JP4814818B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device.

Patent Document 1 is known as a planar antenna. This can be manufactured especially for both circularly polarized waves and linearly polarized waves. Specifically, as shown in FIG. 6, the antenna plate conductive plate 101 is provided on the main plane 100 a side of the ground plane 100, and the other plane 100 b is configured to supply power to a predetermined one of circular polarization and linear polarization. A substrate 102 on which a circuit is formed is installed. The antenna element conductive plate 101 has two circularly polarized feed points and one linearly polarized feed point, and one of the linearly polarized feed points uses one of the circularly polarized feed points. is doing. The core wire of the cable 103 is connected to the substrate 102 on which the power feeding circuit is formed.
Japanese Patent No. 3804924

Although it is possible to manufacture an antenna device that can use circularly polarized waves or linearly polarized waves by using the substrate 102 having the same shape, it cannot be switched during use.
The present invention has been made under such a background, and its purpose is to switch between four types of polarization: horizontal polarization, vertical polarization, right-hand circular polarization, and left-hand circular polarization. An object of the present invention is to provide an antenna device that can be used.

  In order to solve the above-mentioned problem, in the invention according to claim 1, a ground plate having one surface as a first surface and the other surface as a second surface, and a first surface of the ground plate It is arranged facing the ground plane in a spaced state, a rectangular through hole is formed in the center, and the first and second feeding points on the orthogonal sides of the through hole, and the other through the through hole The antenna element conductive plate member having the third and fourth feed points on the sides perpendicular to each other, and a straight line provided on the second surface of the ground plate and having a feed line to the first and second feed points Mounted on the polarization-feeding power supply board, the circularly-polarized power-feeding board provided on the second surface of the ground plane, and having power supply lines to the third and fourth power-feeding points, and the linearly-polarization power-feeding board Provided in the middle of the feeder line to the first and second feeding points, and selectively feeds the first feeding point or the second feeding point. A switch for linear polarization that is possible, and mounted on the feed board for circular polarization, provided in the middle of the feed line to the third and fourth feed points, and the third feed point and the fourth feed point A circularly polarized wave switch capable of supplying a phase of 90 degrees or minus 90 degrees to the point, and when using the horizontally polarized wave, the linearly polarized wave switch is controlled to feed power to the first feeding point. When using the circularly polarized wave, the linearly polarized wave switch is controlled to feed power to the second feeding point. When using right-handed circularly polarized wave, the circularly polarized wave switch is controlled to control the third feeding point. The fourth feeding point is fed with a phase of plus 90 degrees, and when using the left-handed circularly polarized wave, the circularly polarized wave switch is controlled so that the third feeding point and the fourth feeding point have a minus 90 degree phase. And a switch control means for supplying power.

  According to the first aspect of the present invention, the linear polarization switch and the circular polarization switch are controlled by the switch control means. Accordingly, the first feeding point is fed when using the horizontally polarized wave, the second feeding point is fed when using the vertically polarized wave, and the third feeding point and the fourth feeding point are used when using the right turn circularly polarized wave. The phase feed of plus 90 degrees can be fed to this feed point, and the phase feed of minus 90 degrees can be fed to the third feed point and the fourth feed point when using left-handed circularly polarized waves. As a result, it is possible to switch and use four types of polarized waves: horizontal polarization, vertical polarization, right-hand circular polarization, and left-hand circular polarization.

As described in claim 2, in the antenna device according to claim 1, each feeding point is preferably installed at a midpoint position of the side of the rectangular through hole.
According to a third aspect of the present invention, in the antenna device according to the first or second aspect, the power feeding member between the ground plane and the antenna element conductive plate material may include a part of the antenna element conductive plate material as the ground plane. It is good to be comprised by bending to the side.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
The cross-sectional view of FIG. 1 shows the overall configuration of the antenna device. As shown in FIG. 1, a patch antenna 10 is accommodated in the resin case 1. The case 1 includes a case body 2 and a cover 3. The case body 2 has a box shape with one surface opened, and the opening of the case body 2 is closed by a cover 3. The patch antenna 10 includes a ground plane 11 and an antenna element conductive plate 12. A patch antenna support member 4 protrudes from the inner surface of the case body 2, and a ground plane 11 is fixed to the patch antenna support member 4. This antenna device (patch antenna) can be used for RFID, for example, and can switch polarization.

  FIG. 2 shows the patch antenna 10, and FIG. 2A is a plan view of the patch antenna 10, that is, a view of the patch antenna 10 viewed from the α direction in FIG. 1. FIG. 2B is a side view of the patch antenna 10 (viewed in the direction of arrow B in FIG. 2A). FIG. 3 is a rear view of the patch antenna, that is, the patch antenna 10 viewed from the β direction of FIG. FIG. 4 is a longitudinal sectional view taken along line AA in FIG. FIG. 5 shows an exploded perspective view of the patch antenna 10.

  As shown in FIG. 5, the patch antenna 10 is fastened with a ground plane 11, an antenna element conductive plate 12, and spacers (pedestals) 13a, 13b, 13c, 13d disposed between the members 11, 12. Screws 14a, 14b, 14c, and 14d as members, screws 15a, 15b, 15c, and 15d, and power supply terminals (power supply lines) 16a, 16b, 16c, and 16d are provided.

  As shown in FIG. 2, the ground plane 11 is made of a square metal plate, specifically, an iron plate or a copper plate. One surface of the base plate 11 is a first surface 11a and the other surface is a second surface 11b. The antenna element conductive plate 12 is made of a metal plate, specifically, an iron plate or a copper plate.

  The antenna element conductive plate 12 has a square shape as a whole, and the vertical and horizontal sizes are smaller than the main plate 11. Each side of the square antenna element conductive plate 12 is defined as So1, So2, So3, and So4. The antenna element conductive plate 12 is disposed to face the ground plane 11 in a state of being separated from the first surface 11 a of the ground plane 11.

  In the plan view of FIG. 2A, the antenna element conductive plate 12 having a square shape has a through hole 17 formed at the center. The through-hole 17 has the same center as the antenna element conductive plate 12 having a square shape, and has a square shape similar to the antenna element conductive plate 12. Thereby, each side Si1, Si2, Si3, Si4 of the through-hole 17 forming a square is parallel to each side So1, So2, So3, So4 of the square antenna element conductive plate 12. In FIG. 2, the side So1 and the side Si1, the side So2 and the side Si2, the side So3 and the side Si3, and the side So4 and the side Si4 are parallel to each other.

  In this way, the rectangular through hole (opening) 17 is disposed at the center of the antenna element conductive plate 12 so as to resonate at a desired frequency and the input impedance is about 50Ω.

  Feed terminals 16a, 16b, 16c, and 16d extend downward from the midpoint position of the sides Si1, Si2, Si3, and Si4 of the square through-hole 17 in the antenna element conductive plate 12. The power supply terminals 16a, 16b, 16c, and 16d have a triangular strip shape as shown in FIG. 5, and are formed by bending a part of the antenna element conductive plate 12 to the ground plane 11 side.

  With respect to the spacers 13a, 13b, 13c, and 13d, the ground plate 11 and the antenna element conductive plate 12 are disposed to face each other with a predetermined interval by the four spacers 13a, 13b, 13c, and 13d. The spacers 13a, 13b, 13c, 13d are cylindrical, and the inner surfaces of the spacers 13a, 13b, 13c, 13d (inner surfaces of the cylindrical members) are female screw portions, and the screws 14a, 14b, 14c, 14d, 15a, 15b, 15c, 15d can be screwed in. The spacers 13a, 13b, 13c, and 13d are made of an insulating material, and specifically made of ABS resin.

  As shown in FIG. 5, the antenna element conductive plate 12 is formed with four through holes 18a, 18b, 18c, and 18d. The through holes 18a, 18b, 18c, and 18d are intermediate positions between the outer peripheral end and the inner peripheral end of the antenna element conductive plate 12, and the sides So1, So2, So3, So4 of the square antenna element conductive plate 12. Are formed on a line connecting the midpoints of the squares and the midpoints of the corresponding sides Si1, Si2, Si3, Si4 in the square through holes 17.

  As shown in FIG. 5, through holes 19 a, 19 b, 19 c, and 19 d are also formed in the ground plane 11 at positions corresponding to the through holes 18 a, 18 b, 18 c, and 18 d of the antenna element conductive plate 12.

  Screws 14a, 14b, 14c, and 14d are screwed into spacers 13a, 13b, 13c, and 13d through the antenna element conductive plate 12, and screws 15a, 15b, 15c, and 15d are passed through the ground plate 11 and spacers 13a, 13b, and 13c. , 13d. Specifically, the screws 14a, 14b, 14c, 14d, 15a, 15b, 15c, and 15d are screwed into the spacers 13a, 13b, 13c, and 13d in a state of passing through the antenna element conductive plate 12 and the ground plate 11. 11 and the antenna element conductive plate 12 are fixed. That is, the spacers 13a, 13b, 13c, and 13d are placed on the ground plate 11, the antenna element conductive plate 12 is further disposed thereon, and the screws 14a, 14b, 14c, 14d is screwed into the female threaded portions of the spacers 13a, 13b, 13c, 13d through the through holes 18a, 18b, 18c, 18d provided in the antenna element conductive plate 12, and screws 15a, 15b from the lower side of the base plate 11 , 15c, 15d are screwed into the female screw portions of the spacers 13a, 13b, 13c, 13d through the through holes 19a, 19b, 19c, 19d provided in the ground plate 11, and the ground plate 11, the antenna element conductive plate material 12, Is fixed.

  Further, as shown in FIG. 5, through holes 20 a, 20 b, 20 c, and 20 d are formed in the ground plane 11, and the power supply terminals 16 a, 16 b, 16 c, and 16 d are connected to the ground plane 11 through the through holes 20 a, 20 b, 20 c, and 20 d. Projects to the bottom. The base ends (folded portions) of the power supply terminals 16a, 16b, 16c, and 16d are power supply points P1, P2, P3, and P4 as shown in FIG. 2, and the first power supply point P1 is at the power supply terminal 16a. The second feeding point P2 is constituted by the feeding terminal 16b, the third feeding point P3 is constituted by the feeding terminal 16c, and the fourth feeding point P4 is constituted by the feeding terminal 16d. That is, the first and second feeding points P1 and P2 are orthogonal to the orthogonal sides Si1 and Si2 in the rectangular through-hole 17, and the third and fourth are input to the other orthogonal sides Si3 and Si4 in the through-hole 17. It has feeding points P3 and P4. In particular, the feeding points P1, P2, P3, and P4 are installed at the midpoint positions of the sides Si1, Si2, Si3, and Si4 of the rectangular through hole 17.

In this way, four power supply portions are installed on the sides of the through holes (openings) 17 of the antenna element conductive plate 12 so that they are orthogonal to each other.
In this embodiment, the spacers 13a, 13b, 13c, 13d, the screws 14a, 14b, 14c, 14d and the screws 15a, 15b, 15c, 15d constitute four sets of fixing members, and the four spacers 13a, 13b, 13c. , 13d and the four screws 14a, 14b, 14c, 14d and the four screws 15a, 15b, 15c, 15d constitute a plurality of fixing members for fixing the ground plate 11 and the antenna element conductive plate 12. Yes. This fixing member is arranged so that the ground plane 11 and the antenna element conductive plate 12 are in a non-conductive state. That is, a method is adopted in which the screws 14a, 14b, 14c, 14d, 15a, 15b, 15c, and 15d are screwed in using the spacers 13a, 13b, 13c, and 13d having electrical insulation properties, and the base plate 11 and the antenna element are used. The conductive plate 12 is fixed in a non-conductive state.

  As shown in FIG. 3, a linearly polarized power supply substrate 30 and a circularly polarized power supply substrate 40 are provided on the second surface 11 b of the ground plane 11. These power supply boards 30 and 40 are fixed by screwing screws or the like into the base plate 11 at the corners.

  The linearly polarized wave power supply substrate 30 has a power supply line L1 to the first and second power supply points P1 and P2 (power supply terminals 16a and 16b). A linearly polarized wave switch (switching switch: RF switch) 31 is mounted on the linearly polarized wave power supply board 30, and the linearly polarized wave switch 31 is connected to the first and second feed points P1 and P2 in the feed line L1. Inserted at the branch point. In other words, the linear polarization switch 31 is provided in the middle of the power supply line L1 to the first and second power supply points P1 and P2, and is selectively set to the first power supply point P1 or the second power supply point P2 by the control signal. It is the structure which can be supplied with electricity. The linearly polarized power supply board 30 is connected to a power supply cable 32, and a high frequency signal is sent to the power supply line L1. As shown in FIG. 1, the power supply cable 32 is connected to a connector 50 attached to the case 1, and the connector 50 is connected to an RF machine 52 via an external cable 51. The RF machine 52 selects the linearly polarized wave and switches between the horizontally polarized wave and the vertically polarized wave in the linearly polarized wave.

  3 has a feed line L2 to the third and fourth feed points P3 and P4 (feed terminals 16c and 16d). A circularly polarized wave switch (switching switch: RF switch) 41 is mounted on the circularly polarized wave power supply substrate 40. The circularly polarized wave switch 41 is provided in the middle of the third and fourth feed lines L2, and has a phase of plus 90 degrees or minus 90 degrees to the third feed point P3 and the fourth feed point P4 according to the control signal. It has a configuration that can supply power. In detail, the circular polarization switch 41 uses a 90-degree hybrid IC (chip), and the phase of the high-frequency signal can be shifted by 90 degrees by an external signal. The circularly polarized power supply board 40 is connected to a power supply cable 42, and a high-frequency signal is sent to the power supply line L2. As shown in FIG. 1, the power supply cable 42 is connected to a connector 50 attached to the case 1, and the connector 50 is connected to an RF machine 52 via an external cable 51. The RF machine 52 selects circularly polarized waves and switches between right and left polarizations in circular polarization.

Next, the operation of the antenna device will be described.
Polarization is selected in the following four uses (modes) by a signal from the RF machine 52 as a controller. That is, horizontal polarization and vertical polarization can be selected for linear polarization, and right-turn polarization and left-turn polarization can be selected for circular polarization.

  When using horizontally polarized waves, the linearly polarized wave switch 31 is controlled to feed power to the first feeding point P1. When the vertically polarized wave is used, the linearly polarized wave switch 31 is controlled to feed power to the second feeding point P2. Therefore, horizontal polarization and vertical polarization can be used for linear polarization.

  On the other hand, when the right-handed polarized wave is used, the circularly polarized wave switch 41 is controlled to feed the third feeding point P3 and the fourth feeding point P4 with a phase of +90 degrees. Further, when using the left-handed circularly polarized wave, the circularly polarized wave switch 41 is controlled to feed a phase of minus 90 degrees to the third feeding point P3 and the fourth feeding point P4. Therefore, right-handed polarized waves and left-handed polarized waves can be used for circularly polarized waves.

  In this way, polarization is generated and switched, and in a patch antenna using the square antenna element conductive plate 12, circular / straight lines are fed by feeding to the feeding points P1, P2 and feeding points P3, P4. Polarization can be obtained. In other words, by providing four feeding parts, two sets of feeding parts that are orthogonal to each other are realized (two sets of feeding point P1 and feeding point P2, feeding point P3 and feeding point P4). By adopting this four-point power feeding, it is possible to realize the generation of a plurality of polarized waves, and further it is possible to switch the polarized waves during use.

According to the above embodiment, the following effects can be obtained.
(1) As a configuration of the antenna device, the antenna element conductive plate 12 is disposed to face the ground plane 11 in a state of being separated from the first surface 11a of the ground plane 11, and a square through hole 17 is formed at the center. And the first and second feeding points P1 and P2 on the orthogonal sides Si1 and Si2 in the through hole 17 and the third and fourth feedings on the other orthogonal sides Si3 and Si4 in the through hole 17. It has points P3 and P4. The second surface 11b of the ground plane 11 has a linearly polarized power supply substrate 30 having a power supply line L1 to the first and second power supply points P1 and P2, and the third and fourth power supply points P3 and P4. A circularly polarized power supply substrate 40 having a power supply line L2 is provided. The RF machine 52 serving as a switch control unit controls the linearly polarized wave switch 31 to supply power to the first feeding point P1 when using the horizontally polarized wave, and controls the linearly polarized wave switch 31 when using vertically polarized wave. Then, the second feeding point P2 is fed, and when using the right turn circularly polarized wave, the circularly polarized wave switch 41 is controlled so that the third feeding point P3 and the fourth feeding point P4 have a phase of plus 90 degrees. When the left-handed circularly polarized wave is used, the circularly polarized wave switch 41 is controlled to feed a phase of minus 90 degrees to the third feeding point P3 and the fourth feeding point P4. As a result, the number of power feeding locations is increased, and switches (RF switches) 31 and 41 are provided on the power feeding board, so that four types of horizontal polarized waves, vertical polarized waves, right-handed circularly polarized waves, and left-handed circularly polarized waves are provided. The polarization can be switched and used.

  (2) Since each feed point P1, P2, P3, P4 is installed at the midpoint position of the sides Si1, Si2, Si3, Si4 of the rectangular through hole 17, it is preferable in securing antenna performance. .

  (3) The power supply terminals 16a, 16b, 16c, and 16d as power supply members between the ground plate 11 and the antenna element conductive plate 12 are obtained by bending a part of the antenna element conductive plate 12 to the ground plate 11 side. Since it is configured, a power supply terminal can be easily built.

In addition, you may change the said embodiment as follows.
The antenna element conductive plate 12 has a rectangular shape, but may have another shape, for example, a circle. Moreover, although the through-hole 17 was a square, a rectangle may be sufficient.

Although the power supply terminals 16a to 16d are tapered, other shapes such as a rectangle may be used, or power supply lines may be used.
The case 1 is formed of a resin material, but the power supply board surface side of the ground plane 11, that is, the surface 11b side may be made of metal.

  In FIG. 1 and the like, the feeding cables 32 and 42 are centered and electrically connected to the feeding boards 30 and 40. However, the present invention is not limited to this, and the feeding boards 30 and 40 and the feeding cables 32 and 42 are connected via connectors. May be connected.

Sectional drawing which shows the whole structure of the antenna device in this embodiment. (A) is a top view of a patch antenna, (b) is a side view of a patch antenna. The rear view of a patch antenna. The longitudinal cross-sectional view in the AA line of Fig.2 (a). The exploded perspective view of a patch antenna. Sectional drawing for demonstrating background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Ground plane, 11a ... 1st surface, 11b ... 2nd surface, 12 ... Conductive board material for antenna elements, 16a, 16b, 16c, 16d ... Feed terminal, 17 ... Through-hole, 30 ... Feed for linearly polarized wave Substrate, 31 ... switch for linear polarization, 40 ... feed board for circular polarization, 41 ... switch for circular polarization, L1 ... feed line, L2 ... feed line, P1 ... first feed point, P2 ... second Feed point, P3 ... third feed point, P4 ... fourth feed point, Si1, Si2, Si3, Si4 ... side.

Claims (3)

A ground plane (11) having one surface as a first surface (11a) and the other surface as a second surface (11b);
The ground plate (11) is disposed to face the ground plate (11) in a state of being separated from the first surface (11a), and a square through hole (17) is formed at the center and the through hole (17). The first and second feeding points (P1, P2) on the orthogonal sides (Si1, Si2) and the third and third feeding points (Si3, Si4) on the other through-hole (17). An antenna element conductive plate (12) having four feeding points (P3, P4);
A linearly polarized power supply substrate (30) provided on the second surface (11b) of the ground plane (11) and having a power supply line (L1) to the first and second power supply points (P1, P2); ,
A circularly polarized power supply substrate (40) provided on the second surface (11b) of the ground plane (11) and having a power supply line (L2) to the third and fourth power supply points (P3, P4); ,
It is mounted on the linearly polarized wave power supply substrate (30), provided in the middle of the power supply line (L1) to the first and second power supply points (P1, P2), and the first power supply point (P1). Or a linearly polarized wave switch (31) capable of selectively supplying power to the second feeding point (P2);
Mounted on the circularly polarized wave power supply substrate (40), provided in the middle of the power supply line (L2) to the third and fourth power supply points (P3, P4), and the third power supply point (P3) And a circularly polarized wave switch (41) capable of phase feeding of plus 90 degrees or minus 90 degrees to the fourth feeding point (P4),
When the horizontal polarization is used, the linear polarization switch (31) is controlled to feed power to the first feeding point (P1), and when the vertical polarization is used, the linear polarization switch (31) is controlled. Then, the second feeding point (P2) is fed, and when using the right turn circularly polarized wave, the circularly polarized wave switch (41) is controlled to control the third feeding point (P3) and the fourth feeding point (P3). The feeding point (P4) is fed with a phase of +90 degrees, and when using the left-turn circularly polarized wave, the circularly polarized wave switch (41) is controlled to control the third feeding point (P3) and the fourth feeding point. Switch control means (52) for feeding a phase power of minus 90 degrees to (P4);
An antenna device comprising: The antenna device according to claim 1,
Each of the feeding points (P1, P2, P3, P4) is installed at the midpoint position of the side (Si1, Si2, Si3, Si4) of the rectangular through hole (17). The antenna device according to claim 1 or 2,
A feeding member (16a, 16b, 16c, 16d) between the ground plate (11) and the antenna element conductive plate (12) is a part of the antenna element conductive plate (12). An antenna device characterized in that the antenna device is formed by bending to the side.

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