JP2007194761A - Antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna system that is downsized, weight-reduced, cost-effective and can develop a high gain. <P>SOLUTION: The antenna system includes: a ground board (134); an antenna board (131) oppositely arranged to the ground board at a distance; an antenna probe (132) located between the ground board and the antenna board; and a resin-made probe holder (133) for supporting the antenna probe. The probe holder has a size equal to or more than an opposed area between the ground board and the antenna board so as to entirely fill nearly all the space between the ground board and the antenna board by a resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antenna device used for receiving radio waves of digital radio broadcasting.

  In recent years, digital radio receivers that can receive satellite radio waves or terrestrial waves and listen to digital radio broadcasts have been developed and put into practical use in the United States. This digital radio receiver can be mounted on a mobile station such as an automobile or installed in a building, and can receive radio waves by receiving radio waves having a frequency of about 2.3 GHz. Since the frequency of the received radio wave is about 2.3 GHz, the reception wavelength (resonance wavelength) λ at that time is about 128.3 mm. Incidentally, the terrestrial wave is obtained by retransmitting the artificial satellite wave by linearly polarized wave after slightly shifting the frequency after being received by the earth station.

  Since digital radio broadcasting uses radio waves with a frequency of about 2.3 GHz, it is preferable that an antenna device for receiving the radio waves be installed outdoors. Therefore, when the digital radio receiver is mounted on a car or the like, it is often mounted outside the car, for example, on the roof of the car. On the other hand, when a digital radio receiver is used in a building, the antenna device is often installed on a roof or a veranda.

  Digital radio broadcasts use satellite waves, especially circularly polarized waves. As disclosed in Patent Document 1, an antenna device including an antenna module corresponding to circularly polarized waves includes a ground plate, an antenna plate arranged to face the ground plate at a distance, a ground plate, and an antenna plate. The antenna probe is positioned between and a resin probe holder for holding the antenna probe. The probe holder is formed with a recess in which the antenna probe is disposed. A member made of an insulating material such as a tape for electrically insulating the antenna probe and the antenna plate is mounted on the top surface of the probe holder on which the antenna probe is disposed.

JP 2005-20644 A

  In order to reduce the size, weight, and cost of the antenna device including the example shown in Patent Document 1, it is effective to reduce the size, weight, and cost of the antenna module. Specifically, for example, it is conceivable to reduce the size of the ground plate and the antenna plate. However, when the ground plate and the antenna plate are reduced in size, there is a possibility that the capacitance of the antenna module necessary for this type of antenna device to exhibit sufficient gain may be reduced.

  Therefore, an object of the present invention is to provide an antenna device that is small in size, light in weight, low in cost, and capable of exhibiting high gain.

  According to the present invention, a ground plate (134), an antenna plate (131) disposed opposite to the ground plate at a distance, and an antenna probe (132) positioned between the ground plate and the antenna plate. ) And a resin probe holder (133) for holding the antenna probe, the probe holder is such that substantially the entire space between the ground plate and the antenna plate is filled with resin. In addition, an antenna device characterized in that it has a size equal to or larger than the facing area between the ground plate and the antenna plate can be obtained.

  According to the present invention, a groove (133b) is formed on a surface of the probe holder (133) facing the antenna plate (131), and the antenna probe (132) is inserted into the groove. A protrusion (133c) for holding the antenna probe in the groove is formed in the groove, and the depth of the groove and the height of the protrusion are held by the probe holder. The antenna device can be obtained which is set to be electrically insulated by placing a predetermined distance between the antenna probe and the antenna plate.

  According to the present invention, it further comprises an additional ground means (17) made of a material containing a metal, having a size equal to or larger than the area of the ground plate, and disposed below the ground plate, The additional ground means provides the antenna device having the same potential as that of the ground plate.

  According to the present invention, the additional grounding means (17) includes a metal plate, a metal sheet affixed on the bottom surface of the casing of the antenna device, or on the bottom surface of the casing. The antenna device configured by the applied conductive paint is obtained.

  In addition, the code | symbol in the said parenthesis is attached | subjected in order to make an understanding of this invention easy, and it is needless to say that it is only an example and is not limited to these.

  The antenna device according to the present invention is small in size, light in weight and low in cost and can exhibit high gain. The antenna device according to the present invention also has an excellent shielding effect against both incoming noise and radiation noise.

  Embodiments of the present invention will be described below.

  An antenna device according to an embodiment of the present invention is installed in an antenna device for a digital radio receiver, in particular, not only indoors but also outdoors such as a roof or a veranda, and is connected to a digital radio receiver installed indoors. This is an antenna device for a home that assumes

  The directivity of this type of antenna device is omnidirectional. However, in order to ensure the best sensitivity, it is desirable that the antenna device is configured to adjust the mounting angle of the antenna device to avoid the radio wave shielding object. Therefore, the home antenna apparatus has an angle adjustment function.

  Referring to FIG. 1, an antenna device according to an embodiment of the present invention has an angle adjustment function. That is, the antenna device includes a base portion 20 that can be attached to a wall surface, the antenna portion 10 that houses the antenna module 13, and a hinge portion 30 that connects the antenna portion 10 to the base portion 20 so that the angle of the antenna portion 10 can be adjusted. Have.

  The base unit 20 includes a base case 21 and a base plate 22. The base case 21 and the base plate 22 are coupled by a plurality of screws 23. Four rubber pads 24 are attached to the base plate 22. The antenna device can be placed in a bay window of a building. In addition, since the hook hole 222 is formed in the base plate 22, the antenna device can be attached by being hung on a screw or hook provided on the wall.

  The antenna unit 10 includes a top cover 11, a bottom case 12, an antenna module 13 mounted in the top cover 11, a packing member 14, and a ground sheet 17 (described in detail later). The top cover 11 and the bottom case 12 are coupled by a plurality of screws 18.

  The packing member 14 is made of, for example, a resin material such as silicon rubber or EPDM rubber (ethylene propylene rubber). The packing member 14 is also referred to as a waterproof packing because it is disposed at the joint between the bottom case 12 and the top cover 11 to ensure adhesion and perform a waterproof function. As shown in FIG. 2, the packing member 14 is a bush that covers the outer periphery of a signal line (not shown) at the position of a wide frame portion 141 having a substantially rectangular frame shape and a notch portion 123 formed in the top cover 11. Part 142. Since the packing member 14 has the frame portion 141 and the bush portion 142 integrally formed, the number of parts and work man-hours are small compared to the case where both portions are separate parts, and the packing member 14 is reduced in size and weight. This is useful in terms of cost, reliability, and cost reduction.

  The antenna device has a waterproof structure that provides a waterproof function between the top cover 11 and the bottom case 12. As shown in FIGS. 4A to 4E, a waterproof rib 113 protruding in a substantially square frame shape is formed inside the top cover 11. On the other hand, as shown in FIG. 2 and FIGS. 3 (a) to 3 (d), the substantially rectangular frame-shaped frame portion 141 of the packing member 14 corresponds to the waterproof rib 113 protruding in the substantially rectangular frame shape. A substantially square frame-shaped groove 141a is formed. When the bottom case 12 and the top cover 11 are assembled via the packing member 14, the tip of the waterproof rib 113 of the top cover 11 fits into the groove 141 a of the frame portion 141 of the packing member 14 as shown in FIG. 5. Include. Further, when the top cover 11 and the bottom case 12 are fastened by the plurality of screws 18, the waterproof rib 113 is pressed against the groove 141a, and a waterproof function is exhibited. The width of the groove 141a is substantially equal to the thickness of the waterproof rib 113.

  Further, as shown in FIG. 3D, a groove end 141 b continuous to the groove 141 a is formed in the substantially square frame-shaped frame 141 of the packing member 14 up to the vicinity of the bush 142. The groove end 141b has a pocket shape. On the other hand, as shown in FIG. 4E, a rib end 114 continuous with the waterproof rib 113 is formed inside the top cover 11. In addition to the bush 142 being fitted into the bush receiving portion of the top cover 11 and being waterproofed, the lead-out portion of the signal line is improved in waterproofness by fitting the rib end 114 into the groove end 141b. Yes.

  In the waterproof structure of the antenna device, the contact area between the packing member 14 and the waterproof rib 113 is large. For this reason, even if the fastening pressure by each of the plurality of screws 18 is different or the fastening pressure by the screws 18 is relatively large, there is a gap between the waterproof rib 113 of the top cover 11 and the packing member 14. There is nothing you can do. Therefore, this antenna device is excellent in waterproof performance. Further, when the waterproof rib 113 of the top cover 11 is fitted into the groove 141a of the packing member 14, the packing member 14 is not displaced in the horizontal direction.

  In the present antenna device, the angle of the antenna unit 10 can be adjusted with respect to the base unit 20 via the hinge unit 30. 1 and FIGS. 6A and 6B together, the hinge portion 30 includes a hinge base 31, a hinge bush 32, a coil spring 33, a washer 34, and a screw 35. The hinge base 31 is formed on the end of the top surface of the base case 21 of the base portion 20, and extends parallel to the top surface of the base case 21. A first shaft 312 is formed at one end of the hinge base 31. The first shaft 312 has a base portion 312a having a tapered outer peripheral surface and a shaft-shaped tip portion 312b extending from the base portion 312a. The hinge bush 32 is made of low wear resin such as ABS, ASA, PC, etc., has a tapered inner peripheral surface, is fitted around the base portion 312a of the first shaft 312 and is rotatable with friction. is there. A coil spring 33 is fitted on the tip 312b of the first shaft 312 to which the hinge bush 32 is attached. A screw 35 is fastened to the end surface of the first shaft 312 on which the hinge bush 32 and the coil spring 33 are mounted via a washer 34. The biasing force of the coil spring 33 generates a frictional force between the outer peripheral surface of the base portion 312 a of the first shaft 312 and the inner peripheral surface of the hinge bush 32, and the hinge bush 32 slides with respect to the first shaft 312.

  The hinge bush 32 is sandwiched and fixed between the top cover 11 and the bottom case 12 of the antenna unit 10. Due to the frictional force between the base 312a of the first shaft 312 and the hinge bush 32, the antenna unit 10 is fixed at a constant angle without rotating when no external force is applied. On the other hand, when an external force larger than the frictional force between the base 312a of the first shaft 312 and the hinge bush 32 is applied to the antenna unit 10, the antenna unit 10 can be rotated and adjusted to an arbitrary angle.

  In this antenna apparatus, the angle of the hinge part 30 can be adjusted in the range of 0 to 90 °. The angle adjustment is performed as follows, for example. The user manually adjusts the angle of the antenna unit 10 so that the level or sound quality is the best while confirming the level of the broadcast signal or audio information received by the digital radio receiver through the antenna device.

  In the present invention, the hinge base may be formed at the end of the antenna portion, while the hinge bush may be fixed to the end of the base portion.

  In the angle adjustment structure of the antenna device, the number of the hinge bush 32, the coil spring 33, the washer 34, and the screw 35 of the hinge portion 30 is one. For this reason, it is small and lightweight, and the parts cost is low, and the number of manufacturing steps is small, so the cost is low.

  Furthermore, referring to FIGS. 7A and 7B and FIGS. 8A and 8B, a second shaft 313 is formed at the other end of the hinge base 31. The second shaft 313 includes a pair of cantilever pieces 313a formed by cracking the shaft body, and a convex portion 313b formed on one outer peripheral surface of the pair of cantilever pieces 313a. The cantilever piece 313a functions as a cantilever spring. On the other hand, an inner peripheral surface portion 122 is formed at the ends of the top cover 11 and the bottom cover 12 so as to surround the second shaft. The inner peripheral surface part 122 has a protrusion 122a formed corresponding to a predetermined position of the convex part 313b when the antenna part 10 opens and closes with respect to the base part 20. In this example, the predetermined position of the convex portion 313b is a position immediately before the antenna unit 10 forms an angle of 0 ° with respect to the base unit 20. When the antenna unit 10 is opened as shown in FIGS. 7 (a) and 7 (b) and closed toward 0 ° as shown in FIGS. 8 (a) and 8 (b), the cantilever The convex part 313b supported by 313a gets over the protrusion 122a. At this moment, a click feels. Further, when the antenna unit 10 is completely closed at 0 °, the convex portion 313b supported by the cantilever piece 313a is regulated by the protrusion 122a, and therefore, an external force exceeding the elastic force of the cantilever piece 313a is not applied. As long as the antenna unit 10 is not opened carelessly (raised).

  The second shaft 313 further includes a second convex portion 313c formed on the outer peripheral surface of the base. On the other hand, the inner peripheral surface portion 122 further contacts the second convex portion 313c when the antenna portion 10 makes an angle of 90 ° with respect to the base portion 20, and the antenna portion 10 makes an angle larger than 90 °. Wall part 122b which restricts.

  In the present invention, the second shaft may be formed in the antenna portion together with the hinge base, while the inner peripheral surface portion may be formed in the base portion. In addition, it is desirable to impart low wear to at least one of the convex portion formed on the second shaft and the protrusion formed on the inner peripheral surface portion.

  Referring to FIG. 1, the antenna module 13 includes a ground plate 134, an antenna plate 131, an antenna probe 132, a probe holder 133, an LNA (Low Noise Amplifier) 137, and a shield case 138. It is out.

  The ground plate 134 is made of metal and has a substantially square shape. The antenna plate 131 is made of metal, has a substantially square shape, and is disposed facing the ground plate 134 at a distance. The antenna probe 132 is made of metal and is positioned between the ground plate 134 and the antenna plate 131. The probe holder 133 is made of ABS resin, has a substantially cubic shape, and holds the antenna probe 132 at a fixed position.

  The area of each plate surface of the ground plate 134 and the antenna plate 131 is smaller than the conventional one. When the ground plate and the antenna plate are reduced in size, the capacitance of the antenna module is reduced, and the antenna device may not be able to exhibit a sufficient gain. However, in this antenna device, the relative dielectric constant between the ground plate 134 and the antenna plate 131 is increased to ensure a sufficient capacitance. For this reason, this antenna apparatus can exhibit a high gain. Specifically, the probe holder 133 provided between the ground plate 134 and the antenna plate 131 has a size equal to or larger than the facing area between the ground plate 134 and the antenna plate 131. That is, most of the space between the ground plate 134 and the antenna plate 131 is filled with the resin member (probe holder 133). Since the dielectric constant of resin is higher than that of air, the antenna module 13 has a sufficient capacitance.

  As shown in FIGS. 9A to 9C, a substantially L-shaped groove 133 b is formed on the top surface of the probe holder 133. The antenna probe 132 is inserted into the groove 133b. Since the projection 133c is formed in the groove 133b, the antenna probe 132 inserted into the groove 133b is securely held in the groove 133b without being unnecessarily detached. The depth of the groove 133b and the height position of the protrusion 133c are set such that a predetermined distance is placed between the antenna probe 132 held by the probe holder 133 and the antenna plate 131 to be electrically insulated. Yes. For this reason, it is not necessary to mount an insulating member on the antenna probe held by the probe holder as in the conventional case, and the number of parts of the antenna apparatus may be small.

  The LNA 137 is electrically connected to the end of the antenna probe 132 and a signal line (not shown). A shield case 138 is soldered to the LNA 137. The LNA 137 covered with the shield case 138 is affixed to the ground plate 134 with an insulating tape 136. The ground plate 134 to which the LNA 137 is attached is attached in the top cover 11 with a plurality of screws 135. The signal line is led out to the outside of the antenna unit 10 through the bush portion 142 of the packing member 14 located at the position of the notch formed in the bottom case 12.

  As described above, the area of each plate surface of the ground plate 134 and the antenna plate 131 is narrower than the conventional one. When the ground plate is downsized, the shielding effect against incoming noise and radiation noise may be reduced. However, since the present antenna device is provided with an additional ground means, it has an excellent shielding effect against incoming noise and radiation noise. That is, the ground means is made by the ground sheet 17 shown in FIG. The ground sheet 17 is made of an aluminum adhesive seal, has a size equal to or larger than the area of the ground plate 134, and is attached to the inner bottom surface of the bottom case 12. The ground sheet 17 is disposed in a state of being separated from the ground plate 134 and the shield case 138 by a predetermined distance. The additional grounding means in the present invention may be a metal plate or a conductive paint applied to the inner bottom surface of the bottom case 12. The conductive paint may contain, for example, copper or aluminum.

  Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to the above-described embodiments. For example, the present invention is not limited to a home antenna for a digital radio receiver, but is also applicable to an antenna device for receiving GPS signals, an antenna device for mobile communication for receiving other artificial satellite waves and terrestrial waves. Is possible.

1 is a schematic exploded view showing an antenna device according to an embodiment of the present invention. (A) And (b) is the perspective view and partial enlarged view which show the packing member in the antenna apparatus shown in FIG. (A), (b), (c), and (d) are the top views, sectional drawings, other sectional drawings, and a partial enlarged view which show the packing member in the antenna apparatus shown in FIG. (A), (b), (c), (d), and (e) are a bottom view, a sectional view, a plan view, another sectional view, and a part showing a top cover in the antenna device shown in FIG. It is a typical enlarged view. It is a fragmentary sectional view for explaining a waterproof structure of an antenna device by an embodiment of the invention. (A) And (b) is a figure for demonstrating the angle adjustment structure of the antenna apparatus by embodiment of this invention. (A) And (b) is another figure for demonstrating the angle adjustment structure of the antenna apparatus by embodiment of this invention. (A) And (b) is another figure for demonstrating the angle adjustment structure of the antenna apparatus by embodiment of this invention. (A), (b), and (c) are the top views, sectional drawings, and other sectional drawings for demonstrating the probe holder of the antenna device by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antenna part 11 Top cover 113 Waterproof rib 114 Rib edge part 12 Bottom case 122 Inner peripheral surface part 122a Protrusion 122b Wall part 123 Notch part 13 Antenna module 131 Antenna board 132 Antenna probe 133 Probe holder 133b Groove part 133c Protrusion 135 Screw 137 LNA
138 Shield case 14 Packing member 141 Frame portion 141a Groove portion 141b Groove end portion 142 Bush portion 17 Ground sheet 18 Screw 20 Base portion 21 Base case 22 Base plate 222 Hook hole 23 Screw 24 Rubber pad 30 Hinge portion 312 First shaft 312a Base portion 312b Tip portion 313 2nd axis | shaft 313a Cantilever piece 313b Convex part 313c 2nd convex part 32 Hinge bush 33 Coil spring 34 Washer 35 Screw

Claims (4)

A ground plate, an antenna plate disposed opposite to the ground plate at a distance, an antenna probe positioned between the ground plate and the antenna plate, and a resin probe holder for holding the antenna probe; In an antenna device having
The probe holder has a size equal to or larger than a facing area between the ground plate and the antenna plate so that substantially the entire space between the ground plate and the antenna plate is filled with resin. Antenna device to do. A groove is formed on the surface of the probe holder facing the antenna plate,
The antenna probe is inserted into the groove,
In the groove portion, a projection for holding the antenna probe in the groove portion is formed,
The depth of the groove and the height position of the protrusion are set so that a predetermined distance is placed between the antenna probe held by the probe holder and the antenna plate to be electrically insulated. The antenna device according to claim 1.   It is made of a material containing a metal, has a size equal to or larger than the area of the ground plate, and has additional ground means disposed below the ground plate, and the additional ground means includes the ground The antenna device according to claim 1, wherein the antenna device has the same potential as the plate. The additional ground means is constituted by a metal plate, a metal sheet affixed on the bottom surface of the casing of the antenna device, or a conductive paint applied on the bottom surface of the casing. The antenna device according to claim 3.

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