JP3192085B2 - Small antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna for a portable radio, and more particularly, to a structure of a small antenna serving also as a housing of a radio pager.

[0002]

2. Description of the Related Art First, a first prior art will be described. 1 and 2 are sectional views of a conventional portable wireless device. In this portable wireless device, as shown in FIGS. 1 and 2, a printed circuit board 2 on which a wireless circuit is formed is housed in a box 1 made of an insulating hexahedron, and two antenna connecting portions 3a and 3a of the wireless circuit are provided.
3b, both ends of a thin plate-shaped loop antenna 4 arranged along the inner surface of the box 1 as shown in FIG.
As shown in FIG. 2, both ends of a thin plate-shaped loop antenna 4 attached to the inner surface of the box 1 are connected to connection terminals 5a and 5b. However, in such an antenna structure, since the loop antenna 4 is provided on the inner surface of the box 1, the cross-sectional area of the antenna formed by the antenna loop is within the cross-sectional area surrounded by the inner surface of the box 1, Since no more effective antenna cross-sectional area can be obtained, there is a problem that the antenna gain cannot be improved beyond the gain obtained when the antenna cross-sectional area is a cross-sectional area surrounded by the inner surface of the box 1.

Next, a second conventional technique will be described.
3 to 5 are structural examples of a conventional portable wireless device. This portable wireless device solves the above-described problem. As shown in FIGS. 3 to 5, a thin plate-shaped loop antenna 4 is provided on the outer surface of a box 1 made of an insulating hexahedron having a single opening. One end of the printed circuit board 2 on which the wireless circuit is formed is fixed to the inside of the lid 6 and connected to the two antenna connection portions 3a and 3b of the wireless circuit on the side of the printed circuit board 2 opposite the lid. The two connection terminals 7a1 and 7b1 provided are opposed to both end portions 4a and 4b of the loop antenna 4, the printed circuit board 2 is inserted into the box 1, and the cover 6 is attached to and detached from the surface 1a of the box 1. It is configured to be freely attached and to be connected between the two end terminals 4a and 4b of the loop antenna 4 and the two connection terminals 7a1 and 7b1 by connection means 8 which can be detached from each other.
However, this antenna structure is basically limited to the application to a box-shaped portable radio, and is applied to a card-shaped portable radio having an extremely thin side surface.
It is impossible to provide a location such as b and use the connection means 8 as described above. In addition, there is a problem that the number of components and the number of mounting steps by the connecting means 8 are increased as compared with a normal loop antenna.

Next, a third prior art will be described.
6 and 7 are structural examples of a conventional card-type portable wireless device, FIG. 6 is an exploded perspective view, and FIG. 7 is a partially enlarged sectional view.
As an antenna structure used in a thin card-type portable wireless device, an antenna structure as shown in FIGS. 6 and 7 is commonly used. The card-type portable wireless device comprises a frame 11 made of a lid-like insulator in which a printed circuit board 2 on which a wireless circuit is formed is accommodated, and a square plate-shaped conductor fixed with the insulating frame 11 interposed therebetween. It is composed of a conductor plate 12 and a lower conductor plate 13. As shown in FIG. 7, when the upper conductor plate 12 is attached to the upper surface of the lid of the insulating frame 11 with an adhesive or the like,
The insertion portion of the upper conductor plate 12 is inserted into the slit of the insulating frame 11 and bent, and the lower conductor plate 13 and the lower conductor plate 13 are jointly fastened with screws or the like. The printed circuit board 2 is interposed therebetween.

However, in this antenna, a short-circuit point portion (see FIG. 7) for electrically connecting the upper conductor plate 12 and the lower conductor plate 13 is provided.
(A)) and a portion of a power supply point where power is supplied and grounded from the printed circuit board 2 to the upper conductor plate 12 and the lower conductor plate 13 (FIG. 7).
(B)) is used for fixing through the frame 11 using a conductor such as a screw, for example, a few meters from the end face of the insulating frame 11.
m inside. Therefore, there is a problem that the loop opening area of the antenna cannot be further increased, and the antenna gain determined by this structure cannot be further increased. In this structure, the upper conductor plate 12,
There is a problem that the number of assembly steps and the number of parts for fixing and conducting the lower conductor plate 13 are larger than those of a normal loop antenna, and the cost cannot be easily reduced.

[0006]

To summarize the above, the conventional structure has the following problems. In the first conventional example and the third conventional example, the loop cross-sectional area of the antenna is structurally limited, the effective antenna cross-sectional area cannot be increased, and the antenna gain cannot be further improved. The second conventional example cannot be applied to a card-type portable wireless device having an extremely thin side surface. In each of the first to third conventional examples, the number of parts and the number of mounting steps are increased more than the ordinary loop antenna, and the cost cannot be easily reduced.

An object of the present invention is to solve the above-mentioned conventional drawbacks and to provide a small antenna which makes the most of the external dimensions of a card-type portable radio.

[0008]

A small antenna according to the present invention is formed by conductor plating on the upper surface of a lid-like insulating frame in which a printed circuit board on which a radio circuit is mounted is housed.
An upper conductor plate portion to be formed and one of the antenna elements,
The other anchor is fixed by screwing to the lower side of the insulating frame.
A lower conductor plate serving as a tena element;
A short-circuit conductor provided at one opposite end of the conductor plate
Section and a power supply conductor section provided on the other end portion.
A small-sized antenna, wherein the short-circuit conductor portion includes the upper conductor
The outer surface of the side surface of the lid-shaped insulating frame continuous with the plate portion
Through the screw to the lower conductor plate
That is formed by applying a conductive plating to the portion, wherein
The power supply conductor portion is connected to the upper conductor plate portion and has the lid-shaped insulation.
The print on the back side through the outer side of the side of the edge frame
Conducting plating on the part of the board that reaches the power supply terminal
And the loop opening surface of the antenna is
Side of the housing composed of the insulating frame and the lower conductor plate
The feature is that it is determined by the outer peripheral edge seen from the surface
It is assumed that.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 8 is an exploded perspective view of the first embodiment of the present invention, and FIG. 9 is an example of a partial structure thereof. In the figure, 2
1 is a lower conductor plate, 22 is a printed circuit board on which a radio circuit is mounted, 23 is an insulating frame, 24 is an upper conductor plate portion, 25 is a short-circuit conductor portion, and 26 is a power supply conductor portion. In this embodiment, a conductor is plated on the outer surface of an insulating frame 23 formed of a resin or the like to provide an upper conductor plate 24, a short-circuit conductor 25, and a power supply conductor 26. FIG. 9 shows the surface (A),
It is a structural example figure of a side surface (B) and a back surface (C). The two short-circuit conductor portions 25 are provided from the outer surface to the rear surface of the insulating frame 23 so as to be continuous with the upper conductor plate portion 24, and a short-circuit point is formed by screwing the lower conductor plate 21. The feeding point is formed by screwing the lower conductor plate 21 and the printed circuit board 22 on which the radio circuit is mounted to the insulating frame 23 by screwing.
When fixed to the printed circuit board 22, the power supply conductor 26 formed on the insulating frame 23 is electrically connected to the printed circuit board 22.

With this configuration, the short-circuit point,
Since both feeding points are formed on the outer surface of the insulating frame 11, the opening area of the antenna loop is increased.

FIG. 10 is an exploded perspective view showing a second embodiment of the present invention, and FIG. 11 is a partial structural view thereof. The difference from the first embodiment is that the short-circuit conductor 25 of the insulating frame 23 is changed. FIG. 11 shows a front view (A), a side view (B), and a back view (C). . The first
In this embodiment, two short-circuit points are provided, but almost the entire one end surface is made a short-circuit point. The same effect as that of the first embodiment can be obtained by increasing the number of screwed portions to such an extent that conduction with the lower conductor plate 21 can be sufficiently maintained to realize complete short-circuit conduction.

As described above, the number of short-circuit points is not limited to two.
Set by increasing or decreasing the number.

[0013] As a specific example, the present invention is designed to have a thickness of about 4 mm,
If applied to a card-type receiver having a width of about 50 mm and a length of about 80 mm, in the conventional configuration, as shown in FIG.
The fact that the positions of the short-circuit points were respectively about 2 to 3 mm inside the insulating frame means that the loop opening area was 95%.
That is, the absolute gain was degraded by that amount. On the other hand, in the present invention, the upper conductor plate portion 24 is formed so as to surround the outside of the housing, and the feeding point and the short-circuit point are also formed on the outer peripheral surface. The absolute gain is the largest in this enclosure.

[0014]

As described above in detail, according to the present invention, the number of parts can be reduced by integrating the upper conductor plate forming the loop antenna of the small-sized portable radio with the insulating frame. It has a remarkable effect of realizing the maximum absolute gain that can be realized with the outer dimensions of the housing, and is particularly effective for a thin portable wireless device such as a card type.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first prior art portable wireless device.

FIG. 2 is a cross-sectional view of a first prior art portable wireless device.

FIG. 3 is a structural example diagram of a second prior art.

FIG. 4 is a structural exploded perspective view of a third prior art.

FIG. 5 is a structural sectional view of a second prior art.

FIG. 6 is an exploded perspective view of a third prior art structure.

FIG. 7 is a partially enlarged sectional view of a third conventional technique.

FIG. 8 is an exploded perspective view showing the first embodiment of the present invention.

FIG. 9 is a structural example of a main part of the first embodiment of the present invention.

FIG. 10 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 11 is a structural example of a main part of a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Box 2 Printed circuit board 3 Antenna connection part 4 Loop antenna 5 Connection terminal 6 Lid 7 Connection terminal 8 Connection means 11 Insulation frame 12 Upper conductor plate 13 Lower conductor plate 21 Lower conductor plate 22 Printed circuit board 23 Insulation frame 24 Upper conductor plate Part 25 short-circuit conductor part 26 power supply conductor part

Continuation of the front page (72) Inventor Naoki Onishi 3-14-20 Higashinakano, Nakano-ku, Tokyo International Electric Co., Ltd. (56) References JP-A-1-241927 (JP, A) JP-A-9-8535 (JP, A) Fully open Showa 61-151410 (JP, U) Fully open Showa 40-4010 (JP, U) Fully open 4-36315 (JP, U) Fully open flat 2-95943 (JP, U) Actually open Sho-56-79041 (JP, U) JP-A-59-171441 (JP, U) JP-B-58-3405 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 1 / 24 H01Q 1/32 H01Q 1/38

Claims (1)

(57) [Claims] 1. A conductor plating is performed on an upper surface of a lid-shaped insulating frame in which a printed circuit board on which a radio circuit is mounted is housed.
Formed as one of the antenna elements
The body plate portion is screwed and fixed to the lower side of the insulating frame.
A lower conductor plate serving as the other antenna element;
It is provided at one opposite side of the body plate and the lower conductor plate.
Short-circuit conductor part and the power supply conductor part provided on the other end part
A small antenna with bets, the shorting conductor portion, said lid-like continuously on said conductive plate portion
Through the outer surface of the side of the insulating frame,
Conductive plating is applied to the part that reaches the screw
And the power supply conductor portion is connected to the upper conductor plate portion in the form of the lid.
Through the outer side surface of the insulating frame
Conductor plating should be applied to the part of the
The loop opening surface of the antenna is formed by the lid-shaped insulating frame.
Peripheral edge viewed from the side of the housing composed of the lower conductor plate
Small antenna characterized by being determined by
Na.