JP3003604B2 - Microstrip planar antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip planar antenna with a parasitic element used for a radio communication device or the like.

[0002]

2. Description of the Related Art In a microstrip planar antenna with a parasitic element, a feed element is formed on one surface of a dielectric plate, and a ground conductor plate is provided on the other surface of the dielectric plate. A parasitic element is arranged on the feed element side of the body plate at an arbitrary distance from the feed element. The distance between the feeding element and the parasitic element is about 8 mm from the frequency L band to the vicinity of the S band, and it can be reduced to about 1 mm by interposing a dielectric between the feeding element and the parasitic element. it can. A method of directly attaching a parasitic element to a radome for covering a microstrip planar antenna is disclosed in JP-A-2-141007. The radome is typically a rigid thin shell made of a dielectric transparent to radio frequency electromagnetic radiation and is used to house radar antennas and other similarly structured space communication antennas. FIG.
1 is a cross-sectional view of a conventional microstrip planar antenna with a parasitic element according to JP-A-141007.

In a conventional microstrip planar antenna, as shown in FIG. 6, a feeding element 102 is formed on one surface of a dielectric plate 103, and a ground conductor plate (not shown) is formed on the other surface of the dielectric plate 103. Is provided with the feed element 102
Is attached to the surface of the main body member 105 so that The entire dielectric plate 103 is covered by a radome 106 as a dielectric member.
A space is provided between the upper feeding element 102 and the radome 106. The feed element 10 of this radome 106
A parasitic element 101 is formed on the surface facing 2.

Next, the operation of the conventional microstrip planar antenna configured as described above will be described.
When the feed element 102 is excited, the parasitic element 101 resonates via a space between the feed element 102 and the parasitic element 101, and a radio wave is emitted outside the microstrip planar antenna.

A method for reducing the size of a microstrip planar antenna with a parasitic element is disclosed in Japanese Patent Laid-Open No. 3-7 / 1990.
No. 4907. JP-A-3-74907
According to the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-107, the degree of freedom in designing a microstrip planar antenna can be improved and the overall shape of the antenna can be reduced.

[0006]

However, in a microstrip planar antenna with a parasitic element, the parasitic element must be arranged at a certain distance from the feeding element, and the thickness for securing this interval is required. Of the microstrip planar antenna. Therefore, there is a problem that the thickness of the microstrip planar antenna restricts miniaturization and improvement in portability of a wireless communication device having the microstrip planar antenna.

An object of the present invention is to reduce the size and portability of a microstrip planar antenna with a parasitic element and a radio communication device having the microstrip planar antenna in view of the above-mentioned problems of the prior art. Another object of the present invention is to provide a miniaturized microstrip planar antenna.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a main body member forming an outer shell of a radio communication device,
A dielectric plate disposed inside the main body member, a feed element formed on one surface of the dielectric plate and disposed inside the main body member, and a ground conductor plate provided on the other surface of the dielectric plate A parasitic element disposed on the feeder element side of the dielectric plate at an arbitrary distance from the feeder element, and a dielectric member formed with the parasitic element and disposed outside the main body member And a moving means for moving the dielectric member to dispose the parasitic element at a different position with respect to the feed element.

Further, the moving means is a parallel crank mechanism in which the dielectric member is attached to the main body member via two links of the same length arranged at an arbitrary distance in parallel with each other. Is preferred.

Further, it is preferable that the moving means is a cam mechanism attached to the main body member.

Further, the moving means intersects two links of the same length at the center of each link, and attaches the dielectric member to the main body member via the two intersecting links. It is preferable that the link mechanism is formed by a link mechanism.

Further, it is preferable that the moving means is a feed mechanism including a rack provided on the dielectric member and a pinion provided on the main body member, which meshes with the rack.

[0013] According to the invention as described above, in a microstrip planar antenna in which a parasitic element arranged at an arbitrary distance from a feed element is formed on a dielectric member,
There is provided moving means for moving the dielectric member and disposing the parasitic element formed on the dielectric member at a different position with respect to the feed element. By providing such a moving means, the dielectric member is moved when the microstrip planar antenna is not used, and the distance between the feeding element and the parasitic element required for communication using the microstrip planar antenna is reduced. Small or can be eliminated. Therefore, when storing or carrying the wireless communication device provided with the microstrip planar antenna, the thickness of the microstrip planar antenna can be reduced, and the wireless communication device can be downsized.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a sectional view showing a first embodiment of a microstrip planar antenna according to the present invention. In the microstrip planar antenna according to the present embodiment, as shown in FIG. 1, one end of each of two connection nodes 7 of the same length, which are arranged in parallel at an arbitrary distance and function as a link, are, for example, wireless. Main body member 5 serving as an outer surface of main body member 5 forming the outer shell of the communication device
And a plate-shaped radome 6, which is a dielectric member, is connected to the other end of the connection node 7 in parallel with the surface of the main body member 5. In such a connection portion of each connection node 7, the connection node 7 is rotatable in one plane. Therefore, the main body member 5, the two connecting nodes 6, and the radome 6 constitute a parallel crank mechanism as a moving means of the radome 6. In addition, radome 6
The parasitic element 1 is formed on a surface facing the main body member 5. Inside the main body member 5, one in which the feed element 2 and the ground conductor plate 4 are formed with the dielectric plate 3 interposed therebetween is arranged, and the feed element 2 and the parasitic element 1 are arbitrarily arranged between the main body member 5. They face each other at a distance. When the radome 6 is most extended from the main body member 5, the parasitic element 1 faces the feeding element 2 at an arbitrary distance and has a function as an antenna.

In the radio communication device using the microstrip planar antenna configured as described above, when communicating with the radio communication device, the radome 6 is pulled up by the parallel crank mechanism to be in an expanded state, and is bonded to the radome 6. The parasitic element 1 is separated from the feed element 2 by a required distance, and a microstrip planar antenna is used. When storing and transporting the wireless communication device, the radome 6 is brought into the state closest to the main body member 5 by the parallel crank mechanism, and the thickness of the microstrip planar antenna is reduced.

Therefore, the microstrip planar antenna of the present embodiment has a function as an antenna only when communicating with the wireless communication device, and the thickness of the microstrip planar antenna is small when storing and carrying the wireless communication device. As a result, the wireless communication device is downsized.

(Second Embodiment) FIG. 2 is a sectional view showing a microstrip planar antenna according to a second embodiment of the present invention. In the planar microstrip antenna of the present embodiment, as shown in FIG. 2, sliders 31 are formed at both ends of a plate-shaped radome 26 which is a dielectric member and extend perpendicularly to one surface of the radome 26. I have. Then, two grooves for allowing the slider 31 to slide in a direction perpendicular to the surface of the radome 26 are provided on, for example, the outer surface of the main body member 25 forming the outer shell of the wireless communication device. Two cams 28 are attached to the main body member 25 and protrude outward from the surface of the main body member 25, and a radome 26 is mounted on the protruding portion of the cam 28 in parallel with the main body member 25. The slider 31 of the radome 26 is fitted in the groove of the main body member 25. Further, by fixing one end of the tension spring 30 to the radome 26 and fixing the other end of the tension spring 30 to the main body member 25, the radome 26 is always drawn to the main body member 25. The two cams 28 are connected by a connecting node 29 inside the main body member 25, and the rotations of the two cams 28 are synchronized. Therefore, the radome 2 is formed by the two cams 28.
A cam mechanism as moving means 6 is configured, and the radome 26 moves in a direction perpendicular to the surface of the main body member 25 by rotation of the cam 28. The body member 25 of the radome 26
A parasitic element 21 is formed on the side surface. Inside the main body member 25, a feed element 22 and a ground conductor plate 24 are formed with a dielectric plate 23 interposed therebetween as in the first embodiment. The members 25 face each other with an arbitrary distance therebetween.

In the wireless communication device using the microstrip planar antenna configured as described above, when communicating with the wireless communication device, the cam 28 is rotated to move the radome 26 in a direction perpendicular to the surface of the main body member 25. To the state where the radome 26 is farthest from the main body member 25, and the parasitic element 21 formed on the radome 26 is
From the required distance. When storing and transporting the wireless communication device, the cam 28 is rotated to move the radome 26 so that the radome 26 is closest to the main body member 25 to reduce the thickness of the microstrip planar antenna.

Therefore, the microstrip planar antenna of the present embodiment has a function as an antenna only when communicating with the wireless communication device, and the thickness of the microstrip planar antenna is small when storing and carrying the wireless communication device. As a result, the wireless communication device is downsized.

(Third Embodiment) FIG. 3 is a cross-sectional view showing a microstrip planar antenna according to a third embodiment of the present invention. In the microstrip planar antenna of this embodiment, as shown in FIG. 3, two cams 48 attached to the main body member 45 project outward from the main body member 45 forming, for example, an outer shell of the wireless communication device. 4
8, a plate-shaped radome 46 as a dielectric member is placed in parallel with the main body member 45,
The parasitic element 41 is provided on the surface of the radome 46 on the body member 45 side.
Are formed. The two cams 48 are connected by a connecting node 49 inside the main body member 45, and the rotations of the two cams 48 are synchronized. Further, by fixing one end of the leaf spring 52 to the radome 46 and fixing the other end of the leaf spring 52 to the main body member 45, the radome 46 is always drawn to the main body member 45. Therefore, a cam mechanism as a moving means of the radome 46 is constituted by the two cams 48, and the radome 46 moves in a direction perpendicular to the surface of the main body member 45 by the rotation of the cam 48. Inside the main body member 45, a feed element 42 and a ground conductor plate 44 formed with a dielectric plate 43 interposed therebetween as in the first embodiment are arranged. The members 45 face each other with an arbitrary distance therebetween.

In the wireless communication device using the microstrip planar antenna configured as described above, the cam 48 is rotated to communicate the radome 46 with the main body member 45 when communicating with the wireless communication device, similarly to the second embodiment. And the radome 46 is moved farthest from the main body member 45, and the parasitic element 41 formed on the radome 46 is arranged at a position separated by a necessary distance from the feed element 42. When storing and transporting the wireless communication device, the cam 48 is rotated to move the radome 46 so that the radome 46 is closest to the main body member 45 to reduce the thickness of the microstrip planar antenna.

Therefore, the microstrip planar antenna of this embodiment has an antenna function only when communicating with the wireless communication device, and the thickness of the microstrip planar antenna is small when storing and transporting the wireless communication device. As a result, the wireless communication device is downsized.

(Fourth Embodiment) FIG. 4 is a sectional view showing a microstrip planar antenna according to a fourth embodiment of the present invention. In the microstrip planar antenna of the present embodiment, as shown in FIG. 4, two connecting nodes 77 having the same length intersect at the center of each connecting node, and
A plate-shaped radome 66, which is a dielectric member, is attached in parallel to the outer surface of the main body member 65 forming an outer shell of the wireless communication device, for example, via the connection node 77 of the book. Connecting section 77 and radome 66 and connecting section 7
As a connecting portion between the main body member 65 and the main body member 65, two types, a rotation support portion 74 and a slide support portion 75, are provided for the main body member 65 and the radome 66, respectively. And the radome 66 are arranged to face each other. In the rotation support part 74, the connecting node 7
7 is rotatable in one plane and has a slide support 7
In 5, the connecting mechanism 77 is rotatable in one plane and is slidable in a direction parallel to the radome 66, thereby forming a link mechanism as a moving means of the radome 66. The radome 66 is connected to the main body member 65 by a link mechanism formed by crossing the two connecting nodes 77.
Move perpendicular to the plane. Of radome 66,
A parasitic element 61 is formed on the body member 65 side.
Inside the main body member 65, a feed element 62 and a ground conductor plate 64 are formed with a dielectric plate 63 interposed therebetween as in the first embodiment, and the feed element 62 and the parasitic element 61 are connected to the main body member. 65 oppose each other at an arbitrary distance.

In the wireless communication device using the microstrip planar antenna configured as described above, when communicating with the wireless communication device, the radome 6 is linked by the link mechanism.
6 is pulled up from the main body member 65 and deployed,
The parasitic element 61 formed on the radome 66 is
2 at a required distance. When storing and transporting the wireless communication device, the radome 66 is placed closest to the main body member by a link mechanism constituted by two connecting sections 77 having the same length, and the thickness of the microstrip planar antenna is reduced. I do.

Therefore, the microstrip planar antenna according to the present embodiment also has a sufficient function as an antenna only at the time of communication, and the thickness of the microstrip planar antenna becomes small when storing and carrying the wireless communication device. The wireless communication device is downsized.

(Fifth Embodiment) FIG. 5 is a sectional view showing a microstrip planar antenna according to a fifth embodiment of the present invention. In the planar microstrip antenna of the present embodiment, as shown in FIG. 5, a plate-shaped radome 86 as a dielectric member is provided with a rack 94 extending in a direction perpendicular to one surface of the radome 86. This rack 94
Pinion 95 with lever 96 meshing with each other
Is attached to a main body member 85 forming an outer shell of the wireless communication device, for example. The radome 86 is attached in parallel with the surface of the main body member 85 by the engagement between the rack 94 and the pinion 95. Pinion 95 and Rack 9
4 constitutes a feed mechanism as a means for moving the radome 86, and the pinion rotates according to the rotation of the lever 96, whereby the rack 94 is sent and the radome 86 moves in a direction perpendicular to the main body member 85. . Radome 8
6, a parasitic element 81 is formed on the surface facing the main body member 85. A dielectric plate 83 is provided inside the main body member 85.
A power supply element 82 and a ground conductor plate 84 are disposed with the power supply element 82 and the grounded conductor plate 84 interposed therebetween. The power supply element 82 and the parasitic element 81 face each other with an arbitrary distance between the main body member 85.

In the wireless communication device using the microstrip planar antenna configured as described above, the radome 86 is transmitted by the feed mechanism when communicating with the wireless communication device.
Is raised from the main body member 85, and the radome 8
The parasitic element 81 formed in 6 is arranged at a position separated from the feed element 82 by a necessary distance. When storing and carrying the wireless communication device, the radome 86 is brought closest to the main body member by a feed mechanism including the rack 94 and the pinion 95 to reduce the thickness of the microstrip planar antenna.

Therefore, the microstrip planar antenna of the present embodiment also has a sufficient function as an antenna only at the time of communication, and the thickness of the microstrip planar antenna becomes small when storing and carrying the wireless communication device. The wireless communication device is downsized.

In the first to fifth embodiments described above, the components of the microstrip planar antenna will be specifically described.

The radome and the body member are made of resin, and need not be metal. Since the main body member serving as a resin wall is sandwiched between the parasitic element and the power supply element, the thickness of the main body member and the dielectric constant of the resin material used for the main body member cause communication during communication. What is necessary is just to determine the optimal distance between the parasitic element and the feeding element.

A metal plate may be used as the parasitic element, and the metal plate may be fixed to the radome by bonding, fusing, snap-fitting, or the like, or a conductive coating applied to the radome may be used as the parasitic element. Good. It is also possible to form a parasitic element in a layer inside the radome.

If the device requires a waterproof structure, only the main body member may have a waterproof structure, and the radome and the parasitic element do not need to be particularly waterproof, but a metal plate is used as the parasitic element. In this case, the material of the metal plate may be stainless steel, or the metal plate may be formed on the inner layer of the radome as described above.

[0034]

As described above, the present invention provides a microstrip planar antenna with a parasitic element provided with a moving means for moving a dielectric member on which a parasitic element is formed. Secure the space between the parasitic element and the feeding element required for the antenna only during communication, and move the parasitic element closer to the feeding element when storing or transporting the wireless communication device equipped with the microstrip planar antenna. Therefore, there is an effect that the microstrip planar antenna is reduced in size and thickness when not particularly used. Along with that,
There is an effect that the portability of the microstrip planar antenna is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a microstrip planar antenna according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a microstrip planar antenna according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a microstrip planar antenna according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a microstrip planar antenna according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of a microstrip planar antenna according to a fifth embodiment of the present invention.

FIG. 6 is a cross-sectional view of a conventional microstrip planar antenna.

[Explanation of symbols]

 1, 21, 41, 61, 81, 101 Parasitic element 2, 22, 42, 62, 82, 102 Feeding element 3, 23, 43, 63, 83, 103 Dielectric plate 4, 24, 44, 64, 84 Grounding conductor plate 5, 25, 45, 65, 85, 105 Body member 6, 26, 46, 66, 86, 106 Radome 7, 77 Connection node 28, 48 Cam 29, 49 Connection node 30 Tension spring 31 Slider 52 Leaf spring 74 Rotation support part 75 Slide support part 94 Rack 95 Pinion 96 Lever

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 13/08 H01Q 1/40 H01Q 1/42

Claims (5)

(57) [Claims] A body member forming an outer shell of the wireless communication device;
A dielectric plate disposed inside the main body member, a power supply element formed on one surface of the dielectric plate and disposed inside the main body member, and a dielectric plate disposed on the other surface of the dielectric plate. The provided ground conductor plate, a parasitic element disposed at an arbitrary distance from the feed element on the feed element side of the dielectric plate, the parasitic element is formed, and the parasitic element is formed outside the main body member. A microstrip planar antenna having a dielectric member disposed therein, further comprising moving means for moving the dielectric member and disposing the parasitic element at a different position with respect to the feed element. A microstrip planar antenna, characterized in that: 2. The parallel crank mechanism wherein the moving means is a parallel crank mechanism in which the dielectric member is attached to the main body member via two links of the same length arranged at an arbitrary distance in parallel with each other. Item 2. A microstrip planar antenna according to item 1. 3. The microstrip planar antenna according to claim 1, wherein said moving means is a cam mechanism attached to said main body member. 4. The moving means crosses two links of the same length at the center of each link, and attaches the dielectric member to the main body member via the crossed two links. 2. The microstrip planar antenna according to claim 1, wherein the antenna is a link mechanism. 5. The feed mechanism according to claim 1, wherein the moving means is a feed mechanism including a rack provided on the dielectric member, and a pinion provided on the main body member, which meshes with the rack. Microstrip planar antenna.