JPH10178312A - Antenna system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna system in which reduction in the gain is suppressed and the frequency band width is extended. SOLUTION: The antenna system 10 is made up of a chip antenna 11 having a conductor 14 wound in spiral inside a rectangular prism shaped base 13 made mainly of a barium oxide, an aluminum oxide and a silica in the lengthwise direction of the base 13 and having a feeding terminal 15 to apply a voltage to the conductor 14 and up of a mount board 12 made of a glass epoxy resin and having a throughhole 20 on which the chip antenna 11 is mounted. Then the chip antenna 11 is mounted on the mount board 12 so as to entirely cover the throughhole 20 of the mount board 12 and the feeding terminal 15 of the chip antenna 11 and a land 17 on the mount board 12 are electrically and mechanically connected by solder or the like to mount the chip antenna 11 onto the mount board 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antenna device, and more particularly, to an antenna device used for mobile communication and a local area network (LAN).

[0002]

2. Description of the Related Art FIG. 7 is a perspective view of a conventional antenna device 50. In FIG. 7, reference numeral 51 denotes a chip antenna;
Denotes a mounting board for mounting the chip antenna 51, 53
Denotes a transmission line formed on the front surface of the mounting substrate 52, and 54 denotes a ground electrode formed on the back surface of the mounting substrate 52. One end of the transmission line 53 is connected to the chip antenna 51, and the other end is connected to an RF unit (not shown). The ground electrode 54 is connected to the ground.

The chip antenna 51 is, for example, shown in FIG.
As shown in FIG. 5, a rectangular parallelepiped insulator 55 in which an insulator layer (not shown) made of an insulator powder such as alumina or steatite is laminated, and an insulator 5 made of silver, silver-palladium, or the like.
5, a conductor 56 formed in a coil shape, and a magnetic material 57 made of a magnetic material powder such as a ferrite powder, and formed inside the insulator 55 and the coiled conductor 56, and the insulator 55 are fired. Then, a lead end of the conductor 56 (not shown)
External connection terminals 58a and 58
b.

[0004]

However, in the above-mentioned conventional antenna device, the relative permittivity of the mounting board on which the chip antenna is mounted is determined by the difference between the ground electrode formed on the back surface of the mounting board and the conductor of the chip antenna. Capacitance occurs between them. However, there is a problem that the gain of the chip antenna deteriorates or the bandwidth becomes narrow due to the generation of the capacitance.

[0005] The present invention has been made to solve such a problem, and an object of the present invention is to provide an antenna device capable of suppressing deterioration of a gain and widening a bandwidth.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a substrate comprising at least one of a dielectric material and a magnetic material, and at least one substrate formed on at least one of the inside and the surface of the substrate. A chip antenna comprising: a conductor; and at least one power supply terminal formed on a surface of the base body and for applying a voltage to the conductor;
A mounting substrate having a transmission line on the front surface, a ground electrode on the back surface, and a through hole or a notch at a location where the ground electrode is not provided, wherein the chip antenna is provided with the through hole or the notch It is characterized by being mounted so as to cover all or a part of the unit.

According to the antenna device of the present invention, since the chip antenna is mounted so as to cover all or a part of the through hole or the cutout of the mounting board, the relative permittivity immediately below the chip antenna can be reduced. it can.

[0008]

FIG. 1 is an exploded perspective view of an embodiment of an antenna device according to the present invention. Antenna device 1
0 is the chip antenna 11 and the chip antenna 11
And a mounting board 12 for mounting the same.

A chip antenna 11 includes a conductor 14 spirally wound in a longitudinal direction of a base 13 inside a rectangular parallelepiped base 13 mainly composed of barium oxide, aluminum oxide and silica, and a surface of the base 13. And a power supply terminal 15 for applying a voltage to the conductor 14. Here, one end of the conductor 14 is drawn out to the surface of the base 13 and connected to the power supply terminal 15. On the other hand, the other end of the conductor 14 is
A free end 16 is formed inside 3.

The mounting substrate 12 is made of glass epoxy resin. A transmission line 18 having a land 17 to which the power supply terminal 15 of the chip antenna 11 is connected at one end is provided on one surface, and a ground electrode 19 is provided on the back surface. Can be The other end of the transmission line 18 is connected to an RF unit (not shown), and the ground electrode 19 is connected to ground. Further, a through hole 20 is provided at a location where the ground electrode 19 is not provided.

The chip antenna 11 is mounted on the mounting board 1.
The power supply terminal 15 of the chip antenna 11 and the land 17 on the mounting substrate 12 are electrically and mechanically connected to each other by soldering or the like. By doing so, the chip antenna 10
Is mounted on the mounting board 12.

FIGS. 2 and 3 show the chip antenna 1 of FIG.
1 shows a perspective view of a modification of the first embodiment. The chip antenna 11a shown in FIG. 2 includes a rectangular parallelepiped base 13a, a conductor 14a spirally wound in the longitudinal direction of the base 13a along the surface of the base 13a, and a voltage applied to the conductor 14a on the surface of the base 13a. And a power supply terminal 15a for applying a voltage. Here, one end of the conductor 14a is
It is connected to the power supply terminal 15a. The other end of the conductor 14a forms a free end 16a on the surface of the base 13a. In this case, since the conductor 14a can be easily formed spirally on the surface of the base 13a by screen printing or the like, the manufacturing process of the chip antenna 11a can be simplified.

A chip antenna 11b shown in FIG. 3 has a rectangular parallelepiped base 13b, a conductor 14b formed in a meandering shape on the surface of the base 13b, and a conductor 14b formed on the surface of the base 13b.
and a power supply terminal 15b for applying a voltage to the terminal b. Here, one end of the conductor 14b is connected to the power supply terminal 15b on the surface of the base 13b. Also, conductor 1
4b has a free end 16b on the surface of the base 13b.
To form In this case, since the meandering conductor 14b is formed only on one main surface of the base 13b, the height of the base 13b can be reduced.
1b can be reduced in height. The meandering conductor 1
4b may be formed inside the base.

FIGS. 4 to 6 show partially enlarged top views of modifications of the mounting substrate 12 of FIG. The mounting substrate 12a of FIG.
Is compared with the mounting substrate 12 of FIG.
1 in that a notch 21 is provided at a position where the component 1 is mounted. In addition, the mounting substrates 12b and 12c in FIGS.
Compared with the mounting substrates 12 and 12a of FIGS.
The difference is that it is provided on the protruding portion 22 extending in contact with 2a.

Table 1 shows the resonance frequency of each antenna device.
9 shows gain and bandwidth at 9 GHz. Sample a uses the mounting board 12 of FIG. 1 as the mounting board, sample b uses the mounting board 12a of FIG. 4 as the mounting board, and sample c uses the mounting board 12b of FIG. 5 as the mounting board. Sampled, the mounting substrate 12 of FIG.
This is the case where c is used. Sample e is a conventional antenna device 50 (FIG. 7) for comparison.

[0016]

[Table 1]

From Table 1, it is understood that in the samples a to d in which the through holes or the cutout portions are provided in the mounting substrate, the deterioration of the gain can be suppressed and the bandwidth can be widened.
That is, the deterioration of the gain is suppressed to 0 to 0.5 dB, and the bandwidth can be increased by about 30% as compared with the related art.

According to the antenna device of the present embodiment described above, the chip antenna is mounted so as to cover all of the through holes or cutouts of the mounting board, so that the relative dielectric constant immediately below the chip antenna can be reduced. it can.

Therefore, since the capacitance generated between the conductor of the chip antenna and the ground electrode on the back surface of the circuit board can be reduced, it is possible to suppress the deterioration of the gain of the chip antenna and to realize a wider band. Can be.

In the above embodiment, the case where the base of the chip antenna is made of a dielectric material containing barium oxide, aluminum oxide, and silica as a main component has been described, but the base is not limited to this dielectric material. Instead, a dielectric material containing titanium oxide or neodymium oxide as a main component, a magnetic material containing nickel, cobalt, or iron as a main component, or a combination of a dielectric material and a magnetic material may be used.

Further, the case where the chip antenna has one conductor has been described, but the chip antenna may have a plurality of conductors arranged in parallel. In this case, it is possible to have a plurality of resonance frequencies according to the number of conductors, and it is possible to cope with multiband with one antenna.

Furthermore, the case where the chip antenna is mounted so as to cover all the through holes or cutouts of the mounting board has been described. However, the chip antenna is mounted so as to cover part of the through holes or cutouts of the mounting board. Even if implemented,
Similar functions and effects can be obtained.

Although the through hole of the mounting board has a circular cross section, it may have a rectangular or elliptical shape.

[0024]

According to the antenna device of the present invention, since the chip antenna is mounted so as to cover all or a part of the through hole or the cutout of the mounting board, the relative dielectric constant immediately below the chip antenna is reduced. be able to.

Therefore, since the capacitance generated between the conductor of the chip antenna and the ground electrode on the back surface of the circuit board can be reduced, it is possible to suppress the deterioration of the gain of the chip antenna and to realize a wider band. Can be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment of an antenna device according to the present invention.

FIG. 2 is a perspective view showing a modification of the chip antenna of FIG. 1;

FIG. 3 is a perspective view showing another modification of the chip antenna of FIG. 1;

FIG. 4 is a partially enlarged top view showing a modified example of the mounting board of FIG. 1;

FIG. 5 is a partially enlarged top view showing another modified example of the mounting board of FIG. 1;

FIG. 6 is a partially enlarged top view showing still another modified example of the mounting board of FIG. 1;

FIG. 7 is a perspective view showing a conventional antenna device.

FIG. 8 is a transparent side view of a chip antenna constituting the antenna device of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Antenna device 11 Chip antenna 12 Mounting substrate 13 Base 14 Conductor 15 Power supply terminal 17 Through hole 19 Transmission line 20 Ground electrode 21 Notch

Claims (1)

[Claims] 1. A substrate made of at least one of a dielectric material and a magnetic material, at least one conductor formed on at least one of the inside and the surface of the substrate, and a voltage formed on the surface of the substrate, and applying a voltage to the conductor. A chip antenna having at least one power supply terminal for applying voltage; and a mounting board having a transmission line on the front surface, a ground electrode on the back surface, and a through hole or a cutout at a location where the ground electrode is not provided. An antenna device, wherein the chip antenna is mounted on the mounting board so as to cover all or a part of the through hole or the cutout.