JPH0738562A - Antenna system for radio lan - Google Patents

Abstract

PURPOSE:To obtain an antenna system for radio LAN capable of reducing the degradation of communication quality caused by a multipath and making slave station antennas small in size and light in weight. CONSTITUTION:At the radio LAN composed of a master station antenna connected to a cable LAN and installed on the ceiling or walls and the slave station antennas connected to information terminal equipments movable on the floor, the antenna system for radio LAN uses the master station antenna as a formed beam antenna and uses the slave station antennas as movable beam antennas to direct pencil beams toward a master station each time the slave station antennas are moved, and the slave station antennas are provided with plural primary radiators 9a-9e and a spherical mirror 8. This beam switching movable beam antennas is constituted so that the directions of beams can be switched by switching those primary radiators 9a-9e, or a cosecant-square forming beam antenna is used for the master station antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless LAN antenna system in which deterioration of communication quality due to multipath is reduced.

[0002]

2. Description of the Related Art FIG. 15 shows, for example, New Media Development Association of Japan: "Research on electronic networks (research on expansion of wireless LAN system use)", (1
FIG. 16 is a schematic configuration diagram of the wireless LAN antenna system shown in FIG.
t No. Other wireless LAN shown in 5095535 "
It is a figure explaining the antenna system for. 15 and 16
25, reference numeral 25 denotes a master station omnidirectional antenna, and 26a to 26
f is a master station multi-beam antenna, 27a and 27b are slave station omnidirectional antennas, 28a to 28f are slave station multi-beam antennas, 30a to 30c are propagation paths, and 50 is a personal computer. The LAN connected to the master station is not shown.

In FIG. 15, L is wired on the ceiling.
The AN (not shown) is connected to the master station omnidirectional antenna 25 via the master station transceiver 2, and the personal computer 50 on the desk placed on the floor connects the slave station transceivers 4a and 4b, respectively. Through the slave station omnidirectional antenna 27
a, 27b. Since the antennas of the master station and the slave stations are omnidirectional antennas, there are reflected waves from the ceiling, floor surface, and walls. Further, in FIG. 16, master station multi-beam antennas 26a to 26f are installed on the ceiling, and slave station multi-beam antennas 28a to 28f are connected to a terminal device (not shown) on the desk. Since both multi-beam antennas are composed of six horn antennas, there are 36 (6 × 6) propagation paths 30 (only 30a to 30c are shown in FIG. 16). Among them, it is the system that selects the route with the best communication quality.

[0004]

Since the conventional wireless LAN antenna system is constructed as described above, in the case of the omnidirectional antenna, multipath occurs, so that the communication quality deteriorates, and in the case of the multibeam antenna. Had a problem that the master station antenna and each small station antenna were large.

The present invention has been made in order to solve the above problems, and has a small communication effect due to multipath, good communication quality, and a small and lightweight wireless L antenna for each small station antenna.
The purpose is to obtain an antenna system for AN.

[0006]

In order to achieve the above object, a wireless LAN antenna system according to a first aspect of the present invention includes a master station antenna connected to a wired LAN and provided on a ceiling or a wall, and a floor antenna. In a wireless LAN consisting of a slave station antenna connected to a moving information terminal device, a master beam antenna is a shaped beam antenna, and a movable beam antenna that directs a pencil beam to the master station each time the slave station antenna is moved. is there.

The wireless LAN antenna system according to a second aspect is a so-called cosecant 2 which uniformly illuminates the range of the floor surface on which the information terminal device is moved, as a master station antenna of the wireless LAN antenna system according to the first aspect. A square shaped beam antenna is provided.

The wireless LAN antenna system according to claim 3 is a manual movable beam having a horn antenna for manually adjusting the beam direction as a slave station antenna of the wireless LAN antenna system according to claim 1 or 2. An antenna is provided.

The wireless LAN antenna system of claim 4 is a manual type having an end-fire helical antenna for manually adjusting the beam direction as a slave station antenna of the wireless LAN antenna system of claim 1 or 2. A movable beam antenna is provided.

The wireless LAN antenna system according to a fifth aspect is a beam switching type movable beam antenna having a switch circuit as a slave station antenna of the wireless LAN antenna system according to the first or second aspect. It is provided.

Further, a wireless LAN antenna system according to a sixth aspect is provided with a spherical mirror antenna having a plurality of primary radiators as a beam switching type movable beam antenna which is a slave station antenna of the wireless LAN antenna system according to the fifth aspect. , The primary radiator is switched to switch the beam.

According to a seventh aspect of the present invention, there is provided a wireless LAN antenna system, wherein a backfire type antenna for radiating a main beam is provided to the rear as a primary radiator of a spherical mirror antenna of the sixth aspect of the wireless LAN antenna system. Is.

According to the eighth aspect of the present invention, there is provided a wireless LAN antenna system, wherein a short backfire type waveguide antenna is provided as a primary radiator of a spherical mirror antenna of the seventh aspect of the wireless LAN antenna system.

According to a ninth aspect of the present invention, there is provided a wireless LAN antenna system, wherein a backfire type helical antenna is provided as a primary radiator of a spherical mirror antenna of the seventh aspect of the wireless LAN antenna system.

According to a tenth aspect of the present invention, there is provided a wireless LAN antenna system according to any one of the sixth to ninth aspects, wherein the spherical mirror antenna has a radius of a spherical surface including a phase center of a plurality of primary radiators. It is larger than half the radius of.

According to the eleventh aspect of the present invention, there is provided a wireless LAN antenna system according to the fifth aspect, wherein a Luneberg lens antenna fed by a plurality of planar antenna type primary radiators is provided as a slave station antenna of the wireless LAN antenna system. The beam is switched by switching the primary radiator.

[0017]

In the wireless LAN antenna system according to the present invention configured as described above, the master station antenna is a shaped beam antenna that irradiates only the range of the floor surface on which the information terminal equipment moves, so that the wall or ceiling is It is possible to reduce unnecessary reflection from the mobile station antenna and reduce the deterioration of communication quality due to multipath by transmitting and receiving radio waves only in a specific direction by using the mobile beam antenna as the slave station antenna. Can be lightweight.

[0018]

EXAMPLES Example 1. FIG. 1 is a schematic configuration diagram showing a first embodiment of the invention according to claim 1. In FIG. 1, a master station transceiver 2 and slave station transceivers 4a and 4b are the same as in the conventional example of FIG. 1 is a master station antenna, 3a and 3b are slave station antennas, 5 is a shaped beam emitted from the master station antenna 1,
6a and 6b are movable beams emitted from the slave station antenna,
50a and 50b are information terminal devices.

In this wireless LAN antenna system,
The shaped beam 5 of the master station antenna 1 can be formed by one reflecting mirror and one minus secondary radiator, and has been put to practical use in various fields like a shaped beam antenna mounted on a communication satellite (CS). On the other hand, the slave station antennas 3a and 3b are pencil beam type antennas, and point to the master station antenna 1 each time the information terminal device moves.

This wireless LAN antenna system is configured as described above, and multipath can be greatly reduced by using the shaped beam 5 and the movable beams 6a and 6b, and the communication quality is improved. Further, with respect to the master station antenna 1, the slave station antennas may be one antenna each such as 3a and 3b, and do not require a plurality of antennas unlike the multi-beam antenna of the conventional example shown in FIG. The size and weight can be reduced.

Example 2. Second Embodiment FIG. 2 is a schematic configuration diagram showing a master station antenna of a second embodiment of the invention according to claim 2. Figure 2
2A is a schematic view of the master station antenna, and FIG.
It is a beam shape figure of the antenna shown in (a). In the second embodiment of the wireless LAN antenna system, the shaped beam 5 of the master station antenna of FIG. 1 has a specific beam shape. In FIG. 2, reference numeral 7 denotes a master station antenna having a beam shape of a cosecant square beam.

In the second embodiment, the cosecant squared beam antenna 7 of the master station has two reflecting mirrors as shown in FIG. 2 (a) in order to obtain a good axial ratio even when the circularly polarized wave is excited. However, one reflector may be used when the linearly polarized wave is excited. The cosecant square beam antenna 7 of this master station is fixed to the ceiling,
In this beam shape, the radiation level (proportional to the line segment OA) is cosecant squared, that is, (cosec θ) ² , as shown by the broken line in FIG. Where θ is the angle measured from the ceiling. Therefore, this beam has a low radiation level right under the antenna and a high level as it approaches the wall, so that the attenuation due to the propagation distance can be canceled and the floor surface can be irradiated with a uniform electric field level. The slave station antenna is the same as that in the first embodiment.

Example 3. FIG. 3 is a schematic configuration diagram showing a slave station antenna of a third embodiment of the invention according to claim 3. Figure 3
In the slave station transceiver 4 and movable beam 6,
The same operation as in the first embodiment is performed. Three
Reference numeral 1 is a horn antenna used as a slave station antenna, 32 is an antenna mounting device capable of adjusting the direction, and 50 is a personal computer as an example of an information terminal device.

In the third embodiment, each time the information terminal equipment moves, the horn antenna 31 attached to the antenna attachment device 32 whose direction can be adjusted is used as the master station antenna (1 in FIG. 1 or 7 in FIG. 2). Point manually.
As a pointing method, for example, the reception level from the master station antenna 1 is monitored, or the direction of the pilot lamp is directed to the master station antenna 1 with the antenna axis of the horn antenna 31 parallel to the optical axis of the pilot lamp. So that the antenna is mechanically displaced. The master station antenna is the same as in the first or second embodiment.

Example 4. FIG. 4 is a schematic configuration diagram showing a slave station antenna of a fourth embodiment of the invention according to claim 4. Figure 4
In, the slave station transceiver 4, the movable beam 6, the direction-adjustable antenna mounting device 32, and the personal computer 50 are the same as those in the third embodiment, and operate in the same manner as in the third embodiment. Reference numeral 33 is an endfire helical antenna used as a slave station antenna.

In the fourth embodiment, an endfire helical antenna is used instead of the horn antenna of the third embodiment, and there is an advantage that communication using circular polarization can be performed without using a circular polarization generator. The master station antenna is the same as in the first or second embodiment.

Example 5. FIG. 5 is a conceptual diagram showing a slave station antenna of a fifth embodiment of the invention according to claim 5. FIG. 6 is a beam arrangement diagram of the slave station antenna of FIG. 5 and 6, 34 is a radiator, 10 is a switch circuit, 11 is a feeder connecting the output terminal of the switch circuit 10 and the input terminal of the radiator 34, and 12a to 12e are corresponding input terminals of the radiator. A beam direction, 17 is a transceiver end which is an interface with the slave transceiver (4a or 4b in FIG. 1) of the switch circuit 10.

Next, the operation will be described with reference to FIGS. The beam arrangement diagram of FIG. 6 shows the beam direction two-dimensionally, that is, the elevation angle and the azimuth angle, and the beam directions 12a, 12b, 12c, 12d, and 12e of FIG. 5 are the beam directions of the AA cross section in FIG. Corresponding to. Therefore, in order to switch 19 beams as shown in FIG. 6, 19 input terminals of the radiation device are switched by the switch circuit. In the fifth embodiment, which beam is selected from the beam directions of the slave station antenna connected to the information terminal equipment that has moved on the floor is, for example, the reception of radio waves from the master station antenna (1 in FIG. 1). It can be easily selected by monitoring the level. The master station antenna is the same as in the first or second embodiment.

Example 6. FIG. 7 is a schematic configuration diagram showing a slave station antenna of a sixth embodiment of the invention according to claim 6. Figure 7
In the switch circuit 10, the power supply lines 11a to 11e,
The beam directions 12a to 12e and the transmitter / receiver end 17 are the fifth embodiment.
The same operation as in the fifth embodiment is performed. 8
Is a spherical mirror, and 9a to 9e are a plurality of primary radiators.

In the sixth embodiment, when the switch circuit 10 connects the primary radiator 9a to the transceiver end 17,
A beam is formed in the direction of 12a,
When b, 9c, 9d and 9e are sequentially connected to the transceiver end 17, a beam is formed in the direction of 12b, 12c, 12d and 12e, and there is an advantage that beam switching can be performed. The master station antenna is the first embodiment or the second embodiment.
Is the same as.

Example 7. FIG. 8 is a conceptual diagram showing a primary radiator of a spherical mirror antenna used as a slave station antenna according to a seventh embodiment of the present invention. In FIG. 8, the power supply line 11
Is the same as the sixth embodiment, and operates in the same way as the sixth embodiment. Reference numeral 35 is a radiation unit, and 36 is a primary radiation beam.

In the seventh embodiment, since the backfire type antenna having the main beam in the direction of the feeding line is used as the primary radiator of the spherical mirror antenna, there is an advantage that the blocking of the feeding line becomes small. The master station antenna is the same as in the first or second embodiment.

Example 8. FIG. 9 is a schematic configuration diagram showing a primary radiator of a spherical mirror antenna used for a slave station antenna of an eighth embodiment of the invention according to claim 8. In FIG. 9, the primary radiation beam 36 is similar to that of the seventh embodiment.
Same operation as. 37 is a waveguide, 38 is a reflector, 3
Reference numeral 9 is a dielectric material that supports the reflection plate 38.

In the eighth embodiment, the backfire type antenna is realized by reflecting the radio wave radiated from the opening of the waveguide 37 by the reflecting plate 38. In addition,
The master station antenna is the same as that of the first or second embodiment.

Example 9. FIG. 10 is a schematic configuration diagram showing a primary radiator of a spherical mirror antenna used for a slave station antenna of Embodiment 9 of the invention according to claim 9. In FIG. 10, the feeder line 11 and the primary radiation beam 36 are the same as those in the sixth and seventh embodiments, respectively, and operate similarly to the sixth and seventh embodiments.
40 is a helical conductor and 41 is a ground plane.

In the ninth embodiment, the backfire type helical antenna is used as the primary radiator of the spherical mirror antenna, and there is an advantage that communication using circular polarization can be performed without using the circular polarization generator. The master station antenna is the same as in the first or second embodiment.

Example 10. 11 is a schematic configuration diagram showing a spherical mirror antenna used as a slave station antenna according to a tenth embodiment of the present invention. In the tenth embodiment, the spherical mirror antennas of the sixth to ninth embodiments, the spherical mirror and the primary radiator are the same, but the primary radiators 9a to 9a in the spherical mirror 8 are the same.
The geometrical position of e is different. here,
Although there are a plurality of primary radiators, only 9a is represented for convenience of explanation. FIG. 12 is a diagram for explaining the operating characteristics of the spherical mirror antenna of FIG.

Next, the operation will be described with reference to FIGS. In FIG. 11, it is assumed that the radius of the spherical mirror 8 is R and the phase center F of the primary radiator 9 is on a spherical surface having a radius r. Normally, if r / R is selected to be 0.5, the spherical aberration does not increase, so that the pencil beam shown by the curve 14 in FIG. 12 can be formed. On the other hand, if r / R is selected to be 0.5 or more, the spherical aberration becomes large, and the phase becomes opposite around the aperture as shown in FIG. 11, and the twin beam shown by the curve 13 in FIG. 12 is formed. Now, the range in which the information terminal device can move is limited by the size of the room, so the angle range in which the master station antenna is viewed is constant. Therefore, when the twin beam is used, the beam width is wider than that of the pencil beam, and the room can be covered with a smaller number of twin beams than the 19 pencil beams in FIGS. The configuration can be simplified. This Example 10
Has the same operation and effect by combining with the sixth to ninth embodiments. The master station antenna is the same as in the first or second embodiment.

Example 11. FIG. 13 is a schematic configuration diagram showing a slave station antenna of an eleventh embodiment of the invention according to claim 11. In FIG. 13, a switch circuit 10 and a power supply line 11
(11 is representative of 11a to 11e), the beam directions 12a to 12e, and the transceiver end 17 are the same as those in the fifth embodiment, and perform the same operations as in the fifth embodiment. 15a-15
Reference numeral e is a plane antenna, and 16 is a Luneberg lens.

Next, the operation will be described. The Luneberg lens 16 is a dielectric lens, and has a relative permittivity of 2 at the center of the sphere, and a relative permittivity continuously decreases as the diameter increases, and becomes 1 on the spherical surface. Therefore, if a plurality of primary radiators are arranged on the spherical surface, the beam direction 12 shown in FIG.
a to 12e can be obtained. Here, the planar antennas 15a to 15e are used as the primary radiators so that the phase centers of the respective primary radiators are on the spherical surface.

FIG. 14 is a diagram for explaining a specific structure of the Luneberg lens antenna of FIG. 14, the switch circuit 10 and the transmitter / receiver terminal 17 are the same as those shown in FIG. 13, and operate similarly to those shown in FIG. 18a-18f (representatively called 18)
Is a multilayer dielectric, 19a to 19c (typically referred to as 19)
Is a patch antenna, 20 is a spherical conductor, and 21a to 21c.
(Representatively referred to as 21) are slots, and 22a to 22d
A strip line (typically referred to as 22) is a strip line. Here, the patch antenna 19 corresponds to the plane antenna 15 of the Luneberg lens antenna shown in FIG. 13, and the slot 21 and the strip line 22 correspond to the feeder line 11 of the Luneberg lens antenna shown in FIG. 13, respectively. It is integrally formed with the Luneberg lens 16 composed of the dielectric material 18.

The Luneberg lens is a spherical dielectric material whose relative dielectric constant is continuously changed in the radial direction.
As shown in FIG. The patch antenna 19 is used as the primary radiator, and the Luneberg lens is excited from the strip line 22 through the slot 21. The patch antenna 19 and the lower ground conductor of the strip line 22 share the spherical conductor 20. The master station antenna is the same as in the first or second embodiment.

In each of the above embodiments, the case where the wired LAN is laid on the ceiling and the master station is provided on the ceiling or the wall has been described. However, a slave station connected to the wired LAN laid on the floor, When communicating with a plurality of mobile stations that move, the master station may be applied by being provided on the ceiling or wall as a repeater between these slave stations.

[0044]

As described above, according to the first to eleventh aspects of the present invention, the master station antenna is formed of the shaped beam antenna, and the slave station antenna is the movable beam antenna. It is possible to obtain a wireless LAN antenna system in which deterioration can be reduced and the slave station antenna can be made small and lightweight.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a master station antenna according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a slave station antenna according to a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a slave station antenna according to a fourth embodiment of the present invention.

FIG. 5 is a conceptual diagram showing a slave station antenna according to a fifth embodiment of the present invention.

6 is a beam layout diagram of the slave station antenna of FIG. 5;

FIG. 7 is a schematic configuration diagram showing a slave station antenna according to a sixth embodiment of the present invention.

FIG. 8 is a conceptual diagram showing a primary radiator used for a slave station antenna according to a seventh embodiment of the present invention.

FIG. 9 is a schematic configuration diagram showing a primary radiator used for a slave station antenna according to an eighth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram showing a primary radiator used for a slave station antenna according to a ninth embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing a spherical mirror antenna used as a slave station antenna according to embodiment 10 of the present invention.

FIG. 12 is a diagram illustrating operating characteristics of the spherical mirror antenna of FIG.

FIG. 13 is a schematic configuration diagram showing a slave station antenna according to an eleventh embodiment of the present invention.

FIG. 14 is a diagram illustrating a specific configuration of the slave station antenna of FIG.

FIG. 15 is a schematic configuration diagram showing a conventional wireless LAN antenna system.

FIG. 16 is a diagram illustrating another conventional wireless LAN antenna system.

[Explanation of symbols]

 1 master station antenna 2 master station transceiver 3a, 3b slave station antenna 4, 4a, 4b slave station transceiver 5 shaped beam 6, 6a, 6b movable beam 7 master station cosecant squared beam antenna 8 spherical mirror 9a-9e primary radiator 10 Switch Circuit 11a-11e Feed Line 12a-12e Beam Direction 13 Twin Beam 14 Pencil Beam 15a-15e Planar Antenna 16 Luneberg Lens 17 Transceiver End 18a-18f Multilayer Dielectric 19a-19c Patch Antenna 20 Spherical Conductor 21a-21c Slots 22a to 22d Strip line 25 Parent station omnidirectional antenna 26a to 26f Parent station multibeam antenna 27a, 27b Child station omnidirectional antenna 28a to 28f Child station multibeam antenna 30a to 30c Propagation path 31 Horn antenna 32 Antenna With 33 end-fire helical antenna 34 radiation apparatus 35 radiation portion 36 primary radiation beam 37 waveguide 38 reflector plate 39 dielectric 40 helical conductor 41 base plate 50 personal computers 50a, 50b information terminal equipment

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

Since the conventional wireless LAN antenna system is constructed as described above, in the case of the omnidirectional antenna, multipath occurs, so that the communication quality deteriorates, and in the case of the multibeam antenna. Had a problem that the master station antenna and each slave station antenna became large.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

The present invention has been made in order to solve the above-mentioned problems, and has a small communication effect due to multipath, good communication quality, and a small and lightweight wireless antenna for each slave station antenna.
The purpose is to obtain an antenna system for AN.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shuji Urasaki 5-1, 1-1 Ofuna, Kamakura-shi Electronic Systems Research Center, Mitsubishi Electric Corporation

Claims (11)

[Claims] 1. A wireless LAN comprising a master station antenna connected to a wired LAN and provided on a ceiling or a wall, and a slave station antenna connected to an information terminal device moving on a floor surface. An antenna system for a wireless LAN, comprising a shaped beam antenna and a movable beam antenna that directs a pencil beam to a master station each time the slave station antenna is moved. 2. The wireless LAN according to claim 1, wherein a so-called cosecant squared beam antenna is provided as a master station antenna for uniformly illuminating a range of a floor surface on which the information terminal device is moved. Antenna system. 3. The wireless LAN antenna system according to claim 1, wherein a manual movable beam antenna having a horn antenna for manually adjusting the beam direction is provided as the slave station antenna. 4. The antenna system for a wireless LAN according to claim 1 or 2, wherein a manual movable beam antenna having an endfire helical antenna for manually adjusting a beam direction is provided as the slave station antenna. . 5. The antenna system for a wireless LAN according to claim 1, wherein a beam switching type movable beam antenna having a switch circuit and switching a beam is provided as the slave station antenna. 6. The antenna system for a wireless LAN according to claim 5, wherein a spherical mirror antenna having a plurality of primary radiators is provided as the slave station antenna, and the beam is switched by switching the primary radiators. . 7. The antenna system for a wireless LAN according to claim 6, wherein a backfire type antenna for radiating a main beam is provided in the rear as a primary radiator of the spherical mirror antenna. 8. The antenna system for a wireless LAN according to claim 7, wherein a short backfire type waveguide antenna is provided as a primary radiator of the spherical mirror antenna. 9. The wireless LAN antenna system according to claim 7, wherein a backfire type helical antenna is provided as a primary radiator of the spherical mirror antenna. 10. The wireless LAN antenna system according to claim 6, wherein a radius of a sphere including phase centers of a plurality of primary radiators is set to be larger than half a radius of a spherical mirror. . 11. The Luneberg lens antenna feeding with a plurality of planar antenna type primary radiators is provided as a slave station antenna, and the beam is switched by switching the primary radiators. Wireless LAN
Antenna system.