JP4712573B2 - Omnidirectional antenna - Google Patents

Description

  The present invention relates to an omnidirectional antenna and a method for manufacturing the omnidirectional antenna. More specifically, the present invention relates to a non-directional antenna capable of receiving recorded data recorded on a non-contact information recording medium as a radio wave regardless of the orientation and orientation of the non-contact information recording medium. The present invention relates to a directional antenna and a method for manufacturing the omnidirectional antenna.

  In recent years, new information recording media called IC cards are widely available on the market. The IC card is a generic name for a readable / writable recording medium having a card-like or sheet-like shape such as a credit card, a bank card, or a point card, and having an IC incorporated in or on the card. In particular, the non-contact type IC card is often used as a commuter pass or a prepaid card used when entering or leaving a station of a transportation facility such as a railway. Further, as a kind of non-contact type IC card, there is an RF tag (Radio Frequency tag) that is structurally exactly the same as the non-contact type IC card and records management information relating to identification number and history information. As a kind of RF tag, a non-contact type RF tag (hereinafter simply referred to as an RF tag) used for classifying and managing mails or packages is known.

  Conventionally, for example, when management information is read / written by a reader / writer while a baggage attached with an RF tag is conveyed by a belt conveyor, when the reader / writer antenna is fixed at a predetermined position, the baggage is started before the conveyance by the belt conveyor is started. It was necessary to manually set the direction of the baggage in advance so that the position of the RF tag attached to the device was confirmed and the RF tag was directed to the antenna side of the reader / writer. In addition, when it is desired to make it possible to read and write management information without performing such complicated prior operations, the reader / writer is also used in other directions expected to be most suitable for reading and writing information with respect to the RF tag. It was necessary to install multiple antennas.

In order to solve such a problem, the prior art of Patent Document 1 includes an interrogator system in which a plurality of interrogators (reader / writers, etc.) wirelessly communicate the same signal to a moving responder (IC card). A plurality of interrogators are provided with overlapping antenna communicable areas to expand the communicable area and synchronize the transmission and reception of each interrogator with the antenna, thereby transmitting signals from other interrogators to the interrogator. An interrogator system is disclosed that prevents interference such as being received.
However, in the conventional technique disclosed in Patent Document 1 and the conventional method of reading / writing management information by a reader / writer while being conveyed by a belt conveyor, a plurality of antennas must be installed in each direction. In addition to the problem of increased costs due to the increase in the number of installed devices and the securing of a large installation space, there is a problem in that the conveyance distance becomes longer because articles attached with RF tags must be conveyed to all antenna positions. is there.

  As one means for solving this problem, it is conceivable to construct a non-directional antenna by integrating a plurality of antennas. However, the omnidirectional antenna is composed of a plurality of loop coils, and it is necessary to configure each loop coil three-dimensionally. One way to realize this is to manufacture a loop coil by manually winding a wire around a core. However, not only skill is required but also the characteristics of the loop coil may vary. Yes and not suitable for mass production. As another method, mass production is possible by winding a coil at high speed using a machine dedicated to coil winding, and a product with uniform characteristics can be produced. However, a large amount of capital is required for capital investment.

In order to solve such a problem, Patent Document 2 includes a plurality of flat plate-like printed coils having a spiral conductor pattern, a core penetrating the central portion of the conductor pattern of these printed coils, A printed coil type line filter that electrically connects the conductor patterns of each printed coil. The flat printed coil is sandwiched between an upper component mounting board and a lower component mounting board, and these upper component mounting board and lower component mounting are mounted. A printed coil manufacturing method in which electronic components for a filter circuit are mounted on a plate is disclosed.
However, the conventional technique disclosed in Patent Document 2 eliminates the trouble of winding a wire by forming a loop coil with a printed pattern, but a plurality of printed coils must be stacked through the core. There is a problem that a lot of time is required for assembly and the manufacturing cost becomes high.
JP 2003-283367 A JP-A-6-349647

In view of such problems, the present invention integrally forms a three-dimensional loop coil disposed on each of two axial planes of the X, Y, and Z-axis planes and a planar loop coil disposed along one axial plane. It is an object of the present invention to provide an omnidirectional antenna that can receive radio waves of an omnidirectional RF tag with a small area by configuring a single antenna block.
Another object includes two substrates in which a part of a planar loop coil and two three-dimensional loop coils is formed by a laminated pattern, and connection means for connecting between the laminated patterns respectively formed on each substrate. Thus, it is to provide a method for easily manufacturing an omnidirectional antenna having orthogonal axes.

In order to solve the above-mentioned problem, the present invention provides a first aspect of the present invention comprising two axes each having an axis orthogonal to two of the X-axis plane, Y-axis plane, and Z-axis plane orthogonal to each other. An omnidirectional antenna comprising a three-dimensional loop coil and a planar loop coil arranged in parallel with another axial plane, each part of the two three-dimensional loop coils and all of the planar loop coils A first substrate having a first laminated pattern to be formed; a second substrate having a second laminated pattern forming the other part of the two three-dimensional loop coils; and the first laminated pattern. And connecting means for connecting between the first laminated pattern and the second laminated pattern, and connecting the first laminated pattern and the second laminated pattern by the connecting means, thereby providing the two three-dimensional loops. Coil is composed Is, wherein the first substrate and the second substrate are connected by said connection means in a state of being opposed, arranged magnetic core member between the first substrate and the second substrate, The areas where the two three-dimensional loop coils and the planar loop coil can communicate with the non-contact information storage medium are the same .
A feature of the omnidirectional antenna of the present invention is that a three-dimensional loop coil is arranged on two of the X, Y, and Z axis planes, and a planar loop coil is arranged along the remaining one axis plane. In order to arrange the axes of the three-dimensional loop coils so as to be orthogonal to each other and to arrange the planar loop coils in parallel to the axes, a pattern of the three-dimensional loop coils of the respective axis planes is formed on two substrates, By connecting two substrates by connecting means, a three-dimensional loop coil whose axes are orthogonal to each other is formed. Further, in order to configure the omnidirectional antenna of the present invention, since the pattern of the loop coil is formed on the two substrates, it is necessary to arrange the substrates facing each other as much as possible. By connecting by the connection means in that state, a more complete three-dimensional loop coil can be configured. A magnetic field is generated when a current is passed through the air-core loop coil. This magnetic field is uniquely determined by the current and the number of turns of the loop coil. When the current and the number of turns are determined, in order to increase the magnetic field as much as possible, it is necessary to arrange a magnetic core member that increases the magnetic field in the magnetic field.

According to a second aspect of the present invention, the connecting means is constituted by a connector or a wire.
In order to connect two substrates, there is a method using a connector and a wire. In the case of a connector, it is easy to assemble two substrates, and the wire method is excellent in connection reliability, although it takes time to assemble.

According to a third aspect of the present invention, the magnetic core member is ferrite, pure iron, silicon steel, iron / nickel alloy, or dust core.
The magnetic core member that strengthens the magnetic field is preferably a member having a large relative permeability and a small hysteresis phenomenon. Ferrite has low iron loss at high frequencies and has good maximum relative permeability and saturation characteristics. Pure iron is inexpensive and has a high relative permeability. Silicon steel increases both resistivity and relative permeability compared to pure iron. Iron / nickel alloys are used when a magnetic core with as high a permeability as possible is required. The dust core also prevents a decrease in relative permeability at high frequencies.

  According to the present invention, a three-dimensional loop coil is arranged on two of the X, Y, and Z axis planes, and a plane loop coil is arranged along the remaining axis planes, and the axis of each three-dimensional loop coil is In order to arrange the plane loop coils so as to be orthogonal to each other and to arrange the plane loop coils in parallel to the axis, a pattern of a three-dimensional loop coil on each axis plane is formed on two substrates, and the two substrates are connected to each other. Therefore, the three-dimensional loop coil can be easily configured with a simple configuration, and the manufacturing cost can be reduced.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .
FIG. 1 is a block diagram showing a configuration of a general reader / writer. The reader / writer 100 is controlled by a PC 50 that exchanges data with the reader / writer 100 and controls the entire system. The reader / writer 100 includes a transmission / reception device 1 that controls a data communication protocol with an external PC 50, a control device 2 that controls the operation of the entire reader / writer 100, firmware that records a procedure for operating the control device 2, and read data. A memory device 3 for storing data, a modulator 4 for modulating data from the control device 2 on a carrier wave, an input device 5 for inputting an operation command, and a display device 6 for displaying information controlled by the control device 2 A power amplifier 7 that amplifies the power supply signal that is an AC signal from the control device 2 and a write command from the modulator 4, and a detector demodulator that converts the carrier wave received from the loop antenna 9 into binary data 8 and a loop antenna 9 for exchanging power and data with an IC card (RF tag) (not shown). .

  Next, before describing the operation of the reader / writer 100 according to this configuration, the configuration of the IC card (RF tag) (non-contact information recording medium) will be described first. FIG. 2 is a block diagram showing the configuration of the IC card (RF tag). The IC card (RF tag) 200 receives an antenna 20 that transmits / receives data using a power carrier wave from the reader / writer 100, a transmission / reception circuit 21 that generates a write command read command, and a power carrier wave from the antenna 20. A power generation circuit 22 that rectifies and converts it into DC power, a memory device 23 that manages storage of control firmware and data, a modulator 24 that modulates a transmission command from the control circuit 26 with a carrier wave, and transmission / reception It comprises a detector 25 that converts carrier wave data from the circuit 21 into binary data, and a control circuit 26 that controls the overall operation of the IC card (RF tag) 200.

  Next, each operation will be described with reference to FIGS. 1 and 2 together. When a power supply (not shown) is turned on, the reader / writer 100 starts an operation according to a program stored in the memory device 3 after the initial operation of the control device 2. First, initialization is performed. Next, the control device 2 alternately transmits a power supply signal to be supplied to the IC card (RF tag) 200 and a polling signal from the power amplifier 7. The signal is radiated to the outside from the loop antenna 9 as an electromagnetic wave. Next, when the IC card (RF tag) 200 comes close to the reader / writer 100, the antenna 20 receives a power supply signal, rectifies the carrier wave by the power generation circuit 22 and converts it to DC power, and then converts it into the RF tag. To all circuits. When power is supplied and the control circuit 26 is driven, control is started in accordance with a program stored in the memory device 23.

  Next, the control circuit 26 first demodulates the command from the transmission / reception circuit 21 by the detector 25, converts it to a binary signal, and analyzes the command. As a result, when it is recognized that it is called, the response is modulated by the modulator 24 and transmitted from the antenna 20 via the transmission / reception circuit 21. The reader / writer 100 receives the response with the loop antenna 9, converts it into a binary code with the detector demodulator 8, analyzes it with the control circuit 2, and the IC card (RF tag) 200 conforms to the standard IC card ( RF tag). Thereby, polling is performed between the reader / writer 100 and the IC card (RF tag) 200 thereafter.

  FIG. 3 is a diagram for explaining the relationship between the orientation of the IC card and the lines of magnetic force by disassembling the loop coil on each axial plane of the omnidirectional antenna of the present invention. For convenience of explanation, the direction of FIG. 3A is called a Z-axis plane, the direction of FIG. 3B is called a Y-axis plane, and the direction of FIG. 3C is called an X-axis plane. First, on the Z-axis plane, assuming that the loop coil 31 is configured on a plane, the magnetic field lines 30 intersect the IC card 200a arranged in parallel to the loop coil 31 at a substantially right angle. In the Y-axis plane, the loop coil 32 is orthogonal to the Z-axis plane, so that the magnetic lines of force 33 intersect the IC card 200b arranged orthogonal to the IC card 200a at a substantially right angle. Become. In the X-axis plane, the loop coil 34 is configured to be orthogonal to the Z-axis plane and rotated 90 degrees with respect to the Y-axis plane, so that the IC card 200c rotated 90 degrees with respect to the IC card 200b. The magnetic lines of force 35 intersect with each other at a substantially right angle. That is, as shown in FIG. 3D, the three-dimensional loop coils 34 and 32 are arranged on the X, Y, and Z axis planes of the X, Y, and Z axis planes, and the plane loop coils 31 are arranged along the remaining Z axis planes. . The three-dimensional loop coils 34 and 32 are configured such that the axes thereof are orthogonal to each other, and the planar loop coil 31 is arranged in parallel to the axes, so that recording is performed on the IC card 200 regardless of the orientation of the IC card 200. Information can be received as radio waves.

  That is, when the omnidirectional antenna 300 is configured by integrally configuring the loop coils 34, 32, and 31 on the X, Y, and Z axis planes, for example, the loop coil 31 transmits and receives radio waves to and from the IC card 200a. Thus, the IC card 200b is exchanged with radio waves by the loop coil 32, and the IC card 200c is exchanged with radio waves by the loop coil 34. Therefore, radio waves can be transmitted and received by the omnidirectional antenna 40 no matter what direction the IC card 200 is arranged. Note that when the magnetic field lines intersect each IC card at right angles, the magnetomotive force is the largest, and radio waves are exchanged efficiently. However, radio waves can be exchanged even at a predetermined angle. Also, when the IC card is tilted, the magnetic field lines from the loop coils of two different axial planes may intersect the IC card. In this case, information can be received from both loop coils and ORed. Done.

  FIG. 4 is a diagram showing the completed assembly of the omnidirectional antenna according to the first embodiment of the present invention by triangulation. The same components will be described with the same reference numerals as in FIG. 4A is a top view, FIG. 4B is a plan view, and FIG. 4C is a side view. The omnidirectional antenna 300 includes an upper surface substrate (first substrate) 40 in which a part of each of the planar loop coil 31 and the three-dimensional loop coils 32 and 34 is formed by a laminated pattern, and each of the other three-dimensional loop coils 32 and 34. A lower substrate (second substrate) 54 partially formed by a laminated pattern, and connectors (connecting means) 42, 44, 46, 53 for connecting the laminated patterns formed on the upper substrate 40 and the lower substrate 54 respectively; And a magnetic core member 47 disposed between the upper substrate 40 and the lower substrate 54. The connectors 42, 44, 46, and 53 are configured to be soldered and separated from the upper surface substrate 40 (reference symbol a) and the lower surface substrate 54 (reference symbol b). Further, ferrite, pure iron, silicon steel, iron / nickel alloy or dust core is used as the magnetic core member.

  Next, the configuration of the omnidirectional antenna 300 of this embodiment will be described in more detail. In this example, the pattern of the planar loop coil 31 and the three-dimensional loop coils 32 and 34 is formed on the upper surface substrate 40. That is, the planar loop coil 31 is formed so that the pattern 41 circulates around the upper surface substrate 40. The three-dimensional loop coil 32 includes a pattern 45 (solid line) and a pattern 49 (broken line), and each pattern is individually formed on each layer of a two-layer substrate, for example. The upper substrate 40 and the lower substrate 54 are connected by connectors 46 and 44. The three-dimensional loop coil 34 includes a pattern 48 (one-dot chain line) and a pattern 52 (two-dot chain line), and each pattern is individually formed on each layer of a two-layer substrate, for example. The upper substrate 40 and the lower substrate 54 are connected by connectors 42 and 53. For example, if the starting point of the circuit of the pattern of the three-dimensional loop coil 34 is “a” of the connector 46 of the upper surface substrate 40, “a of the connector 46 of the upper surface substrate 40” − “pattern 45” − “b of the connector 44” − One turn of the three-dimensional loop coil 34 by “contact of connector 44” — “b of lower surface board 54” — “pattern 49” — “c of connector 46” — “contact of connector 46” — “c of upper surface substrate 40” Is configured. In the same manner, in this example, a three-dimensional loop coil is configured from the connector 46a to the connector 44f in this example. Similarly, the three-dimensional loop coil 32 is configured from A of the connector 42 to F of the connector 53 to form a three-turn three-dimensional loop coil. The magnetic core member 47 is made of ferrite, pure iron, silicon steel, iron / nickel alloy, dust core, or the like.

  As described above, in the present invention, the connectors 41a, 44a, 46a, 53a are solder-connected to the upper surface substrate 40, and the connectors 41b, 44b, 46b, 53b are solder-connected to the lower surface substrate 54. The three-dimensional loop coils 32 and 34 are electrically connected by simply connecting the connectors so that the substrates 54 are arranged opposite to each other, and a three-turn three-dimensional loop coil can be easily realized. And by manufacturing a board | substrate beforehand and mounting a general purpose connector, mass production can be performed easily and component cost can be reduced. Further, by arranging the magnetic core member 47 so as to be sandwiched between the upper surface substrate 40 and the lower surface substrate 54, the magnetic field generated from the three-dimensional loop coil can be strengthened to efficiently communicate with the IC tag 200. The magnetic core member 47 is not necessarily required and may be omitted.

  FIG. 5 is a perspective view when the omnidirectional antenna according to the first embodiment of the present invention is separated vertically. The same components will be described with the same reference numerals as in FIG. The magnetic core member 47 and some connectors are not shown. In this figure, the connector 46 is separated into a plug side 46a and a socket side 46b. That is, there is a connection pin 60 on the plug side 46a, and an end thereof is inserted into the through hole 57 of the upper surface substrate 40 and soldered. The socket side 46b has a socket pin 61, and an end thereof is inserted into a through hole (not shown) of the lower surface board 54 and soldered. Therefore, when the magnetic core member 47 (not shown) is replaced, it can be easily performed only by releasing the fitting of the connector.

  FIG. 6 is a diagram showing a completed assembly of the omnidirectional antenna according to the second embodiment of the present invention by triangulation. The same components will be described with the same reference numerals as in FIG. 6A is a top view, FIG. 6B is a plan view, and FIG. 6C is a side view. This omnidirectional antenna 310 differs from FIG. 4 in that a wire rod 66 is used instead of the connector. In addition, spacers (holding members) 64 are provided at four corners in order to hold the distance between the upper substrate 40 and the lower substrate 54. The spacer 64 is configured to be fixed by a screw 62 and a nut 65 while maintaining a distance between the upper substrate 40 and the lower substrate 54. The wire 66 is soldered using the through hole of the connector shown in FIG. Thereby, a board | substrate can be shared.

  FIG. 7 is a diagram schematically showing each axial plane of the omnidirectional antenna of the present invention. FIG. 7A is a schematic view, and FIG. 7B is a perspective view. In FIG. 7A, the planar loop coil 31, the Y-axis plane three-dimensional loop coil 32 wound around the magnetic core member 47, and the X-axis plane three-dimensional loop coil 34 wound around the magnetic core member 47 are combined. The omnidirectional antenna 300 is configured. When the omnidirectional antenna 300 as shown in FIG. 7A is integrally formed, it is as shown in FIG. 7B. The cross section of the magnetic core member 47 is configured to be rectangular, and the wire of which the surface is insulated is wound around the magnetic core member 47 as shown in the figure, so that the function of FIG. Can be realized.

FIG. 8 is a perspective view showing an example of the pattern of the upper substrate and the lower substrate constituting the omnidirectional antenna of the present invention. FIG. 8A is a pattern diagram of the upper substrate 40, and FIG. 8B is a pattern diagram of the lower substrate 54. The same components will be described with the same reference numerals as in FIG. As can be seen from the pattern in FIG. 8A, the pattern 48a is formed from the connection portions A to B, the pattern 48b is formed from the connection portions C to D, and the pattern 48c is formed from the connection portions E to F. The pattern 45a is formed from the connection portions a to b so as to be orthogonal to the patterns 48a, b, c, and the pattern 45b is formed from the connection portions c to d so as to be orthogonal to the patterns 48a, b, c. Are formed from the connection portions e to f so as to be orthogonal to the patterns 48a, b, and c. The patterns 45 and 48 can be formed on the same substrate by, for example, forming the pattern 45 on the surface layer of the substrate and forming the pattern 48 on the second layer of the substrate.
As can be seen from the pattern of FIG. 8B, the pattern 52a is formed obliquely from the connection portions B to C, and the pattern 52b is formed obliquely from the connection portions D to E. The pattern 49a is formed obliquely from the connection portions b to c so as to intersect the patterns 52a and b, and the pattern 49b is formed from the connection portions d to e so as to intersect the patterns 52a and b. For example, the patterns 49 and 52 can be formed on the same substrate by forming the pattern 49 on the surface of the substrate and forming the pattern 52 on the second layer of the substrate.

As described above, according to the present invention, the three-dimensional loop coils 34 and 32 are arranged on the X and Y axis planes of the X, Y, and Z axis planes, and the plane loop coil 31 is arranged along the remaining Z axis planes. In order to arrange the three-dimensional loop coils 34 and 32 so that the axes thereof are orthogonal to each other and to arrange the planar loop coil 31 in parallel to the axes, the three-dimensional loop coils of the respective axes are arranged on the upper surface substrate 40 and the lower surface substrate 54. Since the two patterns are formed and the two substrates are connected by the connecting means, the three-dimensional loop coil can be easily configured with a simple configuration.
Further, since the upper substrate 40 and the lower substrate 54 are connected by the connecting means so that the substrates are arranged to face each other, a more complete three-dimensional loop coil can be configured.
Further, since the connecting means is constituted by a connector or a wire, it can be selected depending on whether assembling property is important or connection reliability is important.
In addition, since the magnetic core member 47 is disposed between the upper substrate 40 and the lower substrate 54, the magnetic field can be increased even with a weak current.

The magnetic core member 47 is made of ferrite, pure iron, silicon steel, iron / nickel alloy, or dust core, and can be selected depending on the purpose of use.
Further, the apparatus includes an upper surface substrate 40 on which a partial pattern of the three-dimensional loop coil and the planar loop coil 31 are formed, a lower surface substrate 54 on which another partial pattern of the three-dimensional loop coil is formed, and a connector. Since the connectors are fitted so that the substrates are soldered to the substrates so that the substrates face each other, the manufacturing method is simple and the manufacturing cost can be reduced.
Further, since the upper surface substrate 40 and the lower surface substrate 54 are connected by a wire instead of the connector, the connection reliability can be improved.
In addition, since the magnetic core member 47 is disposed between the upper surface substrate 40 and the lower surface substrate 54 before the connector is fitted or before the wire is connected, the problem of forgetting to dispose the magnetic core member 47 can be reduced. .

It is a block diagram which shows the structure of a general reader / writer. It is a block diagram which shows the structure of an IC card (RF tag). It is a figure explaining the relationship between the direction of an IC card, and a magnetic force line by disassembling the loop coil of each axis plane of the omnidirectional antenna of the present invention. It is the figure which displayed the assembly completion figure of the omnidirectional antenna which concerns on the 1st Embodiment of this invention by the trigonometric method. It is a perspective view when the omnidirectional antenna concerning a 1st embodiment of the present invention is separated up and down. It is the figure which displayed the assembly completion figure of the omnidirectional antenna which concerns on the 2nd Embodiment of this invention by the trigonometric method. It is the schematic diagram and perspective view which represented each axial plane of the omnidirectional antenna of this invention typically. It is a figure which shows an example of the pattern of the upper surface board | substrate and lower surface board | substrate which comprise the omnidirectional antenna of this invention.

Explanation of symbols

  31 Planar loop coil, 32, 34 Three-dimensional loop coil, 40 Upper surface substrate, 42, 44, 46, 53 Connector, 47 Magnetic core member, 54 Lower surface substrate, 66 Wire material, 300 Non-directional antenna

Claims (3)

Two three-dimensional loop coils having axes orthogonal to two of the X-axis plane, Y-axis plane, and Z-axis plane that are orthogonal to each other, and arranged in parallel to the other one axis plane An omnidirectional antenna having a planar loop coil,
A first substrate having a first laminated pattern that forms each part of the two three-dimensional loop coils and the whole planar loop coil; and a second substrate that forms the other parts of the two three-dimensional loop coils. A second substrate provided with a laminated pattern, and connection means for connecting between the first laminated pattern and the second laminated pattern,
By connecting between the first laminated pattern and the second laminated pattern by the connecting means, the two three-dimensional loop coils are configured, the first substrate and the second substrate, Non-contact information storage of the two three-dimensional loop coils and the planar loop coil, which are connected by the connecting means in a state of being opposed to each other, and a magnetic core member is disposed between the first substrate and the second substrate. An omnidirectional antenna characterized by having the same area for communication with a medium .   The omnidirectional antenna according to claim 1, wherein the connection means is configured by a connector or a wire.   The omnidirectional antenna according to claim 1, wherein the magnetic core member is ferrite, pure iron, silicon steel, iron / nickel alloy, or a dust core.

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