JP2000077921A - Antenna for portable radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a configuration suitable for carrying and to prevent damage by making the height of antennas into low profile at the time of rod antenna housing by combining a magnetic current loop antenna and a flexible rod antenna. SOLUTION: A magnetic current loop antenna 11 and a rod antenna 12 are attached through an insulating member to a casing 1 of portable radio equipment. The magnetic current loop antenna 11 is constituted by winding the conductor wire of length corresponding to 1/2 to 1 wavelength in the shape of coil. Besides, one end 11a of the conductor wire is fixedly arranged at the upper part of the easing 1 of the portable radio equipment and connected to a transmission/reception circuit inside the portable radio equipment and power is fed. The rod antenna 12 is composed of a length corresponding to 1/4 to 1/2 wavelength. Besides, this antenna is provided on the central axis of loop of the magnetic current loop antenna 11, flexibly disposed on the casing 1 of the portable radio equipment, connected through a metal fitting 2 for power feeding, which is provided in the easing 1, and power is fed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antenna for a radio, and more particularly to an antenna for a portable radio such as a portable telephone.

[0002]

2. Description of the Related Art Conventionally, in this type of portable radio, a rod antenna having a wide band and high efficiency has been widely adopted as a transmitting / receiving antenna. However, the rod antenna protrudes greatly from the housing, which is inconvenient to carry and has a drawback of being easily damaged.

Conventionally, portable telephone radios such as portable telephones in which a small helical antenna is provided in parallel with the rod antenna and the rod antenna is made extendable and contractible have been used. In the above-mentioned portable telephone radio, the helical antenna is configured to be connected to the receiver by a metal fitting for feeding the antenna in a state where the rod antenna is housed, so that incoming calls can be received. During a call, the rod antenna is used in an extended state, and in this case, a transceiver is configured to be connected to the rod antenna.

[0004]

However, in the portable wireless device, it is necessary to increase the length of the helical antenna to some extent in order to secure a sufficient communication band. In order to secure a specific frequency bandwidth of 2% in a state where
It was necessary to have a length corresponding to the wavelength.
As a result, even when the rod antenna is housed, the helical antenna protrudes from the housing for a length corresponding to 1/10 wavelength, which is inconvenient to carry and has a problem of being easily damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a configuration suitable for portability by combining a magnetic loop antenna and a telescopic rod antenna to make the height of the antenna low when the rod antenna is stored. It is another object of the present invention to provide an antenna for a portable wireless device that can prevent damage.

[0006]

According to the present invention, there is provided an antenna for a portable wireless device provided in a portable wireless device having a transmission / reception circuit.
A first antenna comprising a magnetic current loop antenna in which a conductor wire having a length corresponding to one wavelength is wound in the coil shape;
A rod antenna having a length corresponding to, for example, １ ／ to 波長 wavelength, which is provided on the center axis of the loop of the magnetic current loop and is extendably provided on the housing of the portable wireless device. An antenna for a portable wireless device comprising the two antennas is provided.

That is, a magnetic current loop antenna is used in place of a helical antenna, and it is operated as a small dipole, and has the same radiation directivity as a rod antenna. Become. Also, in the present invention, the first
May be connected to the transmission / reception circuit and supplied with power, and the second antenna may be supplied with electromagnetic coupling via the first antenna.

Further, in the present invention, the first antenna and the second antenna may be electrically connected. Still further, in the present invention, the first antenna and the second antenna may be insulated by, for example, an insulating member.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an antenna for a portable radio device according to the present invention will be described with reference to FIGS. FIG. 1 is a sectional view showing a first embodiment of the antenna of the present invention. In the figure, a magnetic current loop antenna 11 constituting a first antenna of the present invention and a rod antenna 12 constituting a second antenna of the present invention are connected to a portable radio through an insulating member (not shown) provided therearound. Case 1
Attached to.

[0010] The magnetic current loop antenna 11 is
A conductor wire having a length corresponding to the wavelength is wound in a coil shape. In the magnetic current loop antenna 11, one end 11a of the conductor wire is fixedly disposed on the upper part of the housing 1 of the portable wireless device, and is connected to a transmission / reception circuit inside the portable wireless device to be supplied with power. The other end 11b is open.

The rod antenna 12 has a size of 1/4 to 1/2.
It is configured to have a length corresponding to the wavelength, is provided on the center axis of the loop of the magnetic current loop antenna 11, is disposed on the housing 11 of the portable wireless device so as to be extendable and contractable, and 1 is in contact with a power supply fitting 2 provided therein, and is connected to a transmission / reception circuit via the metal fitting 2 to be supplied with power.

Next, the center frequency, the specific frequency band, the gain, and the radiation characteristics obtained using the antenna having such a configuration will be verified. FIG. 2 is a schematic diagram showing a schematic configuration of the antenna of the first embodiment, and FIG. 3 is a plan view thereof. In the figure, the extension length of the conductor wire of the magnetic current loop antenna is 17
0 mm, the wire diameter is 0.3 mm, and the coil inner diameter 2r is 1.
5mm, loop outer diameter 2a is 12mm, height h is 12mm
And One end 11a of the conductor wire is approximately 10 mm.
Are connected to the transmission / reception circuit via the straight line section, and the other end is open.

For comparison, an experiment was also conducted in which the magnetic loop antenna of this embodiment was replaced with a helical antenna having a wire diameter of 0.3 mm and a height of 15 mm.

[0014]

[Table 1]

Here, VSWR is a voltage standing wave ratio, and the maximum gain on the XY plane is a magnetic current loop as shown in the front and side views of the wireless device to which the antenna of FIGS. 4 and 5 is attached. This is the maximum gain on the XY plane when the antenna and the helical antenna emit radio waves of vertically polarized waves (polarized wave Z direction). FIG. 6 is a diagram showing a measurement example of the directivity characteristics of the antennas of the first embodiment and the comparative example. In the drawing, reference numeral 20 denotes an angle in a horizontal coordinate plane, and reference numeral 21 denotes a radial coordinate. Each shows the strength of the radio wave. Reference numeral 22 denotes a directivity characteristic of a vertically polarized wave which is a main polarization component of the antenna of the present embodiment (dotted line portion), and reference numeral 23 denotes a directivity characteristic of the antenna of the comparative example.

As apparent from the above, it has been found that the magnetic loop antenna of this embodiment has sufficient characteristics as a receiving antenna even when the rod antenna is housed. As described above, in the antenna of the present embodiment, the magnetic current loop antenna is used instead of the helical antenna, and the antenna is operated as a small dipole, and has the same radiation directivity as the telescopic rod antenna. Since the height of the antenna is made lower than that of the helical antenna when the rod antenna is housed, the configuration can be made suitable for carrying and the breakage can be prevented.

FIG. 7 is a sectional view showing a second embodiment of the antenna according to the present invention. In the following drawings, the same components as those in FIG. 1 are denoted by the same reference numerals for convenience of explanation. In the drawing, the configuration different from that of the first embodiment is that the other end 11b of the conductor wire of the magnetic current loop antenna 11 is grounded to the housing 1 via a linear portion. Here, the extension length of the conductor wire is 300 mm, the wire diameter is 0.3 mm, the coil inner diameter is 1.5 mm, the loop outer diameter is 11 mm, the height is 11 mm, and one end 11a and the other end 11 of the conductor wire are set.
b has a straight portion of about 10 mm. FIG. 8 shows VSWR characteristics when the rod antenna 12 is housed at this time.
MHz, the specific frequency band (when VSWR = 3) is 37M
Hz.

As apparent from this, it was found that the magnetic current loop antenna 11 of the second embodiment has sufficient characteristics as a receiving antenna even when the rod antenna 12 is housed. As described above, in the present embodiment, the magnetic current loop antenna grounded to the housing and the extendable rod antenna are combined, and the height of the antenna is reduced to a low profile when the rod antenna is stored, so that a configuration suitable for carrying can be achieved. At the same time, damage can be prevented.

Next, FIGS. 9 and 10 are sectional views showing a third embodiment of the antenna of the present invention. FIG. 9 shows a state where the rod antenna is extended, and FIG. 10 shows a state where the rod antenna is housed. FIG. In the figure, the magnetic current loop antenna 11
Is provided at the distal end of the rod antenna 12 and protrudes from the housing 1 of the portable wireless device to the outside. That is, the magnetic current loop antenna 11 is connected to one end 1 of the conductor wire.
1a is mechanically and electrically connected to the rod antenna 12 by being fixedly disposed at the tip of the rod antenna 12 protruding above the housing 1 of the portable wireless device, and the other end 11b of the conductor wire is It is open. Also in this case, as in the first embodiment, the rod antenna 12 is provided on the center axis of the loop of the magnetic current loop antenna 11 and is provided on the housing 11 of the portable wireless device so as to be able to expand and contract.

Therefore, when the rod antenna 12 shown in FIG. 9 is extended, the rod antenna 12 is connected to the transmission / reception circuit inside the portable wireless device via the power supply fitting 2 and supplied with power, and the rod antenna 12 shown in FIG. In this case, the magnetic current loop antenna 11 is connected to the transmission / reception circuit inside the portable wireless device via the power supply fitting 2 to receive power.

As described above, in the present embodiment, the height of the antenna is made lower than that of the helical antenna when the rod antenna is housed, so that it is possible to make the configuration suitable for carrying as in the first embodiment and to prevent breakage. Since the magnetic loop antenna and the rod antenna are integrally formed, each antenna can be connected to a single power supply fitting, simplifying the wiring inside the radio, and contributing to space saving. Can be.

FIGS. 11 and 12 are sectional views showing a fourth embodiment of the antenna of the present invention. FIG. 11 is a diagram showing the rod antenna when it is extended, and FIG. 12 is a diagram showing the rod antenna when it is housed. . In the figure, the configuration different from the third embodiment is as follows.
The point is that the metal fitting 13 for grounding is attached to the other end 11b of the conductor wire of the magnetic current loop antenna 11. Therefore, when the rod antenna 12 is stored, the metal fitting 13 comes into contact with the housing 1 and the other end 11b of the magnetic current loop antenna is grounded.

Thus, also in this embodiment, similar to the above-described embodiment, it is possible to obtain the effect of being suitable for carrying and preventing breakage, and simplifying the wiring inside the radio and saving space. 13 and 14 are sectional views showing a fifth embodiment of the antenna of the present invention.
FIG. 14 is a diagram illustrating a state where the rod antenna is extended and a state where the rod antenna is stored. In the drawing, the configuration different from that of the third embodiment is that the magnetic current loop antenna 11 and the rod antenna 1
2 is mechanically connected via an insulating member 14.

Therefore, the rod antenna 12 shown in FIG.
When the rod antenna 12 is extended, only the rod antenna 12 is connected to the transmission / reception circuit inside the portable wireless device via the power supply fitting 2 and supplied with power. When the rod antenna 12 shown in FIG. The power is connected to the transmission / reception circuit inside the portable wireless device via the metal fitting 2 and supplied with power.

As a result, in this embodiment, the same effects as those of the above-described embodiment can be obtained, and power can be accurately supplied to one of the antennas. FIG. 15 is a cross-sectional view showing a sixth embodiment of the antenna of the present invention.
A metal fitting 15 for grounding is provided at the lower end of the rod antenna 1.
At the time of extension of 2, the metal fitting 15 comes into contact with the housing 1 of the portable wireless device so that the lower end of the rod antenna 12 is grounded, and power is supplied by electromagnetic coupling between the antennas.

Therefore, in the present embodiment, the extendable １ ／
The rod antenna 12 having a length corresponding to the wavelength is electrically connected to the housing 1 via the metal fitting 15 at the time of extension, is excited by the magnetic current loop antenna 11 by electromagnetic coupling, and operates as a transmission antenna. When the rod antenna 12 is stored, the magnetic current loop antenna 11 is excited by the transmission / reception circuit and operates as a reception antenna.

Thus, in this embodiment, the same effects as in the above embodiment can be obtained, and since power is supplied by electromagnetic coupling between antennas, there is no need to connect the rod antenna to the transmission / reception circuit. The wiring inside the wireless device can be simplified, and the space can be saved accordingly. The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the magnetic loop antenna can be attached not only to the upper part of the housing of the portable wireless device but also to the side of the housing. In this case, it is not necessary to provide the rod antenna on the center axis of the loop of the magnetic loop antenna.

[0028]

As described above, according to the present invention, there is provided an antenna for a portable wireless device provided in a portable wireless device having a transmission / reception circuit, the conductor having a length corresponding to 1/2 to 1 wavelength. A first antenna in which a wire is wound in the coil shape, and a 1 / antenna that is provided on the center axis of the magnetic current loop and that is telescopically provided in the housing of the portable wireless device.
Since a second antenna having a length corresponding to 4 to 波長 wavelength is provided, a magnetic current loop antenna and an extendable rod antenna are combined, and the height of the antenna is reduced to a low profile when the rod antenna is stored. A configuration suitable for carrying can be achieved and breakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an antenna according to the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of the antenna shown in FIG.

FIG. 3 is a plan view of the same.

FIG. 4 is a front view of a wireless device to which an antenna is attached.

FIG. 5 is a side view of the wireless device.

FIG. 6 is a characteristic diagram showing a measurement example of directivity characteristics of the antennas of the first embodiment and the comparative example shown in FIG. 1;

FIG. 7 is a sectional view showing a second embodiment of the antenna according to the present invention.

FIG. 8 is a characteristic diagram showing VSWR characteristics of the antenna shown in FIG.

FIG. 9 is a cross-sectional view illustrating a third embodiment of the antenna according to the present invention, and is a view illustrating a rod antenna when it is extended.

FIG. 10 is a view showing a state where the rod antenna is stored.

FIG. 11 is a cross-sectional view illustrating a fourth embodiment of the antenna according to the present invention, and is a view illustrating a rod antenna when it is extended.

FIG. 12 is a diagram showing a state where the rod antenna is stored.

FIG. 13 is a cross-sectional view showing a fifth embodiment of the antenna according to the present invention, showing the rod antenna at the time of extension.

FIG. 14 is a view showing a state where the rod antenna is stored.

FIG. 15 is a sectional view showing a sixth embodiment of the antenna according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing of portable radio apparatus 2 Metal fitting for power supply 11 Magnetic loop antenna 12 Rod antenna 13, 15 Metal fitting for grounding 14 Insulating member

Claims (7)

[Claims] An antenna for a portable wireless device provided in a portable wireless device having a transmitting / receiving circuit, comprising: a first antenna having a loop-shaped coil; and a center axis of a loop of the first antenna. And a second antenna that is provided on the housing of the portable wireless device so as to be extendable and retractable. 2. The antenna for a portable wireless device according to claim 1, wherein the first antenna is fixedly disposed on a housing of the portable wireless device. 3. The portable wireless device according to claim 1, wherein the first antenna is provided at one end of the second antenna and is arranged so as to protrude from a housing of the portable wireless device. Antenna for the machine. 4. The first antenna comprises a magnetic current loop antenna in which a conductor wire having a length corresponding to １ ／ to 1 wavelength is wound in the coil shape.
The antenna for a portable wireless device according to any one of claims 1 to 3, comprising a rod antenna having a length corresponding to / 4 to 1/2 wavelength. 5. The power supply according to claim 1, wherein the first antenna is connected to the transmission / reception circuit and supplied with power, and the second antenna is supplied with power via the first antenna by electromagnetic coupling. 5. The antenna for a portable wireless device according to 1, 2, or 4. 6. The antenna for a portable wireless device according to claim 1, wherein the first antenna and the second antenna are electrically connected. 7. The antenna for a portable wireless device according to claim 1, wherein the first antenna and the second antenna are insulated.