JP2003188628A - Antenna apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna apparatus in which no problem such as twisting of a cable occurs, various types of antennas can be used, and interference with other signals is suppressed to allow transmitting/receiving of signals under optimum condition. <P>SOLUTION: An antenna apparatus 100 is connected to a transmitting/ receiving apparatus for radio signals. It comprises an antenna 102 which is electrically connected to a transmitting/receiving apparatus 10 and is secured to a prescribed position, a reflecting means 104 which is, comprising a reflecting surface that surrounds a prescribed circumference of the antenna, so arranged that the reflecting surface reflects the radio signals transmitted from the antenna in the prescribed direction and that the reflecting surface converges the radio signals incident from outside on the antenna 102, and a turning means 108 which turns the reflecting means 104 with the antenna 102 as a central axis. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antenna device, and more particularly to an antenna device for transmitting and receiving radio signals.

[0002]

2. Description of the Related Art Conventionally, a radio signal transmitting / receiving apparatus has been known. For example, the omnidirectional antenna device has the advantage of transmitting and receiving radio signals over a wide range, but has the drawback of large signal loss due to large propagation loss and interference from other radio waves. Further, a directional antenna device such as a horn antenna has an advantage that it can sensitively transmit and receive radio waves in a predetermined direction, but since the antenna is mechanically rotated when controlling the directivity direction of a radio signal, It is also necessary to mechanically rotate the electrical cable that connects the transceiver. However, a cable that is short enough to cope with the twist of the cable and capable of transmitting high frequency signals has not been realized.

Further, an antenna device capable of electrically controlling directivity, such as an adaptive array antenna, has an advantage that it can realize a sensitive directivity of a radio signal. In this case, a plurality of antenna elements and a transmitting / receiving circuit are provided. However, the antenna device is large and the cost is high.

In recent years, an antenna device has been developed in which a radio signal is reflected by a reflector to give directivity. For example, in Japanese Utility Model Publication No. 5-53314,
There is disclosed an antenna reflector device in which a removable and foldable reflector plate is installed on an omnidirectional antenna, and it is excellent in portability because it is not necessary to carry a plurality of antennas. Further, for example, Japanese Unexamined Patent Publication No. 7-250024 discloses a wireless LAN device in which a reflecting plate separated from an antenna and fixed to a ceiling is constantly rotated.

[0005]

However, in the antenna device disclosed in Japanese Utility Model Laid-Open No. 5-53314, since the antenna and the reflection plate are in mechanical contact with each other, noise due to mechanical operation of the reflection plate is generated. Millimeter wave band,
There is a problem that it cannot be used in the ultra high frequency band such as the quasi-millimeter wave band. It is also a single antenna,
Since it is not combined with the communication device and rotation control mechanism,
Wireless L such as signal bit error rate and reception confirmation signal (ACK)
There is a problem that the rotation of the reflector cannot be automatically controlled due to the performance index peculiar to AN.

Further, in the wireless LAN device disclosed in Japanese Unexamined Patent Publication No. 7-250024, since the reflector is fixed to the ceiling, the use place of the antenna is limited to just below the reflector, and it is used as a portable terminal device. There is a problem that it cannot be used.

Therefore, it is an object of the present invention to allow various antennas to be used without causing problems such as twisting of cables, and to suppress the interference of other signals to transmit and receive signals under optimum conditions. It is an object of the present invention to provide a new and improved antenna device.

[0008]

In order to solve the above problems, according to a first aspect of the present invention, there is provided an antenna device for transmitting and receiving a radio signal, which is electrically connected to a transmitting and receiving device and has a predetermined position. A radio signal having an antenna fixed to the antenna and a reflection surface surrounding a predetermined periphery of the antenna, the reflection surface reflecting a radio signal transmitted from the antenna in substantially the same direction, and being incident from the outside. There is provided an antenna device comprising: a reflecting means arranged so as to focus on the antenna; and a rotating means for rotating the reflecting means around the antenna as a central axis.

In the above-described invention, the directivity of the antenna can be arbitrarily controlled with the antenna fixed, so that the rotating mechanism for the electrical connection between the antenna and the transmitting / receiving device can be omitted. Therefore, even with an antenna that transmits and receives ultrahigh-frequency radio signals in the millimeter wave band and the quasi-millimeter wave band, mechanical rotation control with reduced influence of noise becomes possible.

In order to solve the above problems, in a second aspect of the present invention, there is provided an omnidirectional antenna device for transmitting and receiving radio signals, which is electrically connected to a transmitting and receiving device and fixed at a predetermined position. Directional antenna and a reflection surface surrounding a predetermined circumference of the omnidirectional antenna, and the reflection surface reflects a radio signal emitted from the omnidirectional antenna in substantially the same direction and is incident from the outside. Reflecting means arranged to focus a radio signal on the omnidirectional antenna, a rotating means for rotating the reflecting means with the omnidirectional antenna as a central axis, and a driving means for rotating the rotating means. Drive means for determining the position of the reflecting means according to the transmission / reception state of the radio signal of the omnidirectional antenna,
An antenna device comprising: a control unit that controls the rotation of the reflection unit via the drive unit.

In the above-described invention, since the directivity of the antenna can be arbitrarily controlled while the antenna is fixed, the rotating mechanism for the electrical connection between the antenna and the transmitting / receiving device can be omitted. Therefore, even with an antenna that transmits and receives ultrahigh-frequency radio signals in the millimeter wave band and the quasi-millimeter wave band, mechanical rotation control with reduced influence of noise becomes possible. Further, for example, since it is possible to transmit and receive radio signals by controlling so as to reduce the influence of interference waves from others, it is possible to increase signal power and reduce signal errors. As a result, the antenna characteristics and durability are improved. Further, since the directivity of the high frequency signal antenna can be controlled by only one transmission / reception circuit and the antenna, the antenna device can be downsized and the cost can be reduced.

Further, if the control device is configured to rotate the position of the reflecting means so that the performance index value indicating the transmission / reception state of the radio signal becomes a predetermined value or more,
The pointing direction of the antenna can be automatically controlled to the optimum position.

Further, it is preferable that the performance index value is at least one selected from a signal strength, a signal wave to noise ratio, a signal wave to interference wave ratio, and a code error rate.

Further, if the control device is configured to rotate the reflecting means when a signal notifying reception of the radio signal transmitted from the omnidirectional antenna is not notified a predetermined number of times or more, In the wireless LAN device, for example, even when the transmission and reception of the radio wave is temporarily not performed, the reflector is prevented from being rotated from the optimum position.

In order to solve the above problems, according to a third aspect of the present invention, an omnidirectional antenna device for transmitting and receiving radio signals, which is electrically connected to a transmitting and receiving device and fixed at a predetermined position. Directional antenna and a reflection surface surrounding a predetermined circumference of the omnidirectional antenna, and the reflection surface reflects a radio signal emitted from the omnidirectional antenna in substantially the same direction and is incident from the outside. A wireless signal of the omnidirectional antenna, a reflecting means arranged to focus a radio signal on the omnidirectional antenna, a rotating means for rotating the reflecting means with the omnidirectional antenna as a central axis. An antenna device is provided, comprising: a notification unit that notifies a performance index value indicating a signal transmission / reception state.

In the above-described invention, the transmission / reception state of a signal can be grasped by an indicator (for example, a display plate such as a meter) linked with the optimization parameter. The user
The reflector can be easily rotated manually to the optimum position of the parameter based on the information of the display plate.

Further, it is preferable that the performance index value is at least one selected from signal strength, signal wave to noise ratio, signal wave to interference wave ratio, and code error rate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
In the following description and the accompanying drawings, constituent elements having the same function and configuration will be denoted by the same reference numerals, and redundant description will be omitted.

(First Embodiment) First, an antenna device according to a first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing the configuration of a mobile terminal device using the antenna device according to the first embodiment.

First, as shown in FIG. 1, an antenna device 100 according to the present embodiment is combined with an information terminal device 10 such as a portable personal computer (hereinafter referred to as a personal computer), for example, and a wireless LAN (Local) is used.
It can be used as an antenna for a mobile terminal of an Area Network) device. In the present embodiment, a monopole antenna which is a horizontal omnidirectional antenna will be described as an example.

The antenna device 100 according to the present embodiment
As shown in FIG. 2, a reflector 104 having a substantially parabolic cross section is installed around a horizontal omnidirectional antenna 102 such as a monopole antenna. Such a reflector 1
04 is rotatably installed around the omnidirectional antenna 102 so that the focus of the parabola is at the position of the omnidirectional antenna 102.

The principle of giving directivity to the radio signal transmitted by the omnidirectional antenna by using the reflector according to this embodiment will be described below with reference to FIGS. 3 to 5. In the following, the case where the antenna device according to the present embodiment transmits a radio signal will be described as an example, but the same principle applies when receiving a radio signal.

First, as shown in FIG. 3, the normal horizontal omnidirectional antenna 102 transmits radio signals in a radial manner. Then, as shown in FIG. 4, the omnidirectional antenna 102 is focused around the omnidirectional antenna 102.
When the reflection plate is installed so as to be located at, the radio signal radially transmitted from the omnidirectional antenna is reflected by the reflection plate 104 so as to be in one direction, and the directivity is given.

Further, as shown in FIG.
Is moved around the circle formed by the vertices of the parabola with the omnidirectional antenna 102 as the central axis, whereby the transmission direction of the directional radio signal can be arbitrarily changed.

Next, the configuration of the antenna device capable of obtaining the optimum transmission / reception characteristics according to this embodiment will be described with reference to FIGS. 6 and 7. 6. FIG. 6 is a perspective view showing the external configuration of the antenna device according to this embodiment. FIG. 7 is a block diagram showing the configuration of the antenna device according to the present embodiment.

First, as shown in FIGS. 6 and 7, the antenna device 100 according to the present embodiment has an omnidirectional antenna 102 such as a pole antenna which receives a radio signal.
A reflection plate 104 having a substantially parabolic cross section for reflecting a radio signal, a reception circuit 106 for receiving a signal received by the omnidirectional antenna 102 and deriving a performance index indicating a reception state of the radio signal, Omnidirectional antenna with reflector 1
No. 02 as a central axis, a rotary unit 108 for rotating the rotary unit, a rotary drive unit 110 composed of, for example, a stepping motor, and a rotary drive unit 11 based on a figure of merit.
It is composed of a rotation control unit 112 and the like for controlling 0.

In the above configuration, first, the omnidirectional antenna 102 receives a radio signal and transmits it to the receiving circuit 106. The reception circuit 106 is a performance index (for example, SNR: Signal) of the radio signal received by the omnidirectional antenna 102.
Noise Ratio) is transmitted to the rotation control unit 112. The rotation control unit 112 determines the position of the reflection plate 104 so that the performance index (for example, SNR) has an optimum value, and transmits a control signal to the rotation driving unit 110. Rotation drive unit 110
Is based on a control signal from the rotation control unit 112,
8 is rotated to rotate the reflector 104.

At this time, parameter values such as signal strength, signal wave-to-noise ratio (SNR), signal wave-to-interference wave ratio, and code error rate can be used as the above performance index.
In this embodiment, since the omnidirectional antenna is controlled to rotate at a position where the figure of merit, which is a parameter, is optimized, the directivity of the antenna device does not necessarily point to the arrival direction of the radio signal, but may be, for example, interference. Can be directed in the direction in which is suppressed most, and wireless signals can be transmitted and received under optimal communication conditions.

Further, when the signal (ACK: Acknowlege) for notifying the reception of the transmission signal is transmitted from the receiving side a predetermined number of times, the rotation control of the reflector 102 can be started. In this case, for example, even when the transmission and reception of the radio wave is temporarily not performed, the optimum reflector is prevented from rotating.

Next, a method of controlling the antenna device according to this embodiment will be described with reference to FIG. In addition, in FIG.
6 is a flow sheet for explaining a method for controlling the antenna device according to the present embodiment. In the following, it is assumed that the antenna device according to the present embodiment is used as a wireless LAN device, and a notification signal (AC
It is assumed that the rotation control of the reflection plate is started when K) is not performed twice consecutively. Further, in the present embodiment, the signal wave-to-noise wave (S
An example using NR) will be described.

First, in step S100, a radio signal is transmitted from the antenna device 100 according to this embodiment (step S100). Then, in step S102,
It is determined whether or not there is a signal (ACK) for notifying reception (step S102). If it is determined that there is an ACK, the process proceeds to step S100.

On the other hand, when it is determined that there is no ACK, the process proceeds to step S104, and it is again determined whether or not there is an ACK (step S104). If it is determined that there is no ACK, the wireless signal is retransmitted in step S110 (step S110), and then step S100.
Move to.

On the other hand, when it is determined that there is an ACK, the process proceeds to step S106, and the rotation driving unit 110
The rotating unit 108 is rotated to rotate the reflecting plate 104 (step S106).

Then, in step S108, the reflector 10
2 is fixed at a position where the SNR is maximum (step S1
08). After that, in step S110, the wireless signal is retransmitted (step S110), and then the process proceeds to step S100.

In this embodiment, the directivity of the antenna can be arbitrarily controlled with the antenna fixed, so that the rotating mechanism for the electrical connection between the antenna and the transceiver can be omitted. Therefore, even with an antenna that transmits and receives ultrahigh-frequency radio signals in the millimeter wave band and the quasi-millimeter wave band, mechanical rotation control with reduced influence of noise becomes possible. In addition, since it is possible to transmit and receive radio signals by controlling so as to reduce the influence of interference waves from others, it is possible to increase the signal power,
Signal errors can be reduced. As a result, the antenna characteristics and durability are improved. Further, since the directivity of the high frequency signal antenna can be controlled by only one transmission / reception circuit and the omnidirectional antenna, the antenna device can be downsized and the cost can be reduced.

(Second Embodiment) Next, FIG. 9 and FIG.
The configuration of the antenna device according to the second embodiment will be described with reference to FIG. 9. FIG. 9 is a perspective view showing the external configuration of the antenna device according to the second embodiment. FIG. 10 is a block diagram showing the configuration of the antenna device according to the second embodiment.

First, as shown in FIGS. 9 and 10, the antenna device 200 according to the present embodiment includes an omnidirectional antenna 20 such as a pole antenna for receiving a radio signal.
2, a reflection plate 204 having a substantially parabolic cross section for reflecting a radio signal, a signal received by the omnidirectional antenna 202, and a reception circuit 206 for deriving a performance index indicating a reception state of the radio signal, It is composed of a rotating unit 208 for rotating the reflection plate 204, a display unit 210 for displaying the figure of merit value of the received signal, and the like. The display unit 210
Is preferable because the transmission / reception state of the antenna device 200 can be easily recognized by visually displaying the performance index value.

First, the omnidirectional antenna 202 receives a radio signal and transmits it to the receiving circuit 206. Receiver circuit 20
Reference numeral 6 transmits the performance index (for example, SNR: Signal Noise Ratio) of the radio signal received by the omnidirectional antenna 202 to the display unit 210. The display unit 210 visually displays the figure of merit value (for example, SNR). The user
Based on the information on the display plate 210, the reflector is manually rotated to the optimum position of the parameter.

In the present embodiment, an indicator (for example, a display board such as a meter) that is linked to the optimization parameter
The signal transmission / reception state can be grasped with. The user can easily manually rotate the reflector to the optimum position of the parameter based on the information on the display plate.

(Third Embodiment) In the above embodiment, the configuration using the omnidirectional antenna is described as an example, but the directional direction of the antenna is changed even if the directional antenna is used. be able to. Hereinafter, FIG. 11 and FIG.
An antenna device according to the third embodiment will be described with reference to FIG. Note that FIG. 11 is a side view showing the configuration of the antenna device according to the third embodiment. Figure 1
FIG. 2 is a perspective view showing the configuration of the antenna device according to the third embodiment. In addition, in FIGS. 11 and 12, only the minimum necessary constituent elements are described for easy understanding, and the description of the other constituent elements is omitted. The other components can be the same as those in the first embodiment or the second embodiment.

First, as shown in FIG. 11, an antenna device 300 according to the third embodiment is installed above a directional antenna 302 for transmitting a radio signal in the vertical direction and above the directional antenna 302. The reflecting plate 304, which has a substantially parabolic cross section, is installed so that the focal point is located approximately at the antenna position.

In the antenna device having the above configuration, the directional radio signal transmitted in the vertical direction is reflected by the reflection plate 30.
It is reflected by 4 in a substantially horizontal direction.

Further, as shown in FIG.
By rotating 4 with the intersection of the vertical line from the position of the directional antenna and the reflector as the center of rotation, it is possible to arbitrarily change the horizontal directing direction of the radio signal while maintaining directivity.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this structure.
Those skilled in the art can assume various modifications and changes within the scope of the technical idea described in the claims, and the modifications and changes are also within the technical scope of the present invention. Is understood to be included in.

In the above embodiment, the configuration using the monopole antenna as the omnidirectional antenna device has been described as an example, but the present invention is not limited to this example. For example, dipole antenna, sleeve antenna, collinear antenna, whip antenna, biconical antenna,
A discone antenna or the like can be used.

Further, in the above-mentioned embodiment, the configuration using the parabolic plate as the shape of the reflecting plate has been described as an example, but it is not limited to this example. As long as it is a reflector that can give directivity to an omnidirectional radio signal, it can be a reflector of any shape, such as a parabolic plate, an ellipsoidal plate, an ellipsoidal plate, or a flat plate. be able to.

In the present embodiment, the configuration in which the directivity is changed in the horizontal direction is adopted, but if the antenna device is installed at a predetermined angle in the vertical direction, the directivity is also changed in the vertical direction by the predetermined angle. be able to.

In the above embodiment, the wireless LA
The example of using the antenna as the mobile terminal antenna of the N device has been described, but the present invention is not limited to this example. It can be used for any other wireless signal transmitting / receiving device.

[0049]

As described above, since the directivity of the antenna for radio signals can be arbitrarily controlled while the antenna is fixed, the rotation mechanism for the electrical connection between the antenna and the transceiver can be omitted. Therefore, even with a directional antenna that transmits and receives ultra-high frequency radio signals in the millimeter wave band and the quasi-millimeter wave band, mechanical rotation control with reduced influence of noise is possible. Also, since it is possible to transmit and receive wireless signals by controlling so as to reduce the influence of interference waves from others, it is possible to increase the signal power,
Signal errors can be reduced. As a result, the antenna characteristics and durability are improved. Further, since the directivity of the high frequency signal antenna can be controlled by only one transmission / reception circuit and the antenna, the antenna device can be downsized and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example in which an antenna device according to a first embodiment is used in a mobile terminal device.

FIG. 2 is an enlarged perspective view of the antenna device according to the first embodiment.

FIG. 3 is a top view showing a radiation state of the omnidirectional antenna.

FIG. 4 is a top view showing a radiation state when a reflector is installed on the omnidirectional antenna.

FIG. 5 is a top view showing a rotation trajectory of the reflection plate according to the first embodiment.

FIG. 6 is a perspective view showing an external configuration of the antenna device according to the first embodiment.

FIG. 7 is a block diagram showing the configuration of the antenna device according to the first embodiment.

FIG. 8 is a flowchart showing a control method of the antenna device according to the first embodiment.

FIG. 9 is a perspective view showing an external configuration of an antenna device according to a second embodiment.

FIG. 10 is a block diagram showing a configuration of an antenna device according to a second embodiment.

FIG. 11 is a perspective view showing a configuration of an antenna device according to a third embodiment.

FIG. 12 is a side view showing a radiation state when a reflector is installed in the directional antenna according to the third embodiment.

[Explanation of symbols]

10 Mobile terminal devices 100 antenna device 102 omnidirectional antenna 104 reflector 106 receiver circuit 108 Rotating part 110 rotation drive 112 Rotation control unit 210 Performance index display board 302 Directional antenna

Claims (7)

[Claims] 1. An antenna device for transmitting and receiving a radio signal, comprising: an antenna electrically connected to the transceiver, fixed at a predetermined position; and a reflecting surface surrounding a predetermined periphery of the antenna. Reflecting means arranged so that the reflecting surface reflects the radio signal transmitted from the antenna in substantially the same direction and focuses the radio signal incident from the outside on the antenna, and the antenna is used as a central axis. An antenna device comprising: rotating means for rotating the reflecting means. 2. An antenna device for transmitting and receiving radio signals, comprising an omnidirectional antenna electrically connected to the transceiver device and fixed at a predetermined position, and a reflection surrounding a predetermined periphery of the omnidirectional antenna. Is arranged so that the reflection surface reflects a radio signal radiated from the omnidirectional antenna in substantially the same direction and that a radio signal incident from the outside is focused on the omnidirectional antenna. Reflected means, a rotating means for rotating the reflecting means around the omnidirectional antenna as a central axis, a driving means for driving the rotating means, and a radio signal of the omnidirectional antenna. An antenna device comprising: a control unit that determines a position of the reflection unit according to a transmission / reception state and controls rotation of the reflection unit via the driving unit. 3. The control means rotates the position of the reflecting means such that a performance index value indicating a transmission / reception state of the wireless signal is equal to or more than a predetermined value. The antenna device described. 4. The performance index value is at least one selected from a signal strength, a signal wave to noise ratio, a signal wave to interference wave ratio, and a code error rate. The antenna device according to. 5. The control means rotates the reflecting means when a signal notifying reception of a radio signal transmitted from the omnidirectional antenna is not notified a predetermined number of times or more. The antenna device according to claim 2. 6. An antenna device for transmitting and receiving radio signals, an omnidirectional antenna electrically connected to the transceiver device, fixed at a predetermined position, and a reflecting surface surrounding a predetermined circumference of the omnidirectional antenna. And is arranged so that the reflection surface reflects radio signals radiated from the omnidirectional antenna in substantially the same direction and focuses radio signals incident from the outside to the omnidirectional antenna. A reflection means, a rotation means for rotating the reflection means around the omnidirectional antenna as a central axis, and a notification means for notifying a performance index value indicating a transmission / reception state of a radio signal of the omnidirectional antenna, An antenna device comprising: 7. The performance index value is at least one selected from a signal strength, a signal wave-to-noise ratio, a signal wave-to-interference wave ratio, and a code error rate. The antenna device according to.