Communications: radio wave antennas – Antennas – With radio cabinet
Reexamination Certificate
1999-08-20
2001-03-13
Phan, Tho (Department: 2821)
Communications: radio wave antennas
Antennas
With radio cabinet
C343S7000MS, C343S846000
Reexamination Certificate
active
06201502
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an antenna device and a communication apparatus including the same, and more specifically, the present invention relates to an antenna device and a communication apparatus including the same for use in mobile communications or the like.
2. Description of the Related Art
With a recent advance in miniaturization and high performance of mobile communication devices, particularly in those of mobile phones, an antenna device, which is to be mounted therein, has also been required to be further miniaturized and to have higher gain.
FIG.
5
and
FIG. 6
show a conventional surface-mount type antenna and an antenna device incorporating the same, respectively. The basic structure of the surface-mount type antenna
1
shown in
FIG. 5
is described in Japanese Unexamined Patent Publication No. 9-98015.
In
FIG. 5
, the surface-mount type antenna
1
is arranged by disposing some electrodes on a surface of a base member
2
of a rectangular parallelepiped configuration, which comprises a dielectric material such as ceramic or resin as one of the insulation materials. First, a ground electrode
3
is disposed on substantially the entirety of one major surface
2
a
of the base member
2
. In addition, a strip-shaped radiation electrode
4
is disposed along the length direction of the base member
2
on the other major surface
2
b
of the base member
2
. One end
4
a
of the radiation electrode
4
extends onto one end surface of the base member
2
to form an open-circuited end and the other end
4
b
extends onto a major surface
2
a
and over another end surface of the base member
2
to be connected to the ground electrode
3
. Furthermore, a power feeding terminal
5
is disposed in the vicinity of the end
4
a
of the radiation electrode
4
on the end surface on which the end
4
a
of the radiation electrode
4
of the base member
2
is disposed. In this arrangement, the power feeding terminal
5
extends over the end surface of the base member
2
to the major surface
2
a
to be insulated from the ground electrode
3
.
In an antenna device
6
incorporating the surface-mount type antenna
1
shown in
FIG. 6
, a mounting substrate
7
includes a substrate
8
comprising a dielectric material, i.e., an insulating material, having a major surface
8
a,
another major surface
8
b,
a substrate-ground electrode
9
disposed on the other major surface
8
b
and a power feeding line (not shown) which is insulated from the substrate-ground electrode
9
. The surface-mount type antenna
1
is mounted on the substrate-ground electrode
9
in the vicinity of a corner of the mounting substrate
7
. In this arrangement, the ground electrode
3
and the power feeding terminal
5
of the surface-mount type antenna
1
are connected to the substrate-ground electrode
9
and the power feeding line, respectively, on the mounting substrate
7
by soldering or the like.
In order to achieve miniaturization of a communication apparatus in which an antenna device has been mounted, miniaturization of the antenna device, i.e., reduction in the cubic volume taken by the surface-mount type antenna on a mounting substrate, is required. Thus, the effort required for making the surface-mount type antenna itself smaller is considerable. When the surface-mount type antenna
1
shown in
FIG. 5
is miniaturized, the entire size of the base member
2
of the surface-mount type antenna
1
must be made smaller. However, with a surface-mount type antenna, there is a tendency in which the smaller the size of the base member, the smaller the antenna gain. Accordingly, miniaturization in the size of the base member
2
of the surface-mount type antenna
1
permits the antenna gain of the surface-mount type antenna
1
, i.e., the antenna gain of the antenna device
6
, to be reduced.
SUMMARY OF THE INVENTION
To overcome the above described problems, preferred embodiments of the present invention provide an antenna device (and a communication apparatus including the same) in which miniaturization does not cause the antenna gain to be deteriorated, i.e., antenna gains can be enhanced without increasing in size.
One embodiment of the present invention provides an antenna device comprising a surface-mount type antenna and a mounting substrate on which said surface-mount type antenna is mounted; said surface-mount type antenna comprising: a base member comprising an insulating member and having a first major surface, a second major surface opposite to said first major surface, and a plurality of end surfaces extending between said first and second major surfaces; a ground electrode disposed substantially on said first major surface of said base member; a strip-shaped radiation electrode disposed substantially on said second major surface of said base member and including an open-circuited end and a grounded end; a ground terminal connected to said ground end of the radiation electrode and insulated from said ground electrode; and a power feeding terminal disposed in the vicinity of said open-circuited end of the radiation electrode; said mounting substrate comprising: an insulation substrate comprising a first major surface and a second major surface; a first substrate-ground electrode disposed on said first major surface of said insulation substrate; a second substrate-ground electrode and a connection electrode respectively disposed on said second major surface of said insulation substrate and insulated from each other; and a through-hole connecting said connection electrode and said second substrate-ground electrode to said first substrate-ground electrode; and said ground electrode of said surface-mount type antenna being connected to said second substrate-ground electrode of said mounting substrate; and said ground terminal of said surface-mount type antenna being connected to said connection electrode of said mounting substrate.
Another embodiment of the present invention provides a communication apparatus including the above described antenna device.
Such an arrangement permits the antenna gain in the antenna device of the present invention to be increased without increasing in size. That is, since a ground terminal, to which the other end of a radiation electrode of a surface-mount type antenna is connected, is grounded by connecting to a first substrate-ground electrode disposed on a first major surface of a mounting substrate through a connection electrode and through-holes formed on a second major surface of the mounting substrate, the thickness of the base member of the surface-mount type antenna can be substantially increased, leading to improvement of antenna gains.
Furthermore, in the communication apparatus of the present invention, use of the antenna device above permits communication quality to be enhanced and permits cost reduction to be achieved.
Other features and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention which refers to the accompanying drawings, wherein like reference numerals indicate like elements to avoid duplicative description.
REFERENCES:
patent: 5861854 (1999-01-01), Kawahata et al.
patent: 5867126 (1999-02-01), Kawahata et al.
patent: 5959582 (1999-09-01), Kawahata et al.
patent: 6040806 (2000-03-01), Kushihi et al.
Kawahata Kazunari
Kurita Junichi
Yuasa Atsuyuki
Murata Manufacturing Co. Ltd.
Ostrolenk Faber Gerb & Soffen, LLP
Phan Tho
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