JP3209129B2 - Antenna device and communication device equipped with the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication device such as a cellular phone and a wireless LAN (Local Area N).
The present invention relates to an antenna device in which a surface-mounted antenna used for, for example, a network is mounted on a mounting board, and a communication device including the antenna device.

[0002]

2. Description of the Related Art An antenna device in which a conventional surface mount antenna is mounted on a mounting substrate will be described with reference to FIG. In FIG. 11, reference numeral 40 denotes a surface mount antenna,
It is mounted near one corner of the surface of the mounting board 41 having a rectangular shape. On the surface of the surface mount antenna 40,
The gap g between the L-shaped radiation electrode 42 and the feeding electrode 43
Is formed through.

[0003]

However, in the above-described antenna device, the open end 42a of the radiation electrode 42 of the surface-mount type antenna 40 has two sides forming one corner of the mounting board 41 as shown by arrows. One side 41 of
a, which caused a decrease in gain. This is because the image current flowing through the ground electrode (hatched portion) of the mounting board 41 is concentrated near one side 41a to cause a conductor loss. Also, in a communication device equipped with such an antenna device, a decrease in gain has similarly been caused. Accordingly, the present invention provides an antenna device in which an image current flows near the center of a mounting substrate to reduce conductor loss and improve gain, and a communication device equipped with the antenna device.

[0004]

In order to achieve the above object, an antenna device according to the present invention comprises a square mounting board,
One corner formed by intersecting two sides of the mounting board
From an electro-current type surface-mount antenna mounted near
The surface mount type antenna
Is on one main surface of a substrate made of a dielectric or magnetic material,
One end curved in a substantially L-shape or U-shape is open
A radiation electrode whose end is short-circuited, and for exciting the radiation electrode
And a power supply electrode formed through a gap,
The electrode and the power supply electrode may be any end face of the base.
Connected to the ground terminal and power supply terminal
And the open end of the radiation electrode is
At least one of the two sides forming the one corner portion
It is characterized in that it is configured to face away from one side. In addition, the communication device of the present invention includes the antenna
It is characterized by mounting the device. Configure like this
As a result, the antenna device of the present invention reduces conductor loss.
Thus, the gain can be improved. In addition, according to the present invention,
In the case of a transceiver, it is necessary to reduce conductor loss and improve gain.
Can be.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an antenna device according to the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the antenna device of the present invention. In FIG. 1, reference numeral 10 denotes a surface-mounted antenna, and an enlarged view thereof is shown in FIG. On the surface of the substrate 1 made of a dielectric or magnetic material of the surface mount antenna 10, an L-shaped radiating electrode 2 having a length of approximately λ / 4 and a feeding electrode 3 are formed via a gap g. Have been. The radiation electrode 2 has an open end 2a at one end and a short-circuit end 2b at the other end. The short-circuit end 2b is connected to a short-circuit terminal 4 formed from one end surface 1a of the base 1 to the back surface. In addition, the power supply electrode 3 is
Is connected to a power supply terminal 5 formed from one end face 1a to the back face. The power supply electrode 3 and the open end 2a of the radiation electrode 2 are separated by a distance (d), and are electrically coupled by a capacitance Cd formed between the distance (d). The power supply electrode 3 and the radiation electrode 2 are closest to each other via the gap g in the vicinity of the short-circuit end 2b. However, the vicinity of the short-circuit end 2b of the radiation electrode 2 is inductive, so The degree of coupling is small. Even when the power supply electrode 3 and the open end 2a are separated from each other, the degree of coupling is large because the surface mount antenna 10 itself is small. As shown in FIG. 1, the surface-mounted antenna 10 having the above-described configuration is configured such that two sides of a rectangular mounting substrate 11 intersect.
It is mounted near one corner portion formed. At this time, the surface-mounted antenna 10 has the open end 2a of the radiation electrode 2
As shown by the arrows, the sides first mounting substrate 11 is one of two sides 11a and 11b constituting the one corner of the
It is mounted on the mounting board 11 so as to face in a direction away from 1a. By forming the antenna device by mounting the surface-mounted antenna 10 on the mounting substrate 11 in this manner, an image current flows near the center of the mounting substrate 11, and the conductor loss is reduced. In this case, the open end 2a of the radiation electrode 2 does not stay away from the other side 11b, but gains an effect by increasing the distance from at least one side 11a. next,
FIG. 3 shows radiation pattern characteristics of the antenna device of the embodiment shown in FIG. 1 and the conventional antenna device shown in FIG.
This will be described with reference to FIG. FIGS. 3 and 4 show the radiation pattern characteristics in the XY plane of the antenna apparatus of the present invention and the conventional antenna apparatus shown in FIGS. 1 and 11, respectively.
In the case of the embodiment of the present invention shown in FIG. 3, at 1.9 GHz, the average gain is -8.5 dB. Also, in the case of the conventional example shown in FIG. 4, the average gain is -12.2 dB at 1.9 GHz. FIG. 5 and FIG.
11 shows radiation pattern characteristics in the XZ plane of the antenna device of the present invention and the conventional antenna device shown in FIGS. 1 and 11, respectively. In the case of the embodiment of the present invention shown in FIG. 5, at 1.9 GHz, the average gain is -8.1 dB. In the case of the conventional example shown in FIG. 6, the average gain is -11.4 dB at 1.9 GHz. As described above, from FIGS. 3 to 6, the average gain of the radiation pattern of the antenna device of the present invention is 3 to 4 compared to the conventional antenna device.
It can be seen that the dB has been improved. FIG. 7 shows another embodiment of the antenna device of the present invention. 7, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 7, the surface-mounted antenna 10, the open end 2a of the radiation electrode 2, as shown by the arrow, the direction away from any of the two sides 11a and 11b constituting the one corner <br/> It is mounted on the mounting substrate 11 in a state of being inclined with respect to the corner of the mounting substrate 11 so as to face. By mounting the surface mount antenna 10 on the mounting board 11 in this manner, conductor loss can be further reduced, and the gain of the antenna device can be improved. FIG. 8 shows still another embodiment of the antenna device of the present invention. In FIG. 8, FIG.
The same reference numerals are given to the same or equivalent parts, and the description is omitted. In FIG. 8, reference numeral 20 denotes a surface-mounted antenna, and an enlarged view thereof is shown in FIG. In FIG.
Except that the radiation electrode 22 is formed in a U-shape, the open end 22a of the radiation electrode 22, the power supply electrode 3, and the electric field coupling by the capacitor Cd are the same as those in FIG. The surface mount antenna 20 having such a structure is mounted near one corner of the mounting board 11 as shown in FIG. At this time, in the surface-mounted antenna 20, the direction in which the open end 22a of the radiation electrode 22 moves away from the side 11b, which is one of the two sides 11a and 11b forming one corner, as indicated by the arrow. It is mounted on the mounting board 11 so as to face. By mounting the surface mount antenna 20 on the mounting board 11 in this manner, conductor loss can be reduced and the gain of the antenna device can be improved. FIG. 10 shows an embodiment of the communication device of the present invention. In FIG. 10, the same or equivalent parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Referring to FIG.
Is mounted. In the communication device 30 configured as described above, the radiation pattern characteristics of the antenna device are the same as those in FIGS. 3 and 5, and a communication device with small conductor loss and high antenna gain can be configured.

[0006]

According to the antenna device of the present invention, the surface mounting type antenna is formed by the two sides of the rectangular mounting substrate intersecting each other.
Upon implementing the vicinity of one corner portion formed Te, by the open end of the radiation electrode is implemented to face away from the at least one side of the two sides constituting the corner portion, the image current Flows through the center of the mounting board, the conductor loss is reduced, and the gain is improved. Further, the gain is similarly improved in a communication device equipped with the above antenna device.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an antenna device of the present invention.

FIG. 2 is a perspective view showing a surface-mounted antenna mounted on the antenna device of FIG. 1;

FIG. 3 is an XY plane radiation pattern characteristic diagram of the antenna device of the present invention shown in FIG. 1;

4 is an XY plane radiation pattern characteristic diagram of the conventional antenna device shown in FIG.

FIG. 5 is an XZ plane radiation pattern characteristic diagram of the antenna device of the present invention shown in FIG. 1;

6 is an XZ plane radiation pattern characteristic diagram of the conventional antenna device shown in FIG. 11;

FIG. 7 is a perspective view showing another embodiment of the antenna device of the present invention.

FIG. 8 is a perspective view showing still another embodiment of the antenna device of the present invention.

FIG. 9 is a perspective view showing a surface mount antenna mounted on the antenna device shown in FIG. 8;

FIG. 10 is a perspective view showing an embodiment of the communication device of the present invention.

FIG. 11 is a perspective view showing a conventional antenna device.

[Explanation of symbols]

 Reference Signs List 2 radiation electrode 2a open end 2b short-circuit end 3 feeding electrode 10 surface-mounted antenna 11 mounting substrates 11a and 11b sides

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01Q 1/24-1/38 H04M 1/02 H04B 12/00 H01Q 13/08

Claims (2)

(57) [Claims] 1. A mounting board having a rectangular shape, and
Near one corner formed by two sides
Antenna device consisting of an electromotive force type surface mount antenna
Wherein the surface mount antenna is a dielectric or
Represents a substantially L-shaped or
Is open at one end and short-circuited at the other end.
A radiation electrode, and a power supply electrode for exciting the radiation electrode.
Are formed through a gap, and the radiation electrode and the power supply
An electrode for use is a gutter formed on any end face of the base.
An open end of the radiation electrode is connected to a land terminal and a power supply terminal, and the open end of the radiation electrode is connected to the one corner of the mounting substrate.
Characterized in that the antenna device is configured to face in a direction away from at least one of the two sides forming the antenna. 2. An antenna device according to claim 1, further comprising :
A communication device characterized by the following.