JP4154362B2 - Wireless LAN antenna, wireless LAN antenna control method, wireless LAN base station antenna, wireless LAN mobile station terminal antenna, terminal wireless LAN card, and wireless LAN system - Google Patents

Description

  The present invention relates to a wireless LAN system that transmits high frequency for a wireless LAN system between a wireless LAN base station and a wireless LAN mobile station, a wireless LAN antenna used for the wireless LAN system, and a wireless LAN base station incorporating this antenna. The present invention relates to an antenna, a wireless LAN mobile station antenna incorporating this antenna, and a wireless LAN card for a terminal incorporating this antenna.

(Wireless LAN system)
In recent years, with the development of an advanced information society, offices such as buildings, buildings such as factories and warehouses, indoors such as ordinary houses and offices, and arcades such as shopping streets other than indoors The use of wireless LAN systems (intra-area wireless communication networks) that form wireless communication networks in certain areas, such as station platforms, airport terminals, large temporary structures such as tents, and event venues, is expanding.

(High-frequency line for wireless LAN system)
In this wireless LAN system, high frequency (hereinafter also referred to as electromagnetic waves) in a wide frequency band is generated between a wireless LAN base station (base unit) and a number of wireless LAN mobile stations (slave units) arranged in the area. Communication. For this communication, a high-frequency waveguide (high-frequency line) is indispensable, and other than a waveguide made of a conductive metal such as stainless steel, steel, copper, and aluminum, or a waveguide such as a coaxial cable. In addition to the microwave transmission path, a strip-shaped high-frequency line that can be easily installed without taking up much space is used.

  In such a high-frequency microstrip line, the present inventors first have a long dielectric layer made of a dielectric material and a pair of long ground layers made of a conductive material sandwiching the dielectric layer. A flexible high-frequency microstrip line in which signal lines are disposed in the dielectric layer in the longitudinal direction and a high-frequency coupling opening is provided in a part of the ground layer. Hereinafter, a high-frequency microstrip line is also simply referred to as a high-frequency line) (see Patent Documents 1 and 2).

JP 2002-353707 A (Claim, Fig. 1) JP 2003-174457 (Claim, Fig. 1)

  Such a high-frequency microstrip line has flexibility, the high-frequency strip line itself can be freely deformed according to the purpose, and the obstacle is passed or detoured depending on the installation conditions in the wireless LAN system area. Suitable for macro installations. In addition, handling such as installation work and transportation to the installation site is also simple.

  An example of applying such a high-frequency line to an indoor wireless LAN system is shown in front view in FIG. In FIG. 1, the high-frequency line 1a is provided, for example, along the indoor ceiling of the building (above the area), and one end of the high-frequency line 1a is a non-reflective termination, and the other end is A wireless LAN base station (hereinafter also referred to as a wireless LAN base station or a wireless LAN base unit) 11 is connected via a coaxial cable 12. In addition, a plurality of wireless LAN mobile stations (hereinafter also referred to as slave stations, mobile station terminals, slave unit groups, and terminal unit groups) 9a, 9b, and 9c that communicate with the wireless LAN base station 11 are disposed indoors. . These mobile stations 9a, 9b, and 9c communicate with the antenna 6 of the wireless LAN base station using the antenna elements used in the terminal wireless LAN card 5 that each mobile station 9a, 9b, and 9c has.

  In order to ensure good communication with each of these wireless LAN mobile stations, according to the layout of these mobile stations 9a, 9b, 9c, for example, a patch antenna (planar antenna) 6 is used as the antenna of the wireless LAN base station. As elements, they are arranged on the high-frequency line 1a at regular intervals.

  In such a wireless LAN system, when communicating between a wireless LAN base station and a large number of wireless LAN mobile stations arranged in the area, the area in which the wireless LAN mobile station can communicate is greatly limited. The problem is likely to occur.

(Problems on the wireless LAN mobile station side)
One of the reasons for limiting the area where wireless LAN mobile stations can communicate is the problem of multipath fading due to problems on the wireless LAN mobile station side. From the problem of this multipath fading, it demonstrates below.

  In the wireless LAN system described above, depending on the layout on the wireless LAN mobile station side, high-frequency interference (multipath fading) between adjacent patch antennas 6a and 6b may occur. When this multipath fading occurs, the concentric high-frequency waves transmitted from adjacent antenna units completely cancel each other out and communication errors are likely to occur. The location (location) of the wireless LAN mobile station (terminal) In some cases, data communication becomes difficult.

  To reduce the effects of multipath fading, a wireless LAN base station can be connected to two orthogonally polarized waves (left and right turns) or linearly polarized waves (45 ° and 135 °). There is a transmission method of polarization diversity that transmits radio waves of polarization components. In this polarization diversity transmission system, the wireless LAN mobile station terminal also has, for example, two sets of receiving antennas for receiving two orthogonal polarization components of the transmission radio wave, and the output of the receiving antennas. Are switched or combined to receive polarization diversity (see Patent Document 3).

JP 2000-115044 (Claim, Fig. 1)

  However, even in this polarization diversity transmission method, the reception state of the wireless LAN mobile station is greatly affected by the communication environment. For example, in an indoor area with good visibility, the effect on communication is only reflection from materials with relatively low reflectivity such as ceilings, walls, and floors, and the effect of polarization diversity can be greatly expected. However, in this polarization diversity transmission system, in an environment where the distance between the base station antenna and the mobile station terminal antenna becomes longer (for example, more than 10 m), radio wave reflection increases and high-speed communication becomes difficult. There is. That is, as the distance between the antennas increases, for example, there is an object that shields the line of sight between the antennas, such as a factory building described in FIG. 10 described later, or a metal structure that easily reflects radio waves. Will increase. For this reason, the signal level that can be received by the base station antenna and the mobile station terminal antenna is greatly reduced, and multipath components are increased, so that the received S / N is reduced and high-speed communication becomes difficult.

  In addition, when using the normally used linearly polarized wave as the transmission method of this polarization diversity, when there is no line of sight between the base station antenna and the mobile station terminal antenna, the wave received through multiple paths by reflection It is easy to interfere with each other. For this reason, the reception S / N is lowered and high-speed communication becomes difficult.

  Therefore, in order to reduce the effects of multipath fading without such problems, the wireless LAN base station uses circularly polarized high-frequency waves that propagate by turning to the left or right instead of linearly polarized waves. It is preferable. It is preferable to use a circularly polarized antenna as an antenna for transmitting this circularly polarized high frequency.

  Therefore, in the example of the wireless LAN system in FIG. 1, the antenna on the wireless LAN base station side is configured by alternately arranging circularly polarized antenna elements having different turning directions. More specifically, the patch antenna 6a on the wireless LAN base station side is a clockwise (right-turned) circularly polarized antenna element, and the adjacent patch antenna 6b is counterclockwise (left-turned) left-circularly polarized. Wave antenna elements are used, and circularly polarized antenna elements having different turning directions are alternately arranged.

(Problems on the wireless LAN base station side)
In addition to the multipath fading described above, in the wireless LAN system, due to problems on the wireless LAN base station side, a plurality of independent network groups centered on each wireless LAN base station are spatially included in the communication area. However, due to the radiation characteristics of the base station antenna, there is a problem that the area in which the wireless LAN mobile station can communicate is greatly limited. This problem will be described below.

  In the wireless LAN system, when the plurality of independent network groups are spatially formed, usually, as shown in a perspective view of FIG. 24, for example, antennas 202A of a plurality of access points (wireless LAN base stations), 202B is installed spatially separated in the communication area. In this case, in order to prevent the multipath fading due to radio waves radiated from a plurality of wireless LAN base stations and to form a clear division area, the power radiated from the antenna of the access point is adjusted to be small, Wireless LAN The area in which the slave station can communicate must be restricted.

  In general, half-wave dipole antennas 202A and 202B as shown in a perspective view in FIG. 24 are used as antennas for such an access point (wireless LAN base station). In this case, the area in which the wireless LAN slave station can communicate is within a circle centered on the positions of the dipole antennas 202A and 202B, such as circle A and circle B indicated by dotted lines.

  This inevitably results in a dead zone where the wireless LAN slave station cannot connect to any dipole antenna 202A, 202B (access point). In addition, in the dipole antenna, it is necessary to lay the power source and data line from each antenna 202A, 202B on the floor surface, and there is a problem that it takes time for wiring work for this purpose.

  On the other hand, there is a method of securing a wide communication area by using a plurality of highly directional planar antennas such as the patch antenna used in FIG.

  FIG. 25 is a perspective view showing an example using such a planar antenna. In FIG. 25, for example, four planar antennas 202A, 202B, 202C, and 202D are arranged in each of four directions, two access points (wireless LAN base stations) 200A and 200B, and a switch / combining / distributing circuit 201. In this example, the connector 203 and the coaxial cable 204 are connected via the connector.

  When such a planar antenna is used to spatially form the plurality of network groups, the switch / combining / distributing circuit 201 is controlled so that each of the two access points 200A and 200B has four planes. Each connection with the antennas 202A, 202B, 202C, 202D is switched.

  That is, in the plan view of FIG. 26, the communication coverage areas of these two access points 200A and 200B are indicated by circles. In FIG. 26, for example, the communicable cover area of the access point 200A is indicated by a hatched circle, and the communicable cover area of the access point 200B is indicated by a plain circle. Here, by the switch / combining / distributing circuit 201 described above, the access point 200A is connected to the planar antennas 202A and 202C facing in the vertical direction in the figure, while the access point 200B is planar antenna in the horizontal direction in the figure. It is connected to 202B and 202D.

  Therefore, when a plurality of independent network groups by access points are spatially formed (two groups in the example of FIG. 26) and each cover area is switched, by using such a planar antenna, Generation of dead zones such as dipole antennas can be prevented.

(Issues on the wireless LAN mobile station side)
When the circularly polarized antenna element is used on the wireless LAN base station side, the plane of polarization naturally turns. On the other hand, when a horizontal or vertical linearly polarized antenna element is used as an antenna element in a wireless LAN card for a terminal of a wireless LAN mobile station 9a, 9b, 9c, a circularly polarized antenna element is used. On the other hand, there is a problem that the received power is reduced by about 3dB. General wireless LAN The dipole antenna element used in the wireless LAN card for mobile station terminals is this linearly polarized antenna.

  Therefore, when the wireless LAN base station side uses a circularly polarized antenna element, the above problem of reduction in received power inevitably occurs. In addition, the dipole antenna element has a weak directivity, and there is also a problem that it is particularly susceptible to multipath fading in the upward direction from the terminal side antenna to the wireless LAN base station antenna.

  On the other hand, it is conceivable that the antenna element used in the wireless LAN card for the terminal of the wireless LAN mobile station is a circularly polarized antenna element, similar to the antenna element on the wireless LAN base station side. However, in this case, in the antenna composed of a single high-frequency line in the terminal wireless LAN card, the antenna element is either a right circularly polarized antenna element or a left circularly polarized antenna element. It is necessary to unify the circularly polarized antenna elements.

  In this way, when the mobile LAN terminal side is a single antenna element with either a right circular polarization or a left circular polarization, the wireless LAN in the same direction as the polarization plane turning direction of the circular polarization antenna on the mobile station terminal side is used. Reception is only possible at the location of the LAN base station antenna (circularly polarized antenna element). In other words, at the position of the circularly polarized antenna element (wireless LAN base station antenna) in the opposite direction, no reception is possible. For this reason, depending on the position of the wireless LAN mobile station terminal, a position where it can be received and a position where it cannot be inevitably created. In addition, depending on the attitude (direction and direction) of the circularly polarized antenna element on the mobile station terminal side, it is easy to perform cases where transmission / reception is possible at a high level and cases where it is not.

  In addition, there is no means to select the best antenna element as the transmitting / receiving antenna from the multiple antennas arranged in the wireless LAN base station from the mobile station terminal side, and the best base station side antenna element is selected from the mobile station terminal side. There was also a problem that it was difficult to do.

  Therefore, when the wireless LAN base station antenna uses a circularly polarized antenna element, high-speed communication is possible regardless of the communication environment of the wireless LAN mobile station for the problem of multipath fading that limits the communicable area. There was a need for improvements on the wireless LAN mobile station side.

(Issues on the wireless LAN base station side)
In the wireless LAN system, when a plurality of network groups are spatially formed, if a planar antenna having high directivity such as a strip-shaped high-frequency microstrip line shown in FIG. A wide communication area of the mobile station can be secured.

  However, as shown in FIG. 25, it is necessary to connect the planar antenna to the access point by the connector 203, the coaxial cable 204, and the like. For this reason, as the wiring amount of the connector 203 and the coaxial cable 204 increases, the cost greatly increases. As the communication area becomes larger, it cannot be said that the wireless LAN system is realistic.

  Therefore, in the wireless LAN system, when a plurality of network groups are spatially formed, even when a highly directional planar antenna such as a strip-shaped high-frequency microstrip line as shown in FIG. 25 is used. Therefore, there has been a demand for improvements on the wireless LAN base station side that can secure a wide communication area of the wireless LAN mobile station without greatly increasing the cost.

  The present invention has been made in consideration of the above circumstances, and its purpose is to solve the problems on the wireless LAN mobile station side and the wireless LAN base station side, and not limit the communicable area. We intend to provide LAN antennas, wireless LAN antenna control methods, wireless LAN base station antennas, wireless LAN mobile station terminal antennas, terminal wireless LAN cards, and wireless LAN systems.

In order to achieve the above object, the gist of the wireless LAN antenna of the present invention is that a wireless LAN antenna used in a wireless LAN system that transmits high frequency for a wireless LAN system between a wireless LAN base station and a wireless LAN mobile station. A high-frequency line having a high-frequency microstrip line structure in which a dielectric layer and a signal line are sequentially stacked on a ground layer, and a plurality of circularly polarized antenna elements arranged in the high-frequency line and having different turning directions. When the plurality of circularly polarized antenna elements having different turning directions are spaced apart and arranged on the high frequency line, the high frequency line is composed of a plurality of high frequency microstrip lines, and the circularly polarized antenna element is the Arranged at approximately the same position on each of a plurality of high-frequency microstrip lines, and these arranged circularly polarized antenna elements are respectively Times is that the direction of a different circularly polarized antenna elements.

Also, the gist of the wireless LAN antenna control method of the present invention is a wireless LAN antenna control method used in a wireless LAN system that transmits high frequency for a wireless LAN system between a wireless LAN base station and a wireless LAN mobile station. The wireless LAN antenna includes a high-frequency line having a high-frequency microstrip line structure in which a dielectric layer and a signal line are sequentially stacked on a ground layer, and a plurality of circular polarizations arranged in the high-frequency line and having different turning directions. The high-frequency line is composed of a plurality of high-frequency microstrip lines, and the circularly polarized antenna element is disposed at substantially the same position on each of the plurality of high-frequency microstrip lines. The circularly polarized antenna elements are circularly polarized antenna elements having different turning directions, and the plurality of circularly polarized antenna elements are transmitted and received. The communication state is controlled by switching the communication state.

  The gist of the antenna for a wireless LAN base station of the present invention is that the wireless LAN antenna is incorporated.

  The gist of the antenna for a wireless LAN mobile station terminal of the present invention is that the wireless LAN antenna is incorporated.

  The gist of the terminal wireless LAN card of the present invention is that the wireless LAN antenna is incorporated.

  Also, the gist of the wireless LAN system of the present invention is to form a wireless communication network with the antenna for the wireless LAN base station and / or the antenna for the wireless LAN mobile station in which the wireless LAN antenna is incorporated. .

  By using the wireless LAN antenna of the present invention for a wireless LAN base station and a wireless LAN mobile station terminal, even if there is a shielding object between the wireless LAN base station and the wireless LAN mobile station terminal, the three-dimensional When viewed as a simple space, circularly polarized antenna elements of the same orientation that can be seen from each other are always present in both the wireless LAN base station and the wireless LAN mobile station terminal.

  As a result, the problem on the wireless LAN mobile station side has been solved, and the wireless LAN base station and the wireless LAN mobile station terminal antenna are not affected by the position and orientation of the wireless LAN mobile station terminal antenna and the distance between the wireless LAN base station antenna and the wireless LAN mobile station terminal antenna. Wireless LAN mobile station terminals can perform high-speed communication without restricting the area where wireless LAN mobile stations can communicate.

  The wireless LAN antenna of the present invention is composed of a high-frequency microstrip line structure and circularly polarized antenna elements with different turning directions arranged on the line, and has a compact and simple configuration.

  As a result, by using the wireless LAN antenna of the present invention for a wireless LAN base station, the problems on the wireless LAN base station side are solved, and the wireless LAN system that spatially forms a plurality of network groups has a large cost. Without increasing, it is possible to secure a wide communication area for wireless LAN mobile stations without restricting the communicable area.

  In addition, the wireless LAN antenna of the present invention makes it possible to easily control the communication state by switching the transmission / reception state of a plurality of circularly polarized antenna elements in a wireless LAN system that spatially forms a plurality of network groups. .

  Further, by using the wireless LAN antenna of the present invention as a wireless LAN mobile station terminal antenna or a terminal wireless LAN card, these can be easily applied to a wireless LAN system.

  For this reason, the present invention is preferably applied to an indoor wireless LAN system in which the area forming the wireless communication network is indoor, but further, an arcade, a platform, a terminal, or a large structure or building, factory, High-speed communication is possible even when applied to venues.

  In addition, if the wireless LAN antenna of the present invention is further provided with a switch for electrically controlling transmission / reception of the antenna element, the best antenna as the transmission / reception antenna among the antennas on the mobile station terminal side and the wireless LAN base station side. There is also an advantage that it is easy to select and control.

Embodiments of the present invention will be described below with reference to the drawings.
(Solution of wireless LAN mobile station issues)
First, the wireless LAN antenna of the present invention is used for both a wireless LAN base station and a wireless LAN mobile station terminal to prevent multipath fading caused by the communication environment and the wireless LAN base station, and to Wireless LAN antennas, wireless LAN antenna control methods, wireless LAN base station antennas, wireless LAN antennas that enable high-speed communication without limiting the area in which wireless LAN mobile stations can communicate with LAN mobile station terminals The modes of the LAN mobile station antenna, terminal wireless LAN card, and wireless LAN system are described below.

(Prerequisite indoor wireless LAN system)
Figure 1 is a conceptual diagram showing a premise indoor wireless LAN system. FIG. 2 shows the presupposed high-frequency line for the wireless LAN base station, (a) is a perspective view of the high-frequency line 1a, and (b) is a cross-sectional view of the high-frequency line 1a. FIG. 3 is a perspective view showing a circularly polarized antenna for a wireless LAN base station as a premise. In the present invention, the specific configuration of the wireless LAN base station, excluding the wireless LAN mobile station terminal antenna, the specific configuration of the high frequency microstrip line and the circularly polarized antenna element of the wireless LAN base station, the wireless LAN mobile station itself The specific configuration is basically the same as the Japanese Patent Application No. 2002-312767.

  First, the configuration of the wireless LAN system as a premise of the present invention is as described above with reference to FIG. The wireless LAN system shown in Fig. 1 is assumed to be used indoors such as a normal office or office. In FIG. 1, a high-frequency line 1a constituting a wireless LAN base station antenna is provided, for example, along an indoor ceiling. The antenna for the wireless LAN base station is preferably located above the indoors (above the area) such as the ceiling in order to improve the visibility with the wireless LAN mobile station terminal antenna.

  One end of the high-frequency line 1a is a non-reflective termination, and a wireless LAN base station (also referred to as a wireless LAN master station or wireless LAN master unit) 11 is connected to the other end via a coaxial cable 12 or the like. It is connected. The wireless LAN base station is connected to a hub (HUB: a multiport repeater that connects terminals in a star shape: a LAN component that has signal regeneration and relay functions) 10 via an Ethernet cable 13 and further connected to an external network via a connection line 14. Connected to 15.

  On the other hand, a plurality of wireless LAN mobile stations (mobile station terminals such as personal computers) 9a, 9b, 9c communicating with the wireless LAN base station 11 are arranged indoors. Each of these mobile stations 9a, 9b, 9c communicates with the antenna 6 of the wireless LAN base station using an antenna element incorporated in the terminal wireless LAN card 5.

  Here, in the wireless LAN base station antenna, a plurality of circularly polarized antennas such as the patch antenna 6 are used according to the layout of the mobile stations 9a, 9b, and 9c so as to ensure good communication with each of these wireless LAN mobile stations. The elements are alternately arranged on the high-frequency line 1a at regular intervals. And in the wireless LAN base station antenna, in order to eliminate the influence of multipath fading due to high-frequency interference between adjacent patch antennas 6a, 6b, 6c, the turning directions of adjacent patch antennas are made different from each other. . That is, the patch antenna 6a is a clockwise clockwise circularly polarized antenna element, the adjacent patch antenna 6b is a counterclockwise left circularly polarized antenna element, and these circularly polarized antenna elements are alternately arranged. .

(Each component of the premise wireless LAN base station antenna)
Next, each component of the antenna for the wireless LAN base station which is the premise of the present invention is specifically shown in FIG. The following description will be made on a high-frequency microstrip line structure in which a dielectric layer and a signal line are sequentially stacked on a ground layer as a preferred mode of the high-frequency line constituting the antenna for the wireless LAN base station.

  As a high-frequency line that constitutes an antenna for wireless LAN base stations, there are other microwave transmission lines other than waveguides such as waveguides made of conductive metals such as stainless steel, steel, copper, and aluminum, and coaxial cables. Since the various properties such as thinness, flexibility and workability are inferior to those of the high-frequency microstrip line 1a as shown in FIG. 2 used in the present invention, they are not used in the present invention.

  In FIG. 2 (a), the high-frequency line 1a constituting the antenna for the wireless LAN base station has a long thin plate shape having a length necessary for the wireless LAN system in the area. In FIGS. 2 (a) and 2 (b), the structure in the cross-section (thickness) direction of the high-frequency line 1a is as follows: a ground layer 3 made of a conductor material, a dielectric layer 2 made of a dielectric material, and a high-frequency induction made of a conductor material. It has a high frequency microstrip line structure in which signal lines 4 are sequentially laminated in the order of description. The signal line 4 is disposed in the longitudinal direction of the high-frequency line 1a. Here, the high-frequency line 1a is flexible. Note that a known adhesive material such as a double-sided adhesive tape or an adhesive sheet or an adhesive layer may be provided on the bottom surface of the high-frequency line 1a to facilitate attachment / detachment and installation of the high-frequency line 1a.

(Specific configuration of antenna for wireless LAN base station)
Next, FIG. 3 shows a specific configuration of the antenna for the wireless LAN base station which is the premise of the present invention. In Fig. 3, the antenna element for the wireless LAN base station consists of a patch antenna. The basic structure of the patch antenna is configured, for example, by sequentially laminating a dielectric plate 8 made of a dielectric material and a patch (radiating plate) 7 made of a conductive material. These patch antennas are disposed on the signal line 4 of the high-frequency line 1a in FIG. 2 and are electrically coupled to the signal line 4.

  As the conductive material constituting the patch 7, the same metal material as the conductive material constituting the ground layer of the high-frequency line can be applied. As the dielectric material constituting the dielectric 8a, the same material as the low-loss resin dielectric material constituting the dielectric of the high-frequency line is selected.

  As a means for electrical coupling between the patch antenna and the signal line 4 of the high-frequency line 1a, any appropriate means can be adopted other than arranging the patch antenna on the signal line. For example, a patch antenna may be disposed beside the signal line 4 and a feeder line may be disposed for electrical coupling.

  With the configuration of the patch antenna, the antenna element can be easily attached to and detached from the high-frequency line. Therefore, even when the antenna layout of the wireless LAN system changes, such as a change in the office layout, if the entire area can be covered with the high frequency line of the present invention, basically, according to the new layout, It is only necessary to attach and remove the patch antenna, and there is no need to redo the installation work of the high-frequency line itself. Also, adjust the conditions such as the material and thickness of the radiating plate and dielectric on the side of the patch antenna, even when correction of the radio frequency to be used is required for the main characteristics such as the coupling degree and gain of the antenna element. The correction can be made easily by using a patch antenna adjusted to the conditions to be adapted.

(Circularly polarized antenna element)
In order to reduce the effects of multipath fading using the patch antenna as described above, the present invention assumes that the patch antenna on the wireless LAN base station side is a circularly polarized antenna element and is clockwise. A plurality of circularly polarized antenna elements having different turning directions, such as a right circularly polarized antenna element and a counterclockwise left circularly polarized antenna element, are alternately arranged at intervals.

  In order to give the patch antenna a turning direction as a circularly polarized antenna element, as shown in Fig. 3, the two opposite corners (corner portions) of the square (rectangular) patch 7 were dropped ( Notched) Shape 7a. In FIG. 3, the adjacent patch antenna 6a is a right-hand circularly polarized antenna element turning right, and the patch antenna 6b is a left-hand circularly polarized antenna element turning left. For this reason, as shown in FIG. 3, the patch antenna 6a, which is a right circularly polarized antenna element, drops two opposite corners on the upper left and lower right in the figure, and the patch antenna 6b, which is a left circularly polarized antenna element. Has dropped two opposite corners on the upper right and lower left of the figure.

  By changing the direction of notches at the two opposite corners of the patch 7, the antenna turning direction of the circularly polarized antenna element, that is, the right circularly polarized wave or the left circularly polarized wave, can be controlled. In addition, the planar shape of the patch (radiating plate) 7 and the antenna turning direction can be controlled by using a circularly polarized antenna element other than the rectangular shape shown in FIG. Any shape that can control the turning direction can be selected. As described above, the antenna in which the circularly polarized antenna elements are alternately arranged does not have a point where the electric field strength is extremely decreased between the antenna elements as compared with the normal horizontal and vertical polarized wave (linearly polarized wave) antenna element. There is also an advantage.

(Wireless LAN mobile station terminal antenna)
Based on the configuration of the wireless LAN base station antenna as described above, the embodiment of the wireless LAN mobile station terminal antenna of the present invention applied to an antenna such as a wireless LAN card for a terminal will be described below with reference to FIGS. explain.

  4 and 5 are perspective views showing respective embodiments of the wireless LAN mobile station terminal antenna of the present invention. FIG. 6 is a front view showing the wireless LAN system of the present invention to which the wireless LAN mobile station terminal antenna of the present invention is applied. FIG. 7 is a front view showing a preferred embodiment of the wireless LAN mobile station terminal antenna of the present invention. FIG. 8 is an explanatory view showing another preferred embodiment of the wireless LAN mobile station terminal antenna of the present invention. FIG. 9 is a perspective view showing another preferred embodiment of the wireless LAN mobile station terminal antenna of the present invention.

  First, the wireless LAN mobile station terminal antenna 10a of the present invention shown in FIG. 4 is characterized in that the high-frequency lines 1a and 1b arranged adjacent to each other in parallel with each other and circularly polarized waves arranged on the high-frequency lines at intervals. It is basically composed of a plurality of patch antennas 6a and 6b which are wave antenna elements. As described above, since the plurality of patch antennas 6a and 6b are arranged in the wireless LAN mobile station terminal antenna 10a, a high level reception (base station) is possible regardless of the position, location, or movement of the mobile station terminal. From the antenna). In the mobile station terminal antenna of the present invention, at least two high-frequency lines arranged adjacent to each other in parallel are required. However, the use of two high-frequency lines suppresses multipath fading and suppresses transmission / reception power reduction due to the position of the mobile station terminal antenna. It is not necessary to increase the number of high-frequency lines by three or more.

  The high frequency lines 1a and 1b of the mobile station terminal antenna 10a have a line structure in which a dielectric layer 2 and a signal line 4 are sequentially laminated on a ground layer 3. The high frequency lines 1a and 1b of these mobile station terminal antennas have basically the same configuration as the high frequency line 1a of the wireless LAN base station described in FIG.

  In addition, the patch antennas 6a and 6b, which are circularly polarized antenna elements of the mobile station terminal antenna, are also formed by sequentially laminating a dielectric plate 8 made of a dielectric material and a patch (radiating plate) 7 made of a conductive material. The configuration is the same as that of the patch antennas 6a and 6b of the wireless LAN base station described in 3. Each of these patch antennas is disposed on the signal line 4 of the high-frequency lines 1a and 1b and is electrically coupled to the signal line 4. In addition, the selection of the planar shape of the patch (radiating plate) 7 as a circularly polarized antenna element of this patch antenna and the control method of the antenna turning direction (corner notch, etc.) are also described in FIG. This is the same as the patch antennas 6a and 6b of the wireless LAN base station.

  The wireless LAN mobile station terminal antenna 10a of the present invention shown in FIG. 4 is more characteristically characterized by a patch antenna that is a circularly polarized antenna element having different turning directions at substantially the same position of the two high-frequency lines 1a and 1b. 6a and 6b are arranged adjacent to each other. Therefore, when viewed from one high-frequency line of the same high-frequency line 1a or 1b, the circularly polarized waves of different turning directions of the right-handed circularly polarized antenna element 6a and the left-handed circularly polarized antenna element 6b The antenna elements are alternately arranged at intervals.

  In FIG. 4, among the patch antennas adjacent to each other, 6a is a right-hand circularly polarized antenna element turning right, and 6b is a left-hand circularly polarized antenna element turning left. Then, in order to obtain either one of the left and right circularly polarized antenna elements, two opposite corners (corner corners) of the square (rectangular) patch 7 are connected to the patch antenna 6a of the wireless LAN base station in FIG. Like 6b, it has a cut-out shape.

  FIG. 5 shows a modified example. The mobile station terminal antenna 10b of the present invention shown in FIG. 5 is different from the mobile station terminal antenna 10a of the present invention shown in FIG. The circularly polarized swirl directions of the patch antennas 6a and 6b at the same positions as in FIG. 4 between 1a and 1b are simply different.

(Application example of wireless LAN mobile station terminal antenna to wireless LAN card for terminal and wireless LAN system)
FIG. 6 shows an example in which the wireless LAN mobile station terminal antenna 10a of the present invention shown in FIG. 4 is applied to an antenna such as a terminal wireless LAN card or a wireless LAN system. In FIG. 6, the configuration on the wireless LAN base station 11 side is the same as in FIG. FIG. 6 shows a state where a shielding object 18 that shields the line of sight exists between the wireless LAN base station antennas 6a and 6b and the wireless LAN mobile station terminal antennas 6a and 6b.

In the present invention, a plurality of circularly polarized antenna elements having different antenna turning directions exist in both the wireless LAN base station and the wireless LAN mobile station terminal. For this reason, when viewed as a three-dimensional space, even if the shield 18 is present, circularly polarized antenna elements in the same direction that can be seen from each other are both wireless LAN base stations and wireless LAN mobile station terminals. It will always exist. As a result, it is possible to obtain the effect of suppressing the transmission / reception power due to the multipath fading suppression and the position of the mobile station terminal antenna.
In the case of FIG. 6, the wireless LAN base station side antenna element 6b (left turn) and the wireless LAN mobile station terminal can be seen through the space 18a that is not shielded by the wireless LAN base station antenna shield 18. This is an antenna element 6b (antenna element surrounded by a dotted line in the center of the figure) on the high-frequency line 1a of the side antenna 10a. That is, in the mobile station terminal antenna 10a of FIG. 6, the antenna element 6b (left turn) surrounded by the dotted line in the center of the above figure has the highest received power. In FIG. 6, the directions of the left and right antenna element rotations are different depending on the viewing direction, and are described as viewed from the same direction.

  In FIG. 6, 16 is a diversity circuit, 17 is a radio transmission / reception circuit connected to 16, and the diversity circuit 16 is installed between the high-frequency lines 1a and 1b and is constituted by an electric circuit. Diversity circuit 16 switches (selects) radio transmission / reception to the high-frequency line 1a or 1b circuit so that the patch antenna having the highest received power can be selected in the wireless LAN mobile station terminal antenna 10a. Play a role. These mechanisms and functions are incorporated in the terminal wireless LAN card 5 of the wireless LAN mobile station shown in FIG.

(Circularly polarized antenna element transmission / reception control switch)
A more specific aspect of the switch for electrically controlling transmission / reception of the circularly polarized antenna element will be described with reference to FIG. In FIG. 7, 16 is a diversity circuit, 17 is a radio transmission / reception circuit connected to 16, 23 is an antenna element switching circuit, and 24 is an antenna control circuit. The antenna element switching circuit 23 is connected by a control line 22 to antenna switches 21a and 21b provided in the wireless LAN mobile station terminal antenna elements 6a and 6b on the high-frequency lines 1a and 1b, respectively. These constitute the switch of the circularly polarized antenna element.

  Now, when an electric signal is applied, the antenna switches 21a and 21b are turned on and turned on, and the circularly polarized antenna elements 6a and 6b on the antenna switch operate. On the other hand, when the electric signal is turned off, the circularly polarized antenna elements 6a and 6b do not operate. The antenna control circuit 24 switches the antenna switches 21a and 21b in order, sends data from the mobile station terminal antenna side to the base station side, evaluates the communication quality between them, and minimizes the frequency of occurrence of communication errors. It has a role to control the polarization antenna element to operate.

  Thus, in uplink communication from the mobile station terminal antenna side to the base station side, the transmission power on the mobile station terminal antenna side can be concentrated on the optimum antenna element of the mobile station terminal. Further, in the downlink communication from the base station side to the mobile station terminal antenna side, there is an effect that the received power on the mobile station terminal antenna side can be concentrated on the optimum antenna element of the mobile station terminal. That is, there is an advantage that a mobile station terminal antenna element that maximizes transmission / reception power can be selected at any time.

(Application example to large buildings such as factories)
The application example of the present invention to a normal indoor wireless LAN system has been described above. Next, an application example of the present invention to a large building such as a factory will be described. Assume that the wireless LAN mobile station antenna or wireless LAN system of the present invention is applied to a large building area such as a steel mill rolling mill or machining factory as shown in a perspective view in FIG. In that case, there are three major issues:

(1) The factory 30 has a large number of metal structures (ceilings, walls, manufacturing equipment such as a rolling mill 31, various machines, etc.) that easily reflect radio waves. For this reason, when wireless communication is performed using a wireless LAN system through a base station antenna placed on the ceiling in the factory 30, not only direct waves but also waves that arrive via various propagation paths from the transmission point to the reception point. Some multipath is likely to occur. For this reason, the signal level that can be received by the base station antenna and the mobile station terminal antenna is greatly reduced, and multipath components are increased, so that the received S / N is reduced and high-speed communication becomes difficult. Although this problem also occurs in the above-described ordinary indoor wireless LAN system, it becomes a more significant problem in the factory 30 due to the large number of metal structures.

(2) In the factory 30, there are many large structures 32, there are also overhangs with a medium height, and the line of sight between the antennas is shielded by the movement of equipment such as overhead cranes. In many cases, it is difficult to get a view from the base station antenna. For this reason, depending on the position of the wireless LAN mobile station terminal, a position where it can be received and a position where it cannot be inevitably created. Although this problem also occurs in the above-described normal indoor wireless LAN system, the mobile station moves within the factory 30, and the change in the position of the mobile station terminal is large.

(3) Assuming that workers in operation or maintenance work in the factory 30 while carrying out wireless communication with a mobile terminal to utilize the wireless LAN system, the terminal antenna is worn by the worker. It is preferable that it is movable (wearable). However, in this case, the attitude (direction and direction) of the circularly polarized antenna on the mobile station terminal side changes depending on the attitude of the worker who moves or moves. Also in such a case, it becomes easy to perform the case where transmission / reception can be performed at a high level and the case where it cannot. Although the problem of this attitude also occurs in the above-described normal indoor wireless LAN system, the movement of the mobile station or the change of the position of the mobile station terminal in the factory 30 is three-dimensionally associated with the work in the factory. It can be said that this problem is unique to large buildings.

Hereinafter, means for solving these problems will be described in order.
As for the problem (1) above, the antenna elements of the clockwise circular polarization and the counterclockwise circular polarization are different from the arrangement of the antenna of the wireless LAN base station above the building, for example, on the ceiling, and the turning direction. This can be solved by using high-frequency lines arranged alternately. These are also described in the aforementioned Japanese Patent Application No. 2002-312767 and are the premise of the present invention. In other words, by placing the wireless LAN base station antenna above the building, it becomes possible to see the wireless LAN mobile station terminal antenna moving in the factory, and the signal component due to direct waves increases. In addition, the antenna on the wireless LAN base station side is not a linearly polarized antenna element, but a circularly polarized antenna element that propagates by turning to the left or right, so that the high-frequency wave that is reflected once by a metal wall such as a structure. Therefore, even if there are many structures that reflect high frequencies, the number of reflected waves entering the wireless LAN mobile station terminal antenna is reduced and the effects of multipath fading can be reduced.

  As for the problem (2) above, as in the present invention, the wireless LAN mobile station terminal antenna has a structure in which the high-frequency microstrip lines having the above structure are arranged substantially parallel to each other and adjacent to each other. A plurality of circularly polarized antenna elements having different turning directions are arranged alternately and spaced apart from each other on each high-frequency microstrip line, and circular polarizations having different turning directions are arranged at substantially the same position between these high-frequency microstrip lines. This can be solved by arranging the wave antenna elements adjacent to each other. That is, as described in FIG. 6 above, a plurality of circularly polarized antenna elements having different antenna turning directions between the antenna of the wireless LAN mobile station terminal and the wireless LAN base station in the present invention are connected to the wireless LAN base station and the wireless LAN base station. It exists in both LAN mobile station terminals. For this reason, when viewed as a three-dimensional space, even if the shield 18 is present, circularly polarized antenna elements in the same direction that can be seen from each other are both wireless LAN base stations and wireless LAN mobile station terminals. It will always exist.

  Then, the wireless LAN base station transmits the wireless signal transmitted to the wireless LAN base station or the wireless signal transmitted to the wireless LAN base station by, for example, switching a switch for electrically controlling transmission / reception of the circularly polarized antenna element described in FIGS. The mobile station terminal antenna element having a high transmission / reception signal level (transmission / reception power) is selected. The circularly polarized antenna element is provided with a plurality of installation locations on the base station side and the mobile station terminal side. Therefore, as long as a line of sight can be secured between at least one antenna element on each of the base station side and the mobile station terminal side, it is not affected by the location (position) of the mobile station terminal, and no matter where the mobile station terminal is. Communication at a high level is possible.

  Further, an embodiment for solving the above problem (3) will be described. FIG. 8 shows an example in which the mobile station terminal antenna of the present invention is built in a worker's helmet. FIG. 8 (a) shows a state in which the mobile station terminal antenna 10a of the present invention is built in the helmet 18 of the 19 heads of the worker. FIG. 8B shows the mobile station terminal antenna 10 a built in the helmet 18. In FIG. 8 (b), the mobile station terminal antenna 10a (high-frequency lines 1a, 1b) in FIGS. 4 and 5 described above is provided on the inner periphery of the 10 helmet 18 so as to be built in the helmet 18 in FIG. It is wound in a circular shape along. The structure of the mobile station terminal antenna 10a, that is, patch antennas 6a and 6b, which are circularly polarized antenna elements having different turning directions, are arranged adjacent to each other at substantially the same position between the two high-frequency lines 1a and 1b. The structure thus configured is the same as that shown in FIGS. Note that when viewed with the same high-frequency line 1a or 1b, the right-hand circularly polarized antenna elements 6a and the left-circularly polarized antenna elements 6b that are turned rightward are alternately arranged as shown in FIGS. It is the same.

  Although not shown in FIG. 8, the mobile station terminal antenna 10a has a switch switching device such as a diversity circuit 16 as in FIG. It is also possible to place a terminal device for operating the mobile station terminal antenna 10a in a body place that is easy to operate when necessary, such as placing it in a pocket of work clothes or at hand.

  As shown in FIGS. 8 (a) and 8 (b), by winding the mobile station terminal antenna 10a (high frequency line) of the present invention in a circular shape, circularly polarized antenna elements 6a in the high frequency lines 1a and 1b, 6b are arranged in different normal directions. For this reason, even if the attitude (direction and direction) of the mobile station terminal side circularly polarized antenna changes depending on the attitude of the worker who is working or moving, the mobile station terminal side antenna element that can be seen from the wireless LAN base station side antenna is always Exists. For this reason, even when the attitude of the mobile station terminal antenna changes, transmission and reception can be performed at a high level.

  In addition, in the case of such a helmet built-in type, it is not necessary for the worker to hold the mobile station terminal antenna in his / her hand, so that the worker can easily perform the original work, and the safety in the work is ensured. There is convenience.

  Further, FIG. 9 is a perspective view showing another embodiment of the mobile station terminal antenna of the present invention for solving the above-mentioned problem (3). FIG. 9 assumes a case where, for example, production management data is exchanged with a wireless LAN base station antenna in a mobile vehicle having a relatively large structure such as a cart or a transport vehicle. In FIG. 9, 20 is a mobile vehicle, and the mobile station terminal antenna 10a (high-frequency lines 1a, 1b) of the present invention is wound around the side surface of the mobile vehicle 20, for example, twice, like the helmet of the worker in FIG. Has been.

  As a result, similarly to FIG. 8 (b), the circularly polarized antenna elements 6a and 6b in the high-frequency lines 1a and 1b are arranged in different normal directions. For this reason, even if the attitude of the circularly polarized antenna on the mobile station terminal side changes depending on the attitude of the mobile vehicle 20 that is working or moving, the mobile station terminal side antenna element that can be seen from the wireless LAN base station antenna is always the mobile vehicle 20 antenna. Present on either side. For this reason, even when the attitude of the antenna of the mobile vehicle 20 changes, transmission and reception can be performed at a high level.

  The mobile station terminal antenna 10a may be arranged on the top of the mobile vehicle 20. However, in many cases, it is necessary to secure the top of the mobile vehicle 20 for a work table or for carrying goods. Are arranged around the side surface of the moving vehicle 20 so as not to get in the way. Also, although not shown in FIG. 9, the mobile station terminal antenna 10a has a switch switching device such as the diversity circuit 16 as in FIG.

(Specific structure of high-frequency microstrip line)
Here, the description of the embodiments of the respective layers constituting the high frequency microstrip line 1a of the wireless LAN base station, the high frequency microstrip lines 1a and 1b of the mobile station terminal antenna 10a, the patch antenna, etc., as described above. Do the following:

  First, the dielectric layer 2 of each high-frequency line in FIGS. 2 to 5 does not have a ground layer on the surface of the dielectric layer 2 on the signal line 4 side. Conditions that do not occur are appropriately selected. In general, high-frequency loss from a high-frequency line is roughly classified into radiation loss, conductor loss, and dielectric loss. Among these, in order to reduce the radiation loss, it is preferable to increase the dielectric constant of the dielectric layer 2. This dielectric constant is determined from the dielectric constant of the dielectric material itself constituting the dielectric layer 2 and the thickness of the dielectric layer 2. For this reason, it is preferable to select the thickness of the dielectric material and the dielectric layer so as to increase the dielectric constant. However, as the thickness of the material having a high dielectric constant or the dielectric layer increases, the flexibility is lost. Therefore, when flexibility is required, the optimum material and the thickness of the dielectric layer should be determined in consideration of this. select.

  Further, since the conductor loss becomes smaller as the electric conductivity of the signal line 4 becomes higher, it is preferable to determine the optimum electric conductivity of the signal line 4 from the electric conductivity necessary for the high-frequency line. Furthermore, since the dielectric loss is determined by the dielectric material itself constituting the dielectric layer 2, it is preferable to select a low dielectric loss material. However, the width and thickness of the dielectric layer 2 are required to have a certain width and thickness depending on the relationship between the frequency of the signal required for the wireless LAN system and the loss of high frequency. In this regard, for example, on the basis of a standard indoor wireless LAN system such as an office, it is preferable that the thickness is 0.1 to 2.0 mm and the width is about 10 to 50 mm.

  Accordingly, as the dielectric material for the dielectric layer 2, it is preferable to select a material that does not cause high-frequency radiation loss and has a low dielectric loss on the premise of the width and thickness of the dielectric layer 2 selected from the above-described preferred range. The dielectric material itself can be selected from resin dielectric materials such as Teflon (registered trademark), polyimide, polyethylene, polystyrene, polycarbonate, vinyl, and mylar. It is preferable to select and use as a composition or a mixture of a plurality of these. These resin dielectric materials can maintain desired flexibility required for a high-frequency line by setting conditions such as composition.

  The overall thickness of the high-frequency line is preferably as thin as 2 mm or less for the purpose of reducing the cross-sectional area and volume of the high-frequency line. Therefore, the thickness of the ground layer 3 and the signal line 4 is preferably as thin as possible for this purpose. The thickness of the ground layer 3 is preferably 0.2 mm or less as long as the required thin plate strength can be ensured. The width of the ground layer 3 corresponds to the width of the dielectric layer 2 so as to cover the dielectric layer 2 and suppress high-frequency loss.

  The conductive material constituting the ground layer 3 includes various metals, alloys such as copper, aluminum, tin, gold, nickel, and solder, and various kinds of these metals and alloys plated on composite, laminated, or resin substrates. The aspect is appropriately selected as the highly conductive metal material. Among these, a metal material which can be easily processed into a thin plate, has a flexibility corresponding to the dielectric material, and further has a required thin plate strength is preferable.

  As the signal line 4 for high frequency induction, a fine wire or a thin plate of the above-mentioned highly conductive metal material is selected. The signal line 4 may be projected or placed on the dielectric layer 2 as shown in the high-frequency line 1a of FIG. 2, or embedded in the dielectric layer 2 in the longitudinal direction of the high-frequency line 1a. It may be arranged.

  The high-frequency microstrip line having the above configuration is thin and flexible, so that it is not only a long plate shape, but also a long coil shape wound around the high-frequency line. Easy to handle. Moreover, it has excellent basic characteristics as a high-frequency line, such as low-loss propagation of high-frequency waves. Therefore, by using the high-frequency line having such a structure, the wiring is easier and the degree of freedom of wiring is increased and the cost is increased as the amount of wiring is increased as compared with the case where the above-described connector or coaxial cable is used. Does not increase significantly.

(Solution of wireless LAN base station issues)
Next, by using the wireless LAN antenna of the present invention particularly in the wireless LAN base station, the wireless LAN system that spatially forms a plurality of network groups does not significantly increase the cost and does not limit the communicable area. , Wireless LAN antenna that can secure a wide communication area of wireless LAN mobile station, wireless LAN antenna control method, wireless LAN base station antenna, wireless LAN mobile station terminal antenna, terminal wireless LAN card and wireless LAN system aspects, This will be described below.

(Wireless LAN system that forms multiple network groups)
FIG. 11 is a block diagram showing a system on the wireless LAN base station side that spatially forms a plurality of network groups. FIG. 12 is a structural diagram showing an antenna structure that embodies the wireless LAN base station system of FIG. FIG. 13 is a perspective view of the wireless LAN base station side in which the antenna structure of FIG. 12 is assembled.

  In FIG. 11, two access points (wireless LAN base stations) 101A and 101B are not connected to the conventional connector 203 and coaxial cable 204 in FIG. The four antenna elements 103A, 103B, 103C, and 103D are connected by the high-frequency line 104 having the same structure as the microstrip line 1a.

  In FIG. 12, the four antenna elements 103A, 103B, 103C, 103D of the wireless LAN base station are patch antennas having the same structure as the patch antenna shown in FIG. However, these patch antennas 103A, 103B, 103C, and 103D are arranged on the signal line 4 of the high-frequency line 104 on the end side of the high-frequency line 104 (the left-side end side in the figure). Electrically coupled.

  In FIG. 11, a portion 102 surrounded by a circle is a switch / combining / distributing circuit (same as the antenna element switching circuit 23 in FIG. 7), and 105 connected thereto is a control circuit for the switch / combining / distributing circuit 102 (in FIG. 7). Same as the antenna control circuit 24).

  In FIG. 13 showing the wireless LAN base station side in which these are assembled, two access points (wireless LAN base stations) 101A and 101B are connected to the high-frequency line 104 by a high-frequency line 104 via a switch / combining distribution circuit 102. It is connected to four antenna elements 103A, 103B, 103C, and 103D arranged at the tip. Here, the four antenna elements 103A, 103B, 103C, and 103D each face four directions (front and rear, right and left directions in the figure), and secure a wide communication area toward the four surrounding directions.

  In such a configuration, signals from the two access points 101A and 101B are selected and controlled by the switch / combining / distributing circuit 102 from which antenna element 103A, 103B, 103C, and 103D. Then, the signal is transmitted by the high-frequency line 104 and radiated in four directions from the four antenna elements 103A, 103B, 103C, and 103D arranged at the tip of the high-frequency line 104. Therefore, wireless LAN base station arrangements that can transmit and receive wireless LAN signals in four directions can be freely configured.

  As a result, a dead zone on the wireless LAN mobile station side can be prevented, a wide communication area can be secured, and a plurality of network groups can be formed spatially. Further, since the conventional connector 203 and coaxial cable 204 in FIG. 25 are not used, the cost does not increase greatly as the amount of wiring increases, and a realistic wireless LAN system can be provided even if the communication area is large. .

  At this time, the switch / combining / distributing circuit 102 controls the communication state by switching the transmission / reception state of a plurality of circularly polarized antenna elements having different turning directions arranged in the high-frequency line, so that the wireless LAN base station and the wireless Wireless LAN system high-frequency can be transmitted to and from LAN mobile stations at higher speeds, wider communication areas, and multiple independent network groups that can be spatially formed.

  Further, the above-described effects can be further improved by switching the transmission / reception states of the plurality of circularly polarized antenna elements in a set of at least a pair of circularly polarized antenna elements having different turning directions.

(Double-sided antenna)
However, the directivity of these antenna elements 103A to 103D arranged on one side of the high-frequency line 104 is about ± 45 °, and there is almost no directivity to the back surface of the antenna element. On the other hand, if antenna elements are arranged on both sides of the high-frequency line 104, directivity is provided on both sides of the high-frequency line 104 compared to an antenna element arranged on one side (hereinafter also referred to as a single-sided antenna). An antenna can be formed, and a more efficient antenna can be configured.

(Double-sided antenna structure)
A specific structure of a double-sided antenna in which antenna elements are arranged on both sides of the high-frequency line will be described with reference to FIGS. 14 is a cross-sectional view of a double-sided antenna, FIG. 15 is a perspective view of the double-sided antenna of FIG. 14, and FIG. 16 is a perspective view showing another aspect of the double-sided antenna.

  In FIG. 14, 1a and 1a are two high-frequency microstrip lines, 105 and 105 are line terminators of lines 1a and 1a, 103A1 and 103A2 are antenna elements of lines 1a and 1a, and 6a and 6b are antenna elements. Each of the patch antennas 103A1 and 103A2.

  As shown in FIGS. 15 and 16, the double-sided antenna structure has a structure in which the single-sided antenna shown in FIG. 3 is bonded back to back with two antenna elements facing each other and the antenna elements facing outward. More specifically, the two high-frequency microstrip lines shown in FIG. 3 and the ground layer 3 (shown in FIG. 15) are used in common, and the positions of the antenna elements 103 on the lines are substantially the same. They are pasted together.

  In FIG. 15, the structure in the cross-section (thickness) direction of each high-frequency line 1a is the same as in FIG. 2, and a ground layer 3 made of a conductor material is connected to a dielectric layer 2 made of a dielectric material and a high-frequency induction made of a conductor material. Signal line 4. Further, the antenna elements 103A1 and 103A2 are also composed of patch antennas 6a and 6b having the same structure as the patch antenna shown in FIG. 12 or FIG. That is, a dielectric plate 8 made of a dielectric material and a patch (radiating plate) 7 made of a conductive material are sequentially laminated. Each of these patch antennas is disposed on the signal line 4 and is electrically coupled to the signal line 4.

  The basic structure of the antenna and patch antennas 6a and 6b shown in FIG. 16 is the same as that shown in FIG. However, in order to have a turning direction as a circularly polarized antenna element, similarly to the patch antenna shown in FIG. 3, a rectangular (rectangular) patch 7 has a shape 7a in which two opposite corners are dropped. . In FIG. 16, the patch antennas 6a and 6b on both sides are left-handed left circularly polarized antenna elements.

  When such a double-sided antenna is used, signals from the same or different wireless LAN access points (for example, 101A and 101B) can be transmitted to the high-frequency lines 1a and 1a bonded together. Also, it is smaller than the single-sided antenna shown in FIGS. 4 to 10 and the single-sided antenna shown in FIGS. 11 to 13, and the antenna element on the wireless LAN base station side or wireless LAN mobile station terminal side is reduced. There is also an advantage that it can be made compact.

  As described above, the antenna in which the circularly polarized antenna elements are alternately arranged does not have a point where the electric field strength is extremely decreased between the antenna elements as compared with the normal horizontal and vertical polarized wave (linearly polarized wave) antenna element. There is also an advantage.

(Usage of double-sided antenna)
The perspective view of FIGS. 17 and 18 exemplifies the mode on the wireless LAN base station side using these double-sided antennas. In addition, the perspective views of FIGS. 19 and 20 illustrate patterns of radio waves radiated from the wireless LAN base stations of FIGS.

  17 and 18, the high-frequency line 104 connected to the two access points (wireless LAN base stations) 101A and 101B is branched in directions different from each other by 180 ° to the left and right in the figure. Then, for each branched high-frequency line 104, two antenna elements 103A1 and 103A2, 103B1 and 103B2 arranged at intervals, and in FIG. 15, 103C1 and 103C2 and 103D1 and 103D2 Are arranged on both sides.

  Here, each antenna element 103A, 103B, 103C, 103D spreads in the left-right direction in the figure depending on the length of each branched high-frequency line 104, and in both directions (front-rear direction in the figure) of each high-frequency line 104 A wider communication area is secured.

  In such a configuration, signals from the two access points 101A and 101B are selected and controlled by the switch / combining / distributing circuit 102 from which antenna element 103A, 103B, 103C, and 103D. Then, the signals are transmitted by the branched high-frequency lines 104 and arranged on both surfaces of the high-frequency lines 104 as shown in perspective views in FIGS. 19 (a) and 19 (b) and FIGS. 20 (a) and 20 (b). Radiation is radiated from the four antenna elements 103A, 103B, 103C, and 103D in the horizontal direction to the front-rear direction in the figure.

  19 (a), 19 (b) and 20 (a), 20 (b) are communicated by the switch / combining / distributing circuit 102 using the two base stations (access points 101A, 101B) in FIGS. The state of the radiation signal when the area is switched is shown. If both base stations transmit in the same direction, they can be operated as one and the same network group. When two base stations are transmitted separately in directions different from each other by 180 °, they can be operated separately in two separate network groups.

  In FIGS. 19 (a) and 19 (b) and FIGS. 20 (a) and 20 (b), the concentric waves shown by solid lines are, for example, radiation signals from the access points 101A and 101B, and the concentric circles shown by dotted lines For example, the wave that spreads out is an emission signal from the access point 101B.

  FIG. 19 (a) and FIG. 20 (a) show that when the access points 101A and 101B are the same network group (constitute one group), FIG. 19 (b) and FIG. The case where the network group by the point 101A and the network group by the access point 101B are separated into two groups is shown.

  When Fig. 21 (a) is composed of one group (the same group) in Fig. 19 (a) and Fig. 20 (a) above, Fig. 21 (b) is the same as 2 in Fig. 19 (b) and Fig. 20 (b). Shows the radio wave pattern of the radiated signal from each access point when configuring a group (another group). When configuring one group (same group) in FIG. 19 (a) and FIG. 20 (a) above, as shown in FIG. 21 (a), the wireless LAN movement with the access points 101A and 101B as the same network group A station can communicate on both sides of the high-frequency line 104.

  Further, when two groups (another group) in FIG. 19 (b) and FIG. 20 (b) are configured, as shown in FIG. 21 (b), each access point is provided on each side of the high-frequency line 104. Only wireless LAN mobile stations (No1 group or No2 group) in the same network group as 101A or 101B can communicate.

  Therefore, as described above, when a double-sided antenna is used, a signal from the same or different wireless LAN access point can be transmitted to each of the bonded high-frequency lines 1a and 1a. As a result, the antenna of the present invention can freely select from which antenna element 103A, 103B, 103C, 103D the radiated signal from the access points 101A, 101B is transmitted / received. In addition, wireless LAN base station arrangements that can transmit and receive wireless LAN signals and wireless LAN network groups centered on specific wireless LAN base stations can be formed more freely.

  Such a double-sided antenna may be used as an antenna element in FIG. 1 for both a wireless LAN base station and a wireless LAN mobile station terminal to prevent multipath fading caused by the communication environment and the wireless LAN base station. . In addition, by applying to the wireless LAN system of FIG. 6, it is possible to obtain an effect of suppressing transmission / reception power reduction due to the position of the mobile station terminal antenna. Note that such a double-sided antenna can be applied to the wireless LAN mobile station card 5 of the wireless LAN mobile station in FIG. 1 or the wireless LAN system in FIG. 6 by replacing the antenna with a double-sided antenna. It is.

(Antenna element material)
The material of the antenna element and the high-frequency line used in the present invention has been described above. Hereinafter, a preferred mode when a plurality of network groups are spatially formed by a wireless LAN antenna will be described with reference to the drawings. FIG. 22 is a cross-sectional view in the cross-section (thickness) direction of the single-sided antenna of the present invention, and FIG. 23 is a cross-sectional view in the cross-section (thickness) direction of the double-sided antenna of the present invention.

  In FIG. 22, from the bottom of the laminated structure, the ground layer 3 made of a conductor material is a copper foil, and the dielectric layer 2 made of a dielectric material is a laminate of a Teflon (registered trademark) sheet and a glass cloth impregnated with a fluororesin, a conductor The signal line 4 made of material is made of copper foil and constitutes a high-frequency microstrip line (high-frequency line) 1a.

  In antenna element 6 (103) in FIG. 22, dielectric plate 8 made of a dielectric material is a Teflon (registered trademark) sheet, patch (radiation plate) 7 made of a conductive material is made of copper foil, and is selectively provided. The upper cover 105 is made of a Teflon (registered trademark) sheet.

  23 has a structure in which the two high-frequency microstrip lines (high-frequency lines) 1a of FIG. 22 are bonded back to back with the ground layer 3 in common and the antenna elements 6 (103) facing each other outward. is doing. The positions of the antenna elements 103 on the line 1a are substantially the same.

  As described above, according to the present invention, the wireless LAN mobile station communication area limitation problem due to multipath fading and the wireless LAN mobile station communication area limitation problem on the wireless LAN base station side can be solved, and wireless LAN mobile station communication is possible. Wireless LAN antennas, wireless LAN antenna control methods, wireless LAN base station antennas, wireless LAN mobile station terminal antennas, terminal wireless LAN cards, and wireless LAN systems can be provided. . Therefore, since the big restrictions of the conventional wireless LAN system can be eliminated, the industrial value of the wireless LAN system can be greatly expanded.

1 is a front view showing one embodiment of a wireless LAN system as a premise of the present invention. FIG. 2 (a) is a perspective view and FIG. 2 (b) is a cross-sectional view showing one embodiment of a base station high-frequency line as a premise of the present invention. It is a perspective view which shows one embodiment of the base station antenna used as the premise of this invention. FIG. 3 is a perspective view showing one embodiment of the mobile station terminal antenna of the present invention. It is a perspective view which shows the other embodiment of the mobile station terminal antenna of this invention. 1 is a front view showing one embodiment of a wireless LAN system using a mobile station terminal antenna of the present invention. It is a front view which shows the other embodiment of the mobile station terminal antenna of this invention. It is a front view which shows the other embodiment of the mobile station terminal antenna of this invention. It is a front view which shows the other embodiment of the mobile station terminal antenna of this invention. FIG. 2 is an explanatory diagram showing an example in which the wireless LAN system of the present invention is applied to a factory building. It is a block diagram which shows the embodiment of this invention wireless LAN antenna. FIG. 12 is a structural diagram of the wireless LAN antenna of FIG. 11. It is a perspective view which shows the aspect which assembled the antenna structure of FIG. It is sectional drawing which shows the aspect of the double-sided antenna of this invention wireless LAN antenna. It is a perspective view of the double-sided antenna of FIG. It is a perspective view which shows another aspect of a double-sided antenna. It is a perspective view which shows the mode by the side of the wireless LAN base station using a double-sided antenna. It is a perspective view which shows another mode by the side of the wireless LAN base station using a double-sided antenna. FIG. 18 is a perspective view illustrating an example of patterns of radio waves radiated from the wireless LAN base station of FIG. 17. FIG. 19 is a perspective view showing patterns of radio waves radiated from the wireless LAN base station of FIG. 18. It is a top view which shows the pattern of the electromagnetic wave of FIG. It is sectional drawing which shows the single-sided type antenna of this invention wireless LAN antenna. It is sectional drawing which shows the double-sided type antenna of this invention wireless LAN antenna. It is a perspective view which shows the aspect of the wireless LAN system which forms the some conventional network group. FIG. 10 is a perspective view showing another conventional wireless LAN system forming a plurality of network groups. It is a top view which shows the cover area which can communicate of the wireless LAN system of FIG.

Explanation of symbols

1: high frequency line (microstrip line), 2: dielectric layer, 3: ground layer, 4: signal line, 5: wireless LAN card for terminal, 6: patch antenna, 7: patch, 88: dielectric layer, 9 : Mobile station terminal, 10: HUB, 11: Base station, 12: Coaxial cable,
13: Ether cable, 14: Connection line, 15: Network,
16: Diversity circuit, 17: Radio transceiver circuit, 18: Helmet, 19: Worker, 20: Mobile vehicle, 21: Antenna switch, 22: Control line,
23: Antenna element switching circuit, 24: Antenna control circuit, 30: Building,
31: Rolling mill (row), 32: Structure
101: Access point, 102: Switch / synthesis distribution circuit, 103: Antenna element,
104: High-frequency line, 105: Terminator

Claims (16)

A wireless LAN antenna used in a wireless LAN system that transmits high frequency for wireless LAN systems between a wireless LAN base station and a wireless LAN mobile station. A dielectric layer and a signal line are sequentially stacked on the ground layer. A high-frequency line having a high-frequency microstrip line structure and a plurality of circularly polarized antenna elements having different turning directions disposed on the high-frequency line, and the plurality of circularly polarized antenna elements having different turning directions are spaced apart from each other. When the high-frequency line is arranged , the high-frequency line is composed of a plurality of high-frequency microstrip lines, and the circularly polarized antenna elements are arranged at substantially the same position on the plurality of high-frequency microstrip lines, No that arranged circularly polarized wave antenna element, characterized in that it is a different circularly polarized antenna elements of each turning direction LAN antenna.   The wireless LAN antenna according to claim 1, wherein the circularly polarized antenna elements are arranged on both surfaces of the high-frequency line.   A plurality of the circularly polarized antenna elements having different swirl directions are circularly polarized antenna elements that generate clockwise and counterclockwise polarized waves, and generate the clockwise and counterclockwise polarized waves. The wireless LAN antenna according to claim 1 or 2, wherein circularly polarized antenna elements are alternately arranged on the high-frequency line.   The wireless LAN antenna according to any one of claims 1 to 3, wherein the circularly polarized antenna elements are arranged in different normal directions with respect to an installation surface of the wireless LAN antenna. 5. The radio according to claim 1 , wherein the high-frequency line has a high-frequency microstrip line structure in which a plurality of signal lines are stacked on a substrate including a ground layer and a dielectric layer. LAN antenna. The wireless LAN antenna according to claim 5, wherein the circularly polarized antenna elements are arranged at substantially the same position on each of the plurality of signal lines . The wireless LAN antenna according to claim 6, wherein the circularly polarized antenna elements arranged at substantially the same position on each of the plurality of signal lines are circularly polarized antenna elements having different turning directions . The wireless LAN antenna according to claim 1, further comprising a control unit that controls a transmission / reception state of the plurality of circularly polarized antenna elements . The wireless LAN antenna according to claim 8 , wherein the control unit is a control circuit that switches a transmission / reception state of the plurality of circularly polarized antenna elements . The high-frequency line has a high-frequency microstrip line structure in which a plurality of signal lines are stacked on a substrate composed of a ground layer and a dielectric layer, and the control unit connects a plurality of signal lines provided on the substrate. The wireless LAN antenna according to claim 8 , wherein the wireless LAN antenna is a control circuit for switching a state . A method of controlling a wireless LAN antenna used in a wireless LAN system that transmits high frequency for a wireless LAN system between a wireless LAN base station and a wireless LAN mobile station, wherein the wireless LAN antenna has a dielectric on a ground layer. a high-frequency line with the high-frequency micro-strip line structure in which sequentially laminating a layer and the signal line consists of a turning direction which is disposed in the high-frequency line is different circularly polarized wave antenna element, the transmission line a plurality of high-frequency micro The circularly polarized antenna elements are arranged at substantially the same position on each of the plurality of high frequency microstrip lines, and the circularly polarized antenna elements are arranged in circularly polarized waves having different turning directions. an antenna element, to control the communication state by switching the state of transmission and reception of the plurality of circularly polarized wave antenna element Control method for a wireless LAN antenna, characterized in that. The wireless LAN antenna control method according to claim 11 , wherein switching of the transmission / reception state of the plurality of circularly polarized antenna elements is performed by switching at least a pair of circularly polarized antenna elements having different turning directions as a set. . An antenna for a wireless LAN base station in which the wireless LAN antenna according to any one of claims 1 to 10 is incorporated. A wireless LAN mobile station terminal antenna incorporating the wireless LAN antenna according to claim 1 . A wireless LAN card for a terminal in which the wireless LAN antenna according to claim 1 is incorporated. A wireless LAN system for forming a wireless communication network with a wireless LAN base station antenna and / or a wireless LAN mobile station terminal antenna, wherein the wireless LAN antenna according to claim 1 is incorporated.

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