JP5388943B2 - Waveguide / MSL converter and planar antenna - Google Patents

Description

  The present invention relates to a waveguide / MSL converter and a planar antenna, and more particularly, a waveguide / MSL converter having a radiation function, and a planar antenna including such a waveguide / MSL converter. About.

  In recent years, millimeter wave radars are being put into practical use as in-vehicle radars for monitoring the surrounding environment of automobiles. The millimeter wave radar can realize a radar device having a relatively high resolution by using a millimeter wave having a wavelength of 1 to 10 mm as a radar signal. Further, it can be realized as a planar antenna in which an antenna pattern is formed on a dielectric substrate, the device can be easily reduced in size and weight, and a cost reduction effect due to mass production can be expected.

  When connecting a waveguide and a microstrip line (MSL), a waveguide / MSL converter that can mutually convert transmission power of the waveguide and the strip line is used (for example, Patent Document 1). If an antenna pattern made of MSL is formed on a dielectric substrate having such a waveguide / MSL converter, a small and lightweight waveguide-excited antenna can be realized.

  16 and 17 are diagrams showing the configuration of a conventional waveguide / MSL converter described in Patent Document 1. FIG. 16 is a perspective view, and FIG. 17 is a plan view of the dielectric substrate 1 of FIG. 16. In FIG. 16, (a) shows the upper surface of the dielectric substrate 1, and (b) shows the lower surface of the dielectric substrate 1. ing. In this waveguide / MSL converter 190, the opening of the waveguide 2 is closely fixed to the lower surface of the dielectric substrate 1, and the short-circuit plate 3 is formed on the upper surface of the dielectric substrate 1. A feeding terminal 5 is formed in the notch 11. Meanwhile, a rectangular matching element 7 is formed on the lower surface of the dielectric substrate 1. The power supply terminal 5 and the matching element 7 are electromagnetically coupled to each other by being disposed close to each other with the dielectric substrate 1 interposed therebetween, and power conversion is performed by this electromagnetic coupling.

  FIG. 18 is a plan view showing a configuration of a conventional planar antenna. The planar antenna 290 is composed of the dielectric substrate 1 on which the waveguide / MSL converter 190 and the antenna pattern 30 are formed. Is connected to the feeding terminal 5 of the waveguide / MSL converter 190 as a feeding point. The antenna pattern 30 forms a linear array by a feed line 31 extending on a straight line and a plurality of radiating elements 32 formed along the side thereof.

  FIG. 19 is a plan view showing another configuration of a conventional planar antenna. This planar antenna 291 is a centrally fed antenna composed of a waveguide / MSL converter 191 and a pair of antenna patterns 30a and 30b. is there. The pair of antenna patterns 30a and 30b extend in opposite directions with a waveguide / MSL converter 191 serving as a feeding point. The waveguide / MSL converter 191 has two power supply terminals 5 and supplies power to one end of the antenna patterns 30a and 30b via these power supply terminals 5, respectively.

  In such conventional planar antennas 290 and 291, the waveguide / MSL converters 190 and 191 occupy a relatively large area on the dielectric substrate. For this reason, there is a problem that the area for forming the antenna patterns 30, 30a, 30b is reduced and the antenna gain is reduced.

  In particular, in the case of the central feed type planar antenna 291, the radiating element is arranged in the middle of the element array in which the radiating elements 32 are aligned by disposing the waveguide / MSL converter 191 in the middle of the pair of antenna patterns 30 a and 30 b. 32 omissions occur. For this reason, there has been a problem that the excitation distribution is broken, the side lobe level is increased, and good directivity characteristics cannot be obtained.

JP 2000-244212 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a waveguide / MSL converter having a radiation function without significantly increasing the manufacturing cost.

  Another object of the present invention is to improve antenna gain without increasing the substrate area of a planar antenna. In particular, an object is to improve the gain of a planar antenna in which a waveguide / MSL converter and an antenna pattern are formed on a dielectric substrate.

  Furthermore, it aims at improving the directivity characteristic of a planar antenna, without increasing the board | substrate area of a planar antenna. In particular, an object is to improve the directivity characteristics of a centrally fed planar antenna in which a pair of antenna patterns are formed with a waveguide / MSL converter interposed therebetween.

  A planar antenna according to a first aspect of the present invention includes a dielectric substrate having a first surface that closes an opening of a waveguide, and a short-circuit plate that is formed on the second surface of the dielectric substrate and shorts the waveguide. A matching element formed on the first surface of the dielectric substrate, a power supply terminal having one end formed in the notch of the shorting plate and electromagnetically coupled to the matching element, and the dielectric An antenna pattern formed on the second surface of the substrate and connected to the power supply terminal, and a radiation slot is formed in the short-circuit plate.

  By forming a matching element on the first surface of the dielectric substrate that closes the opening of the waveguide and forming a shorting plate and a feed line on the second surface, the transmission power of the waveguide and the feed line can be mutually exchanged. Can be converted. In such a waveguide / MSL converter, a radiation function can be added to the waveguide / MSL converter by forming a radiation slot on the short-circuit plate. Therefore, in a planar antenna composed of a waveguide / MSL converter and an antenna pattern, by adopting such a waveguide / MSL converter, the gain of the planar antenna can be increased without increasing the substrate area. Can do.

  A planar antenna according to a second aspect of the present invention includes, in addition to the above configuration, two or more of the power supply terminals and a pair of the antenna patterns, each of the pair of antenna patterns having one end connected to the power supply terminal, It has a shape extending in the opposite direction across the matching element.

  With such a configuration, a radiating element is not formed in the arrangement region of the waveguide / MSL converter in the central feed type planar antenna in which a pair of antenna patterns are formed with the waveguide / MSL converter interposed therebetween. As a result, it is possible to suppress the excitation distribution from being lost and the directivity from being deteriorated.

  A planar antenna according to a third aspect of the present invention is configured such that, in addition to the above-described configuration, the antenna pattern includes two or more radiating elements, and the excitation directions of the slots and the radiating elements are matched. With such a configuration, the planes of polarization of the emission waves from the radiation elements of the slot and antenna pattern can be made uniform. Therefore, the planar antenna having good characteristics can be realized by causing the slot to function as one of the radiating elements of the antenna pattern.

  A planar antenna according to a fourth aspect of the present invention is configured so that, in addition to the above configuration, the antenna pattern includes two or more radiating elements, and the slots and the radiating elements are excited in the same phase. With such a configuration, it is possible to realize a planar antenna having good directivity and large antenna gain by radiating radio waves having the same phase from the radiating elements of the slot and the antenna pattern.

  A planar antenna according to a fifth aspect of the present invention is configured by arranging the slots and the radiating elements so as to pass through a common straight line in addition to the above configuration. With such a configuration, the slot can function well as one of the radiating elements of the antenna pattern. The common straight line preferably passes through all of the radiating elements, but may be a straight line passing through a majority of the radiating elements, for example.

  In the planar antenna according to the sixth aspect of the present invention, in addition to the above configuration, the antenna pattern is connected to the power supply terminal, and extends in parallel with the short direction of the opening. And a plurality of radiating elements arranged to be inclined.

  A planar antenna according to a seventh aspect of the present invention is formed such that, in addition to the above configuration, the antenna pattern has a shape extending in parallel with the short direction of the opening by arranging two or more crank shapes. ing.

  A waveguide / MSL converter according to an eighth aspect of the present invention is formed on a dielectric substrate having a first surface for closing an opening of the waveguide, and on the second surface of the dielectric substrate, and the waveguide A short-circuit plate for short-circuiting, a matching element formed on the first surface of the dielectric substrate, and a planar line formed in the notch of the short-circuit plate and electromagnetically coupled to the matching element. A radiation slot is formed in the plate.

  By forming a slot in the short-circuit plate, the slot can function as a radiating element. Therefore, a radiation function can be added to the waveguide / MSL converter without increasing the substrate area. Moreover, the slot can be formed simultaneously with the etching process for forming the cut in the short-circuit plate. For this reason, it can implement | achieve, without increasing manufacturing cost.

  A waveguide / MSL converter according to a ninth aspect of the present invention is configured such that, in addition to the above configuration, the matching element has a hypotenuse that faces the short side of the opening and is inclined with respect to the short direction of the opening. And the slot is formed so as to cross the hypotenuse and is formed in parallel with the lateral direction of the opening. With such a configuration, even a radiating element whose excitation direction is orthogonal to the short direction of the opening can be added to the waveguide / MSL converter.

  According to the present invention, it is possible to provide a waveguide / MSL converter having a radiation function without significantly increasing the manufacturing cost.

  Moreover, according to the present invention, the antenna gain can be improved without increasing the substrate area of the planar antenna. In particular, the gain of a planar antenna in which a waveguide / MSL converter and an antenna pattern are formed on a dielectric substrate can be improved.

  Furthermore, according to the present invention, the directivity characteristics of the planar antenna can be improved without increasing the substrate area of the planar antenna. In particular, it is possible to improve the directivity characteristics of a centrally fed planar antenna in which a pair of antenna patterns are formed with a waveguide / MSL converter interposed therebetween.

It is the expansion | deployment perspective view which showed the example of 1 structure of the waveguide and the MSL converter 100 by Embodiment 1 of this invention. FIG. 2 is a plan view of the waveguide / MSL converter 100 of FIG. 1. It is sectional drawing by the AA cutting line of FIG. It is sectional drawing by the BB cutting line of FIG. It is the top view which showed one structural example of the planar antenna 200 by Embodiment 1 of this invention. It is the top view which showed the example of 1 structure of the waveguide and the MSL converter 110 by Embodiment 2 of this invention. It is the top view which showed one structural example of the planar antenna 210 by Embodiment 2 of this invention. It is the figure which showed the directional characteristic of the planar antenna 210 of FIG. It is the top view which showed one structural example of the waveguide and the MSL converter 112-115 by Embodiment 3 of this invention. It is the top view which showed the other structural example of the waveguide and the MSL converter 112-115 by Embodiment 3 of this invention. It is the top view which showed the other structural example of the waveguide and the MSL converter 112-115 by Embodiment 3 of this invention. It is the top view which showed the other structural example of the waveguide and the MSL converter 112-115 by Embodiment 3 of this invention. It is the top view which showed the example of 1 structure of the waveguide and the MSL converter 116 by Embodiment 4 of this invention. It is the top view which showed one structural example of the planar antenna 211 by Embodiment 4 of this invention. It is the figure which showed the directional characteristic of the planar antenna 211 of FIG. It is the perspective view which showed one structural example of the conventional waveguide / MSL converter 190. FIG. It is a top view of the dielectric substrate 1 of FIG. It is the top view which showed the structure of the conventional planar antenna 290. It is the top view which showed the structure of the conventional planar antenna 291.

Embodiment 1 FIG.
1 to 4 are diagrams showing a configuration example of a waveguide / MSL converter according to a first embodiment of the present invention, in which a waveguide / MSL converter 100 having a radiation function is shown. . 1 is a developed perspective view, FIG. 2 is a plan view, FIG. 3 is a sectional view taken along the line AA in FIG. 2, and FIG. 4 is a sectional view taken along the line BB in FIG. Yes.

  The waveguide / MSL converter 100 includes a dielectric substrate 1 having a short-circuit plate 3 and a power supply terminal 5 formed on the upper surface and a ground plate 6 and a matching element 7 formed on the lower surface. By making the lower surface of the dielectric substrate 1 face the opening 21 of the waveguide 2, the transmission power of the waveguide 2 and the power supply terminal 5 can be mutually converted via the matching element 7. Furthermore, radio waves can be radiated by forming the slot 12 on the short-circuit plate 3.

  The waveguide 2 is a block body made of a conductive material, for example, a rectangular parallelepiped block formed by an aluminum die casting method. The waveguide 2 has a hollow portion 23 surrounded by a tube wall 22. Propagates. The waveguide 2 is a rectangular waveguide in which the tube wall 22 is composed of two narrow walls and two wide walls, and the cross section of the hollow portion 23 orthogonal to the propagation direction has a long side corresponding to the wide wall, It is a rectangle composed of a short side corresponding to a narrow wall. Furthermore, an opening 21 having the same shape as the cross section of the hollow portion 23 is formed at one end of the waveguide 2.

  The dielectric substrate 1 is disposed such that the lower surface thereof closes the opening 21 of the waveguide 2. The dielectric substrate 1 is wider than the opening 21, and the end face of the waveguide 2 is tightly fixed around the closed region 10 corresponding to the opening 21. On the dielectric substrate 1, a short-circuit plate 3, a power supply terminal 5, a ground plate 6 and a matching element 7 are formed as a conductive metal thin film pattern. These thin film patterns are formed by forming a thin film such as copper on the entire surface of the dielectric substrate 1 by sputtering or vapor deposition, and then patterning the thin film by a photoetching method.

  The short-circuit plate 3 is formed so as to cover the closed region 10 of the dielectric substrate 1 and constitutes a short-circuit surface that terminates the waveguide 2. The short-circuit plate 3 in the figure has a rectangular shape, and a strip-shaped cut 11 is formed from the long side to the inside. This cut 11 extends parallel to the short side of the closed region 10 and reaches the closed region 10. Two slots 12 are formed in the closed region 10 of the short-circuit plate 3.

  The power supply terminal 5 is a planar line formed on the upper surface of the dielectric substrate 1, one end of which is formed in the cut 11 of the short-circuit plate 3, and crosses the long side of the closed region 10 and the long side of the short-circuit plate 3, The other end is drawn to the outside of the short-circuit plate 3. The feed terminal 5 is arranged at a certain distance from the short-circuit plate 3 in the cut 11 and forms a coplanar line together with the short-circuit plate 3. Further, outside the closed region 10, it is disposed so as to face the ground plate 6 through the dielectric substrate 1, and forms an MSL together with the ground plate 6.

  The ground plate 6 is formed so as to surround the closed region 10, and the ground plate 6 and the waveguide 2 are made conductive by bringing the end face of the waveguide 2 into close contact with the ground plate 6. In the drawing, the outer edge of the dielectric substrate 1 is made to coincide with the outer edge of the end face of the waveguide 2, and the ground plate 6 has an inner edge that coincides with the closed region 10. It is formed on the entire lower surface.

  The matching element 7 is an element formed in the closed region 10 so as not to be electrically connected to the ground plate 6. A part of the matching element 7 is disposed so as to overlap the tip of the power supply terminal 5 with the dielectric substrate 1 interposed therebetween. The terminal 5 is electromagnetically coupled. Generally, in the waveguide 2, there is only an electric field in the short direction, and this electric field distribution is known to be maximum at the longitudinal center. For this reason, the matching element 7 has a shape in which the length in the short direction of the opening 21 is about ½ of the wavelength λd in the dielectric substrate 1 through the vertical bisector of the long side of the opening 21. It is desirable that Note that impedance matching can be achieved by adjusting the amount of insertion of the power supply terminal 5 into the closed region 10 and the distance from the short center of the waveguide 2.

  The through hole 8 is formed by filling the through hole of the dielectric substrate 1 with a conductive material. Through this through hole 8, the short-circuit plate 3 and the ground plate 6 are conducted, and the short-circuit plate 3 is held at the same potential as the waveguide 2. In addition, by disposing a large number of through holes 8 around the closed region 10 and surrounding the closed region 10, power loss in the dielectric substrate 1 is suppressed.

  The slot 12 is a through hole formed in the short-circuit plate 3 and has an elongated planar shape. By forming such a slot 12 in a region surrounded by the through holes 8, it can function as a radiating element that radiates radio waves in free space. Here, the slot 12 is formed in the closed region 10, but may be formed outside the closed region 10 as long as it is within the region surrounded by the through hole 8. If a slot is formed in a conductor flat plate formed on a dielectric substrate, it becomes a radiating element that radiates an electromagnetic wave propagating through the dielectric, and its radiation characteristic can be adjusted by the length and width of the slot. For this reason, if a slot 12 having an appropriate length and width is formed in the short-circuit plate 3, a radiation function can be added to the waveguide / MSL converter 100.

  In this waveguide / MSL converter 101, since the slot 12 is formed in the closed region 10 of the short-circuit plate 3, a radiating element can be added without increasing the area of the dielectric substrate 1. Further, since the slot 12 can be formed simultaneously in the process of forming the short-circuit plate 3 and the power supply terminal 5, a radiation function can be added to the waveguide / MSL converter without increasing the manufacturing cost.

  In FIG. 2, the longitudinal direction (stretching direction) of the slot 12 is formed to be orthogonal to the short direction of the opening 21. The excitation direction Dr of the slot 12 is the short direction (width direction) of the slot 12, and can be arbitrarily determined so that the radiated wave has a desired polarization plane. However, if the excitation direction Dr of the slot 12 is orthogonal to the excitation direction Ds of the matching element 7, the slot 12 does not function as a radiating element. Since the excitation direction Ds of the matching element 7 is the short direction of the opening 21, the slot 12 needs to be formed so that the excitation direction Dr is not orthogonal to the short direction of the opening 21. That is, the slot 12 can be formed in an arbitrary direction according to the polarization plane of the radiated wave as long as the longitudinal direction does not coincide with the short direction of the opening 21.

  FIG. 5 is a plan view showing one configuration example of the planar antenna according to the first embodiment of the present invention. The planar antenna 200 includes a dielectric substrate 1 having a waveguide / MSL converter 101 and an antenna pattern 30 connected to the converter 101. The top surface of the dielectric substrate 1 is shown in FIG. Has been. The waveguide / MSL converter 101 has the same configuration as the waveguide / MSL converter 100 of FIGS. 1 to 4 except that the excitation direction Dr of the slot 12 is different. The planar antenna 200 is a tip feeding type antenna device in which one end of an antenna pattern 30 is connected to the feeding terminal 5 of the waveguide / MSL converter 101.

  The antenna pattern 30 forms a linear array by a feed line 31 extending linearly and a plurality of radiating elements 32 branched from the feed line 31 and excited in the same phase. The feed line 31 is a microstrip line whose one end is connected to the feed terminal 5 of the waveguide / MSL converter 101, extends parallel to the short direction of the opening 21, and has the other end for reflection suppression. A termination element 33 is formed. On the other hand, the radiation element 32 is a microstrip element for radiating a traveling wave propagating on the feed line 31 to free space, and has a linear or strip shape extending in a direction intersecting the feed line 31 at a certain angle. Consists of.

  The radiation element 32 has one end connected to the side of the feed line 31 and the other end open. A plurality of radiating elements 32 are aligned along the side of the feeder line 31. Here, radiating elements 32 are formed on both sides of the feed line 31, and the radiating elements 32 are arranged at regular intervals according to the wavelength so as to be excited in the same phase, and so that the polarization planes are aligned with each other. They are arranged in parallel.

  The slot 12 is formed such that its excitation direction Dr coincides with the excitation direction Dt of the radiating element 32. Here, the excitation direction Dt of the radiating element 32 is a direction in which the feed line 31 is inclined 45 ° counterclockwise. For this reason, by similarly tilting the excitation direction Dr of the slot 12, the excitation directions Dr and Dt of the radiating element 32 and the slot 12 can be matched, and the polarization planes of the radiated waves from the slot 12 and the radiating element 32 can be made uniform. .

  The radiating elements 32 are aligned for each side of the feed line 31 to form two element rows. Each radiating element 32 is associated with one of these element rows, and the slots 12 are arranged on the corresponding element row so as to be aligned with other radiating elements 32. Here, the slot 12 and the radiating element 32 are aligned so as to pass through a common straight line parallel to the feed line 31.

  In general, by increasing the number of radiating elements 32, the array antenna can improve its directivity and increase the antenna gain. For this reason, if the slot 12 is formed so as to be excited in the same phase as the radiating element 32 and have the plane of polarization coincide with the radiating element 32, the slot 12 can function in the same manner as the radiating element 32. Therefore, if such a slot 12 is formed in the short-circuit plate 3, the number of radiating elements 32 can be increased and the directivity and antenna gain of the planar antenna 200 can be improved without increasing the manufacturing cost.

  In the waveguide / MSL converters 100 and 101 according to the present embodiment, the short-circuit plate 3 and the feeding terminal 5 are formed on one main surface of the dielectric substrate 1, and the ground plate 6 and the matching element 7 are formed on the other main surface. And a slot 12 is formed in the short-circuit plate 3. For this reason, a radiation function can be added to the waveguide / MSL converter without significantly increasing the manufacturing cost.

  Further, the planar antenna 200 according to the present embodiment forms the slot 12 in the radiating element 32 by forming the slot 12 in the waveguide / MSL converter 101 that feeds the antenna pattern 30 having the plurality of radiating elements 32. It is functioning as one. For this reason, it is possible to improve the directivity characteristics and antenna gain of the planar antenna without significantly increasing the manufacturing cost.

Embodiment 2. FIG.
In the first embodiment, an example in which the slot 12 is formed in the short-circuit plate 3 of the waveguide / MSL converter having one power supply terminal 5 has been described. In contrast, in the present embodiment, a case where the slot 12 is formed in the short-circuit plate 3 of the waveguide / MSL converter having the two power supply terminals 5 will be described.

  FIG. 6 is a plan view showing a configuration example of the waveguide / MSL converter according to the second embodiment of the present invention. The waveguide / MSL converter 110 is different from the waveguide / MSL converter 100 of FIG. 2 in that it includes two power supply terminals 5, but the other configurations are the same, and overlapping. The description to be omitted is omitted.

  The short-circuit plate 3 has cuts 11 formed on two opposing sides, and one end of the power supply terminal 5 is formed in each cut 11. Each power supply terminal 5 is formed so as to traverse the opposing long sides of the closed region 10, one end overlaps with the matching element 7, and the other end is drawn to the outside of the short-circuit plate 3. That is, the two power supply terminals 5 are formed so as to be symmetrical.

  That is, even in the case of the waveguide / MSL converter 110 having the two feeding terminals 5, the slot 12 is formed in the short-circuit plate 3 in the same manner as the waveguide / MSL converter 100 in the first embodiment. A radiation function can be added to the waveguide / MSL converter without increasing the manufacturing cost.

  FIG. 7 is a plan view showing a configuration example of a planar antenna according to Embodiment 2 of the present invention. The planar antenna 210 includes a dielectric substrate 1 having a waveguide / MSL converter 111 and a pair of antenna patterns 30a and 30b connected to the converter 111, and the upper surface of the dielectric substrate 1 is It is shown in FIG.

  The waveguide / MSL converter 111 has the same configuration as the waveguide / MSL converter 110 of FIG. 6 except that the excitation direction Dr of the slot 12 is different. The pair of antenna patterns 30a and 30b has the same configuration as the antenna pattern 30 of FIG. For this reason, the overlapping description is omitted.

  Each feed line 31 is arranged so as to extend in the opposite direction with the converter 111 interposed therebetween, and a plurality of radiating elements 32 are formed on the sides thereof. That is, the planar antenna 210 is a central feeding type antenna in which two antenna patterns 30a and 30b are arranged with a feeding point interposed therebetween.

  Here, the antenna patterns 30a and 30b have substantially the same shape, and are arranged with the other rotated 180 °. For this reason, the antenna patterns 30a and 30b have substantially the same radiation characteristics. In addition, the radiating element 32 is formed so that each of the antenna patterns 30a and 30b extends in a direction in which the feed line 31 is inclined 45 ° counterclockwise. The antenna patterns 30a and 30b have shapes when the feed line 31 extends in the opposite direction with the feed point interposed therebetween and the excitation directions Dt of the radiating elements 32 belonging to both the antenna patterns 30a and 30b coincide. It may not be substantially the same.

  The slot 12 is formed such that the excitation direction Dr coincides with the excitation direction Dt of the radiating elements 32 of both antenna patterns 30a and 30b. Here, the excitation direction Dt of each radiating element 32 is a direction in which the feed line 31 is inclined 45 ° counterclockwise. For this reason, by similarly tilting the excitation direction Dr of the slot 12, the excitation directions Dr and Dt of the radiating element 32 and the slot 12 can be matched, and the polarization planes of the radiated waves from the slot 12 and the radiating element 32 can be made uniform. .

  The radiating elements 32 are aligned across the antenna patterns 30a and 30b for each side of the feeder line 31 to form two element rows. Each radiating element 32 is associated with one of these element rows, and the slots 12 are arranged on the corresponding element row so as to be aligned with other radiating elements 32. Here, the slot 12 and the radiating element 32 are aligned so as to pass through a common straight line parallel to the feed line 31.

  FIG. 8 is a diagram showing the directivity characteristics of the planar antenna 210 of FIG. On the horizontal axis, the directing direction is shown as an angle with respect to the front direction of the dielectric substrate 1, and on the vertical axis, the relative gain with respect to the gain in the front direction is shown. A directivity characteristic D1 in the figure is a characteristic of the planar antenna 210 according to the present embodiment, and a directivity characteristic D2 is a characteristic of the conventional planar antenna 291 shown in FIG.

  A simulation condition for obtaining the directivity characteristic D1 will be described with reference to FIG. The dielectric substrate 1 was made of a dielectric material having a thickness of 0.124 mm and a relative dielectric constant of 2.22, and a copper foil having a thickness of 18 μm was bonded to both surfaces thereof. The copper foil is etched to form the power supply terminal 5, the matching element 7, and the slot 12. The power supply terminal 5 has a width L1 of 0.3 mm and an insertion length L2 into the closed region 10 of 0.475 mm. The matching element 7 has a short side L3 of 1 mm and a long side L4 of 1.6 mm. The slot 12 has a length L5 of 1.0 mm, a width L6 of 0.1 mm, a pitch L7 of 1.6 mm, and its longitudinal direction is a direction in which the feed line 31 is rotated 45 ° counterclockwise. It is formed to extend. On the other hand, in the simulation of the directivity D2 to be compared, a square matching element in which the insertion length L2 is 0.375 mm and L3 and L4 are 1.1 mm so that good characteristics can be obtained without the slot 12. 7 was used.

  Comparing the directivity characteristics D1 and D2, the planar antenna 210 according to the present embodiment has a side lobe level that is 1.8 dB lower than that of the conventional planar antenna 291. Thus, good directivity characteristics can be obtained. I understand.

  In the waveguide / MSL converters 110 and 111 according to the present embodiment, two feeding terminals 5 are formed and a slot 12 is formed in the short-circuit plate 3 to have a radiation function. Therefore, a radiation function can be added to the waveguide / MSL converter having the two power supply terminals 5 as in the case of the first embodiment.

  The planar antenna 210 according to the present embodiment is a center-feed type array antenna in which a pair of antenna patterns 30a and 30b are formed with the waveguide / MSL converter 111 interposed therebetween. A slot 12 is formed in the front. With such a configuration, by disposing the waveguide / MSL converter 111 in the middle of the element array of the radiating elements 32, it is possible to prevent the radiating elements 32 from being lost and the excitation distribution from being disrupted. As a result, the side lobe level can be reduced, and a planar antenna with good directivity can be realized. Further, by increasing the number of radiating elements 32, the antenna aperture area can be increased without increasing the area of the dielectric substrate 1.

Embodiment 3 FIG.
In the present embodiment, another configuration example of the waveguide / MSL converter in which the slot 12 is formed will be described. Note that in this embodiment, differences from the above embodiment will be described, and redundant description of the same components will be omitted.

  FIG. 9 is a plan view showing a configuration example of the waveguide / MSL converter according to the third embodiment of the present invention. This waveguide / MSL converter 112 is different from the waveguide / MSL converter 110 of FIG. 6 in that the matching element 7 is circular. Even if the matching element 7 is circular, if it passes through the perpendicular bisector in the short direction of the closed region 10 and overlaps with a part of each power supply terminal 5, the same effect as in the first and second embodiments is obtained. Is obtained. That is, the shape of the matching element 7 is not limited to a rectangle.

  FIG. 10 is a plan view showing another configuration example of the waveguide / MSL converter according to the third embodiment of the present invention. Compared with the waveguide / MSL converter 110 in FIG. 6, the waveguide / MSL converter 113 has a V-shaped matching element 7, and the excitation direction Dr of the slot 12 is shorter than the opening 21. It differs in that it is orthogonal to the hand direction.

  In the first and second embodiments, if the excitation direction Dr of the slot 12 is orthogonal to the short direction of the opening 21, the excitation direction Ds of the matching element 7 is also orthogonal. For this reason, the slot 12 cannot be excited, and the slot 12 does not function as a radiating element. On the other hand, in the waveguide / MSL converter 113 of FIG. 10, even if the excitation direction Dr of the slot 12 is orthogonal to the short direction of the opening 21 by making the matching element 7 V-shaped. The slot 12 functions as a radiating element.

  If attention is paid to a portion where the slots 12 overlap in the matching element 7 constituting the V shape, the matching element 7 has a shape extending in a direction inclined with respect to the short direction of the opening 21. For this reason, the excitation direction Ds of the matching element 7 can be inclined with respect to the short direction of the opening 21. For this reason, even if the excitation direction Dr of the slot 12 is orthogonal to the short direction of the opening 21, the excitation directions Dr and Ds of the slot 12 and the matching element 7 are not orthogonal to each other. Can be made to function as a radiating element. That is, if the extending direction of the matching element 7 is tilted as necessary, the excitation direction Dr of the slot 12 can be arbitrarily determined. Therefore, the polarization plane of the radiated wave by the slot 12 can be arbitrarily determined.

  FIG. 11 is a plan view showing another configuration example of the waveguide / MSL converter according to the third embodiment of the present invention. The waveguide / MSL converter 114 is different from the waveguide / MSL converter 110 shown in FIG. 6 in that four slots 12 are formed.

  In FIG. 6, one slot is provided corresponding to two element rows arranged for each side of the feeder line 31. On the other hand, in the waveguide / MSL converter 114, two slots 12 are formed for one element row. Thus, by forming two or more slots for one element row, the directivity characteristics and antenna gain of the planar antenna can be further improved.

  FIG. 12 is a plan view showing another configuration example of the waveguide / MSL converter according to the third embodiment of the present invention. This waveguide / MSL converter 115 is different from the waveguide / MSL converter 110 of FIG. 6 in that only one slot 12 is formed.

  6 and 9 to 11 show an example of a waveguide / MSL converter in which two or four slots 12 are formed. However, the present invention is a waveguide in which two or more slots 12 are formed. -It is not limited only to an MSL converter. That is, one slot 12 may be formed in the waveguide / MSL converter. For example, when the radiating element 32 is formed along only one side of the feed line 31, one slot 12 may be formed so as to align with these radiating rows. That is, the number of the slots 12 can be determined to an arbitrary value of 1 or 2 as necessary.

  2, 6, and 10, a part of the slot 12 is overlapped with the matching element 7, whereas in FIGS. 9, 11, and 12, the slot 12 is overlapped with the matching element 7. Absent. If the slot 12 and the matching element 7 are overlapped with each other, the excitation efficiency of the slot 12 can be improved and good radiation characteristics can be obtained. For this reason, although it is desirable to make both overlap, even if it is not made to overlap, the slot 12 can be functioned as a radiation element.

Embodiment 4 FIG.
In the above-described embodiment, an example of a comb line antenna in which the antenna pattern includes the feeder line 31 and the radiating element 32 has been described. On the other hand, in the present embodiment, a case where the antenna pattern is a crank antenna having a plurality of crank shapes will be described. Note that in this embodiment, differences from the above embodiment will be described, and redundant description of the same components will be omitted.

  FIG. 13 is a plan view showing a configuration example of the waveguide / MSL converter according to the fourth embodiment of the present invention. In the waveguide / MSL converter 116, the excitation direction Dr of the slot 12 is orthogonal to the short direction of the opening 21 as in the waveguide / MSL converter 113 of FIG. It is different in that it is not V-shaped but trapezoidal.

  The excitation direction Dr of the slot 12 is orthogonal to the short direction of the opening 21 as in the case of FIG. Therefore, if the matching element 7 is rectangular as shown in FIG. 6, the excitation directions Ds and Dr of the matching element 7 and the slot 12 are orthogonal, and the slot 12 cannot be excited. However, if the matching element 7 is trapezoidal and the slot 12 is formed so as to overlap the hypotenuse, the slot 12 can be excited.

  The matching element 7 of FIG. 13 has a trapezoidal shape, and the hypotenuse opposite to the short side of the opening 21 is inclined with respect to the short direction of the opening 21. In the case of such a shape, the excitation direction Ds1 at the central portion of the matching element 7 is the short direction of the opening 21, but the excitation direction Ds2 along the trapezoidal inclination is inclined with respect to the short direction of the opening 21. The direction is That is, the excitation direction Ds2 of the matching element 7 is not orthogonal to the excitation direction Dr of the slot 12. For this reason, if the slot 12 is formed so as to cross the oblique side of the matching element 7, the slot 12 can be excited by the matching element 7.

  FIG. 14 is a plan view showing a configuration example of a planar antenna according to the fourth embodiment of the present invention. The planar antenna 211 includes a dielectric substrate 1 including the waveguide / MSL converter 116 of FIG. 13 and a pair of antenna patterns 31a and 31b connected to the converter 116. Is shown in FIG.

  The antenna patterns 31a and 31b are MSLs having a shape extending in one direction by arranging a plurality of crank shapes bent in a crank shape, that is, a rectangular wave shape, and one end of which is guided. It is connected to the feeding terminal 5 of the tube / MSL converter 116 and extends parallel to the short direction of the opening 21.

  The antenna patterns 31a and 31b are arranged so as to extend in directions opposite to each other with the converter 116 interposed therebetween. That is, the planar antenna 211 is a central feeding type antenna in which two antenna patterns 31a and 31b are arranged with a feeding point interposed therebetween.

  Here, the antenna patterns 31a and 31b have substantially the same shape, and are arranged with the other rotated 180 °. For this reason, the antenna patterns 30a and 30b have substantially the same radiation characteristics. The antenna patterns 31a and 31b may extend in opposite directions with respect to the feeding point, and the shapes of the antenna patterns 31a and 31b do not have to be substantially the same as long as the excitation directions Dt coincide with each other.

  Since the excitation direction Dt of the antenna patterns 31 a and 31 b is orthogonal to the short direction of the opening 21, the excitation direction Dr of the slot 12 is set to the short direction of the opening 21 using the waveguide / MSL converter 116. By making them orthogonal, the excitation directions Dr and Dt of the slot 12 and the antenna patterns 31a and 31b can be made to coincide with each other, and the polarization planes of the radiated waves from the slot 12 and the antenna patterns 31a and 31b can be made uniform.

  FIG. 15 is a diagram showing the directivity characteristics of the planar antenna 211 of FIG. On the horizontal axis, the directing direction is shown as an angle with respect to the front direction of the dielectric substrate 1, and on the vertical axis, the relative gain with respect to the gain in the front direction is shown. A directivity characteristic D1 in the figure is a characteristic of the planar antenna 211 according to the present embodiment, and a directivity characteristic D2 is a characteristic of the same planar antenna that does not have the slot 12.

  Simulation conditions for obtaining the directivity characteristic D1 will be described with reference to FIGS. The dielectric substrate 1 was made of a dielectric material having a thickness of 0.124 mm and a relative dielectric constant of 2.22, and a copper foil having a thickness of 18 μm was bonded to both surfaces thereof. Further, this copper foil is etched to form the power supply terminal 5, the matching element 7, and the slot 12.

  The power supply terminal 5 has a width L1 of 0.3 mm and an insertion length L2 into the closed region 10 of 0.465 mm. The matching element 7 has a trapezoidal height L3 of 0.95 mm, an upper base L41 of 1.35 mm, and a lower base L42 of 2.24 mm. The slot 12 has a length L5 of 1.0 mm, a width L6 of 0.1 mm, a pitch L7 of 1.6 mm, and the longitudinal direction thereof is parallel to the extending direction of the antenna patterns 31a and 31b. Has been.

  The crank-shaped structures of the antenna patterns 31a and 31b that radiate parallel polarized waves are arranged such that the length L8 is 0.8 mm, L9 is 1.0 mm, and the pitch L10 is 1.6 mm. . The antenna termination is a port equivalent to a 50Ω termination without reflection. Since L1 to L3 and L5 to L7 are the same as those in FIG. 6, they are omitted in FIG.

  Comparing the directivity characteristics D1 and D2, in the planar antenna 211 according to the present embodiment, the level of the side lobe is reduced by 3.7 dB compared to the conventional planar antenna, and a good directivity characteristic can be obtained. Recognize.

  In the waveguide / MSL converter 116 according to the present embodiment, the matching element 7 has a trapezoidal shape so that the side opposite to the short side of the opening 21 is a hypotenuse, and the slot 12 is formed so as to cross the hypotenuse. ing. Therefore, the slot 12 whose excitation direction Dr is orthogonal to the short direction of the opening 21 can be formed, and a radio wave having a polarization plane orthogonal to the short direction of the opening 21 can be emitted.

  The planar antenna 211 according to the present embodiment is a center-feed type array antenna in which a pair of antenna patterns 31a and 31b are formed with the waveguide / MSL converter 116 interposed therebetween. A slot 12 is formed in the front. With such a configuration, by arranging the waveguide / MSL converter 116 in the middle of the element array of the radiating elements 32, it is possible to prevent the radiating elements 32 from being lost and the excitation distribution of the entire antenna from being destroyed. it can. As a result, the side lobe level can be reduced, and a planar antenna with good directivity can be realized. Further, by increasing the number of the radiating elements 32, the antenna aperture area can be increased without increasing the area of the dielectric substrate 1.

DESCRIPTION OF SYMBOLS 1 Dielectric board | substrate 2 Waveguide 3 Shorting board 5 Feeding terminal 6 Grounding board 7 Matching element 8 Through hole 10 Closed area 12 Slot 21 Opening part 30,30a, 30b, 31a, 31b Antenna pattern 31 Feeding line 32 Radiating element 100- 116 Waveguide / MSL converter 200-211 Planar antenna Dr, Ds, Ds1, Ds2, Dt Excitation direction

Claims (9)

A dielectric substrate having a first surface closing the opening of the waveguide;
A short-circuit plate formed on the second surface of the dielectric substrate and short-circuiting the waveguide;
A matching element formed on the first surface of the dielectric substrate;
One end is formed in the notch of the short-circuit plate, and a feeding terminal composed of a planar line electromagnetically coupled to the matching element;
An antenna pattern formed on the second surface of the dielectric substrate and connected to the feed terminal;
A planar antenna characterized in that a radiation slot is formed in the short-circuit plate. Including two or more of the power supply terminals and a pair of the antenna patterns;
2. The planar antenna according to claim 1, wherein the pair of antenna patterns has a shape in which one end is connected to each of the power supply terminals and extends in the opposite direction across the matching element. The antenna pattern is composed of two or more radiating elements,
3. The planar antenna according to claim 1, wherein excitation directions of the slot and the radiating element are matched. The antenna pattern is composed of two or more radiating elements,
3. The planar antenna according to claim 1, wherein the slot and the radiating element are excited in the same phase.   5. The planar antenna according to claim 3, wherein the slot and the radiating element are aligned and arranged so as to pass through a common straight line.   The antenna pattern includes a linear feed line that is connected to the feed terminal and extends in parallel with a short direction of the opening, and a plurality of radiating elements arranged to be inclined with respect to the feed line. The planar antenna according to any one of claims 1 to 5.   The planar antenna according to any one of claims 1 to 5, wherein the antenna pattern has a shape extending in parallel with a short direction of the opening by arranging two or more crank shapes. A dielectric substrate having a first surface closing the opening of the waveguide;
A short-circuit plate formed on the second surface of the dielectric substrate and short-circuiting the waveguide;
A matching element formed on the first surface of the dielectric substrate;
A plane line formed in the notch of the short-circuit plate and electromagnetically coupled to the matching element;
A waveguide / MSL converter characterized in that a radiation slot is formed in the short-circuit plate. The matching element has a hypotenuse facing the short side of the opening and inclined with respect to the short direction of the opening,
9. The waveguide / MSL converter according to claim 8, wherein the slot is formed so as to cross the hypotenuse and is formed in parallel with the lateral direction of the opening.

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