JPH07321527A - Portable radio equipment - Google Patents

Abstract

PURPOSE:To reduce the size remarkably by varying the length of an antenna element as required and to avoid the adverse effect on peripheral electronic components in the reduced state of the antenna length through the variable operation. CONSTITUTION:The small sized portable radio equipment has an antenna system the length of the antenna element of which is varied at least into two kinds of expanding state and reduction state, and the antenna system is provided with a coil antenna 7 comprising a conductor coil provided to its upper end, a 1st connector 8 connecting electrically to a feeder terminal 16, a rod antenna 9, an impedance conversion section 10, a 2nd connector 11 connecting electrically to the feeder terminal 8, and a Sperrtopf section 12, and the reduction state is obtained by connecting the 1st connector 8 and the feeding terminal 16 and the expanding state is obtained by connecting the 2nd connector 11 and the feeder terminal 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio device,
In particular, it is possible to achieve a significantly shortened shape by changing the length of the antenna element as needed, and a mobile phone having an antenna device capable of avoiding adverse effects on peripheral electronic components when the shortened state is achieved by the variable operation. For radios for mobile phones.

[0002]

2. Description of the Related Art Conventionally, in an antenna device such as a portable radio, the antenna element length is usually set to about λ / 2 or about λ / 4 for use. An antenna element having a length of λ / 4 has a wavelength of λ
It is advantageous that it is shorter than an antenna element of length / 2. For example, in 150MH _Z antenna element lambda / 2 in the band whereas requires a length of about 1 m, the antenna element having a length of lambda / 4 is sufficient if the length of the half.

Next, based on FIGS. 4A and 4B, λ / 4
The input / output impedance will be described by taking an antenna of wavelength and λ / 2 wavelength as an example. FIG. 4A shows a current-voltage distribution when the antenna element length corresponds to a length corresponding to λ / 2, and FIG. 4B shows a current-voltage distribution of an antenna having an element length of λ / 4. Indicates. Further, this λ / 4 type antenna is required to generate an image current by a large housing having a sufficiently large horizontal area.

First, the λ / 2 type antenna device is shown in FIG.
As shown in (a), the power is fed in the vicinity of the point where the current is maximum and the voltage is minimum, so the impedance becomes extremely large. Actually, some kind of impedance conversion means is required so that it can be connected to the antenna terminal of the wireless device, which is normally set to 50Ω or 75Ω, with a point having an impedance of several hundreds Ω as a feeding point. Further, as shown in FIG. 4B, the 1/4 wavelength type antenna device feeds power at the point where the voltage value is minimum and the current is large, that is, the point where the impedance is small (lower end portion). Actually, by making it slightly shorter than λ / 4, it is directly connected to the wireless device as a feeding impedance of 50Ω or 75Ω. Also, this λ /
Since the 4-type antenna is formed by grounding the feeding point, a predetermined transmission / reception performance can be ensured by connecting a large-area ground to a large-sized housing or the like.

However, in recent years VHF band and UHF
In portable radios for bands, it is becoming difficult to secure a sufficient ground for the case because the case is extremely small, and with this, the λ / 4 type antenna is provided. Sufficient transmission and reception performance cannot be secured.

As described above, in an environment with poor radio wave conditions, an antenna having an element length of λ / 4
Since a sufficiently good transmission / reception state cannot be obtained, a highly efficient λ / 2 antenna element is widely used despite its large size. However, since the λ / 2-long antenna is as long as about 1 m in the 150 MH _Z band, it is difficult to always use it in a portable wireless device. For this reason, two types of antennas, λ / 2 type and λ / 4 type, are prepared in advance, and the λ / 4 type antenna is used in a place where the radio wave condition is good, while it is used only in a place where the radio wave condition is bad. In many cases, a proper use method according to the radio wave environment such as using a λ / 2 type high efficiency antenna was adopted.

However, in such a selective use method, since it is necessary to always carry two types of antennas, not only the portability which is a characteristic of the λ / 4 type antenna is impaired, but also the element replacement work is required. It had a problem of being complicated. Further, as described above, the portable wireless device in recent years has been extremely miniaturized, so that there is an increasing demand for miniaturization of the antenna device in use.

[0008]

The present invention has been made in view of the above circumstances, and it is possible to achieve a greatly shortened shape by varying the antenna element length as necessary, and to achieve a shortened state by the variable operation. An object of the present invention is to provide a portable wireless device having an antenna device capable of preventing radio waves from being radiated from an antenna portion housed in a wireless device housing and avoiding adverse effects on peripheral electronic components.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a portable radio, which comprises an antenna device capable of varying the antenna element length in at least two types of a stretched state and a shortened state. A coil antenna section provided with a conductor coil provided at an upper end section, a first connector electrically connected to a power supply terminal, a rod antenna section, an impedance conversion section, and electrically connected to a power supply terminal. A second connector and a spell top portion are provided, the first connector is disposed between the coil antenna portion and the rod antenna portion, and the second connector is the rod antenna. Section and the impedance conversion section, and is in a shortened state when the first connector and the power supply terminal are connected, and the second connector and the power supply terminal are connected. Characterized in that the under tension state.

Still another feature of the present invention is that the spell top portion accommodates the rod antenna portion and the impedance conversion portion in the shortened state, and the rod accommodated in the shortened state. And short-circuiting means for short-circuiting the lower ends of the antenna part and the impedance conversion part.

[0011]

The present invention will be described below based on the illustrated embodiments. FIG. 1 is an external view of an embodiment of a portable wireless device according to the present invention. As shown in FIG. 1, in this portable wireless device, a switch unit 1 for turning on / off a power source, switching channels, etc. is provided on an upper surface of a housing (body) 2, and a display unit 3 is provided.
A voice device 4 such as a microphone or a speaker is provided on the front surface of the housing 2, and an antenna device 5 is provided on the right end portion of the top surface of the housing 2.

FIG. 2 is a sectional view showing the antenna device 5 shown in FIG. 1 in an expanded state. As shown in FIG. 2, the antenna device includes a coil antenna section 7, a first connector 8 connected to the coil antenna section 7, a rod antenna section 9, an impedance conversion section 10 provided in the rod antenna, and an end section thereof. It has a second connector 11 attached to and a spell top portion 12 made of a conductor tube.

The coil antenna portion 7 is located at the tip of the antenna element, and has an insulating hollow cylindrical portion 13 and
The hollow cylindrical portion 13 has a cylindrical conductor portion 14 connected to the lower end thereof. The hollow cylindrical portion 13 has a conductor coil 15 incorporated therein, and the lower end of the conductor coil 15 is It is electrically connected to the upper end of the cylindrical conductor portion 14.

The first connector 8 is formed integrally with the lower end of the cylindrical conductor portion 14 of the coil antenna portion 7, and is in a shortened state (see FIG. 3) to be described later.
To be electrically connected. In addition,
The conductor coil 1 is in a shortened state (see FIG. 3) described later.
The electrical length from the tip of 5 to the first connector 8 is approximately λ /
It has a length corresponding to four wavelengths. The rod antenna section 9 is composed of a thin-diameter cylinder or a conductor rod electrically connected to the lower end of the first connector 8.

The impedance conversion portion 10 is provided at the lower end of the rod portion 9, and the lower end portion 9 of the rod portion 9 is provided.
Insulating rubber member 17 provided so as to cover a, hollow cylindrical portion 18 provided at the lower end of insulating rubber member 17, and cylindrical conductor portion 19 provided at the lower end of hollow cylindrical portion 18. And an impedance matching coil 20 that electrically connects the lower end of the lower end 9a of the rod portion 9 and the upper end of the cylindrical conductor portion 19 to each other.

The outer diameters of the cylindrical conductor portion 14, the insulating rubber member 17, and the hollow cylindrical portion 18 are the same, and are fixed in the vertical direction with the inner diameter of the insulating support member 21 described later. It is designed to come in contact with each other freely. The second connector 11 is integrally formed at the lower end of the cylindrical conductor portion 19, and is adapted to engage with the power supply terminal 16 and be electrically connected in the extended state (state of FIG. 2). It has become. In this extended state, the length from the tip of the conductor coil 15 to the second connector 11 is approximately λ / 2 wavelength.

The spell top portion 12 has an insulating support member 21 and a hollow cylindrical conductor (accommodation member) 23 which are inserted into 22 provided at the right end of the upper surface of the housing 2 of the portable radio device. is doing. And the hollow cylindrical conductor 2
3 is fixedly fitted between the insulating support member 21 and the outer peripheral portion of the insertion hole 22 so that the upper end thereof is electrically connected to the outer peripheral portion of the insertion hole 22 and grounded. It has become.

Further, the hollow cylindrical conductor 23 has the first
And a power feeding opening 24 for the second connectors 8 and 11 to come into contact with the power feeding terminal 16, and a short portion 25 to come into contact with the lower end of the second connector 11 and short-circuit it in the antenna shortened state. Have This short section 25
Comprises a conductor piece attached to the lower end of the hollow cylindrical conductor 23 so as to electrically connect the lower end of the second connector 11 and the lower end of the hollow cylindrical conductor 23 in the antenna shortened state.

The hollow cylindrical conductor 23 is a coaxial cable (for example, 50) for power supply to which the power supply terminal 16 is connected.
Wire 2 to the ground wire of 26)
It is connected via 7. In addition, the hollow cylindrical conductor 2
The inner diameter of 3 is larger than the outer diameter of the impedance conversion section 10 in order to accommodate the rod antenna section 9 and the impedance conversion section 10 in the antenna shortened state.

Next, the operation of the antenna device having the above configuration will be described. First, in the state in which the hollow cylindrical portion 13 is pulled up and expanded as shown in FIG.
6 is engaged with the second connector 11 to be connected, and this antenna device has an antenna element length corresponding to λ / 2 wavelength.
It is fed by the antenna and functions as a λ / 2 wavelength antenna.

Next, when the hollow cylindrical portion 13 is pushed down, the impedance conversion portion 10 moves downward inside the hollow cylindrical conductor (housing member) 23, and in the shortened state shown in FIG. The power supply terminal 16 is engaged and connected to the first connector 8, and the lower end of the second connector 11 is connected to the short-circuit portion 25 and short-circuited. Therefore, this antenna device has an antenna element length corresponding to λ / 4 wavelength, is fed as it is with 50Ω and functions as an antenna of λ / 4 wavelength, and a greatly shortened form can be achieved as shown in FIG.

At the same time, in the shortened state, the first
The antenna portion below the connector 8 is inserted into the portable wireless device in which the antenna device is mounted, but since the lower end of the second connector 11 is short-circuited, the first connector The antenna portion of 8 or less is stored in the conductor tube of the spell top portion 12, but its electrical length is approximately λ / 4 length with respect to the frequency used, and the spell The conductor 23 of the central rod antenna 9 is short-circuited at the lower end of the top portion.

Therefore, the lower end of the λ / 4 distributed constant line is short-circuited when viewed from the power feeding portion 16, so that the input impedance is infinite when viewed from the open end, that is, the power feeding end. Or it will be extremely high. Therefore, the high frequency electric signal supplied from the power feeding end does not flow into the spell top portion but flows only to the other coil antenna portion. Therefore, in the shortened state, the peripheral electronic components located near the spell top portion 12 in the communication device are not adversely affected (magnetic field or the like).

An embodiment of the present invention has been described above. Regarding the impedance matching means of the λ / 2 antenna, the above-mentioned Japanese Patent Laid-Open No. 61-1 of the same applicant is used.
Although detailed description is omitted in Japanese Laid-Open Patent Publication No. 25206, “Antenna Device”, the characteristic impedance is z.
_When a resistor of z ₁ is connected to the other end of the distributed constant line of λ / 4 of ₀ or an odd multiple thereof, the relationship between the input impedances z _IN seen from the other end is z ₀ = √ (z _IN・ Z ₁ )
Becomes

By determining the characteristic impedance z ₀ of the distributed constant line of λ / 4 length, the input / output impedance z _{IN of the} radio device, and the feeding point impedance of the antenna so as to satisfy this relationship, the high impedance of the antenna is set to the high impedance of the radio device. It can be matched to input / output impedance, for example 50Ω or 75Ω. It is also possible to use the λ / 4 distributed constant line as it is as the impedance matching section, but since it is long and inconvenient, the λ / 4 distributed constant line is equivalent to the lumped constant circuit or the used frequency for the used frequency. The method disclosed in the above-mentioned publication discloses a method of implementing a mixed circuit of a lumped constant circuit and a distributed constant circuit, so that method may be used.

In practice, as shown in FIG. 1 or 2,
The impedance matching part can be realized by a structure in which a coil is arranged at the center of a conductor cylinder having a required diameter. Further, the antenna length is not limited to λ / 2, and if it is an integral multiple, especially an odd multiple, a similar matching circuit can be used. Further, the entire structure is not limited to those shown in FIGS. 1 and 2, and any structure that satisfies the same principle is included in the scope of the present invention.

[0027]

As described above, according to the present invention, the antenna element length is set to λ / 2 ((extended state) and λ) as needed.
Since it can be changed to / 4 (shortened state), it can be used properly according to the radio wave condition. In addition, since the coil antenna part is provided at the upper end and the short part is provided at the lower end of the spell top part, it is possible to achieve a significantly shortened shape in the above shortened state, and at the same time around the portable wireless device equipped with the antenna. It is possible to avoid adverse effects on electronic parts.

[Brief description of drawings]

FIG. 1 is an external view of an embodiment of a portable wireless device according to the present invention.

FIG. 2 is a cross-sectional configuration diagram showing an expanded state of the antenna device shown in FIG.

3 is a cross-sectional configuration diagram showing a shortened state of the antenna device shown in FIG.

4 (a) and (b) are antenna element lengths of λ / 4.
FIG. 6 is a current-voltage distribution diagram in the case of and λ / 2.

[Explanation of symbols]

1 ... switch part, 2 ... housing,
3 ... Display unit, 4 ... Audio device, 5 ... Antenna device, 7 ... Coil antenna unit, 8, 11 ... First and second connectors,
9 ... Rod antenna part, 9a ... Lower end part,
10 ... Impedance converter, 12
... Spell top part, 13 ... Hollow cylindrical part, 14, 19 ... Cylindrical conductor part, 15 ...
Conductor coil, 16 ... Power supply terminal,
17 ... Insulating rubber member, 18 ... Hollow cylindrical portion,
20 ... Matching coil, 21 ... Insulating support member, 22 ... Insertion hole, 23 ... Hollow cylindrical conductor, 24 ... Feed opening, 25
… Short section, 26… Coaxial cable for feeding, 27… Electric wire,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsukasa Saito 2-1-1 Kotani, Samukawa-cho, Takaza-gun, Kanagawa Toyo Communication Equipment Co., Ltd.

Claims (3)

[Claims] 1. A portable wireless device, comprising an antenna device capable of varying an antenna element length in at least two states of an extended state and a shortened state, and the antenna device is a conductor coil provided at an upper end portion. A coil antenna part, a first connector electrically connected to the power supply terminal, a rod antenna part, an impedance conversion part, a second connector electrically connected to the power supply terminal, and a switch. A pel top part, the first connector is disposed between the coil antenna part and the rod antenna part, and the second connector is below the rod antenna part and the impedance conversion part. And is in a shortened state when the first connector and the power supply terminal are connected, and is in an extended state when the second connector and the power supply terminal are connected. When Portable radio that does. 2. A storage member for storing the rod antenna section and the impedance conversion section in the shortened state of the spell top section, and lower ends of the rod antenna section and the impedance conversion section stored in the reduced state. 2. The portable wireless device according to claim 1, further comprising a shorting unit that short-circuits. 3. The antenna device has an antenna element length corresponding to an electrical length of approximately λ / 2 wavelength or an odd multiple thereof in the extended state, and an electrical length corresponding to approximately λ / 4 wavelength or an odd multiple thereof in a shortened state. 2. The portable wireless device according to claim 1, wherein the antenna element has a length.