JPH0927711A - Radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress electric characteristic variation of a built-in antenna by providing a shield plate which has plural through holes between an antenna element and a device substrate and is connected to a ground surface, and connecting a feeder and a short-circuit line to corresponding lands through the through holes. SOLUTION: Between the antenna element 12 and the device substrate formed of a multilayered printed board including the ground surface 11, the trapezoidal shield plate 3 which is formed of a copper plate, etc., and has the through holes 31 and 32 bored is provided at a distance (d) from the antenna element 12. Then the shield plate 3 is fixed to the ground surface 11 in the device substrate. Further, the feeder 21 and short-circuit line 22 which are molded integrally with the antenna element 12 are connected to the feeding land and short- circuit land on the device substrate through the holes 31 and 32. Consequently, the ground surface for the antenna element 12 can be secured and at the same time, an unnecessary radio wave from the antenna is prevented from traveling around to the circuit side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device used for a mobile communication mobile device, for example.

[0002] Mobile communication has been gradually expanding its service to automobiles, ships, trains, and people against the backdrop of the development of high-frequency circuit technology and small-circuit technology, and has greatly contributed to social activities. In recent years, small mobile phones and cordless phones have been put to practical use, but these mobile devices have been made smaller and lighter so that people can carry them around at any time.
Parts are now mounted near the built-in antenna.

For this reason, the degree of influence on the built-in antenna changes in accordance with changes in the size of components and mounting conditions.
The electric characteristics of the antenna are more likely to change. Therefore, it is necessary to suppress changes in the electrical characteristics of the built-in antenna even if the components are mounted near the built-in antenna.

[0004]

2. Description of the Related Art FIG. 8 is an explanatory view of a conventional example, FIG. 9 is an explanatory view of another conventional example, (a) is a perspective view of an apparatus casing, and (b) is an X of (a).
-X 'cross-sectional view, FIG. 10 is an explanatory view of still another conventional example, (a) is a perspective view of the apparatus housing, (b) is a cross-sectional view of XX' in (a), (c) is a power supply line, and a short circuit. It is sectional drawing of a line.

9 (b) and 10 (b) are shown in FIG. 9 (a) and FIG.
FIG. 6 is a view of (a) cut along a chain line as seen from the direction of the arrow. Hereinafter, FIGS. 8 to 10 will be described.

In FIG. 8, the antenna of the inverted F antenna
The element 12 is arranged above the ground plane 11 in the device board constituted by the multilayer printed circuit board by a distance d, but at the end of the element, an integrally formed length d
, For example, a strip-shaped power supply line 13 and a short-circuit line 14 are provided.

Then, the end of the linear feed line 13 bent substantially at a right angle to the antenna element 12 is connected to a radio circuit (not shown) via a feed land 15 provided on the device substrate. It is connected to the core wire of the coaxial cable 16, and the end of the linear short-circuit wire 14 is soldered to the short-circuit land. The short-circuit land is connected to the ground plane.

The linear short-circuit wire 14 is a matching element for matching between the antenna element and the radio circuit,
In order to achieve matching, the distance between the linear feed line 13 and the linear short-circuit line 14 is not changed, and the connection position with the antenna is straight.
At least one of the width and width (for strips) must be changed.

Here, the antenna element 12 is a metal plate.
It is manufactured by processing (for example, a copper plate), and as described above, it is fixed by soldering it to the corresponding land by floating it by a distance d above the ground plane 11 in the device substrate in which no component is mounted on the surface.

However, since it is fixed by a person, there is a defect that the resonance frequency of the antenna varies due to variation in the interval. To compensate for this drawback, an inverted F antenna with a device housing attached as shown in Fig. 9 is used.

In FIG. 9, an antenna element 12 of an inverted F-type antenna is attached to, for example, a plastic device housing 1 with an adhesive, and when the device is assembled, a linear feed line 13 and a linear short-circuit line 14 are provided. Are soldered to the lands on the device substrate in the same manner as above.

As a result, the distance between the antenna element and the ground plane becomes constant, but man-hours are required for soldering the linear feed line 13 and the linear short-circuit line 14 to the ground plane 11. In FIG. 10, the feeder line 21 and the short-circuit line 22 are brought into contact with the ground plane 11 to be connected to reduce the man-hour for soldering. The wire 22 is integrally molded, but the power supply wire 21 and the short-circuit wire 22 are bent into a modified "inverted shape" as shown in Fig. 10 (c), and the height d ₁ is the ground plane 11 and the antenna.・ It is larger than the element spacing d.

Therefore, when the antenna element is attached to the device housing with an adhesive or the like, the power supply line 21 and the short-circuit line 22 are pressed downward, and the power-supply land and the short-circuit land, not shown, are used as described above. , Is in mechanical contact with the ground plane 11 for connection.

Here, with the configuration shown in FIG. 10 (b), the man-hours for soldering the power supply line 21 and the short-circuit line 22 are reduced, but with the miniaturization of the device, it is possible to place the antenna element 12 directly below. In some cases, for example, the components housed in the metal cases 17a to 17d must be mounted.

In such a case, the electrical characteristics of the built-in antenna change due to the capacitance between the metal case and the antenna element.

[0016]

As described above, when a large number of components must be mounted directly below the antenna element as the device becomes smaller, the electrical characteristics of the antenna are reduced.
The ground contact area that affects (for example, resonance frequency) decreases.

When the components housed in the metal case are mounted up to the vicinity of the antenna element, due to the influence of the capacitance generated between the metal case and the antenna element,
There is a problem that the electric characteristics of the built-in antenna may change.

An object of the present invention is to make it possible to suppress changes in the electrical characteristics of a built-in antenna even when high-density component mounting of the device is carried out.

[0019]

According to a first aspect of the present invention, a plurality of through holes are provided between an antenna element and a device substrate.
A shield plate connected to the ground plane is provided, and the power supply line and the short-circuit line are connected to the corresponding land by contacting them through the through hole.

In the second aspect of the present invention, a dielectric material is inserted between the antenna element and the shield plate. In the third aspect of the present invention, the through hole provided in the shield plate allows only the power supply line to pass through, and the short-circuit line is in contact with the shield plate for connection.

According to a fourth aspect of the present invention, a shield plate having a plurality of through holes, which is connected to the ground plane, is provided between the antenna element and the device substrate, and the power feed line is for feeding power through the through holes. It was connected to the land, and the short-circuit line was configured to change the connection position on the ground plane to change the contact position of the antenna element.

The fifth aspect of the present invention has a configuration in which the shapes of the power supply line and the short-circuit line are changed. According to a sixth aspect of the present invention, the shield plate is cut and raised to be in contact with the antenna element and used as a short-circuit wire.

[0023]

According to the present invention, a shield plate, which is made of, for example, a copper plate and has a through hole, is provided between the antenna element and the device substrate and is separated from the antenna element by d, and the shield plate is provided on the device substrate. Connect and fix to the ground plane inside.

Then, the power feed line and the short-circuit line integrally formed with the antenna element are connected to the power-feed land and the short-circuit land, which are formed on the device substrate, through the through holes.

As a result, even if the device is mounted with high density components, the shield plate is provided between the components mounted with high density and the antenna element, so that the change in the electrical characteristics of the built-in antenna can be suppressed. .

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment of the present invention (a perspective view in a partially broken state), and FIG. 3 is a perspective view of a third embodiment of the present invention (a perspective view in a partially broken state), and FIG. 4 is a main configuration of a fourth embodiment of the present invention. It is a figure (a perspective view in a state where a part is broken).

FIG. 5 is a schematic view of the essential parts of a fifth embodiment of the present invention (a perspective view in a partially broken state), and FIG. 6 is a schematic view of the essential parts of a sixth embodiment of the present invention (one FIG. 7 is a perspective view of a main part of another embodiment of the sixth aspect of the present invention (a perspective view in a partially broken state).

The same reference numerals denote the same objects throughout the drawings. The operation of the drawings will be described below, but the portions described in detail above will be briefly described, and the portions of the present invention will be described in detail.

In FIG. 1, between the antenna element 12 and a device substrate (not shown) (for example, a multilayer printed board including the ground plane 11), which is made of, for example, a copper plate, and through holes 31, 32 are provided. A trapezoidal shield plate 3 is provided at a distance d from the antenna element. Then, this shield plate is fixed to the ground plane 11 in the device substrate by, for example, soldering.

Further, the power feed line 21 and the short-circuit line 22 integrally formed with the antenna element are connected by contacting with the power-feed land and the short-circuit land (not shown) formed on the device substrate through the through holes 31 and 32. .

This makes it possible to secure a ground plane for the antenna element 12 and prevent unnecessary radio waves from the antenna from wrapping around to the circuit side. In FIG. 2, in order to reduce the size of the antenna element, by inserting a dielectric material 4 having a relative permittivity ε _r between the antenna element 12 and the shield plate 3, the antenna is maintained while maintaining its electrical characteristics. It is a mounting method that realizes miniaturization of.

Since the resonance frequency of the inverted F antenna is determined by the outer peripheral length of the antenna element, the dielectric material is used as the antenna.
By combining with the element, the electric length of the outer circumference looks long, and in order to obtain the same resonance frequency, the outer length can be made shorter than that in the air, and the antenna can be miniaturized.

In FIG. 3, a feeder line 21,
When it is difficult to secure a space for forming two types of lands, that is, a power supply land with which the short-circuit line 22 contacts and a short-circuit land, a power supply land (not shown) is formed on the device substrate to contact the power supply line 21. . However, the short-circuit land is not formed, and the short-circuit line 22a is made shorter than the power supply line 21 and the shield plate 3 is formed.
I made contact with and connected.

As described in the conventional example, the height of the short-circuit wire 22 is made larger than the distance between the antenna element and the shield plate so that the antenna element presses the short-circuit wire against the shield plate. .

This makes it possible to reduce the space used for the device substrate. In FIG. 4, a shield plate 3 having a plurality of through holes 31 to 34 between the antenna element 12 and a device substrate (not shown) and connected to the ground plane 11 in the device substrate is provided.

The feed line 21 integrally formed with the antenna element is connected to the feed land (not shown) through the through hole 31, but the short-circuit line 22b provided separately from the antenna element is connected to the ground plane 11. By changing the position, the contact position with the antenna element 12 can be changed.

As a result, the influence of the inductance component of the short-circuit wire 22b on the antenna element changes, and the resonance frequency of the antenna element 12 can be changed. In FIG. 5, one end is connected to the ground plane 11 and the other end is in contact with the antenna element 12 and is connected to the short-circuit wire 22c.
By changing the thickness of the antenna, the inductance of the short-circuit wire changes, and the resonance frequency of the antenna element can be changed.

Since the short-circuit wire can be matched even by contacting it with the shield plate, a part of the shield plate 3 is cut and raised to make contact with the antenna element 12 as shown in FIG. And As a result, it is not necessary to provide the short circuit land on the device substrate, and the space can be reduced.

In FIG. 7, a plurality of short-circuit lines 22e and 22f are formed by cutting and raising a part of the shield plate 3,
By changing the position and the number of short-circuit lines that come into contact with the antenna element 12, the resonance frequency of the antenna element can be changed.

[0040]

As described above in detail, according to the present invention, it is possible to suppress the change in the electric characteristics of the built-in type antenna even when the high density component mounting of the device is carried out.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a first embodiment of the present invention (a perspective view in a partially broken state).

FIG. 2 is a main part configuration diagram of a second embodiment of the present invention (a perspective view in a partially broken state).

FIG. 3 is a main part configuration diagram of a third embodiment of the present invention (a perspective view in a partially broken state).

FIG. 4 is a main part configuration diagram of a fourth embodiment of the present invention (a perspective view in a partially broken state).

FIG. 5 is a main part configuration diagram of a fifth embodiment of the present invention (a perspective view in a partially broken state).

FIG. 6 is a main part configuration diagram of a sixth embodiment of the present invention (a perspective view in a partially broken state).

FIG. 7 is a configuration diagram (a perspective view in a partially broken state) of a main part of another embodiment of the sixth invention.

FIG. 8 is an explanatory diagram of a conventional example.

9A and 9B are explanatory views of another conventional example, in which FIG. 9A is a perspective view of an apparatus housing, and FIG. 9B is a sectional view taken along line XX ′ of FIG.

FIG. 10 is an explanatory view of still another conventional example, (a) is a device housing perspective view, (b) is a sectional view taken along line XX ′ of (a), and (c) is a sectional view of a power supply line and a short-circuit line. is there.

[Explanation of symbols]

1 Equipment housing 3 Shield plate 4 Dielectric material 11 Ground plane 12 Antenna element 13 Linear feed line 14 Linear short-circuit line 21 Feed line 22 Short-circuit line 31, 32 Through hole

Claims (6)

[Claims] 1. A radio having a device housing having a power supply land, a short circuit land and a ground plane built-in, and a device housing to which a flat plate antenna element integrally formed with a power supply line and a short circuit line is adhered. In a communication device, a shield plate having a plurality of through holes and connected to the ground plane is provided between the antenna element and the device substrate, and the power supply line and the short-circuit line are associated with each other through the through holes. A wireless communication device having a configuration of contacting and connecting to a land. 2. The wireless communication device according to claim 1, wherein a dielectric material is inserted between the antenna element and the shield plate. 3. The wireless communication device according to claim 1, wherein the through hole provided in the shield plate passes only the power supply line, and the short-circuit line is in contact with the shield plate for connection. 4. A device substrate having a power feeding land, a short circuit land and a ground plane is built-in, and a device housing to which a flat plate antenna element integrally formed with a power feeding line is bonded and a short circuit line are provided. In the wireless communication device, a shield plate having a plurality of through holes and connected to the ground plane is provided between the antenna element and the device substrate, and the power supply line is connected to the power supply land through the through holes. A wireless communication apparatus, wherein the short-circuit line is connected and the connection position on the ground plane is changed to change the contact position of the antenna element. 5. The wireless communication device according to claim 1, wherein the shapes of the power supply line and the short-circuit line are changed. 6. The wireless communication device according to claim 1, wherein the shield plate is cut and raised to be in contact with the antenna element and used as a short-circuit wire.