This application claims priority to prior application JP 2005-90852, the disclosure of which is incorporated herein by reference.
This invention relates to an antenna unit and a feeding component included therein, particularly, to a satellite signal receiving antenna unit for receiving a circular polarized wave such as a satellite radio broadcast.
A GPS (Global Positioning System) receiving antenna is currently known as an example of an antenna for receiving a radio wave from an artificial satellite. As the GPS receiving antenna, what is called a patch antenna is used, for example. The patch antenna has a ceramic board, which is an insulating material, with a pair of main surfaces. On one of the main surfaces of the ceramic board, a ground electrode is provided. On the other of the main surfaces of the ceramic board, a receiving electrode and a feeding pin are provided. The feeding pin is used for supplying a receiving signal to an external circuit.
Recently, it is propelled to execute a radio broadcast and so on using a circular polarized wave transmitted from the artificial satellite. To receive the radio broadcast, what is called a satellite radio broadcast receiving antenna is used.
The satellite radio broadcast receiving antenna includes a pair of feeding components each of which consists of a feeding line and an attaching member. The feeding line and the attaching member are made of metal and resin, respectively. The feeding line is attached to the attaching member. To stabilize the attaching state of the feeding line to the attaching member, a tape, such as a plastic tape, is applied.
Thus, the satellite radio broadcast receiving antenna needs the tape. Accordingly, the satellite radio broadcast receiving antenna has a problem that components and assembling processes are large in number.
It is therefore an object of this invention to provide a feeding component which a feeding line can be stably attached to an attaching member without increase of the numbers of components.
Another object of this invention is to provide a feeding component which can be made by a small number of assembling processes.
Still another object of this invention is to provide an antenna unit having the feeding component mentioned above.
Other objects of this invention will become clear as the description proceeds.
According to an aspect of this invention, an antenna unit comprises a first metal plate as a ground electrode. A second metal plate is opposite to the first metal plate. A feeding component is located between the first metal plate and the second metal plate and includes a wire and an attaching member made of resin. The wire has a base end portion and a feeding portion which is continuous with the base end portion and which extends in a plane. The attaching member provides a through hole for receiving the base end portion and a wire receiving groove for supporting the feeding portion and has a pair of wire fixing parts which are formed on inner walls defining the wire receiving groove. The wire fixing parts are opposite to each other and inclined inward to narrow a width of the wire receiving groove with increasing proximity to an upper side of the wire receiving groove.
In the antenna unit, a distance between the wire fixing parts may be in a range from φ/1.09 to φ/1.2, where φ represents a diameter of the wire. Furthermore, the attaching member may provide an opening corresponding to the wire fixing parts at a bottom of the wire receiving groove. Still furthermore, the wire receiving groove may be formed to receive either of the wires which have two symmetric shapes.
According to another aspect of this invention, a feeding component comprises a wire having a base end portion and a feeding portion which is continuous with the base end portion and which extends in a plane. An attaching member is made of resin. The attaching member provides a through hole for receiving the base end portion and a wire receiving groove for supporting the feeding portion. The attaching member further has a pair of wire fixing parts which are formed on inner walls defining the wire receiving groove. The wire fixing parts are opposite to each other and inclined inward to narrow a width of the wire receiving groove with increasing proximity to an upper side of the wire receiving groove.
In the feeding component, a distance between the wire fixing parts may be in a range from φ/1.09 to φ/1.2, where φ represents a diameter of the wire. Furthermore, the attaching member may provide an opening corresponding to the wire fixing parts at a bottom of the wire receiving groove. Still furthermore, the wire receiving groove may be formed to receive either of the wires which have symmetric shapes.
Referring to
In
The first metal plate 21 is made of metal material and shaped into a rectangular flat plate. The first metal plate 21 is attached to a lower cover 24. On the other hand, the second metal plate 22 is made of metal material and attached to an upper cover 25. The lower cover 24 and the upper cover 25 are assembled to form an internal space which contains the first metal plate 21, the pair of the feeding components 23 and the second metal plate 22.
As illustrated in
The feeding line 31 has a horizontal part which is supported by the attaching member 28 over a main surface of the first metal plate 21 to be apart from the first metal plate 21.
In the satellite radio broadcast receiving antenna having the structure mentioned above, the feeding components 23 are arranged so that their horizontal parts are perpendicular to each other and thereby good receiving characteristics are obtained regarding to both of right and left circular polarized waves. Accordingly, the feeding lines 31 of the feeding components 23 are attached to the attaching members 28 in symmetrical arrangement. In other words, two types of the feeding components 23 having symmetrical arrangements are necessary to assemble the satellite radio broadcast receiving antenna.
The insert molding, which is used for integrating the feeding line 31 with the attaching member 28, raises manufacturing cost of the satellite radio broadcast receiving antenna. Especially, in a case where two of the feeding components 23 having symmetrical arrangements are necessary to deal with the right and the left circular polarized waves, the insert molding further rises the manufacturing cost because two types of insert molding dies are necessary.
To solve the problems mentioned above, the applicants have already proposed a satellite signal receiving antenna unit which is made by a technique that either of the symmetrical feeding components 23 can be obtained by changing bending direction of a feeding line and thereby the manufacturing cost is considerably reduced. Such an antenna unit is disclosed in Unexamined Japanese Patent Application Publication (JP-A) No. 2005-20644.
The feeding line 2 has a shape bent at two points on the square. Accordingly, the feeding line 2 has a base end portion 2a bent in a vertical direction, a supporting portion 2b continuing on the base end portion 2a and extending on a horizontal plane, and a feeding portion 2c bent at a right angle with the supporting portion 2b on the horizontal plane.
At the middle of the first wire receiving groove 3a, a through hole 3c is bored through the attaching member 3 along the vertical direction. The through hole 3c is for receiving the base end portion 2a of the feeding line 2. The base end portion 2a inserted into the through hole 3c may be connected to a circuit board (not shown) to serve as an signal output electrode of the feeding line 2.
A plurality of tiny projections 3d is formed on inner walls defining the first wire receiving groove 3a of the attaching member 3. The tiny projections 3d press and hold the supporting portion 2b put into the first wire receiving groove 3a to prevent the supporting portion 2b of the feeding line 2 from falling away from the first wire receiving groove 3a. Thus, the tiny projections 3d allow the feeding line 2 to be fixed to the attaching member 3 without extra parts.
As mentioned above, in the conventional feeding component 1, the plural tiny projections 3d projecting into the first wire receiving groove 3a hold the supporting portion 2b of the feeding line 2 put into the first wire receiving groove 3a. Accordingly, it is necessary that the first wire receiving groove 3a has a width which is little larger than a diameter of the feeding line 2. This is because the tiny projections 3d are obstacles and make hard to put the supporting portion 2b of the feeding line 2 into the first wire receiving groove 3a when the width of the first wire receiving groove 3a is substantially equal to the diameter of the feeding line 2. To the contrary, when the width of the first wire receiving groove 3a is too wide in comparison with the diameter of the feeding line 2, it is hard to stably hold the support portion 2b of the feeding line 2 in the first wire receiving groove 3a.
Therefore, in the conventional feeding component 1, a tape, such as a plastic tape, is affixed to the attaching member 3 to cover the wire receiving grooves 3a and 3b and to further stabilize an attaching state of the feeding line 2 put in the attaching member 3.
Referring to
As shown in
The feeding line 42 has a shape bent at two points on the square. Accordingly, the feeding line 42 has a base end portion 42a bent in a vertical direction, a supporting portion 42b continuing on the base end portion 42a and extending on a horizontal plane, and a feeding portion 42c bent at a right angle with the supporting portion 42b on the horizontal plane. The supporting portion 42b may be called a feeding portion together with the feeding portion 42c.
The attaching member 43 is a molding body having an almost rectangular parallelepiped shape. At the upper side of the attaching member 43, a first wire receiving groove 43a for receiving the supporting portion 42b of the feeding line 42 is formed along a longitudinal direction. At one of ends of the first wire receiving groove 43a, a second wire receiving groove 43b perpendicular to the first wire receiving groove 43a is formed to correspond to the feeding portion 42c perpendicular to the supporting portion 42b.
The attaching member 43 provides a wire holding protrusion 431 while the second wire receiving groove 43b extends at a surface of the wire holding protrusion 431.
At the other end of the first wire receiving groove 43a, a through hole 43c is bored through the center of the attaching member 43 along the vertical direction. The through hole 43c is for receiving the base end portion 42a of the feeding line 42. The base end portion 42a inserted into the through hole 43c may be connected to a circuit board (not shown) to serve as an signal output electrode of the feeding line 42.
Two pairs of wire fixing parts 43d are formed on inner walls of the wire receiving grooves 43a and 43b.
As depicted in
The wire fixing parts 43d of each pair are opposite to each other and inclined to narrow a space between them at a top surface side of the attaching member 43. In other words, the wire fixing parts are inclined inward to narrow a width of the wire receiving groove with increasing proximity to an upper side of the wire receiving groove 43a or 43b. That is, each of the wire fixing parts 43d has an inverted triangle shape as illustrated in
The attaching member 43 further provides openings 43e corresponding to the pairs of the wire fixing parts 43d. The openings 43e facilitate transformation of attaching member 43 when the feeding line 42 is put into the wire receiving grooves 43a and 43b. That is, the openings 43e facilitate putting the feeding line 42 into wire receiving grooves 43a and 43b.
In this embodiment, to make easy to put the feeding line 42 into wire receiving grooves 43a and 43b, a distance D between the pair of the wire fixing parts 43d at the top surface of the attaching member 43 is in a range from φ/1.09 to φ/1.2, where φ represents the diameter of the feeding line 42. When the distance D is larger than φ/1.09, the feeding line 42 is easy to fall away from the attaching member 43. To the contrary, when the distance D is smaller than φ/1.2, the feeding line 42 is hard to be put into the first and the second wire receiving grooves 43a and 43b of the attaching member 43. For instance, when the feeding line 42 is 1.2 [mm] in diameter, the distance D between the wire fixing parts 43d opposite to each other is set to a value of a range from 1.0 [mm] to 1.1 [mm].
As mentioned above, according to this embodiment, the feeding line 42 can be easily put input the wire receiving grooves 43a and 43b of the attaching member 43 and stably held in them because the pair of the wire fixing parts 43d is provided in each of the wire receiving grooves 43a and 43b.
According to the structure mentioned above, it is unnecessary to affix a tape to further stabilize the attaching state of the feeding line put in the attaching member. Therefore, the number of parts for the feeding component 40 is reduced. In addition, because the tape is unnecessary, a tape affixing process is unnecessary for manufacturing the feeding component 40 and thereby the number of assembly processes of the satellite signal receiving antenna unit is reduced.
That is, according to this invention, the feeding component 40 can be assembled by merely putting the feeding line 42 into the wire receiving grooves 43a and 43b of the attaching member 43 and thereby reduction of the number of the parts and simplification of the manufacturing process of the feeding component 40 are implemented.
That is, in the attaching member 43A, the pair of the wire fixing parts 43d is provided in the wire receiving groove 43a.
According to the structure mentioned above, the feeding line 42 (see
In particular, the attaching member 43B is a molding body having an almost rectangular parallelepiped shape. At the upper side of the attaching member 43B, a first wire receiving groove 43a for receiving the supporting portion 42b of the feeding line 42 (see
At the middle of the first wire receiving groove 43a, a through hole 43c is bored through the attaching member 43B along the vertical direction. The through hole 43c is for receiving the base end portion 42a of the feeding line 42. The base end portion 42a inserted into the through hole 43c may be connected to a circuit board (not shown) to serve as an signal output electrode of the feeding line 42.
Two pairs of wire fixing parts 43d are formed on inner walls defining the wire receiving grooves 43a symmetrically. Each pair of the wire fixing parts 43d is for holding the supporting portion 42b put into the first wire receiving groove 43a.
According to the structure mentioned above, the feeding line 42 (see
While this invention has thus far been described in conjunction with the preferred embodiments thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, the number of the pairs of the wire fixing parts is not limited in one or two and may be equal to three or more.
Number | Date | Country | Kind |
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2005-090852 | Mar 2005 | JP | national |
Number | Name | Date | Kind |
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5181044 | Matsumoto et al. | Jan 1993 | A |
6049314 | Munson et al. | Apr 2000 | A |
6133883 | Munson et al. | Oct 2000 | A |
6246368 | Deming et al. | Jun 2001 | B1 |
6861990 | Hung et al. | Mar 2005 | B2 |
6879288 | Byrne et al. | Apr 2005 | B2 |
Number | Date | Country |
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2005-020644 | Jan 2005 | JP |
Number | Date | Country | |
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20060214852 A1 | Sep 2006 | US |