JP2923928B2 - Microstrip slot array antenna - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip slot array antenna having a structure in which an antenna and a feeder are integrated into a substrate on which a plurality of dielectric layers are stacked. is there.

(Prior Art) An example of a microstrip slot array antenna is described in Japanese Patent Publication No. 57-13163. In this technique, a power supply strip line is formed on one surface of one dielectric substrate, and a plurality of half-wavelength slots are arranged in the conductive film arranged on the other surface along the power supply strip line. , And a plurality of slots are successively supplied with power from a feed strip line.

When power is supplied to the slot from the middle of the array in which the slots are arranged, the leading end of one feed strip line led to the middle is branched into two, and the two branched feed strips are split. A technique for supplying power to each of a plurality of slots divided into two blocks at an intermediate portion by a branch line of the line is shown.

(Problems to be Solved by the Invention) Meanwhile, in the technique disclosed in Japanese Patent Publication No. 57-13163, in which a power supply stripline is branched into two at an intermediate portion and power is supplied, the power supply stripline is provided at the branch portion. Since the bent portion is formed in the bent portion, unnecessary radiation is easily emitted from the bent portion, and the side lobe level is deteriorated accordingly.

Therefore, if a microwave signal is fed to the intermediate portion of a linear feed strip line by a coaxial line perpendicular to the substrate, unnecessary radiation is reduced because the feed strip line has no bent portion. However, the feed structure using the coaxial line perpendicular to the substrate has a problem that the structure of the feed unit is complicated and the antenna characteristics are likely to be unstable. In addition, since the power supply unit is large in space and complicated in structure, there is a problem that the power supply unit is expensive.

The present invention has been made in view of the circumstances of the above-described conventional microstrip slot array antenna, and uses a substrate on which a plurality of dielectric layers are stacked to obtain a micro antenna that has stable antenna characteristics and can be manufactured at low cost. An object of the present invention is to provide a strip slot array antenna.

(Means for Solving the Problems) In order to achieve the above object, a microstrip slot array antenna according to the present invention has a structure in which first, second, and third dielectric layers are sequentially laminated, Forming a feed strip line on a surface of the layer, arranging a plurality of slots along a feed strip line in a conductive film disposed between the first and second dielectric layers,
A second feed strip line having one end serving as a feed point is disposed between the first feed strip line and the third dielectric layer so as to cross the feed strip line, and the second feed strip line and the feed strip line are connected to each other. The first and second dielectric layers are connected by through holes penetrating therethrough, and a substrate conductor facing the second feed strip line is arranged on the back surface of the third dielectric layer.

Further, a fourth dielectric layer is further laminated on the laminate of the first, second and third dielectric layers, and a substrate conductor disposed on the back surface of the third dielectric layer is provided with a small area. The reflection conductor may be arranged on the entire back surface of the fourth dielectric layer.

The substrate conductor may be arranged on the entire back surface of the third dielectric layer.

Further, a reflecting plate made of a conductive metal may be arranged parallel to the back surface of the third dielectric layer away from the back surface.

Further, the first, second and third dielectric layers are sequentially laminated, a feed strip line is formed on the surface of the first dielectric layer, and between the first and second dielectric layers. A plurality of slots are arranged in the arranged conductive film along the power supply strip line, and a reflecting conductor is arranged on the entire surface between the second and third dielectric layers. A second power supply strip line having one end serving as a power supply point is arranged on the back surface of the layer so as to cross the power supply strip line, and the second power supply strip line and the power supply strip line are connected to the first, second, and second power supply strip lines. The connection may be made by connecting through holes penetrating the third dielectric layer.

Further, a fourth dielectric layer is further laminated on the laminate of the first, second, and third dielectric layers, and a shielding conductor is arranged on the entire back surface of the fourth dielectric layer. It can also be configured.

(Operation) Since the microwave signal is propagated from the second power supply strip line disposed between the dielectric layers so as to cross the power supply strip line to the power supply strip line via a through hole penetrating the dielectric layer, Neither the feeding stripline nor the second feeding stripline has a bent portion and does not generate unnecessary radiation. In addition, since the antenna and the feeder are incorporated in a substrate in which a plurality of dielectric layers are stacked and integrated, the structure is simpler and the antenna characteristics are stable compared to the feed by a coaxial line. .

Further, if the reflecting conductor is arranged by laminating the fourth dielectric layer, the beam emitted toward the reflecting conductor side from the slots arranged in the dielectric film is reflected, and
The reflection pattern is formed only in one direction on the surface of the dielectric layer.

If the substrate conductor is arranged on the entire back surface of the third dielectric layer, the substrate conductor also serves as a reflector, and a radiation pattern is formed only in one direction with a simple configuration.

Furthermore, if a reflector is provided in parallel away from the back surface of the third dielectric layer, a radiation pattern is similarly formed in only one direction.

Further, a feed strip line is formed on the surface of the first dielectric layer, slots are arranged in a conductive film disposed between the first and second dielectric layers, and the second and third dielectric layers are arranged. A reflective conductor is arranged between the layers, and a second conductor is provided on the back surface of the third dielectric layer.
If the power supply strip line is formed, unnecessary radiation by the second power supply strip line is shielded by the reflective conductor, and there is no metal conductor other than the through hole between the slot and the reflective conductor. The beam emitted toward the reflecting conductor is reflected without being disturbed. As a result, the radiation pattern on the surface side of the first dielectric layer is not affected by the power supply unit.

Then, a fourth dielectric layer is further laminated,
If the shield conductor is arranged on the entire back surface of the dielectric layer, unnecessary radiation by the second feed stripline is shielded by the shield conductor, and the front-to-back ratio is improved.

(Example) Hereinafter, the structure of an example of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is an exploded perspective view of a microstrip slot array antenna according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.

In FIG. 1 and FIG. 2, first, second, third and fourth dielectric layers 10, 12, 14, 16 having the same rectangular planar shape and low dielectric constant are sequentially laminated. An integrated substrate is configured. On the surface of the first dielectric layer 10, two substantially parallel feed strip lines 18, 18 are formed in the longitudinal direction of the dielectric layer. In addition, the first and second dielectric layers 1
A plurality of half-wavelength slots 22, 22,... Having half-wavelengths substantially perpendicular to the feed strip lines 18, 18 are formed in the conductive film 20 disposed almost over the entire surface between the feed strips 0, 12. Two rows are arranged along both sides of the lines 18 to form a slot array antenna. The spacing between these slots 22, 22... Is effectively one wavelength in the first dielectric layer 10, and the two feed strip lines
The spacing between 18 and 18 is effectively an integral multiple of one wavelength in the first dielectric layer 10.

Further, between the second and third dielectric layers 12 and 14, at a position orthogonal to the center of the feed strip lines 18 and 18, and from the center of the interval in the arrangement direction of the slots 22 and 22. At a position offset by 1/4 wavelength in the array direction of 22 ...
A second feed stripline 24 is formed. And
A small-area substrate conductor 26 is arranged between the third and fourth dielectric layers 14 and 16 so as to face the second feed strip line 24. Further, a reflecting conductor 28 is arranged on the entire back surface of the fourth dielectric layer 16.

The power supply strip lines 18 and 18 and the second power supply strip line 24 are electrically connected at the intersections through through holes 30 and 30 passing through the first and second dielectric layers 10 and 12. . Note that these through holes 30, 30 and conductive film 20
However, it is a matter of course that it is insulated.

Then, the center conductor 34 of the coaxial line 32 is electrically connected to one end of the second feeding strip line 24, and the external conductor 36 is electrically connected to the conductive film 20, the substrate conductor 26, and the reflecting conductor 28.

In such a configuration, the second feeding strip line 24
Is a conductive film 2 sandwiching the second and third dielectric layers 12 and 14 above and below.
The microwave signal fed from the coaxial line 32 is propagated to the second feed strip line 24, and is further formed on the feeder strip via the through holes 30, 30. Propagated to lines 18,18. Then, the microwave signal is propagated toward both ends by the feed strip lines 18 and 18, and the slots 22 and 2
2 ... are successively supplied with power and excited. Here, the excited slots 22, 22... Emit a beam to both sides of the conductive film 20, but are reflected by the reflecting conductor 28 and emitted toward the surface of the first dielectric layer 10. Superimposed on the beam. The spacing between the reflective conductor 28 and the conductive film 20 in which the slots 22, 22 are arranged is effectively 1/4 in the dielectric layer.
At a distance that is an integral multiple of the wavelength.

The microstrip slot array antenna of the present invention configured as described above incorporates an antenna and a power supply unit in a substrate in which a plurality of dielectric layers are stacked and integrated, and uses a high-precision printed wiring technology. Therefore, stable antenna characteristics can be obtained, which is suitable for mass production and can be manufactured at low cost. Furthermore, since it is an integrated, simple and robust structure, it is excellent in earthquake resistance.

In the first embodiment, the microwave signal is fed using the coaxial line 32 connected in the same direction to the second feed strip line 24. However, the present invention is not limited to this. Alternatively, power can be supplied using a waveguide.

FIGS. 3 and 4 show a second embodiment of the microstrip slot array antenna of the present invention. FIG. 3 is an exploded perspective view of the second embodiment, and FIG.
It is the BB arrow sectional drawing made into the lamination state in the figure. In FIGS. 3 and 4, the same members as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted.

In FIGS. 3 and 4, the difference between the second embodiment and the first embodiment is as follows. The first, second and third dielectric layers 10, 12, 14 are stacked, but the fourth dielectric layer 16 is not. The substrate conductor 26 is disposed on the entire back surface of the third dielectric layer 14. In addition,
The conductive film 2 in which the substrate conductor 26 and the slots 22, 22 are arranged
The distance from 0 is effectively a distance of an integral multiple of 1/4 wavelength in the dielectric layer.

In this configuration, the substrate conductor 26 causes the second feed strip line 24 to act as a micro triplate line together with the conductive film 20, and is radiated from the slots 22, 22,... To the third dielectric layer 14 side. It also acts as a reflector for the beam. In the second embodiment, the fourth
Since the integrated dielectric layer 16 is not laminated, the integrated substrate becomes thinner, which is advantageous for miniaturization.

FIGS. 5 and 6 show a third embodiment of the microstrip array antenna of the present invention, and FIG.
FIG. 6 is an exploded perspective view of the embodiment shown in FIG. 6, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. FIG. 5 and FIG.
In the drawings, the same members as those in FIGS. 1 to 4 are denoted by the same reference numerals, and redundant description will be omitted.

5 and 6, the third embodiment differs from the first embodiment in the following points. The first, second and third dielectric layers 10, 12, 14 are stacked, but the fourth dielectric layer 16 is not. Then, a small-area substrate conductor 26 is arranged on the back surface of the third dielectric layer 14 so as to face the second power supply strip line 24, and the third
A reflector 38 made of a conductive metal is arranged in parallel with and away from the back surface of the dielectric layer 14. The reflection plate 38 and the slots 22, 22
Are effectively the distance of an integer part of 1/4 wavelength in the dielectric layer and in the space. Further, both ends of the reflection plate 38 are bent by 90 degrees, and are brought into contact with both ends of the first, second and third dielectric layers 10, 12, 14 to be electrically connected to the conductive film 20.

With this configuration, the same operation and effect as those of the first embodiment can be obtained, and it is convenient to fix the integrated substrate using the reflection plate 38.

7 and 8 show a microstrip slot array antenna according to a fourth embodiment of the present invention. FIG. 7 is an exploded perspective view of the fourth embodiment, and FIG.
FIG. 3 is a cross-sectional view taken along the line DD in the figure in a stacked state. 7 and 8, the same members as those in FIGS. 1 to 6 are denoted by the same reference numerals, and redundant description will be omitted.

In FIGS. 7 and 8, the differences between the fourth embodiment and the first embodiment are as follows. A reflecting conductor 28 is disposed on the entire surface between the second and third dielectric layers 12 and 14. Then, a second feed strip line 24 is disposed between the third and fourth dielectric layers 14 and 16, and the second feed strip line 24 and the feed strip lines 18 and 18 are arranged.
Are electrically connected by through holes 30, 30 penetrating the first, second and third dielectric layers 10, 12, 14. Further, a shield conductor 40 is arranged on the entire back surface of the fourth dielectric layer 16. Needless to say, the through holes 30, 30 are insulated from the conductive film 20 and the reflective conductor.

In such a configuration, the second feeding strip line 24
Is a reflecting conductor 28 sandwiching the third and fourth dielectric layers 14 and 16 therebetween.
The microwave signal fed to the coaxial line 32 is propagated through the second feed strip line 24 and further formed through the through holes 30, 30. Feed stripline 1
8,18 and slots 22,22 ... are excited.

In such a structure, the slots 22, 22,.
Reflective conductors placed between feed striplines 24
By 28, unnecessary radiation from the second feeding strip line 24 is shielded. Also, the beam radiated from the slots 22, 22,... Toward the reflective conductor 28 has no conductor other than the through holes 30, 30 between the slots 22, 22,. Reflective conductor without disturbing
Reflected at 28. As a result, the radiation pattern on the front surface side of the first dielectric layer 10 is not affected by the feeder. In addition, the shield conductor 40 blocks unnecessary radiation from the second feed strip line 24 radiated to the back surface side of the fourth dielectric layer 16, thereby improving the front-rear ratio.

By the way, in the fourth embodiment, the fourth dielectric layer
The front-to-back ratio is improved by arranging the shielding conductor 40 on the entire back surface of the third dielectric layer 16. However, if improvement of the front-to-back ratio is not particularly required, the second power supply is provided on the back surface of the third dielectric layer 14. The fourth dielectric layer 16 and the shield conductor 40 may be omitted by forming the strip line 24. Even in such a case, the second feeding strip line 24 is formed as a microstrip line by the reflection conductor 40 with the third dielectric layer 14 interposed therebetween, and the microwave signal can be propagated.

In the above embodiment, the first, second, third, and fourth dielectric layers 10, 12, 14, and 16 may have the same dielectric constant, but may have different dielectric constants. You may.

(Effects of the Invention) Since the present invention is configured as described above,
The following effects are obtained.

First, in the microstrip slot array antenna according to the first aspect, a feed portion of the antenna is incorporated in a substrate in which a plurality of dielectric layers are laminated and integrated, and the antenna is manufactured accurately using a printed wiring technology. As a result, the antenna characteristics are stable and the earthquake resistance is excellent. Moreover, by manufacturing using the printed wiring technology, it is suitable for mass production and can be manufactured at low cost.

Further, in the microstrip slot array antenna according to the second aspect, since the reflecting conductor is arranged on the back surface of the substrate in which a plurality of dielectric layers are laminated and integrated, the efficiency is increased only in one direction on the surface of the substrate. A good radiation beam can be formed.

According to the microstrip slot array antenna of the third aspect, the same effect as that of the microstrip slot array antenna of the second aspect is obtained, and the substrate is thinner by the amount that the fourth dielectric layer is not laminated. This is advantageous for miniaturization.

Further, in the microstrip slot array antenna according to the fourth aspect, the same effect as that of the microstrip slot array antenna according to the second aspect is obtained, and the substrate is easily fixed using a reflector made of a conductive metal. can do.

Further, in the microstrip slot array antenna according to the fifth aspect, since the reflecting conductor is arranged between the slot and the second feeding strip line,
Unwanted radiation from the second feed stripline is shielded by the reflective conductor. Further, since there is no conductor other than the through hole between the slot and the reflecting conductor, the beam emitted from the slot toward the reflecting conductor is reflected without being disturbed. Therefore, the radiation pattern on the surface side of the first dielectric layer is not affected by the feeder at all, and a radiation pattern with a low side lobe level according to an appropriate design value can be easily obtained.

Further, in the microstrip slot array antenna according to the sixth aspect, unnecessary radiation by the second feed strip line is shielded by the shielding conductor disposed on the entire back surface of the fourth dielectric layer, and Improvements are made.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a microstrip slot array antenna according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an exploded perspective view of a microstrip slot array antenna according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line 3-B in FIG.
FIG. 5 is an exploded perspective view of a microstrip slot array antenna according to a third embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along the line CC in FIG.
FIG. 7 is an exploded perspective view of a fourth embodiment of the microstrip slot array antenna according to the present invention, and FIG. 8 is a sectional view taken along the line DD in FIG. 10: first dielectric layer, 12: second dielectric layer, 14: third dielectric layer, 16: fourth dielectric layer, 18: feeding strip line, 20: conductive film, 22: slot , 24: second feed strip line, 26: substrate conductor, 28: reflective conductor, 30: through hole, 38: reflective plate, 40: shield conductor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01Q 13/10 H01Q 21/08 H01P 5/12

Claims (6)

(57) [Claims] 1. A first power supply strip line is formed on a surface of the first dielectric layer by laminating first, second, and third dielectric layers in order, and the first and second dielectric layers are A plurality of slots are arranged in the conductive film disposed therebetween along the power supply strip line, and a second power supply strip line having one end serving as a power supply point is provided between the second and third dielectric layers. The second power supply strip line and the power supply strip line are connected to each other by a through hole passing through the first and second dielectric layers. A microstrip slot array antenna, wherein a substrate conductor facing the second feed strip line is arranged on the back surface of the body layer. 2. The microstrip slot array antenna according to claim 1, wherein said first, second, and third antennas are arranged in parallel.
A fourth dielectric layer is further laminated on the laminated body of the dielectric layers of the above, and a substrate conductor disposed on the back surface of the third dielectric layer is provided in a small area, and the entire back surface of the fourth dielectric layer is provided. A microstrip slot array antenna, characterized in that a reflecting conductor is disposed on the antenna. 3. The microstrip slot array antenna according to claim 1, wherein said substrate conductor is disposed on the entire back surface of said third dielectric layer. 4. A microstrip slot array antenna according to claim 1, wherein a reflector made of a conductive metal is arranged parallel to and spaced from the back surface of said third dielectric layer. . 5. A power supply strip line is formed on a surface of said first dielectric layer by laminating first, second and third dielectric layers in order. A plurality of slots are arranged along the power supply strip line in the conductive film disposed therebetween, and a reflecting conductor is disposed on the entire surface between the second and third dielectric layers. A second power supply strip line, one end of which is a power supply point, is disposed on the back surface of the dielectric layer so as to cross the power supply strip line, and the second power supply strip line and the power supply strip line are connected to the first and second power supply strip lines. A microstrip slot array antenna, wherein the antennas are connected by through holes penetrating the second and third dielectric layers. 6. The microstrip slot array antenna according to claim 5, wherein said first, second, and third antennas are arranged in parallel.
A fourth dielectric layer is further laminated on the laminate of the above dielectric layers, and a shield conductor is disposed on the entire back surface of the fourth dielectric layer.