3 denotes a feeding waveguide extraction portion provided on the metal plate 1d. Reference numerals 4a and 4b denote radiation slots provided in the metal plate 1a, reference numerals 5a and 5b denote coupling slots provided in the metal plate 1c, reference numeral 6 denotes a power supply slot provided in the metal plate 1e, and reference numeral 7 denotes an input waveguide.

  The radiation waveguides 11a and 11b are configured by overlapping metal plates 1a, 1b, and 1c. 1 to 3, among the radiation waveguide portions (reference numerals 11a and 11b), the left half constitutes the radiation waveguide 11a, and the right half constitutes the radiation waveguide 11b. That is, in the present embodiment, as shown in FIG. 1, the radiation waveguides 11a and 11b are configured using common metal plates 1a, 1b, and 1c, which are adjacent to each other in the tube axis direction. Are arranged in a row. However, it is not always necessary to form the common metal plates 1a, 1b, and 1c. The metal plates 1a, 1b, and 1c have the same structure and half separate metal plates. May be arranged in a line in the tube axis direction.

  The feed waveguide 12 is configured by overlapping metal plates 1c, 1d, and 1e. One feeding waveguide 12 is arranged on the back surface of the two radiation waveguides 11a and 11b. Due to this positional relationship, power is supplied from the single power supply waveguide 12 to each of the two radiation waveguides 11a and 11b provided in parallel and adjacent to each other.

  The configurations of the radiation waveguide 11a and the feeding waveguide 12 will be described. Since the configuration of the radiation waveguide 11b is the same as the configuration of the radiation waveguide 11a in line symmetry, only the radiation waveguide 11a will be described here. In the radiation waveguide 11a, the metal plate 1a is provided with four radiation slots 4a and 4b. The radiation slots 4a and 4b are all the same type, and each has a rectangular shape extending in the tube axis direction. In FIG. 1, four radiation slots 4a are arranged from the left end, and thereafter four radiation slots 4b are arranged. Adjacent radiation slots 4a are arranged so as to be alternated on the left and right with respect to the tube axis of the radiation waveguide 11a, and the interval between adjacent ones in the tube axis direction is the wavelength of the in-tube wavelength in the radiation waveguide 11a. It is equal to 1/2. Similarly, the adjacent radiation slots 4b are alternately arranged on the left and right with respect to the tube axis, and the interval in the tube axis direction is also equal to ½ of the in-tube wavelength in the radiation waveguide 11a. The radiation slot 4a is provided near the end of the metal plate 1a, and the radiation slot 4b is provided near the center of the metal plate 1a (ie, near the radiation waveguide 11b). Therefore, as shown in FIG. 2, the radiation slot 4b of the radiation waveguide 11a and the radiation slot 4b of the radiation waveguide 11b are arranged adjacent to each other, and the radiation slot 4a and the radiation waveguide of the radiation waveguide 11a are arranged. The 11b radiation slots 4a are disposed at both ends of the metal plate 1a.

  Further, in the radiation waveguide 11a, one radiation waveguide extraction portion 2a, 2b formed on the metal plate 1b is provided. Further, the radiation waveguide extraction portions 2a and 2b are all the same type, and each has a rectangular shape extending in the tube axis direction. The length in the tube axis direction of the radiation waveguide extraction portions 2a and 2b is slightly shorter than the length of 1/4 of the metal plate 1b, and the tube between the adjacent radiation waveguide extraction portions 2a and 2b. The axial distance is shorter than the distance between adjacent radiation slots 4a, 4b. Further, the radiation waveguide extraction portion 2a is provided near the end of the metal plate 1b, and the radiation waveguide extraction portion 2b is provided near the center of the metal plate 1b (that is, close to the radiation waveguide 11b). . Accordingly, the radiation waveguide extraction portion 2b of the radiation waveguide 11a and the radiation waveguide extraction portion 2b of the radiation waveguide 11b are arranged adjacent to each other as shown in FIG. The radiation waveguide extraction portion 2a and the radiation waveguide extraction portion 2a of the radiation waveguide 11b are disposed at both ends of the metal plate 1b, respectively.

  The metal plate 1c is used in common in both the radiation waveguides 11a and 11b and the feed waveguide 12. One coupling slot 5a and 5b provided in the metal plate 1c is provided for each of the radiation waveguides 11a and 11b, and two coupling slots 5a and 11b are provided for the feeding waveguide 12, for a total of four. Is provided. The interval between the coupling slots 5 a and 5 b in the tube axis direction is an integral multiple of ½ of the in-tube wavelength in the feed waveguide 12. Further, as shown in FIG. 2, the coupling slot 5a is provided at a position that is exactly in the middle of the positions of the four radiation slots 4a with respect to the tube axis direction of the radiation waveguides 11a and 11b. Similarly, the coupling slot 5b is provided at a position just in the middle of the positions of the four radiation slots 4b with respect to the tube axis direction of the radiation waveguides 11a and 11b. The coupling slot 5a is provided near the end of the metal plate 1c, and the coupling slot 5b is provided near the center of the metal plate 1c (that is, near the radiation waveguide 11b). Therefore, the coupling slot 5b of the radiation waveguide 11a and the coupling slot 5b of the radiation waveguide 11b are arranged adjacent to each other as shown in FIGS. The coupling slot 5a of the wave tube 11b is disposed at both ends of the metal plate 1c. Further, the coupling slot 5b is formed so that the length of the slot is longer than that of the coupling slot 5a. The coupling slot 5 a and the coupling slot 5 b are both provided in a direction perpendicular to the tube axis of the feed waveguide 12. The coupling slot 5a has a rectangular shape extending in a direction perpendicular to the tube axis direction (vertical direction). On the other hand, the shape of the coupling slot 5b is as shown in FIG. Although it has a rectangular shape extending in a direction (vertical direction) perpendicular to the tube axis direction, its end extends in the tube axis direction of the feed waveguide 12 and is generally H-shaped. It has a shape.

  Further, the metal plate 1d is provided with one feed waveguide extraction portion 3. The feed waveguide extraction portion 3 has a rectangular shape extending in the tube axis direction. As shown in FIG. 3, the length of the feed waveguide extraction portion 3 in the tube axis direction is slightly longer than the distance between the two coupling slots 5a provided at both ends of the metal plate 1c.

  One feeding slot 6 formed in the metal plate 1e is provided for the feeding waveguide 12, and is arranged at the center of the metal plate 1e. The position of the power supply slot 6 corresponds to the position of the input waveguide 7, and the power supply slot 6 and the input waveguide 7 are disposed so as to face each other with a predetermined distance therebetween.

  Each of the metal plates 1a, 1b, 1c, 1d, and 1e only needs to be electrically connected vertically along the periphery of the radiating waveguide extraction portions 2a and 2b and the feed waveguide extraction portion 3. They may be connected by metal diffusion bonding, soldering, brazing, or the like, or may be fixed with screws at an interval of less than ¼ of the wavelength.

Next, the operation will be described.
The high-frequency signal input to the input waveguide 7 enters the power supply waveguide 12 through the power supply slot 6 and is divided into two, and the power supply waveguide 12 is directed toward both ends of the power supply waveguide 12 respectively. Propagate. On the way, a part of the power is coupled to the coupling slot 5b and the rest is coupled to the coupling slot 5a. At this time, since the coupling slot 5b has a longer slot length than the coupling slot 5a, the admittance seen from the coupling slot 5b when viewed from the radiation waveguides 11a and 11b is increased, and the coupling slot 5b has a larger admittance. The amount of coupling becomes larger.

  The high-frequency signals input to the radiation waveguides 11a and 11b through the coupling slots 5a and 5b are radiated into the space with equal amplitude and in phase from the radiation slots 4a and 4b, respectively. At this time, since the coupling slot 5b has a larger coupling amount than the coupling slot 5a, the radiation amount from the radiation slot 4b closer to the center is larger than the radiation slot 4a closer to the end as the whole array antenna. Therefore, the excitation distribution of the array antenna has a large amplitude near the center, and the side lobe level of the radiation pattern can be reduced as compared with the case where all the radiation slots 4a and 4b are excited with equal amplitude.

  In particular, in the first embodiment, since the shape of the coupling slot 5b is an H shape with the slot end extending in the tube axis direction of the feeding waveguide 12, the side of the radiation waveguide 11b from the coupling slot 5b is changed. The observed admittance can be further increased, and the excitation distribution of the array antenna having a large amplitude difference between the end and the center can be realized.

  As described above, according to the first embodiment, power is supplied to the plurality of radiation waveguides 11a and 11b arranged in a row from the power supply waveguides 12 provided on the back surfaces thereof. As a result, even in a waveguide slot array antenna that is long in the tube axis direction, the number of radiation slots 4a and 4b that are fed by standing waves by one radiation waveguide 11a and 11b is small. A broadband waveguide slot array antenna can be obtained. Further, by appropriately determining the arrangement pattern and the number of the radiation slots 4a and the radiation slots 4b, a desired excitation distribution can be easily realized as the entire array antenna, thereby easily realizing a desired radiation pattern. Can do. Furthermore, since a plurality of radiating waveguides 11a and 11b are serially fed by one feeding waveguide 12 disposed on the back surface thereof, a thin waveguide slot array antenna can be realized.

  Further, according to the first embodiment, the coupling provided near the end of the feeding waveguide 12 among the plurality of coupling slots 5 a and 5 b provided in the tube axis direction of the feeding waveguide 12. Since the length of the coupling slot 5b provided closer to the center than the length of the slot 5a is made longer, the amplitude of the high-frequency signal fed to the radiation waveguides 11a and 11b closer to the center of the array antenna becomes larger, and the side lobe is increased. A good radiation pattern with a low level can be obtained.

  Further, according to the first embodiment, the shape of the coupling slot 5b provided near the center of the power supply waveguide 12 is changed to an H shape in which the slot end is extended in the tube axis direction of the power supply waveguide 12. Therefore, the admittance when the radiation waveguides 11 a and 11 b are viewed from the coupling slot 5 b can be further increased without being limited by the width of the feed waveguide 12. Therefore, an excitation distribution having a large amplitude difference can be realized between the radiation slot 4a closer to the end and the radiation slot 4b closer to the center, and it is easy to obtain a good radiation pattern with a lower sidelobe level.

  In the first embodiment, the number of radiation slots 4a provided in the radiation waveguide 11a and the number of radiation slots 4b provided in the radiation waveguide 11b are both four. It is not a thing. The number of the radiation slots 4a and the radiation slots 4b may be determined according to the excitation distribution required for realizing the desired radiation pattern for the entire array antenna, and the numbers may not necessarily be the same, but they may be different from each other. But you can.

Embodiment 2. FIG.
4 is an exploded configuration diagram of a waveguide slot array antenna according to Embodiment 2 of the present invention. In the second embodiment, dielectric substrates 8a, 8b and conductor patterns 9a, 9b, 9c are alternately stacked one above the other, and conductor vias 10a, 10b, 10c are provided on the dielectric substrates 8a, 8b to form a post wall waveguide. A waveguide slot array antenna is configured by forming the. FIG. 5 is a plan view of the conductor pattern 9a provided on the dielectric substrate 8a, and FIG. 6 is a plan view of the conductor pattern 9b provided on the dielectric substrate 8b. In FIGS. 5 and 6, the structure of slots and the like provided in other conductor patterns is indicated by broken lines in order to show the relative positional relationship.

  4-6, 10a and 10b are comprised from a conductor with high electroconductivity, The conductor via provided in the dielectric substrate 8a, 10c is similarly comprised from a conductor with high electroconductivity, and dielectric substrate 8b Is a conductor via. Also in the present embodiment, the left half is the radiation waveguide 11a and the right half is the radiation waveguide 11b. The radiation waveguide 11a is a post wall waveguide composed of a dielectric substrate 8a, conductor patterns 9a and 9b, and conductor vias 10a and 10b. Similarly, the radiating waveguide 11b is a post wall waveguide composed of a dielectric substrate 8a, conductor patterns 9a and 9b, and conductor vias 10a and 10b. The power supply waveguide 12 is a post wall waveguide composed of a dielectric substrate 8b, conductor patterns 9b and 9c, and a conductor via 10c. The conductor patterns 9a, 9b, 9c are electrically connected to each other through conductor vias 10a, 10b, 10c. The conductor vias 10a, 10b, and 10c must be arranged in a row at intervals of less than ½ of the guide wavelength in the radiation waveguides 11a and 11b and the feed waveguide 12 in order to prevent leakage of high-frequency signals. In the second embodiment, the radial waveguides 11a and 11b and the feeding waveguide 12 are provided at intervals of 1/4 of the in-tube wavelength with respect to the tube axis direction.

  4 to 6, 4a and 4b are radiation slots provided in the conductor pattern 9a, 5a and 5b are coupling slots provided in the conductor pattern 9b, 6 is a power supply slot provided in the conductor pattern 9c, 7 Is an input waveguide. Four radiation slots 4a and 4b are provided for each of the radiation waveguides 11a and 11b. The radiation slots 4a and 4b are all provided with respect to the tube axis of the radiation waveguides 11a and 11b. Arranged on the same side, the interval in the tube axis direction is equal to the in-tube wavelength in the radiation waveguides 11a and 11b. In the second embodiment, the radiation slots 4a and 4b are all arranged on the same side with respect to the tube axes of the radiation waveguides 11a and 11b, and this point is different from the first embodiment. On the other hand, one coupling slot 5a, 5b is provided for each of the radiation waveguides 11a, 11b, and the interval between the coupling slots 5a, 5b is ½ of the in-tube wavelength in the feed waveguide 12. It is an integer multiple of. The coupling slot 5a (or 5b) is the second of the four radiation slots 4a (or 4b) counted from the central portion of the conductor pattern 9a with respect to the tube axis direction of the radiation waveguide 11a (or 11b). Are provided at a position separated from the slot by a quarter of the guide wavelength toward the end of the conductor pattern 9a (the coupling slot 5a is exactly the same as the inner two slots of the four radiation slots 4a). It is not located in the middle, but at a position where the space is divided by 3: 1, and is not limited to this position, but is located at a position away from an adjacent radiation slot by an odd multiple of 1/4 of the guide wavelength. Just do it.) Further, the power supply slot 6 is provided at the center in the tube axis direction with respect to the power supply waveguide 12. Further, as shown in FIG. 5, the conductor vias 10a are arranged in a substantially rectangular shape so as to surround the four radiation slots 4a. Similarly, as shown in FIG. 5, the conductor vias 10b are arranged in a substantially rectangular shape so as to surround the four radiation slots 4b. Further, as shown in FIG. 6, the conductor vias 10c are arranged in a substantially rectangular shape so as to surround the four coupling slots 5a and 5b. Since other configurations are the same as those in the first embodiment, description thereof is omitted here.

  The second embodiment shows a case where the radiation waveguides 11a and 11b and the feeding waveguide 12 are each constituted by a post wall waveguide, and the operation is the same as that of the first embodiment. That is, the high-frequency signal input to the input waveguide 7 enters the power supply waveguide 12 through the power supply slot 6 and is divided into two, and propagates through the power supply waveguide 12 toward both ends. On the way, a part of the power is coupled to the coupling slot 5b and the rest is coupled to the coupling slot 5a. At this time, since the coupling slot 5b has a longer slot length than the coupling slot 5a, the admittance seen from the coupling slot 5b when viewed from the radiation waveguides 11a and 11b is increased, and the coupling slot 5b has a larger admittance. The amount of coupling becomes larger. The high-frequency signals input to the radiation waveguides 11a and 11b through the coupling slots 5a and 5b are radiated into the space with equal amplitude and in phase from the radiation slots 4a and 4b, respectively. At this time, since the coupling slot 5b has a larger coupling amount than the coupling slot 5a, the radiation amount from the radiation slot 4b closer to the center is larger than the radiation slot 4a closer to the end as the whole array antenna. Therefore, the excitation distribution of the array antenna has a large amplitude near the center, and the side lobe level of the radiation pattern can be reduced as compared with the case where all the radiation slots 4a and 4b are excited with equal amplitude.

  As described above, also in the second embodiment, the coupling slot 5b has a longer slot length than the coupling slot 5a, and the shape of the coupling slot 5b is the slot end portion in the tube axis direction of the feed waveguide 12. Due to the extended H shape, the admittance of the coupling waveguide 5b viewed from the radiation waveguide 11b side can be increased, and the radiation slot closer to the center is radiated than the radiation slot closer to the end. The excitation distribution of the array antenna having a large amplitude of the high-frequency signal can be realized.

  As described above, according to the second embodiment, similarly to the first embodiment, the plurality of radiation waveguides 11a and 11b arranged in a row are respectively separated from the feeding waveguide 12 on the back surface. Since power is supplied, even in a waveguide slot array antenna that is long in the tube axis direction, the number of radiation slots that are standing-wave-fed by a single radiation waveguide is small. A wave tube slot array antenna is obtained. Further, by appropriately determining the arrangement pattern and the number of the radiation slots 4a and the radiation slots 4b, a desired excitation distribution can be easily realized as the entire array antenna, thereby easily realizing a desired radiation pattern. Can do. In addition, since a plurality of radiation waveguides 11a and 11b are serially fed by one feeding waveguide 12 arranged in parallel to the back surface, a thin waveguide slot array antenna can be realized.

  Of the plurality of coupling slots 5 a and 5 b provided in the tube axis direction of the feeding waveguide 12, the coupling slot 5 a is provided closer to the center than the coupling slot 5 a provided near the end of the feeding waveguide 12. The length of the coupled slot 5b is increased, and the shape of the coupled slot 5b is H-shaped with the slot end extending in the tube axis direction of the feed waveguide 12, so that the radiation waveguide 11a of the array antenna is formed. , 11b, the amplitude of the high-frequency signal radiated from the radiation slot 4b provided near the center is increased, and a good radiation pattern having a low sidelobe level can be obtained.

  In addition, since the second embodiment is configured by a multilayer substrate in which the dielectric substrates 8a and 8b and the conductor patterns 9a, 9b, and 9c are overlapped, the structure is compared with a structure in which a metal having a hollow waveguide is stacked. Thus, a small and lightweight antenna can be obtained. Further, when a two-dimensional array antenna is configured by arranging a plurality of one-dimensional waveguide slot array antennas as shown in the second embodiment in the waveguide width direction, dielectric substrates 8a and 8b are used. Since the waveguide width is small due to the wavelength shortening effect due to the dielectric constant, the arrangement interval in the waveguide width direction can be narrowed, and even if beam scanning is performed in the waveguide width direction, grating lobes are hardly generated in the radiation pattern. There is an effect.

  Further, since the conductor vias 10a, 10b, and 10c are arranged at intervals of 1/4 of the in-tube wavelength in the radiation waveguides 11a and 11b and the feeding waveguide 12, the radiation slots 4a and 4b and the coupling slots 5a and 5b are arranged. The relative positions of the conductor vias 10a, 10b, and 10c with respect to the same are all the same, and the influence of the conductor vias 10a, 10b, and 10c on the admittance of the slot having the same shape is the same, so that the design is easy.

Embodiment 3 FIG.
FIG. 7 is an exploded configuration diagram of the waveguide slot array antenna according to the third embodiment of the present invention. FIG. 8 is a plan view of the conductor pattern 9a on the dielectric substrate 8a, and FIG. 9 is a plan view of the conductor pattern 9b on the dielectric substrate 8b. In the third embodiment, in the waveguide slot array antenna shown in the second embodiment, the number of radiation slots 4a and 4b provided in the radiation waveguides 11a and 11b and the positions of the coupling slots 5a and 5b are determined. It has changed. Since the other configuration is the same as that of the second embodiment, the description thereof is omitted, and the following description focuses on a configuration different from that of the second embodiment.

  In FIG. 7, the radiation waveguide 11a is provided with five radiation slots 4a and three radiation slots 4b. Specifically, in order from the left end, first, five radiation slots 4a are arranged, and then three radiation slots 4b are arranged. Similarly, the radiation waveguide 11b is provided with five radiation slots 4a and three radiation slots 4b. Since the configuration of the radiation waveguide 11b is symmetrical with the radiation waveguide 11a, in the radiation waveguide 11b, first, five radiation slots 4a are arranged in order from the right end, and then the radiation slot 4b is arranged. Three are lined up. Further, as shown in FIG. 8, the coupling slots 5a and 5b are located at positions separated from the adjacent radiation slots 4a and 4b by ¼ of the in-tube wavelength, respectively, in the vicinity of the boundary between the adjacent radiation waveguides 11a and 11b. The interval between the coupling slots 5a and 5b is 1.5 times the guide wavelength.

  The operation of the third embodiment is the same as that of the first and second embodiments. However, in the third embodiment, the coupling slots 5a and 5b are not near the center of the radiation waveguides 11a and 11b, but near the ends (that is, near the boundaries of the radiation waveguides 11a and 11b). However, since standing waves are generated in the radiation waveguides 11a and 11b, the distance between the radiation slots 4a and 4b and the coupling slots 5a and 5b is an odd multiple of 1/4 of the guide wavelength. If this relationship is maintained, the amount of radiation from the radiation slots 4a and 4b becomes equal amplitude regardless of the positions of the coupling slots 5a and 5b.

  As described above, according to the third embodiment, not only the same effect as in the second embodiment is obtained, but also the positions of the coupling slots 5a and 5b with respect to the adjacent radiation waveguides 11a and 11b are set to each other. Since the distance between the coupling slots 5a and 5b in the feed waveguide 12 is reduced to 1.5 times the guide wavelength, the frequency characteristic in the series feed portion of the feed waveguide 12 becomes gentle, and the broadband waveguide slot There is an effect that an array antenna can be obtained.

  1a, 1b, 1c, 1d, 1e Metal plate, 2a, 2b Radiation waveguide extraction part, 3 Feeding waveguide extraction part, 4a, 4b Radiation slot, 5a, 5b Coupling slot, 6 Feeding slot, 7 Input waveguide Tube, 8a, 8b Dielectric substrate, 9a, 9b, 9c Conductor pattern, 10a, 10b, 10c Conductor via, 11a, 11b Radiation waveguide, 12 Feeding waveguide.

Claims (4)

A feeding waveguide;
A first radiating waveguide and a second radiating waveguide, arranged parallel to and adjacent to each other with respect to the feeding waveguide, and fed by the feeding waveguide;
A plurality of radiation slots provided in the first radiation waveguide and the second radiation waveguide;
A plurality of first coupling slots provided between the feed waveguide and the first radiation waveguide and the second radiation waveguide;
A plurality of second coupling slots provided between the feed waveguide and the first radiation waveguide and the second radiation waveguide;
The first coupling slot and the second coupling slot are provided in a direction orthogonal to the tube axis direction of the feeding waveguide, and the end of the first coupling slot is at the feeding waveguide. Extending in the direction of the tube axis of the tube ,
The waveguide slot array antenna, wherein the first coupling slot is provided at a position closer to the center of the feeding waveguide than the second coupling slot . The first radiation waveguide and the second radiation waveguide each comprise a first radiation waveguide subarray and a second radiation waveguide subarray,
The first coupling slot is provided in the first radiation waveguide subarray closer to the second radiation waveguide subarray than the center position in the tube axis direction,
The second coupling slot is provided in the second radiating waveguide subarray closer to the first radiating waveguide subarray than the center position in the tube axis direction. Item 11. A waveguide slot array antenna according to Item 1 . At least one of the first radiating waveguide, the second radiating waveguide, and the feeding waveguide is a post wall conductor formed of a dielectric substrate, a conductor pattern, and a conductor via. The waveguide slot array antenna according to claim 1 or 2 , comprising a wave tube. 4. The conductor according to claim 3 , wherein the conductor vias are arranged at intervals of 1/4 of a propagation wavelength in the post wall waveguide along a tube axis direction of the post wall waveguide. Wave tube slot array antenna.

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