GB2469209A - Antenna including a coil having two offset and non-overlapping portions - Google Patents
Antenna including a coil having two offset and non-overlapping portions Download PDFInfo
- Publication number
- GB2469209A GB2469209A GB1005634A GB201005634A GB2469209A GB 2469209 A GB2469209 A GB 2469209A GB 1005634 A GB1005634 A GB 1005634A GB 201005634 A GB201005634 A GB 201005634A GB 2469209 A GB2469209 A GB 2469209A
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- conductor
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- magnetic
- material core
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- 239000004020 conductor Substances 0.000 claims abstract description 160
- 239000000696 magnetic material Substances 0.000 claims abstract description 61
- 239000000758 substrate Substances 0.000 claims description 17
- 230000004907 flux Effects 0.000 claims description 16
- 101001004851 Cicer arietinum Legumin Proteins 0.000 claims 1
- 230000008878 coupling Effects 0.000 description 11
- 238000010168 coupling process Methods 0.000 description 11
- 238000005859 coupling reaction Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000000593 degrading effect Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
- G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
- G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
- G06K19/07749—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/27—Adaptation for use in or on movable bodies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
- H01Q7/06—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop with core of ferromagnetic material
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- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Details Of Aerials (AREA)
- Support Of Aerials (AREA)
Abstract
An antenna comprises an antenna coil 21 and a planar conductor 2. The antenna coil includes a magnetic-material core 1 and a coil conductor CW. The coil is arranged toward a certain side S of the planar conductor 2. A first conductor part 11 of the coil conductor is situated close to a first main face MS1 of the core, and a second conductor part 12 is close to a second main face MS2 of the core. The two conductor parts are arranged such that they are offset from one another and do not overlap. The second conductor part 12 is arranged further from the center of the planar conductor than is the first conductor part 11. In addition, a coil axis CA of the coil conductor CW is orthogonal to a side S of the planar conductor 2. The antenna is suited to application with a radio frequency identification device (RFID). The antenna can provide for a longer communicable distance.
Description
ANTENNA
[Technical Field]
[00011 The present invention relates to an antenna used in, for example, a Radio Frequency Identification (RFID) system that communicates with an external device by using
electromagnetic field signals.
[Background Art]
[0002] An antenna mounted in a mobile electronic device used in an RFID system is disclosed in Patent Document 1. Fig. 1 is a top view illustrating the structure of an antenna apparatus described in Japanese unexamined patent application publication No. 2002-325013 (Patent Document 1).
[00031 An antenna coil 30 illustrated in Fig. 1 includes an air core coil 32 and a planar magnetic core member 33. The air core coil 32 is configured by spirally winding conductors 31 (31a, 31b, 31e, and 31d) in a plane on a film 32a. The magnetic core member 33 is inserted into the air core coil 32 so as to be substantially parallel to a plane of the air core coil 32. The air core coil 32 has an aperture 32d and the magnetic core member 33 is inserted into the aperture 32d. A first terminal 31a is connected to a connecting conductor 31e via a through hole 32b, and a second terminal 31b is connected to the connecting conductor 31e via a through hole 32c. And, the magnetic-material antenna is arranged on a conductive plate 34.
[Summary of the Invention]
[0005] The rear face of the magnetic-material antenna in Patent Document 1 illustrated in Fig. 1 is a metal plate, and the magnetic flux flows laterally (from right to left in the state illustrate in Fig. 1) . The flowing magnetic flux produces an electromotive force in the coil conductor to pass an electric current through the coil conductor.
[0006] However, the magnetic-material antenna in Patent Document 1 has a structure in which coupling with the magnetic flux that is parallel to the rear conductive plate 34 is achieved, as illustrated in Fig. 1. Accordingly, when the antenna is mounted in, for example, a mobile phone terminal, the mobile phone terminal cannot be used with being held over the surface of a reader-writer in parallel if the antenna is installed in parallel with a circuit board in the casing of the mobile phone terminal. In addition, when the antenna coil is placed near the center of the conductive plate 34, the communication is established only within a short range and the position where the maximum communication distance is achieved is greatly shifted from the center of the casing, thus degrading the usability.
[0007] Embodiments of the present invention have the advantage of providing an antenna that has a longer maximum communicatable distance and that has the position where the communicatable distance is maximized at substantially the center of the casing.
The invention is defined in the independent claims to which reference is now directed. Preferred features are set out in the dependent claims.
[0008] An antenna embodying the present invention includes an antenna coil and a planar conductor. The antenna coil includes a flexible substrate having a coil conductor formed thereon and a plate magnetic-material core having a first main face and a second main face. The antenna coil is arranged closely to the planar conductor.
The first main face of the magnetic-material core opposes the planar conductor.
The planar conductor has a substantially rectangular shape.
The antenna coil is arranged toward a certain side with respect to the center of the planar conductor.
Of the coil conductor, a first conductor part close to the first main face of the magnetic-material core is positioned so as not to be over a second conductor part close to the second main face of the magnetic-material core in view from the normal line direction of the first main face or the second main face of the magnetic-material core.
The second conductor part is arranged in a position far from the center of the planar conductor, compared with the first conductor part.
A coil axis of the coil conductor is orthogonal to the side of the planar conductor.
[0009] And, the coil conductor has a shape in which a coil having a helical shape is cut out along a certain cutout line, and the flexible substrate is wound around four faces of the magnetic-material core to join the coil conductor at the part corresponding to the cutout line.
[00101 And, the coil conductor has a spiral shape, and the flexible substrate is wrapped over three faces of the magnetic-material core.
And, the coil conductor has a spiral shape, the flexible substrate has a through hole provided at a central part of the position where the coil conductor is formed, and the magnetic-material core is inserted into the through hole.
And, a relationship W �= Y is established, where W denotes the distance between the narrowest parts of the coil conductor, which connect the first conductor part to the second conductor part, and Y denotes the length of the magnetic-material core1 which is orthogonal to the side of the planar conductor.
[00111 And, an end of the magnetic-material core, where magnetic flux comes in and out, is made wider than the remaining part.
And, a relationship Y > X is established, where X denotes the distance from the end of the antenna toward the side of the planar conductor to the side of the planar conductor and Y denotes the length of the antenna coil, which is orthogonal to the side of the planar conductor.
And, the planar conductor is a circuit board on which the antenna coil is installed.
[Advantages] [00121 According to embodiments of the present invention, it is possible to have a longer maximum communicatable distance and to have the position where the communicatable distance is maximized at substantially the center of a casing.
[Brief Description of the Drawings]
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which [0013] [Fig. 1] Fig. 1 is a top view illustrating the structure of an antenna apparatus described in Patent Document 1.
[Fig. 21 Fig. 2 includes diagrams illustrating the structure of a magnetic-material antenna and an antenna apparatus according to a first embodiment.
[Fig. 31 Fig. 3(A) illustrates the distribution and directivity of the magnetic flux around an antenna 101 and Fig. 3(B) illustrates the distribution and directivity of the magnetic flux around an antenna having a conventional structure, which is illustrated in contrast to the antenna according to the first embodiment.
[Fig. 4] Fig. 4 includes diagrams illustrating a state in which an electronic device, such as a mobile phone terminal, including the antenna 101 according to the first embodiment communicates with an IC card for RFID.
[Fig. 5] Fig. 5 illustrates the relationship between the maximum communicatable distance and a shift between the center of the casing of an electronic device including the antenna 101 according to the first embodiment and the center of a reader-writer-side antenna.
[Fig. 6] Fig. 6 includes diagrams illustrating the positional relationship between a planar conductor 2 and an antenna coil 21.
[Fig. 7] Fig. 7(A) is a plan view illustrating the positional relationship between the planar conductor 2 and the antenna coil 21 and Fig. 7(B) illustrates the relationship between a distance X and the coupling coefficient in the antenna coil 21 according to the first embodiment and an antenna coil 20 having a conventional structure.
[Fig. 8] Fig. 8(A) illustrates a state before an antenna coil 22 according to a second embodiment is assembled and Fig. 8(B) is a plan view of the antenna coil 22.
[Fig. 9] Fig. 9(A) is a bottom view of an antenna 102 including the antenna coil 22 according to the second embodiment, Fig. 9(B) is a front view of the antenna 102, and Fig. 9(C) illustrates an example in which the antenna coil 22 is fixed in a casing 202 including the planar conductor 2, which is a circuit board.
[Fig. 101 Fig. 10(A) is a plan view before an antenna coil 23 according to a third embodiment is assembled and Fig. 10(B) is a plan view of the antenna coil 23.
[Fig. 11] Fig. 11(A) is a bottom view of an antenna 103 including the antenna coil 23 according to the third embodiment, Fig. 11(B) is a front view of the antenna 103, and Fig. 11(C) illustrates an example in which the antenna coil 23 is fixed in a casing 203 including the planar conductor 2, which is a circuit board.
[Fig. 121 Fig. 12 illustrates the relationship between W and the coupling coefficient when the product of W and Y is set to a constant value and W is varied, where W denotes the distance between the narrowest parts of a coil áonductor, which connect a first conductor part 11 to a second conductor part 12, and Y denotes the length of a magnetic-material core, which is orthogonal to a side of the planar conductor.
[Fig. 13] Fig. 13(A) is a plan view before an antenna coil 24A according to a fourth embodiment is assembled and Fig. 13(B) is a plan view of the antenna coil 24A.
[Fig. 14] Fig. 14(A) is a plan view before another antenna coil 24B according to the fourth embodiment is assembled and Fig. 14(B) is a plan view of the antenna coil 24B.
[Fig. 15) Fig. 15(A) is a plan view before another antenna coil 24C according to the fourth embodiment is assembled and Fig. 15(B) is a plan view of the antenna coil 24C.
[Fig. 16] Fig. 16(A) is a plan view before an antenna coil 25 according to a fifth embodiment is assembled, Fig. 16(B) is a top view of the antenna coil 25, and Fig. 16(C) is a bottom view of the antenna coil 25.
[Fig. 17] Fig. 17(A) is a bottom view of an antenna 104 including the antenna coil 25 according to the fifth embodiment, Fig. 17(B) is a front view of the antenna 104, and Fig. 17(C) illustrates an example in which the antenna coil 25 is fixed in a casing 204 including the planar conductor 2, which is a circuit board.
[Fig. 18] Fig. 18(A) is a plan view before an antenna coil 26A according to a sixth embodiment is assembled and Fig. 18(B) is a plan view of the antenna coil 26A.
[Fig. 19] Fig. 19(A) is a plan view before another antenna coil 26B according to the sixth embodiment is assembled and Fig. 19(E) is a plan view of the antenna coil 26B.
[Fig. 20] Fig. 20(A) is a plan view before another antenna coil 26C according to the sixth embodiment is assembled and Fig. 20(B) is a plan view of the antenna coil 26C.
Description of embodiments of the invention
[0014] <<First Embodiment>> Fig. 2 includes diagrams illustrating the structure of an antenna according to a first embodiment.
Fig. 2(A) is a perspective view of an antenna 101 including an antenna coil 21 and a planar conductor 2, such as a circuit board, on which the antenna coil 21 is installed and which is a rectangular plate. Fig. 2(E) is a front view of the antenna 101.
[0015] A magnetic-material core 1 is a ferrite core having a rectangular planar shape, and the bottom face in Fig. 2 corresponds to a first main face MS1 and the top face in Fig. 2 corresponds to a second main face MS2. A coil conductor CW is wound around the magnetic-material core 1, as illustrated in Fig. 2. A part denoted by reference numeral 11 in the figure indicates a first conductor part of the coil conductor CW, which is close to the first main face MS1 of the magnetic-material core 1. And, a part denoted by reference numeral 12 in the figure indicates a second conductor part that is close to the second main face MS2 of the magnetic-material core 1. The magnetic-material core 1 and the coil conductor CW compose the antenna coil 21.
[00161 The antenna coil 21 is arranged toward a certain side (the right side in Fig. 2) S with respect to the center of the planar conductor 2. And, the first conductor part 11 and the second conductor part 12 are arranged such that the second conductor part 12 is not over the first conductor part 11 in view from (in a perspective view from) the normal line direction of the first main face MS1 or the second main face MS2 of the magnetic-material core 1. In addition, the second conductor part 12 is arranged in a position far from the center of the planar conductor 2, compared with the first conductor part 11. Furthermore, a coil axis CA of the -10 -coil conductor CW is orthogonal to the side S of the planar conductor 2.
[0017) Fig. 3(A) illustrates the distribution and directivity of the magnetic flux around the antenna 101. And, Fig. 3(B) illustrates the distribution and directivity of the magnetic flux around an antenna having a conventional structure, which is illustrated in contrast to the antenna according to the first embodiment. In the antenna 101, the antenna coil 21 is arranged in a position close to a reader-writer-side antenna 301, compared with the planar conductor 2. This state corresponds to a state in which an electronic device including the antenna 101 is held over a reading part of the reader-writer.
[0018] Since the second conductor part 12 of the coil conductor CW is positioned toward the outside with respect to the center of the planar conductor 2, compared with the first conductor part 11, the long axis of the loop of a magnetic flux H passing through the magnetic-material core of the antenna coil 21 is inclined from the surface of the planar conductor 2, as illustrated in the figure. In other words, the component in the normal line direction (the Z-axis direction) of the planar conductor 2 is intensified.
Accordingly, a directivity beam DB of the antenna 101 is -11 -directed to the center of the reader-writer-side antenna 301.
[0019] On the other hand, as illustrated in Fig. 3(B), in an antenna coil 20 in related art having a positional relationship in which the second conductor part close to the second main face of the magnetic-material core is over the first conductor part close to the first main face of the magnetic-material core, the long axis of the loop of the magnetic flux H passing through the magnetic-material core is parallel to the planar conductor 2 and, therefore, the directivity beam DB of the antenna is directed to a direction along the surface of the planar conductor 2.
Consequently, the maximum communicatable distance is reduced if an antenna 100 is made close to the reader-writer-side antenna 301 in parallel and the maximum communicatable distance is increased if the antenna 100 is made close to the reader-writer-side antenna 301 at a tilt, instead.
[0020] In contrast, according to the first embodiment, it is possible to increase the maximum communicatable distance and the maximum communicatable distance is achieved in a state in which the center of the antenna 101 coincides with the center of the reader-writer-side antenna 301.
[0021] Next, an example of communication between an integrated -12 -
S
circuit (IC) card for RFID and an electronic device, such as a mobile phone terminal, including the antenna 101 will now be described.
Fig. 4 includes diagrams illustrating the arrangement relationship between an IC card for RFID and an electronic device, such as a mobile phone terminal, including the antenna 101. An antenna configured by arranging the antenna coil 21 along an end of the planar conductor 2 is included in a casing 201 of the electronic device. Fig. 4(A) illustrates a state in which the electronic device is made close to an IC card 401 and in which both of the electronic device and the IC card 401 are longitudinally directed. Fig. 4(B) illustrates a state in which the electronic device is arranged so as to be orthogonal to the IC card 401. The IC card 401 includes an antenna coil that is formed along the outer edge of the IC card 401 and that has a plural number of turns, and the antenna coil in the IC card 401 is magnetically coupled to the antenna coil 21.
[0022] In the above state in which the antenna coil 21 is arranged along an end of the planar conductor 2, if an IC card having approximately the same size as that of the planar conductor 2 is made close to the electronic device, the distance between the coil conductor of the antenna coil in the IC card 401 and the coil conductor of the antenna -13 -
S
coil 21 of the antenna according to the present embodiment is decreased. As a result, strong coupling is achieved between the antennas.
[0023] As described above, the antenna is adapted not only to the communication with, for example, a reader-writer that is apart from the antenna by around 100 mm but also to the communication in a state in which the antenna is substantially in contact with an IC card.
[00241 Specifically, in the antenna of the present invention, the coil conductor is wound so as to achieve excellent communication performance even if the antenna coil is arranged along an end of the planar conductor. Compared with the antenna using the antenna coil having a conventional structure in which the coil conductor is simply wound around the magnetic-material core, the antenna of the present invention achieves a greater magnetic field strength contributing to the communication and a higher communication performance (the performance concerning the communicatable distance and the error rate of the communication data).
[0025] Fig. 5 illustrates the relationship between the maximum communicatable distance and a shift between the center of the casing of an electronic device including the antenna 101 -14 -
S
according to the first embodiment and the center of a reader-writer-side antenna. Referring to Fig. 5, the position where the center of the reader-writer-side antenna coincides with the center of the casing of the electronic device is set as the origin, and the amount of shift between the center of the reader-writer-side antenna and the center of the casing of the electronic device is represented as the horizontal axis.
[0026] The size of the loop of the reader-writer-side antenna is about 65 mm x 100 mm, the size of the casing of the electronic device is about 45 mm x 90 mm, and the size of the antenna coil 21 is about 20 mm x 15 mm.
As illustrated in Fig. 5, the maximum communicatable distance is peaked when the center of the reader-writer-side antenna coincides with the center of the casing of the electronic device.
[0027] Fig. 6 includes diagrams illustrating the positional relationship between the planar conductor 2 and the antenna coil 21. A relationship Y > X is established, where X denotes the distance from an end of the antenna coil 21 toward the side S of the planar conductor 2 to the side S and Y denotes the length of the antenna coil 21, which is orthogonal to the side S of the antenna coil 21.
-15 -
S
[0028] The relationship between X and Y will now be described with reference to Fig. 7.
Fig. 7(A) is a plan view illustrating the positional relationship between the planar conductor 2 and the antenna coil 21. In this example, the planar conductor 2 has a size of 42 mm x 90 mm and the antenna coil 21 has a size of 20 mm x 15 mm. Fig. 7(B) illustrates the relationship between the distance X and the coupling coefficient in the antenna coil 21 according to the first embodiment and an antenna coil having a conventional structure. In the antenna coil having a conventional structure, which is a comparative example, the first conductor part and the second conductor part have a positional relationship in which the second conductor part close to the second main face of the magnetic-material core is over the first conductor part close to the first main face of the magnetic-material core. In addition, the antenna of the reader-writer has a size of 100 mm x 100 mm and the antenna including the antenna coil 21 opposes the antenna of the reader writer at a distance of 30 mm.
[0029] As illustrated in Fig. 7(B), the coupling coefficient of the antenna coil 21 is greater than that of the antenna coil having a conventional structure when X < 15 mm. Since Y = 15 here, it is found that a greater coupling coefficient -16 -is achieved, compared with the antenna coil having a conventional structure, when Y > X. [0030] As also illustrated in Fig. 7(B), the dimension X may have a negative value. Specifically, as in an example in Fig. 6(B), an end of the antenna coil 21 may be positioned outside the side S of the planar conductor 2.
The above relationship allows the orientation of the directivity beam DB illustrated in Fig. 3(A) to be raised to achieve the object of the present invention.
[00311 <<Second Embodiment>> Fig. 8(A) illustrates a state before an antenna coil 22 according to a second embodiment is assembled. Fig. 8(B) is a plan view of the antenna coil 22. As illustrated in Fig. 8(A), a coil conductor CW is formed on a flexible substrate 10. The coil conductor CW has a conductor pattern in which a coil having a helical shape is cut out along a certain cutout line. The flexible substrate 10 is wound around four faces of a magnetic-material core 1 and ends of the coil conductor CW connect to the corresponding ends of the coil conductor CW at the parts corresponding to the cutout line.
In this example, an end a connects to an end a', an end b connects to an end b', and an end c connects to an end c' with solder or the like. This composes the antenna coil 22 -17 -illustrated in Fig. 8(B) [00321 In the orientation illustrated in Fig. 8(B), a second conductor part 12 is close to the top face (the second main face) of the magnetic-material core 1 and a first conductor part 11 is close to the bottom face (the first main face) of the magnetic-material core 1.
[0033] Fig. 9(A) is a bottom view of an antenna 102 including the antenna coil 22. Fig. 9(3) is a front view of the antenna 102. The antenna coil 22 is installed along a central part of one side of the planar conductor 2, which is a circuit board.
[00341 Fig. 9(C) illustrates an example in which the antenna coil 22 is fixed in a casing 202 including the planar conductor 2, which is a circuit board. Also in this case, the second conductor part 12 is arranged in a position far from the center of the planar conductor 2, compared with the first conductor part 11.
Operational advantages similar to those described in the first embodiment are offered in the above manner.
[0035] <<Third Embodiment>> Fig. 10(A) is a plan view before an antenna coil 23 -18 -according to a third embodiment is assembled. Fig. 10(B) is a plan view of the antenna coil 23. A coil conductor CW having a spiral shape is formed on a flexible substrate 10, and a through hole A is provided at a central part of the position where the spiral coil conductor is formed. A magnetic-material core 1 is inserted into the through hole A of the flexible substrate 10 to compose the antenna coil 23 illustrated in Fig. 10(3).
[00361 Fig. 11(A) is a bottom view of an antenna 103 including the antenna coil 23. Fig. 11(B) is a front view of the antenna 103. The antenna coil 23 is installed along a central part of one side of the planar conductor 2, which is a circuit board.
[00371 Fig. 11(c) illustrates an example in which the antenna coil 23 is fixed in a casing 203 including the planar conductor 2, which is a circuit board, unlike the examples in Fig. 11(A) and Fig. 11(B). Also in this case, the second conductor part 12 is arranged in a position far from the center of the planar conductor 2, compared with the first conductor part 11.
Operational advantages similar to those described in the first embodiment are offered in the above manner.
[00381 -19 -The relationship between W and Y will now be described with reference to Fig. 12, where W denotes the distance between the narrowest parts of the coil conductor, which connect the first conductor part 11 to the second conductor part 12, and Y denotes the length of the magnetic-material core, which is orthogonal to the side of the planar conductor, as illustrated in Fig. 10(B).
Fig. 12 illustrates the relationship between W and the coupling coefficient when the product of W and Y is set to a constant value, 15 x 15 = 225 mm2 and w is varied. In this example, the antenna of the reader-writer has a size of 100 mm x 100 mm and the antenna including the antenna coil 23 opposes the antenna of the reader writer at a distance of 30 mm.
[0039] When W < Y (when W < 15 mm), the coupling coefficient is decreased with the decreasing W, thus degrading the communication performance. Accordingly, it is possible to ensure an excellent communication performance by establishing a relationship W �= Y. <<Fourth Embodiment>> Figs. 13 to 15 illustrate the structures of antenna coils 24A, 24B, and 24C according to a fourth embodiment.
Fig. 13(A) is a plan view before the antenna coil 24A is assembled. Fig. 13(B) is a plan view of the antenna coil -20 -
S
24A. Fig. 14(A) is a plan view before the antenna coil 24B is assembled. Fig. 14(B) is a plan view of the antenna coil 24B. Similarly, Fig. 15(A) is a plan view before the antenna coil 24C is assembled. Fig. 15(B) is a plan view of the antenna coil 24C.
[00401 Each of the antenna coils 24A to 24C differs from the antenna coil 23 illustrated in Fig. 10 in that the end where the magnetic flux around the magnetic-material core 1 comes in and out is made wider than the remaining part. In the antenna coil 24A illustrated in Fig. 13, one end of the magnetic-material core 1 is wholly made wider (thicker). In the antenna coil 24B in Fig. 14, one end of the magnetic-material core 1 is expanded in a trapezoid shape. In the example of the antenna coil 24C in Fig. 15, the magnetic-material core 1 has a shape in which both ends are made wider than the central part.
[00411 The use of the magnetic-material cores 1 having the above shapes causes the magnetic flux passing through the magnetic-material core 1 to be expanded to increase the magnetic field coupling with a target antenna. As a result, the communication performance is improved, for example, the maximum cornmunicatable distance is increased.
[0042] -21 - <<Fifth Embodiment>> Fig. 16(A) is a plan view before an antenna coil 25 according to a fifth embodiment is assembled. Fig. 16(B) is a top view of the antenna coil 25. Fig. 16(C) is a bottom view of the antenna coil 25. A flexible substrate 10 is folded along a line indicated by a broken line in the figure and a magnetic-material core 1 is caught in the folded flexible substrate 10 (the flexible substrate 10 is wrapped over tree faces of the magnetic-material core 1). A coil conductor CW having a spiral shape around a position shifted from the fold line is formed on the flexible substrate 10.
Of the coil conductor CW, a side far from the fold line is used as a second conductor part 12 and a side near the fold line is used as a first conductor part 11.
[0043] Fig. 17(A) is a bottom view of an antenna 104 including the antenna coil 25. Fig. 17(B) is a front view of the antenna 104. The antenna coil 25 is installed along a central part of one side of the planar conductor 2, which is a circuit board.
[0044] Fig. 17(C) illustrates an example in which the antenna coil 25 is fixed in a casing 204 including the planar conductor 2, which is a circuit board, unlike the examples in Fig. 17(A) and Fig. 17(B). Also in this case, the second -22 -conductor part 12 is arranged in a position far from the center of the planar conductor 2, compared with the first conductor part 11.
Operational advantages similar to those described in the first embodiment are offered in the above manner.
[0045] <<Sixth Embodiment>> Figs. 18 to 20 illustrate the structures of antenna coils 26A, 263, and 26C according to a sixth embodiment.
Fig. 18(A) is a plan view before the antenna coil 26A is assembled. Fig. 18(B) is a plan view of the antenna coil 26A. Fig. 19(A) is a plan view before the antenna coil 26B is assembled. Fig. 19(B) is a plan view of the antenna coil 26B. Similarly, Fig. 20(A) is a plan view before the antenna coil 26C is assembled. Fig. 20(B) is a plan view of the antenna coil 26C.
[0046] Each of the antenna coils 26A to 26C differs from the antenna coil 25 illustrated in Fig. 16 in that the end where the magnetic flux around the magnetic-material core 1 comes in and out is made wider than the remaining part. In the antenna coil 26A illustrated in Fig. 18, one end of the magnetic-material core 1 is wholly made wider (thicker). In the antenna coil 263 in Fig. 19, one end of the magnetic-material core 1 is expanded in a trapezoid shape. In the -23 - example of the antenna coil 26C in Fig. 20, the magnetic-material core 1 has a shape in which both ends are made wider than the central part.
[0047] The use of the magnetic-material cores 1 having the above shapes causes the magnetic flux passing through the magnetic-material core 1 to be expanded to increase the magnetic field coupling with a target antenna. As a result, the communication performance is improved, for example, the maximum communicatable distance is increased.
[Reference Numerals] [0048] A through hole CA coil axis CW coil conductor DB directivity beam H magnetic flux MS1 first main face rvlS2 second main face S side 1 magnetic-material core 2 planar conductor flexible substrate 11 first conductor part 12 second conductor part -24 - 21 to 23 antenna coil 24A, 24B, 24C antenna coil antenna coil 26A, 26B, 26C antenna coil to 104 antenna 201 to 204 casing 301 reader-writer-side antenna 401 IC card -25 -
Claims (9)
- CLAI MS1. An antenna comprising an antenna coil and a planar conductor, the antenna coil including a plate magnetic-material core having a first main face and a second main face and a coil conductor wound around the magnetic-material core, the antenna coil being arranged closely to the planar conductor, wherein the first main face of the magnetic-material core opposes the planar conductor, wherein the planar conductor is a substantially rectangular plate, wherein the antenna coil is arranged toward a certain side with respect to the center of the planar conductor, wherein, of the coil conductor, a first conductor part close to the first main face of the magnetic-material core is positioned so as not to be over a second conductor part close to the second main face of the magnetic-material core in view from the normal line direction of the first main face or the second main face of the magnetic-material core, wherein the second conductor part is arranged in a position far from the center of the planar conductor, compared with the first conductor part, and wherein a coil axis of the coil conductor is orthogonal to the side of the planar conductor.
- 2. The antenna according to Claim 1, wherein the coil conductor has a conductor pattern in which a coil that is formed on a flexible substrate and that has a helical shape is cut out along a certain cutout line, and the flexible substrate is wound around four faces of the magnetic-material core to join the conductor pattern at the part corresponding to the cutout line.
- 3. The antenna according to Claim 1, wherein the coil conductor has a spiral shape, and the flexible substrate is wrapped over three faces of the magnetic-material core.
- 4. The antenna according to Claim 1, wherein the coil conductor has a spiral shape, the flexible substrate has a through hole provided at a central part of the position where the coil conductor is formed, and the magnetic-material core is inserted into the through hole.
- 5. The antenna according to any of Claims 1 to 4, wherein a relationship W �= Y is established, where W denotes the distance between the narrowest parts of the coil conductor, which connect the first conductor part to the second conductor part, and Y denotes the length of the magnetic-material core, which is orthogonal to the side of the planar conductor.
- 6. The antenna according to any of Claims 1 to 5, wherein an end of the magnetic-material core, where magnetic flux comes in and out, is made wider than the remaining part.
- 7. The antenna according to any of Claims 1 to 6, wherein a relationship Y > X is established1 where X denotes the distance from the end of the antenna toward the side of the planar conductor to the side of the planar conductor and Y denotes the length of the magnetic-material core, which is orthogonal to the side of the planar conductor.
- 8. The antenna according to any of Claims 1 to 7, wherein the planar conductor is a circuit board on which the antenna coil is installed.
- 9. An antenna substantially as herein described with reference to the accompanying drawings 2 to 20.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009091381A JP4883125B2 (en) | 2009-04-03 | 2009-04-03 | antenna |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201005634D0 GB201005634D0 (en) | 2010-05-19 |
| GB2469209A true GB2469209A (en) | 2010-10-06 |
| GB2469209B GB2469209B (en) | 2011-12-14 |
Family
ID=42228840
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1005634.9A Active GB2469209B (en) | 2009-04-03 | 2010-04-01 | Antenna |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP4883125B2 (en) |
| CN (2) | CN101859923B (en) |
| GB (1) | GB2469209B (en) |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004048135A (en) * | 2002-07-09 | 2004-02-12 | Mitsui Chemicals Inc | Rfid antenna |
| JP2005033461A (en) * | 2003-07-11 | 2005-02-03 | Mitsubishi Materials Corp | Rfid system and structure of antenna therein |
| US20060187053A1 (en) * | 2005-01-13 | 2006-08-24 | Werner Koele | Identifiable packaging |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5638080A (en) * | 1993-01-22 | 1997-06-10 | Texas Instruments Incorporated | Manufacture of a flexible antenna, with or without an inner permeable magnetic layer |
| JP2001028510A (en) * | 1999-07-13 | 2001-01-30 | Yoshikawa Rf System Kk | Antenna for data carrier and data carrier using the same |
| US6396455B1 (en) * | 2000-11-14 | 2002-05-28 | Sensormatic Electronics Corporation | Antenna with reduced magnetic far field for EAS marker activation and deactivation |
| JP4196554B2 (en) * | 2001-09-28 | 2008-12-17 | 三菱マテリアル株式会社 | Tag antenna coil and RFID tag using the same |
| CN101308947A (en) * | 2002-01-17 | 2008-11-19 | 三菱麻铁里亚尔株式会社 | Antenna for reader/writer and reader/writer having the antenna |
| JP2003318634A (en) * | 2002-04-24 | 2003-11-07 | Smart Card:Kk | Noncontact sensor coil |
| AU2003304672A1 (en) * | 2003-11-28 | 2005-06-17 | Fujitsu Limited | Information processing device having non-contact reader and/or writer and coil antenna for magnetic connection |
| JP3933191B1 (en) * | 2006-03-13 | 2007-06-20 | 株式会社村田製作所 | Portable electronic devices |
-
2009
- 2009-04-03 JP JP2009091381A patent/JP4883125B2/en active Active
-
2010
- 2010-04-01 GB GB1005634.9A patent/GB2469209B/en active Active
- 2010-04-02 CN CN2010101547243A patent/CN101859923B/en active Active
- 2010-04-02 CN CN201310052252.4A patent/CN103178346B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004048135A (en) * | 2002-07-09 | 2004-02-12 | Mitsui Chemicals Inc | Rfid antenna |
| JP2005033461A (en) * | 2003-07-11 | 2005-02-03 | Mitsubishi Materials Corp | Rfid system and structure of antenna therein |
| US20060187053A1 (en) * | 2005-01-13 | 2006-08-24 | Werner Koele | Identifiable packaging |
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| US9917366B2 (en) * | 2011-02-15 | 2018-03-13 | Murata Manufacturing Co., Ltd. | Antenna device and communication terminal apparatus |
| EP2693562A4 (en) * | 2011-03-30 | 2014-09-17 | Dexerials Corp | Antenna apparatus and communication apparatus |
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| US9252488B2 (en) | 2011-03-30 | 2016-02-02 | Dexerials Corporation | Antenna apparatus and communication apparatus |
| US8669909B2 (en) | 2011-11-30 | 2014-03-11 | Panasonic Corporation | Antenna, antenna apparatus, and communication apparatus |
| US9172141B2 (en) | 2011-11-30 | 2015-10-27 | Panasonic Corporation | Antenna, antenna apparatus, and communication apparatus |
| US9543656B2 (en) | 2014-01-31 | 2017-01-10 | Toko, Inc. | Three-axis antenna |
| EP2903087A1 (en) * | 2014-01-31 | 2015-08-05 | Toko, Inc. | Three-axis antenna |
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| US9972909B2 (en) | 2014-05-13 | 2018-05-15 | Murata Manufacturing Co., Ltd. | Three-axis antenna |
| EP2945221A1 (en) * | 2014-05-13 | 2015-11-18 | Toko, Inc. | Three-axis antenna |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN101859923B (en) | 2013-03-13 |
| CN103178346A (en) | 2013-06-26 |
| JP4883125B2 (en) | 2012-02-22 |
| JP2010245776A (en) | 2010-10-28 |
| CN101859923A (en) | 2010-10-13 |
| CN103178346B (en) | 2016-08-10 |
| GB201005634D0 (en) | 2010-05-19 |
| GB2469209B (en) | 2011-12-14 |
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