JPH06244755A - Portable radio equipment - Google Patents

Abstract

PURPOSE:To miniaturize a radio equipment without degrading band characteristics and gain by making a planar antenna element face each other so as to surround one side of a grounded conductor, electrically connecting a part of the antenna element to the grounded conductor and connecting a power feeding line to the other one part. CONSTITUTION:A resin 7 composed of a dielectric material with less high-frequency loss is provided around one side of the plate-like grounded conductor 13 so as to make the cross section U-shaped. The antenna element 11 composed of a metallic film is formed on the surface of the resin 7 by a plating vapor deposition method or the like. Then, a part of the antenna element 11 is connected through a stub 2 for matching to the grounded conductor 13 and also the other one part of the antenna element 11 is connected through the power feeding line 5 to a high-frequency circuit 6. As a result, the degradation of the gain the band characteristics of communication is eliminated. Also, capacitance formed between the grounded conductor 13 and the antenna element 11 tends to be smaller compared with the plate facing system of the antenna element. Thus, a width h1 can be selected to be smaller and the antenna element 11 can be further miniaturized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable wireless device, and more particularly to a portable wireless device used for mobile communication and the like. 2. Description of the Related Art In recent years, in the field of mobile communication, development of terminal devices such as cordless phones, pagers, and mobile phones that are directly carried by humans has been actively conducted. It is preferable that these devices are small and lightweight for the purpose of being carried and used by humans. However, at present, electrical circuits are LSI
Although the miniaturization is progressing drastically due to the miniaturization, the miniaturization of the antenna circuit and the speaker required for generating the alarm sound has a certain limit. Under such a background, not only downsizing of the antenna circuit but also how to downsize the entire device is an important issue.

[0002]

2. Description of the Related Art FIG. 6 is a diagram for explaining a conventional portable radio device, which has a built-in antenna called a so-called "inverse F antenna". In the inverted F antenna, the antenna element 1 is provided in parallel at a height h from the ground plane 4 of the metal case 3, a part of the antenna element 1 is connected to the ground plane 4 with a matching stub 2, and The other part of the element 1 is connected to a high-frequency circuit 6 inside the device via a power supply line 5. Generally, this type of antenna is considered as a modification of the slot antenna, and assuming that the outer peripheral length of the antenna element 1 is 2 (a + b), its resonance frequency is a frequency such that the outer peripheral length is λ to λ / 2. Becomes For example, if this type of antenna is manufactured in the 900 MH _Z band, its outer peripheral length is about 170 mm, and if it is configured as a square, the length of one side of the antenna element 1 is about 43 mm.
Becomes However, this size is quite large in view of the size required for the current mobile communication terminal equipment, and is difficult to implement.

If the height h is lowered, the antenna element 1
Since the capacitance between the ground plane 4 and the ground plane 4 increases, which lowers the resonance frequency, the above resonance frequency can be obtained even with an antenna element having a smaller outer circumference. However, if the height h is too low, problems such as narrowing the band of the antenna circuit and lowering the gain occur.
About 0 mm is required.

[0004]

As described above, the conventional portable radio apparatus still occupies a large space in the antenna circuit, which has been an obstacle to the miniaturization of the apparatus. An object of the present invention is to reduce the size of a portable wireless device without degrading the band characteristic and gain of communication.

[0005]

The above-mentioned problems can be solved by the structure shown in FIG. That is, the portable wireless device of the present invention has a U-shaped cross section so as to surround one side of the flat-plate ground conductor 13.
The plate-shaped antenna elements 11 having a V shape are opposed to each other at a predetermined interval, a part of the antenna element 11 is electrically connected to the ground conductor 13, and the feeder line 5 is connected to another part of the antenna element 11. It is provided with an antenna circuit formed by.

The above problem can be solved by the configuration of FIG. 2 or 3. That is, in the portable wireless device of the present invention, the antenna element 2 is provided on both surfaces of the insulating substrate 8 with the ground conductor 23 interposed therebetween.
The metal films 21 ₁ and 21 ₂ to be ₁ are formed and fixed to electrically connect both metal films, and the antenna element 21
Of the antenna element 21 is electrically connected to the ground conductor 23, and the feeder line 5 is connected to the other portion of the antenna element 21.

The above problem can be solved by the configuration of FIG. That is, in the portable wireless device of the present invention, the insulator resin 7 having the cavity 36 inside, the antenna element 31 provided on one surface of the insulator resin 7, and the antenna element 31.
And a ground conductor surface 33 that is provided on the other surface of the insulator resin 7 and is electrically connected to a part of the antenna element 31, and an electrical connection from a part of the antenna element 31. The power supply line 5 to be connected and the sounding body 40 provided in the cavity 36 are provided.

[0008]

The antenna circuit of FIG. 1 has a flat ground conductor 13
A plate-shaped antenna element 1 having a U-shaped cross section so as to surround one side
1 are opposed to each other at a predetermined interval. Therefore, most of the ground conductor 13 and the antenna element 11 face each other with a predetermined distance h ₁ .
As for the resonance frequency, as in the case of the inverted F antenna, the outer peripheral length {2 (2a ₁ + a ₂ + b)} of the antenna element 11 is λ.
The frequency is set to λ / 2.

Mounting surface of the antenna element 11 viewed from above
The product is (a₂Xb). Where a₂Is about 2h (eg
20 mm), and this 2h is the same as the conventional one in FIG.
Since it is sufficiently smaller than the example a (for example, 43 mm),
The mounting area (a₂Xb) is
Compared with the mounting area (a x b) of the conventional antenna element 1,
Significantly smaller. Next, in this state, the height of the antenna element 11 is increased.
A₁And the height h of the conventional antenna element 1 (a₁/
Consider h). According to the above, a = 2a₁+ A ₂= 2a
₁Since there is a + 2h relationship, a₁= (A / 2) -h
It Therefore, a ₁/ H = (a / 2h) -1
Be done. Here, for example, the frequency 9 at which a is about 4 times h
00MH_ZConsidering the obi, the ratio (a₁/ H) is about 1
From the height a of the antenna element 11₁On the structure of its cross section
Even if estimated a little higher, the height h of the conventional antenna element 1
You can keep it from changing too much. Therefore, the antenna element
Mounting volume of the antenna element 11 without changing the height of the child
(A₂Xbxa₁) Is the mounting volume of the conventional antenna element 1.
It can be made significantly smaller than (a × b × h). Therefore,
A wireless device for a band can be provided in a small size. In addition, preferably
A plate-shaped grounding conductor 13 and a plate-shaped antenna element having a U-shaped cross section
The insulating resin 7 is provided between the insulating resin 7 and the insulating resin 7.

In the antenna circuit of FIG. 2 or 3, the antenna element 21 is provided on both outer surfaces of the insulating substrate 8 with the ground conductor 23 interposed therebetween.
The metal films 21 ₁ and 21 ₂ to be formed are formed and fixed, and both metal films are electrically connected. Also in this case, as in the case of FIG. 1, the outer peripheral length of the antenna element 21 {2 (2a
A resonance frequency such that ₃ + a ₄ + b)} is set to λ to λ / 2 is obtained, and its mounting volume is significantly smaller than that of the conventional antenna element 1. Moreover, since such an antenna circuit can be easily manufactured by a manufacturing technique for a multilayer printed wiring board, and preferably at the time of manufacturing the multilayer printed wiring board, a portable wireless device can be provided at low cost in addition to the above.

The antenna circuit of FIG. 4 has a cavity 36 inside.
And an antenna element 31 provided on one surface of the insulator resin 7, and an antenna element 31 provided on the other surface of the insulator resin 7 in parallel with the antenna element 31. Ground conductor surface 3 electrically connected to part of the
3, a feeder line 5 electrically connected from a part of the antenna element 31, and a sounding body 4 provided in the cavity 36.
It has 0 and.

That is, since this antenna circuit accommodates the sounding body 40 such as a speaker, which is originally required by this type of wireless device, in the space, the installation space for that portion can be deleted from the wireless device body. The size of the wireless device can be reduced. In this case, since the cavity portion 36 acts as a kind of acoustic resonance chamber due to the Helmholtz resonance effect, the sound pressure of the sounding body 40 is increased by appropriately selecting the volume of the cavity portion 36 and the opening area of the opening portion 35. It is possible to change the timbre, widen the acoustic frequency band, and so on.

Preferably, as shown in FIG. 5, the insulating resin 7 has a first hollow portion 36 ₁ and a second hollow portion 36 ₂ provided in parallel therewith. For example, as shown in the figure, the sounding body 40 is provided in the second cavity portion 36 ₂ and
The part of the ground conductor surface 33 or a conductor surface having the same potential as the ground conductor surface 33 is partitioned so as to be acoustically connected to the cavity 36 ₁ . In this way, the presence of the sounding body 40 does not affect the electrical characteristics of the antenna.

[0014]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals denote the same or corresponding parts throughout the drawings. 1A and 1B are diagrams for explaining a first mounting example of the present invention. FIG. 1A is a perspective view of an antenna circuit included in a wireless device (not shown) of the first mounting example, and FIG. It is a figure explaining a cross section.

A resin 7 made of a dielectric material having a small high frequency loss is provided around one side of the flat grounding conductor 13 so that its cross section has a U shape, and a metal is formed on the surface of the resin 7 by a plating deposition method or the like. The antenna element 11 made of a film is formed. Then, a part of the antenna element 11 is replaced with the matching stub 2
Connected to the ground conductor 13 via the antenna element 11
The other part is connected to the high-frequency circuit 6 via the power supply line 5.

With such a structure, for example, 2a ₁ + a ₂ = 43
When mm, b = 43 mm and h ₁ = 10 mm are selected, the antenna element 11 of about 900 MH _Z band can be obtained as in the conventional antenna circuit of FIG. However, a ₂ = 2h ₁ = 20
mm, the mounting area (a ₂ × b) viewed from the upper side of the antenna element 11 is 20 × 43 = 860 mm ² ,
This is about 47% of the mounting area (a × b) = 43 × 43 = 1849 mm ² seen from the upper side of the conventional antenna element 1. On the other hand, the height a ₁ of the antenna element 11 is (43-2
This is about the same as the height h (= 10 mm) of the conventional antenna element 1 because it becomes about 12 mm by (0) / 2. Therefore, the mounting volume of the antenna element 11 of this example (a
₁ × b × a ₂ ) is 12 × 43 × 20 = 10320 mm ³
This is the mounting volume of the conventional antenna element 1 (a ×
b × h) = 43 × 43 × 10 = 18490 mm ³ approximately 5
6%. Then, the antenna element 1 having such a size
In the wireless device of the present embodiment in which No. 1 is mounted, deterioration of communication band characteristics and gain was not confirmed.

Further, when the cross-sectional shape is as shown in FIG. 1B, the capacitance formed between the ground conductor 13 and the antenna element 11 is somewhat larger than that of the conventional antenna element 1 which is a flat plate type. Tends to be smaller, and in reality h
It is possible to choose ₁ <h. Therefore, the antenna element 11 of this example can be further downsized. Although the antenna element 11 of this example has the resin 7, the resin 7 is not always necessary.

FIG. 2 is a diagram for explaining a second mounting example of the present invention. FIG. 2A is a perspective view of an antenna circuit included in a wireless device (not shown) of the second mounting example, and FIG. ) Is a figure explaining the cross section. Insulating substrate 8 with the ground conductor 23 sandwiched therebetween
The metal film 2 to be the antenna element 21 on both outer surfaces of the
1 _1, between 21 ₂ to form fixed to both the metal film as well as connected by the through hole 9 _1, 9 _2, connected to a portion of the antenna element 21 to the ground conductor 23 through the through hole (matching stub) 2 In addition, the other part of the antenna element 21 is connected to the high-frequency circuit 6 via the feeder line 5.

In the antenna element 21 of this example, for example, h
By selecting ₂ = 5 mm, the mounting volume (a ₃ × b
Xa ₄ ) is 17 × 43 × 10 = 7310 mm ³ ,
The mounting volume is reduced to about 40% of the conventional antenna element 1. Even in this case, no remarkable deterioration was confirmed in the band characteristic and the gain of the antenna circuit. Moreover, since the antenna element 21 can be manufactured collectively at the time of manufacturing the multilayer printed wiring board, it is easy to manufacture, so that the wireless device can be provided at low cost.

In the antenna element 21 of this example, the positions of the through holes 9 ₁ and 9 ₂ are moved in the directions of arrows i and j, respectively, so that the substantial length a ₄ that contributes to the resonance frequency is obtained.
Can be increased. As a result, the inductance is increased and the resonance frequency is lowered, so that the antenna element 21 can be further downsized. Also, the through hole 9 ₁ ,
Instead of providing 9 ₂ , the metal films 21 ₁ and 21 ₂ may be connected by a metal film having a predetermined width. Then, by reducing the predetermined width of the metal film, it is possible to increase the substantial length a ₄ contributing to the resonance frequency in the same manner as described above.

FIG. 3 is a diagram for explaining a third mounting example of the present invention. FIG. 3A is a perspective view of an antenna circuit included in a wireless device (not shown) of the third mounting example, and FIG. ) Is a figure explaining the cross section. In this example, the thickness h ₁ of the dielectric material sandwiched between the antenna elements 21 is set to be larger than the thickness h ₃ of a normal multilayer printed wiring board. This makes it possible to improve the band characteristic and gain of the antenna circuit.

FIG. 4 is a diagram for explaining a fourth mounting example of the present invention, which shows a perspective view of an antenna circuit provided in a wireless device (not shown) of the fourth mounting example. The basic structure of this antenna is the same as the conventional inverted F antenna of FIG.
By integrally molding the antenna element 31 and the resin 7, the antenna element is made solid and the dimensional accuracy of the height h between the antenna element 31 and the ground conductor surface 33 is improved. Further, one end of the antenna element 31 is connected to the side P,
It is folded back at the positions of Q, R and S, and the tip of the folded portion is connected to the antenna element 31 at the position of the side T. By doing so, capacitance is generated by the gap d between the antenna element 31 and the ground conductor surface 33, and the resonance frequency can be lowered. Therefore, the lengths a and b of the antenna element 31 of this example are smaller than the lengths a and b of the conventional antenna element 1. In addition, since the loop is added to the tip of the antenna element 31, the change of the reactance with respect to the frequency becomes slow, and the band characteristic becomes a wide band. Note that such an antenna circuit has already been proposed by the applicant of the present application.

In the fourth mounting example, a cavity 36 having an opening 35 is provided in a part of the insulating resin 7, and a sounding body 40 such as a speaker or a buzzer is provided in the cavity 36. The size of the example sounding body 40 is, for example, 5 mm in diameter and height. According to the fourth implementation example, by designing the antenna circuit in consideration of the presence of the sounding body 40 in advance, the surplus space can be effectively used without affecting the antenna characteristics, and the sounding body 40 can be generated from the device main body. The installation space of can be deleted, and the main body of the device can be downsized.

Moreover, as is known as the Helmholtz resonance effect, if the sounding body 40 is provided in the cavity 36 of the resin 7, the cavity 36 acts as a kind of acoustic resonance chamber, and as a result, the cavity is formed. By appropriately selecting the volume and shape of 36 and the area and shape of the opening 35, the sound pressure of the sounding body 40 can be increased, the acoustic frequency band can be widened, and the tone color can be changed. For example, the sound pressure is improved by about 8 dB by optimally selecting the shape condition of the resonance chamber.

FIG. 5 is a diagram for explaining a fifth mounting example of the present invention. FIG. 5 (A) is a perspective view of an antenna circuit included in a wireless device (not shown) of the fifth mounting example, and FIG. 5 (B). FIG. 3 is a diagram for explaining the cross section. In the fifth mounting example, a cavity portion 36 ₁ forming a resonance chamber and a cavity portion 36 ₂ accommodating the sounding body 40 are separately provided, and the boundary between them is part of the ground conductor surface 33 or the ground conductor surface 33. It is partitioned by a conductor surface of the same potential as. A plurality of minute holes are provided in this boundary portion, and the sound wave generated from the sounding body 40 is transmitted to the outside through the minute hole, the resonance chamber, and the resonance chamber. At this time, the sound pressure, tone color, etc. are improved by the resonance effect as described above. Moreover, in this example, the sounding body 40 is connected to the ground conductor surface 33.
Since it is mounted in the shadow of and the minute hole provided at the boundary is sufficiently short for a high frequency wavelength, it works as a metal plate, and thus the operation of the sounding body 40 is an electrical operation of the antenna. Has no effect on.

It is obvious that the structure of the resonance chamber composed of the resin portion 7 and the sounding body 40 may be applied to the conventional antenna circuit as shown in FIG.

[0027]

As described above, the portable radio apparatus of the present invention has a structure in which plate-shaped antenna elements 11 each having a U-shaped cross section are opposed to each other at a predetermined interval so as to surround one side of the flat-plate ground conductor 13. Since it has a small antenna circuit, the wireless device can be significantly downsized without deteriorating the band characteristic and gain of communication.

Further, in the portable radio apparatus of the present invention, metal films 21 ₁ and 21 ₂ to be antenna elements 21 are formed and fixed on both surfaces of the insulating substrate 8 with the ground conductor 23 sandwiched therebetween, and the metal films are electrically connected to each other. Since such a wireless device is provided with a small-sized and easy-to-manufacture antenna circuit having an electrically connected structure, such a wireless device can be provided at a lower cost. Further, in the portable wireless device of the present invention, the cavity portion 36 is provided in a part of the insulating resin 7 that fixes the antenna element 31.
Since the sounding body 40 is provided, the size of the entire apparatus can be reduced, and the sounding body 40 can provide a notification sound of a desired sound pressure and tone color.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a third embodiment of the present invention.

FIG. 4 is a diagram illustrating a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating a fifth embodiment of the present invention.

FIG. 6 is a diagram illustrating a conventional portable wireless device.

[Explanation of symbols]

 2 Matching stub 5 Feed line 6 High frequency circuit 7 Resin 11 Antenna element 13 Ground conductor

Claims (4)

[Claims] 1. A plate-shaped antenna element (11) having a U-shaped cross section is arranged so as to surround one side of a plate-shaped grounding conductor (13) at a predetermined interval, and a part of the antenna element (11) is aforesaid. A portable radio device comprising an antenna circuit electrically connected to a ground conductor (13) and having a feeder line (5) connected to another part of the antenna element (11). 2. Metal films (21 ₁ , 21 ₂ ) to be antenna elements (21) are formed and fixed on both surfaces of an insulating substrate (8) sandwiching a ground conductor (23) to electrically connect both metal films. And a part of the antenna element (21) is electrically connected to the ground conductor (23), and the feeder line (5) is connected to the other part of the antenna element (21). A portable radio device, comprising: 3. An insulator resin (7) having a cavity (36) inside, an antenna element (31) provided on one surface of the insulator resin (7), and the antenna element (31) with respect to the antenna element (31). Parallel to each other and provided on the other surface of the insulating resin (7), and the antenna element (3
Ground conductor surface (33) electrically connected to part of 1)
And a power supply line (5) electrically connected to a part of the antenna element (31), and a sounding body (40) provided in the cavity (36). Wireless device. 4. The insulator resin (7) has a first cavity (36).
₁ ) and a second cavity (3) provided in parallel therewith
6 ₂₎ portable radio apparatus according to claim 3, characterized in that it comprises a.