JP2000101334A - Antenna and gps device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna with which waste of a coaxial cable is reduced, malfunctions hardly take place, and its assembling does not become complicated. SOLUTION: In this antenna, a printed circuit board 2 is placed in a case 1, and the case 1 is provided with a connector 3. A through-hole 4 is made to the printed circuit board 2, which penetrates the side of the printed circuit board 2 towards the connector 3 and a side of the printed circuit board 2 opposite to the connector 3. The opening of the through-hole 4 toward the connector 3 is formed as an inlet hole 5 and an opening of the through-hole 4 opposite to the connector 3 is formed as an exit hole 6. A coaxial cable 7 is fitted to the case 1 by using the connector 3, and an end of the coaxial cable 7 is introduced into the case 1. The end of the coaxial cable 7 is inserted into the through-hole 4 from the inlet hole 5 and the end of the coaxial cable 7 is let through out of the exit hole 6 of the through-hole 4. A tip of the coaxial cable 7 connects to a circuit provided on a side of the printed circuit board 2 opposite to the side thereof toward the connector 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna used as a GPS receiving antenna and the like, and a GPS device using the same.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional example of an antenna. The case 1 of the antenna is formed hollow with a body 20 having an open upper surface and a cover 21 having an open lower surface. A connector 3 is provided on the outer surface (bottom surface) of the body 20. A circuit board 2 is housed in the case 1. On the circuit board 2, an antenna circuit forming a high-frequency amplifier circuit and the like, and a ground circuit for ground (GND) are formed. An antenna element 22 is mounted on the upper surface of the circuit board 2 (the surface on the cover 21 side), and various electronic components 23 are mounted on a lower surface of the circuit board 2 (the surface on the body 20 side). 22 and the electronic component 23 are electrically connected to the antenna circuit. When the circuit board 2 is stored in the case 1, the edge of the lower surface of the circuit board 2 is placed and supported on the stepped portion 24 recessed at the inner opening edge of the upper surface of the body 20. .

In assembling such an antenna, the following is performed. First, as shown in FIG. 4A, the coaxial cable 7 is fixed to the body 20 by the connector 3, and the end of the coaxial cable 7 is introduced into the body 20 (upper side of the body 20) as an introduction portion 7a. Next, the circuit board 2 is placed upright (so that the thickness direction of the circuit board 2 is substantially horizontal), and the lower end thereof is placed on the step portion 24. Next, in this state, the leading end of the introduction portion 7a of the coaxial cable 7 is connected to the circuit board 2. That is, at the tip of the introduction portion 7a,
The insulating layer that insulates the inner conductor (core wire) from the outer conductor and the covering material that covers the outer surface of the outer conductor are removed, the inner conductor (core wire) and the outer conductor are exposed, and the inner conductor (core wire) is connected to the antenna circuit connection portion 25. And the outer conductor of the coaxial cable 7 is connected to a grounding circuit as a grounding conductor.

[0004] Thereafter, the circuit board 2 in the upright state is pivoted downward about its lower end to thereby obtain the body 2.
The edge of the lower surface of the circuit board 2 is placed and supported on the step portion 24 of 0. At this time, as shown in FIG. 4B, the introduction portion 7a of the coaxial cable 7 is housed in the body 20 housing recess 27 on the lower side of the circuit board 2 while being bent. After this,
The antenna is formed by covering the cover 21 so as to cover the upper surface of the circuit board 2 and joining the body 20 and the cover 21 together.

[0005]

However, in the above-mentioned antenna, the introduction portion 7a of the coaxial cable 7 has a required length so that the connection portion 25 of the circuit board 2 in the upright state can be connected by the coaxial cable 7. (The shortest distance between the connection part 25 and the connector 3 when the circuit board 2 is attached to the body 20 with the circuit board 2 substantially horizontal is set), so that the coaxial cable 7 is wasted. There was a problem of becoming. Moreover, a long coaxial cable 7 for the antenna
, The electromagnetic coupling between the high-frequency amplifier circuit and the like and the introduction portion 7a of the coaxial cable 7 is increased, so that oscillation is likely to occur, and a malfunction is likely to occur. In addition, when the circuit board 2 is attached to the body 20, it is necessary to rotate the circuit board 2 or to connect the coaxial cable 7 to the coaxial cable 7 such as by soldering while the circuit board 2 is standing. As a result, there has been a problem that the assembly work becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides an antenna capable of reducing waste of a coaxial cable, less likely to cause a malfunction, and preventing a complicated assembly operation. The purpose is to do so. The present invention also provides a GP using this antenna.
It is intended to provide S equipment.

[0007]

According to the antenna of the present invention, a circuit board is disposed in a case and a connector is provided in the case.
A through hole 4 is formed to penetrate the surface of the circuit board 2 opposite to the connector 3, and an opening of the through hole 4 on the connector 3 side is formed as an inlet 5, and the through hole 4 is opposite to the connector 3. The opening on the side is formed as an outlet 6, the coaxial cable 7 is attached to the case 1 by the connector 3, and the end of the coaxial cable 7 is introduced into the case 1. 4, the end of the coaxial cable 7 is led out from the outlet 6 of the through hole 4, and the end of the coaxial cable 7 is connected to a circuit 8 provided on the surface of the circuit board 2 opposite to the connector 3. It is characterized by the following.

[0008] The antenna according to claim 2 of the present invention comprises:
In addition to the configuration of claim 1, a through hole 4 is formed in a through hole 10 connected to a ground circuit 9 provided on the circuit board 2, and an end of the coaxial cable 7 introduced into the case 1 is grounded. 9, the ground conductor of the coaxial cable 7 is connected to the ground circuit 9.

According to a third aspect of the present invention, there is provided a GPS device comprising:
It is characterized by being connected by.

[0010]

Embodiments of the present invention will be described below.

The case 1 is formed hollow with a body 20 and a cover 21. The metal body 20 having a shielding function is formed by erecting a side part 51 around a bottom plate part 50, and the body 20 has an opening on the upper surface so as to be surrounded by the side part 51 above the bottom part 50. The receiving recess 27 is formed. Further, the storage recess 27 is provided on the inner surface of the upper portion of the side portion 51.
And a stepped portion 24 which is open on the upper surface is recessed. Body 2
The connector 3 is provided on the outer surface of the bottom plate portion 50 of the “0”. The cover 21 of the body 20 is formed by projecting a leg 53 around an upper plate 52 and opening the lower surface. The circuit board 2 is housed in the case 1 formed by combining the body 20 and the cover 21.

An antenna circuit 30, which is a circuit 8 constituting a high-frequency amplifier circuit and the like, and a ground (GN)
A ground circuit 9 for D) is formed. Antenna circuit 3
Numeral 0 is formed on the lower surface of the circuit board 2 (the surface facing the connector 3 when the case 1 is housed, that is, the surface on the body 20 side). Various electronic components 23 are mounted. Further, a through hole 35 penetrating in the thickness direction (vertical direction) is formed in the circuit board 2, and a conductor 40 covering the through hole 35 is connected to the antenna circuit 30. On the upper surface of the circuit board 2 (the surface facing the connector 3 when the case 1 is stored, that is, the surface on the cover 21 side), the land portion 41 integrally formed with the conductor 40 of the through hole 35 It is formed as a connection part 25 connected to.

A grounding circuit 9 is formed on the upper surface of the circuit board 2, and a through hole 4 penetrating through the circuit board 2 in the thickness direction so as to open to the grounding circuit 9 at a substantially central portion of the circuit board 2.
Is provided. The through hole 4 is formed by a through hole 10 covered with a conductor 42, and the conductor 42 is connected to the ground circuit 9. An opening on the upper surface side of the circuit board 2;
That is, the opening in the grounding circuit 9 is formed as the outlet 6, and the opening of the through hole 4 on the lower surface side of the circuit board 2 is formed as the inlet 5. An antenna element 22 is mounted on the upper surface of the circuit board 2.
2 is electrically connected to the antenna circuit 30.

In assembling such an antenna, the following is performed. First, the coaxial cable 7 is inserted into the connector 3 from below, and the coaxial cable 7 is fixed to the body 20 by the connector 3, and the end of the coaxial cable 7 is passed through the connector 3 and the bottom plate 50 of the body 20. As an introduction portion 7a into the storage recess 27 on the upper side of the body 20. At the tip of the introduction portion 7a, the outermost covering material 70 is removed to expose the outer conductor 61, which is a grounding conductor. The exposed portion of the outer conductor 61 is formed as a ground circuit connecting portion 71. . Further, on the distal end side of the grounding circuit connection portion 71 of the introduction portion 7a,
The outer conductor 61 and the insulating layer 72 between the inner conductor 60 and the outer conductor 61 are removed to expose the inner conductor 60, and the exposed portion of the inner conductor 60 is formed as an antenna circuit connecting portion 73.

Next, the introduction portion 7a of the coaxial cable 7 is inserted into the through hole 4 from the introduction hole 5 of the through hole 4 of the circuit board 2, and the introduction portion 7a is further led out from the outlet 6 of the through hole 4. . Next, the introduction portion 7a of the coaxial cable 7 is
The circuit board 2 is moved toward the body 20 while moving toward the outlet 6 inside the
The edge of the lower surface of the circuit board 2 is placed on the body 20, and the circuit board 2 is disposed substantially horizontally on the body 20 and supported. In this state, the through hole 4 is located almost directly above the connector 3.

Next, as shown in FIG. 2, the antenna circuit connecting portion 73 of the coaxial cable 7 led out above the circuit board 2.
Is connected to the connection portion 25 of the antenna circuit 30 by soldering from above, and the ground circuit connection portion 71 of the coaxial cable 7 is soldered to the ground circuit 9 between the connection portion 25 and the through hole 4 from above. And so on. Connection part 2
Between the outlet 5 and the outlet 6 of the through hole 4, the introduction part 7 a of the coaxial cable 7 is arranged along the upper surface of the grounding circuit 9. Thereafter, the antenna of the present invention is formed by covering the cover 21 so as to cover the upper surface of the circuit board 2 and joining the upper end of the side portion 51 of the body 20 and the lower end of the leg portion 53 of the cover 21 by joining. Because

As shown in FIG. 1, a GPS device can be formed by connecting the coaxial cable 7 and the GPS receiver 63 outside the case 1.

As described above, according to the present invention, the through hole 4 is formed in the circuit board 2 so as to open on the upper and lower surfaces, and the introduction portion 7a of the coaxial cable 7 extends from the inlet 5 of the through hole 4 which opens on the lower surface of the circuit board 2. Is inserted into the through hole 4, the introduction portion 7 a is led out from the outlet 6 on the upper surface of the circuit board 2, and the antenna circuit connection portion 73 provided on the introduction portion 7 a of the coaxial cable 7 is provided on the upper surface of the circuit board 2. Since the connection portion 25 of the antenna circuit 30 was connected to the connection portion 25 by, for example, soldering from above, the distance between the connection portion 25 of the circuit board 2 and the connector 3 which were arranged substantially horizontally was changed as shown in FIGS. b) The distance between the connecting portion 25 of the circuit board 2 and the connector 3 in the standing state as shown in FIG. Reduce the length of the introduction part 7a of the coaxial cable 7 It is possible. Therefore, there is no need to lengthen the introduction portion 7a excessively, so that waste is eliminated, and the length of the introduction portion 7a stored on the lower surface side of the circuit board 2 (the storage concave portion 27 on the mounting surface side of the electronic component) is shortened. The electromagnetic coupling between the introduction portion 7a of the coaxial cable 7 and the antenna circuit 30 is reduced, and oscillation is less likely to occur. In addition, the introduction section 7 of the coaxial cable 7
a along the grounding circuit 9 so that the introduction portion 7a of the coaxial cable 7 and the antenna circuit 30
And the oscillation becomes even less likely to occur. Further, the connecting portion 25 of the coaxial cable 7
Since the connection to the circuit board 2 is performed from the upper side of the circuit board 2, the work of rotating the circuit board 2 and the like are eliminated and soldering is easily performed, and the assembly efficiency is increased and the processing cost can be reduced. It is.

FIG. 4A and FIG. 4B show a specific example.
In the case where the antenna of the conventional example is formed by the method shown in the above, the introduction portion 7a of the coaxial cable 7 needs 60 mm, but according to the present invention, the length of the introduction portion 7a is 37 mm, and the length of the introduction portion 7a is reduced. About 40% reduction was achieved. In the conventional antenna, the introduction portion 7a stored in the storage recess 27 is used.
Is 60 mm, whereas in the antenna of the present invention, the length of the introduction portion 7a stored in the storage recess 27 is 1 mm.
1 mm. From this, the electromagnetic coupling between the antenna circuit 30 and the introduction section 7a is 18% (11/60 ≒ 0.
18), a reduction of 82%. The coaxial cable 7 is soldered to the circuit board 2 and the circuit board 2 is
The time required for the mounting work to be mounted on the base plate was shortened by about 30%, and the jig used for assembling could be reduced in size.

[0020]

As described above, according to the first aspect of the present invention, a circuit board is provided in a case and a connector is provided in the case, and the connector side of the circuit board and the connector of the circuit board are opposite to each other. Forming a through hole in the side surface, forming an opening on the connector side of the through hole as an inlet, and forming an opening on the opposite side of the connector of the through hole as an outlet,
Attach the coaxial cable to the case with the connector, introduce the end of the coaxial cable into the case, insert the end of the coaxial cable into the through hole from the inlet, and derive the end of the coaxial cable from the outlet of the through hole. Since the end of the coaxial cable is connected to the circuit provided on the surface of the circuit board opposite to the connector, the distance between the connector and the circuit can be shortened, and the length of the end of the coaxial cable required for connection is reduced. Thus, waste of the coaxial cable can be reduced, and the electromagnetic coupling between the circuit and the end of the coaxial cable is also reduced, so that malfunctions are less likely to occur. Furthermore, the connection between the end of the coaxial cable and the circuit can be easily performed, and the assembling work can be prevented from becoming complicated.

According to a second aspect of the present invention, a through hole is formed in a through hole connected to a ground circuit provided on a circuit board, and an end of the coaxial cable introduced into the case is connected to the ground circuit. And the grounding conductor of the coaxial cable is connected to the grounding circuit, so that the end of the coaxial cable introduced into the case follows the grounding circuit to enhance the grounding effect of the coaxial cable. Electromagnetic coupling between the circuit and the end of the coaxial cable can be further reduced, and malfunctions are less likely to occur.

According to a third aspect of the present invention, a first aspect is provided.
Or, because the antenna for 2 and the GPS receiver are connected by a coaxial cable, the electromagnetic coupling between the circuit and the coaxial cable is small, and by using an antenna that does not easily malfunction, the GPS radio wave can be reliably received. It is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of the circuit board according to the first embodiment.

FIG. 3 is a sectional view showing a conventional example.

FIGS. 4A and 4B are cross-sectional views showing an assembling process of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Circuit board 3 Connector 4 Through hole 5 Inlet 6 Outlet 7 Coaxial cable 8 Circuit 9 Grounding circuit 10 Through hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Furuta 1048 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works F-term (reference) 5J045 AA01 AB06 DA10 EA07 FA02 HA06 LA01 MA04 NA02 NA06 5J046 AA09 AA19 AB03 TA01 TA05 5J062 CC07

Claims (3)

[Claims] A circuit board is provided in a case and a connector is provided in the case. A through hole is formed through a surface of the circuit board on a connector side and a surface of the circuit board on a side opposite to the connector. An opening on the connector side is formed as an inlet, and an opening on the opposite side of the through hole is formed as an outlet.A coaxial cable is attached to the case with the connector, and the end of the coaxial cable is introduced into the case. Insert the end of the coaxial cable from the inlet into the through hole and derive the end of the coaxial cable from the outlet of the through hole, and connect the end of the coaxial cable to the circuit provided on the surface of the circuit board opposite to the connector. An antenna, comprising: 2. A through hole is formed in a through hole connected to a ground circuit provided on a circuit board, and an end of a coaxial cable introduced into a case is disposed along the ground circuit and a coaxial cable is provided. 2. The antenna according to claim 1, wherein said grounding conductor is connected to a grounding circuit. 3. A GPS device comprising the antenna according to claim 1 and a GPS receiver connected by a coaxial cable.