JP2005027104A - Short range low power radio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short range low power radio device suitable for specific position detection and specific mobile communication. <P>SOLUTION: The short-range low power radio device comprises a device body unit 4 and a conductor unit 5 provided close to the device body unit 4 having antenna effect. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a short-distance low-power wireless device such as a wireless tag or a wireless LAN or Bluetooth (registered trademark) PC card.
[0002]
[Prior art]
For example, in the case of a wireless tag as this type of short-distance low-power wireless device, as shown in FIG. 12, the controller 2 detects a wireless tag 1 provided on a moving body (not shown), thereby detecting the position of the moving body. Used for.
[0003]
Further, as shown in FIG. 13, in the case of a wireless LAN, Bluetooth (registered trademark) PC card 3, it is in the form of a card that can be inserted into a personal computer or the like (not shown). It is used for wireless communication and the like.
[0004]
In addition to the above, there is also known a wireless tag for achieving a wider band as shown in Patent Document 1.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-332523 [0006]
[Problems to be solved by the invention]
However, since the short-range low-power wireless device performs general-purpose and simple mobile position detection and mobile communication, the reach of radio waves is naturally limited, and is generally omnidirectional. For this reason, there are cases where the position detection of a specific mobile body and the specific mobile communication cannot be performed.
[0007]
An object of the present invention is to provide a short-distance low-power wireless device that is suitable for detecting the position of a specific mobile object or performing specific mobile communication.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, a short-distance low-power wireless device according to the present invention includes a short-distance low-power wireless device main body and a conductor having an antenna effect provided in the vicinity of the device main-body. Features.
[0009]
According to the present invention, the radio wave radiated from the device body part induces an electromagnetic field in the adjacent conductor part, and the radio wave is secondarily radiated from this conductor part. Therefore, the radio wave is more efficient than the case of only the device body part. Radiated into space.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment: corresponding to claims 1 and 2)
Hereinafter, a first embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG. 1 in which the same parts as those in FIG.
[0011]
In this embodiment, a wireless tag is used as a device main body as a short-distance low-power wireless device.
[0012]
Here, the wireless tag will be described.
[0013]
Currently, wireless tags that can be used in Japan are roughly divided into the following four types.
[0014]
(1) 124 KHz band wireless tag (2) 13 MHz band wireless tag (3) 2.4 GHz band wireless tag (4) Weak radio wave type wireless tag Among the above, (1) and (2) have a search distance of about several tens of centimeters (3) and (4) are long-distance types with a search distance of several tens to several tens of meters. Further, (3) has the characteristic that the straight traveling property is remarkable due to the property of the microwave band, and it is difficult to propagate to the shadow. (4) has a frequency of about 300 MHZ, which is advantageous in terms of radio wave propagation characteristics and antenna size, since there is no frequency limitation, and is a low-frequency device because it is a UHF frequency band electronic device.
[0015]
As shown in FIG. 1, the short-distance low-power wireless device according to the present embodiment uses the above-described wireless tag, for example, the weak radio wave type wireless tag as the device body 4, and is close to the device body 4 and the device body 4. And a conductor portion 5 having an antenna effect.
[0016]
As shown in FIG. 2, the device body 4 includes an electronic circuit board 4B including an unillustrated integrated circuit element, an antenna 4C, and a battery 4D in a plastic case 4A. The radio wave transmitted from the controller 2 is transmitted by the antenna 4C. The signal is received, predetermined signal processing is performed by the integrated circuit element of the electronic circuit board 4B based on the received signal, and a signal based on the signal processing is transmitted to the controller 2 via the antenna 4C.
[0017]
The conductor portion 5 has, for example, electrical conductivity in which the longitudinal direction surface is fixed to the short side portion of the plastic case 4A as an end portion of the device body portion 4, and preferably has a shape as described later. However, it can basically take any shape.
[0018]
In the present embodiment, the radio wave radiated from the device main body 4 excites the conductor part 5, and the radio wave is radiated into the space by secondary radiation from the conductor part 5.
[0019]
As described above, according to the present embodiment, by providing the conductor portion 5 in the device main body portion 4 that is a wireless tag with limited radio wave transmission power, the device main body portion can be generated by the secondary radiation wave from the conductor portion 5. Radio waves are radiated into the space more efficiently than in the case of only four, and the desired directivity can be obtained by the form of the conductor portion 5. Accordingly, it is possible to cope with the case where the position of a specific mobile body is detected and the specific mobile body communication is performed.
[0020]
(Second embodiment: corresponding to claim 3)
Next, a second embodiment of the short-range low-power wireless device according to the present invention will be described with reference to FIG. 3 in which the same parts as those in FIG.
[0021]
In the present embodiment, as in the first embodiment, a wireless tag is used as a device main body as a short-distance low-power wireless device.
[0022]
As shown in FIG. 3, the short-range low-power wireless device according to the present embodiment uses, for example, a weak radio wave type wireless tag as the device main body 4, which is an integral multiple of a quarter wavelength with respect to the transmission frequency of the device main body 4. In this configuration, the longitudinal direction of the conductor portion 6 having the radio wave length as the longitudinal direction length is arranged along the short side direction of the device main body portion 4.
[0023]
In the present embodiment, the radio wave radiated from the device main body 4 excites the conductor 6, and the radio wave is radiated into the space by the secondary radiation from the conductor 6. In this case, since the conductor part 6 has an electric wavelength that is an integral multiple of approximately ¼ wavelength with respect to the transmission frequency of the device main body part 4, radio wave radiation is efficiently performed.
[0024]
The inventor measured the horizontal reach distance of the radio wave in the case where the conductor part 6 having an electric wavelength of approximately ¼ wavelength with respect to the transmission frequency of the device body part 4 was used. The result will be described with reference to FIG.
[0025]
As shown in FIG. 4, measurement points P <b> 11 and P <b> 12 are determined as front and rear of the device main body 4, and detection and disappearance of radio waves at the points are approximately ½ wavelength with respect to the transmission frequency of the device main body 4. It measured using the antenna (1/2 wavelength whip antenna) and the Yagi antenna which have an electric wavelength of integral multiple of. In this measurement, a transmission radio wave from the short-distance low-power wireless device of the present embodiment is received by the ½ wavelength antenna and the Yagi antenna. In actual measurement, a short-distance low-power wireless device is placed on a wooden box placed on a concrete floor, and the height from the concrete floor to the short-distance low-power wireless device is 25 cm. The reception measurement was performed with the Yagi antenna.
[0026]
(Measurement with 1/2 wavelength whip antenna)
According to the measurement, the radio wave was detected at the measurement point P11 40m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P11 41m away. That is, the radio wave arrival at the measurement point P11 was 40 m.
[0027]
In addition, radio waves were detected at a measurement point P12 that was 20 m away from the same short-distance low-power wireless device, and the disappearance of radio waves was confirmed at a measurement point P12 that was 21 m away. That is, the radio wave arrival was 20 m at the measurement point P12.
[0028]
In this way, when the conductor part 6 having an electromagnetic wavelength of approximately ¼ wavelength with respect to the transmission frequency of the device body part 4 is used and reception measurement is performed with a ½ wavelength antenna, it is directed to the measurement point P11 side which is the forward direction. It was confirmed that the radio wave characteristic with the characteristic was obtained.
[0029]
(Measurement of horizontal and vertical polarization with Yagi antenna)
When the horizontal polarization was measured with the Yagi antenna, the following results were obtained. That is, the detection and disappearance of radio waves were confirmed at the measurement point P1 50 m away from the short-range low-power wireless device. That is, the arrival of radio waves was 50 m at the measurement point P11. In addition, detection and disappearance of radio waves were confirmed at a measurement point P12 that is 1 m away from the short-range low-power wireless device. That is, at the measurement point P12, radio wave arrival was 1 m.
[0030]
When vertical polarization was measured with a Yagi antenna, the following results were obtained. That is, the detection and disappearance of radio waves were confirmed at the measurement point P1 that is 43 m away from the short-range low-power wireless device. In addition, detection and disappearance of radio waves were confirmed at a measurement point P2 that was 2 meters away from the short-range low-power wireless device.
[0031]
In this way, when using the conductor part 6 having an electric wavelength of approximately ¼ wavelength with respect to the transmission frequency of the device body part 4 and receiving measurement with the Yagi antenna, a large directivity is given to the measurement point P11 side which is the forward direction. It was confirmed that the radio wave characteristics possessed were obtained.
[0032]
As described above, according to the present embodiment, the same operational effects as those of the first embodiment can be obtained, and radio wave radiation can be efficiently performed according to the transmission frequency of the device body 4 as shown in FIG. Since the directional characteristic of the eight-character shape is exhibited, the position detection of the specific mobile body and the specific mobile body communication can be performed satisfactorily by using this directivity characteristic.
[0033]
(Third embodiment: corresponding to claim 4)
Next, a third embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG. 5 in which the same parts as those in FIGS.
[0034]
In this embodiment, as in the first and second embodiments, a wireless tag is used as a device main body as a short-distance low-power wireless device.
[0035]
As shown in FIG. 5, the short-distance low-power wireless device according to the present embodiment uses, for example, a weak radio wave type wireless tag as the device main body unit 4, and has an electric wavelength of approximately ½ wavelength with respect to the transmission frequency of the device main body unit 4. This is a configuration in which a conductor portion 7 configured so that two long conductors having two axes are orthogonal to each other is placed on the device main body portion 4.
[0036]
In the present embodiment, the radio wave radiated from the device main body 4 excites the conductor part 7, and the radio wave is radiated into the space by the secondary radiation from the conductor part 7. In this case, the conductor portion 7 is configured so that two long conductors having an electric wavelength of approximately ½ wavelength with respect to the transmission frequency of the device body portion 4 are orthogonal to each other. Radio waves are efficiently emitted.
[0037]
Next, an antenna (1/2 wavelength whip) having an electromagnetic wavelength that is an integral multiple of approximately ½ wavelength with respect to the transmission frequency of the device main body 4 with respect to the horizontal reach distance of the radio wave in the case where the conductor portion 7 is used. Antenna) and measurement results using the Yagi antenna will be described with reference to FIG. In this measurement, a transmission radio wave from the short-distance low-power wireless device of the present embodiment is received by the ½ wavelength antenna and the Yagi antenna.
[0038]
As shown in FIG. 6, measurement points P21, P22, and P23 are determined as the forward direction, the left direction, and the right direction of the device body 4, and the detection and disappearance of radio waves at the points are determined by a half-wave whip antenna, Measurements were made using a Yagi antenna. In actual measurement, a short-distance low-power wireless device is placed on a wooden box placed on a concrete floor, and the height from the concrete floor to the short-distance low-power wireless device is 25 cm. The reception measurement was performed with the Yagi antenna.
[0039]
(Measurement with 1/2 wavelength whip antenna)
According to the measurement, the radio wave was detected at the measurement point P21 that was 24 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P21 that was 25 m away. That is, the radio wave arrival at the measurement point P21 was 24 m.
[0040]
Further, radio waves were detected at a measurement point P22 that was 32 m away from the same short-distance low-power wireless device, and the disappearance of the radio waves was confirmed at a measurement point P22 that was 33 m away. That is, the radio wave arrival at the measurement point P22 was 32 m.
[0041]
Furthermore, the detection and disappearance of radio waves were confirmed at a measurement point P23 that is 16 meters away from the same short-distance low-power wireless device. That is, the radio wave arrival at the measurement point P23 was 23 m.
[0042]
In this way, using the conductor portion 7 configured such that two elongated conductors having an electromagnetic wavelength of approximately ½ wavelength with respect to the transmission frequency of the device body portion 4 are orthogonal to two axes, reception is performed with a ½ wavelength antenna. When measured, it was confirmed that radio wave characteristics having directivity were obtained on the measurement points P21, P22, and P23 sides.
[0043]
(Measurement of horizontal polarization with Yagi antenna)
When the horizontal polarization was measured with the Yagi antenna, the following results were obtained. That is, the radio wave was detected at the measurement point P21 that was 35 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P21 that was 36 m away. That is, the radio wave arrival at the measurement point P21 was 35 m. In addition, detection and disappearance of radio waves were confirmed at a measurement point P22 that is 60 m away from the short-range low-power wireless device. That is, the arrival of radio waves was 60 m at the measurement point P22. Furthermore, the radio wave was detected at the measurement point P23 that was 21 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P23 that was 22 m away. That is, the radio wave arrival at the measurement point P23 was 22 m.
[0044]
In this way, using the conductor portion 7 configured so that two elongated conductors having an electromagnetic wavelength of approximately ½ wavelength with respect to the transmission frequency of the device main body portion 4 are orthogonal to each other, horizontal polarization is performed by the Yagi antenna. When measured, it was confirmed that radio wave characteristics having directivity were obtained on the measurement points P21, P22, and P23 sides.
[0045]
(Measurement of vertical polarization with Yagi antenna)
When vertical polarization was measured with a Yagi antenna, the following results were obtained. That is, the radio wave was detected at the measurement point P21 that was 38 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P21 that was 39 m away. That is, the radio wave arrival at the measurement point P21 was 38 m. In addition, detection and disappearance of radio waves were confirmed at a measurement point P22 that is 55 m away from the short-range low-power wireless device. That is, the radio wave arrival at the measurement point P22 was 55 m. Furthermore, the radio wave was detected at the measurement point P23 that was 21 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P23 that was 22 m away. That is, the radio wave arrival at the measurement point P23 was 22 m.
[0046]
In this way, using the conductor part 7 configured so that two long conductors having an electromagnetic wavelength of approximately ½ wavelength with respect to the transmission frequency of the device body part 4 are orthogonal to two axes, the Yagi antenna performs vertical polarization. When measured, it was confirmed that radio wave characteristics having directivity were obtained on the measurement points P21, P22, and P23 sides.
[0047]
Next, when the short-distance low-power wireless device using the conductor portion 7 of the present embodiment is disposed in the vicinity of the metal object, the horizontal reach distance of the radio wave is approximately 1 with respect to the transmission frequency of the device body portion 4. The results of measurement using an antenna (1/2 wavelength whip antenna) having a power wavelength that is an integral multiple of / 2 wavelengths and a Yagi antenna will be described with reference to FIG.
[0048]
As shown in FIG. 7, a wooden box 10 is placed on a horizontal leg 9 of a hand trailer 8 on a concrete floor as a metal object, and a short-distance low-power wireless device using the conductor portion 7 of this embodiment on the wooden box 10. Is placed.
[0049]
As shown in FIG. 7, the measurement point P31 was determined as the right direction of the device body 4, and the detection and disappearance of radio waves at the point were measured using a half-wave whip antenna and a Yagi antenna. In actual measurement, reception measurement was performed with a 1/2 wavelength antenna and a Yagi antenna with a height of 27 cm from the concrete floor to the short-distance low-power wireless device.
[0050]
(Measurement with 1/2 wavelength whip antenna)
According to the measurement, the radio wave was detected at the measurement point P31 that was 27 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P31 that was 28 m away. That is, the radio wave arrival was 27 m at the measurement point P31.
[0051]
(Measurement of horizontal polarization with Yagi antenna)
When the horizontal polarization was measured with the Yagi antenna, the following results were obtained. That is, the radio wave was detected at the measurement point P35 that was 35 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P31 that was 36 m away. That is, the radio wave arrival at the measurement point P31 was 35 m.
[0052]
(Measurement of vertical polarization with Yagi antenna)
When vertical polarization was measured with a Yagi antenna, the following results were obtained. That is, the radio wave was detected at the measurement point P31 that was 35 m away from the short-range low-power wireless device, and the disappearance of the radio wave was confirmed at the measurement point P31 that was 36 m away. That is, the radio wave arrival at the measurement point P31 was 35 m.
[0053]
As described above, according to the present embodiment, the same operational effects as those of the first and second embodiments can be obtained, and radio wave radiation can be efficiently performed according to the transmission frequency of the device main body 4, as shown in FIG. As shown in the figure, the cross-shaped composite directivity is crossed with the 8-character directivity so that the position detection of the specific mobile body and the specific mobile communication can be performed satisfactorily by using this directivity. Can do.
[0054]
(Fourth embodiment: corresponding to claim 5)
Next, a fourth embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG. 8 in which the same parts as those in FIGS.
[0055]
In this embodiment, as in the first to third embodiments, a wireless tag is used as a device main body as a short-distance low-power wireless device. As shown in FIG. 8, the short-range low-power wireless device according to the present embodiment uses, for example, a weak radio wave type wireless tag as the device body 4, and has an electric wavelength of approximately ½ wavelength with respect to the transmission frequency of the device body 4. And a conductor portion 7 ′ having a cross shape is placed so that the two center portions are on the device main body portion 4. It is a configuration.
[0056]
According to the present embodiment, the radio wave radiated from the device main body 4 can be efficiently coupled to the conductor portion 7 ′ as a magnetic field component of the near electromagnetic field components. That is, the conductor portion 7 ′ can receive electromagnetic field energy from the device body portion 4 as a kind of magnetic coupling antenna, and can efficiently radiate the electromagnetic field as a ½ wavelength dipole antenna to the space.
[0057]
(Fifth embodiment: corresponding to claim 6)
Next, a fifth embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG. 9 in which the same parts as those in FIGS.
[0058]
In this embodiment, as in the first to fourth embodiments, a wireless tag is used as a device main body as a short-distance low-power wireless device.
[0059]
As shown in FIG. 9, the short-range low-power wireless device according to the present embodiment uses, for example, a weak radio wave type wireless tag as the device main body unit 4, and has an electric wavelength of approximately ½ wavelength with respect to the transmission frequency of the device main body unit 4. Two elongated conductors having two orthogonal axes, and a conductor portion 11 provided with a rectangular conductor having an electrical wavelength of approximately ¼ wavelength with respect to the transmission frequency of the device main body 4 at the intersection of the two orthogonal axes. Is mounted on the device main body 4.
[0060]
According to the present embodiment, the radio wave radiated from the device main body 4 excites the conductor part 7, and the radio wave is radiated into the space by the secondary radiation from the conductor part 11. In this case, the conductor portion 11 has two elongated conductors having an electric wavelength of approximately ½ wavelength with respect to the transmission frequency of the device main body portion 4 as two orthogonal axes, and the device main body portion 4 has an intersection of the two orthogonal axes. Since it has a configuration in which a long conductor having an electric wavelength of approximately ¼ wavelength with respect to the transmission frequency is provided at a right angle, it is almost non-directional by secondary radiation not only in two orthogonal directions but also in all directions. The radio waves are radiated into the space approximately evenly at 360 degrees. By using this directivity, it is possible to satisfactorily detect the position of a specific mobile body and perform specific mobile body communication.
[0061]
(Sixth embodiment: corresponding to claim 7)
Next, a fourth embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG. 10 in which the same parts as those in FIGS.
[0062]
In this embodiment, as in the first to fourth embodiments, a wireless tag is used as a device main body as a short-distance low-power wireless device.
[0063]
As shown in FIG. 10, the short-distance low-power wireless device according to the present embodiment uses, for example, a weak radio wave type wireless tag as a device body portion 4, and the device body portion 4 and the annular body 12 constitute a conductor portion 11. ing. In this case, the annular body 12 is composed of a long conductor 12A having an electrical wavelength that is an integral multiple of approximately ½ wavelength with respect to the transmission frequency of the device body 4 and a string 13 made of an insulating material. In this configuration, the intermediate portion in the longitudinal direction of the conductor 12 </ b> A is placed on the device main body 4.
[0064]
In such a configuration, since the annular body 12 can be easily hung on the human body's neck as a moving body, a short-distance low-power wireless device with improved radio wave characteristics can be easily applied to the human body or the like.
[0065]
(Seventh embodiment: corresponding to claim 8)
Next, a seventh embodiment of a short-distance low-power wireless device according to the present invention will be described with reference to FIG.
[0066]
In the present embodiment, a wireless LAN and Bluetooth (registered trademark) PC card is used as a device main body as a short-distance low-power wireless device.
[0067]
As shown in FIG. 11, the short-distance low-power wireless device of this embodiment has a configuration in which a PC card is used as a device main body 14 and a conductor 15 is detachably attached to the device main body 14 by a stopper 16. .
[0068]
Here, as the conductor portion 15, a substrate 15A in which a director 15B of a Yagi antenna, for example, can be employed.
[0069]
Further, the stopper 16 is formed of a clip or the like including a concave portion and a convex portion. For example, a concave portion 16A is provided at an end portion of the device main body portion 14 and a convex portion 16B is provided at an end portion of the conductor portion 15, thereby The end portion of the conductor portion 15 is attached to the end portion of 14.
[0070]
As described above, according to the present embodiment, by providing the conductor portion 15 in the device main body portion 14 which is a PC card with limited radio wave transmission power, the device main body portion is generated by the secondary radiated radio wave from the conductor portion 15. The radio wave is radiated into the space more efficiently than the case of only 14, and the desired directivity can be obtained by the form of the conductor portion 15. Accordingly, it is possible to cope with the case where the position of a specific mobile body is detected and the specific mobile body communication is performed.
[0071]
In addition, when the device main body 14 is applied to a PC card, the communication range can be given directivity, interference can be reduced, stable communication and improvement in data throughput can be expected, and normal communication can be expected. Since the antenna built-in type PC card can be used without any modification, it is possible to easily change the communication area without disconnecting the communication in the operating state.
[0072]
Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. In addition, the embodiments may be appropriately combined as much as possible, and in that case, combined effects can be obtained. Further, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, when an invention is extracted by omitting some constituent elements from all the constituent elements shown in the embodiment, when the extracted invention is implemented, the omitted part is appropriately supplemented by a well-known common technique. It is what is said.
[0073]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a short-distance low-power wireless device that is suitable for detecting the position of a specific mobile object or performing specific mobile communication.
[Brief description of the drawings]
FIG. 1 is a diagram showing a short-distance low-power wireless device according to a first embodiment of the present invention together with a controller.
FIG. 2 is a diagram showing in detail the short-range low-power wireless device according to the embodiment.
FIG. 3 is a diagram showing a short-distance low-power wireless device according to a second embodiment of the present invention together with a controller.
FIG. 4 is a diagram illustrating directivity in the embodiment.
FIG. 5 is a diagram showing a short-distance low-power wireless device according to a third embodiment of the present invention together with a controller.
FIG. 6 is a view for explaining directivity in the embodiment.
FIG. 7 is a diagram showing a short-distance low-power wireless device according to a fourth embodiment of the present invention together with a trailer.
FIG. 8 is a diagram showing a short-range low-power wireless device according to a fifth embodiment of the present invention.
FIG. 9 is a diagram showing a short-range low-power wireless device according to a sixth embodiment of the present invention.
FIG. 10 is a diagram showing a short-range low-power wireless device according to a seventh embodiment of the present invention.
FIG. 11 is a diagram showing a short-range low-power wireless device according to an eighth embodiment of the present invention.
FIG. 12 is a diagram showing a wireless tag together with a controller as a conventional short-distance low-power wireless device.
FIG. 13 is a diagram showing a PC card as a conventional short-distance low-power wireless device.
[Explanation of symbols]
2 ... Controller, 4, 14 ... Device body, 5, 6, 7, 7 ', 11, 12, 15 ... Conductor.

Claims (9)

A short-distance low-power wireless device comprising a short-distance low-power wireless device main body and a conductor having an antenna effect provided in the vicinity of the device main-body. The short-distance low-power wireless device main body includes an electronic circuit board including at least an integrated circuit element and an antenna, performs predetermined signal processing on the integrated circuit element of the electronic circuit board, and outputs a signal based on the signal processing 2. The short-distance low-power wireless device according to claim 1, wherein the wireless tag transmits to the external controller via an antenna. The short-distance low-power wireless device according to claim 1, wherein the conductor has an electric wavelength that is an integral multiple of a quarter wavelength with respect to the transmission frequency of the device body. The said conductor part is comprised so that two elongate conductors which have an electrical wavelength of about 1/2 wavelength with respect to the transmission frequency of the said device main-body part may become two orthogonal axes. Or the short-range low-power wireless device according to 2; 3. The short distance according to claim 1, wherein the conductor portion has an electric wavelength of approximately ½ wavelength with respect to a transmission frequency of the device main body portion, and the central portion thereof is configured in a loop shape. Low power wireless device. In the conductor portion, two elongated conductors having an electromagnetic wavelength of approximately ½ wavelength with respect to the transmission frequency of the device main body portion are orthogonal to two axes, and the transmission frequency of the device main body portion is at the intersection of the two orthogonal axes. 3. The short-distance low-power wireless device according to claim 1, wherein a long conductor having a substantially 1/4 wavelength is provided at right angles. The short-distance low-power wireless device according to claim 1, wherein the conductor part is a part of a string that suspends the device main body part. The short-distance low-power wireless device body is a PC card, and the conductor is provided close to the PC card and has an electric wavelength that is an integral multiple of a quarter wavelength with respect to the transmission frequency of the PC card. The short-range low-power wireless device according to claim 1, wherein the short-range low-power wireless device is an antenna. The short-distance low-power wireless device according to claim 1, wherein the conductor is a director of a directional antenna.

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