JP2014086945A - Antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device capable of improving communication characteristics by increasing an area for generating a magnetic flux therein and increasing the magnetic flux.SOLUTION: The antenna device comprises: a circuit board 2 on which a feeder FP is formed; and an antenna part 3 which is connected to the feeder, provided on the circuit board and receives data. The antenna part includes a plurality of coil-like conductors connected to the feeder, and at least one of the plurality of coil-like conductors is built in a laminate chip antenna 4 packaged on the circuit board. The laminate chip antenna includes: a plurality of laminated ceramics material layers which are chip-shaped as a whole; a chip-side conductor pattern 13 to be a coil-like conductor provided between neighboring ceramics material layers; and a pair of terminal electrodes 14 provided on a pair of end faces, connected to an end of the chip-side conductor pattern and connected to the feeder. The plurality of coil-like conductors are disposed side by side on the circuit board and wound in the same direction.

Description

  The present invention relates to an antenna device used in an RFID reader device or the like that reads or writes data without contact.

  Conventionally, non-contact communication devices such as RFID (Radio Frequency Identification) reader devices or RFID reader / writer devices are various as wireless ICs, IC cards, non-contact data carriers and readers / writers thereof that communicate with each other by electromagnetic induction. (See Patent Documents 1 and 2). In recent years, this non-contact communication apparatus has been mounted on small information terminals such as smartphones and tablet PCs.

  As shown in FIG. 9, the wireless communication function of the RFID reader / writer device includes, for example, an IC unit 7, a matching circuit unit 8 (matching circuit), and an antenna unit 103. By downsizing the RFID reader / writer device, the antenna unit 103, the IC unit 7, and the matching circuit unit 8 are arranged in a very small space of the circuit board 101.

JP2012-19330A JP 2008-186327 A JP 2000-261230 A

The following problems remain in the conventional technology.
In recent years, as shown in FIG. 10, it has been studied to further reduce the size of the whole by adopting a small antenna element 100 incorporating a coiled conductor pattern 102 as an antenna portion. This small RFID antenna element 100 has the greatest feature that it is made into a chip and is small, and the inductance is increased by the magnetic flux converging effect of the magnetic material as compared with the pattern antenna of the same size as shown in FIG. As a result, the characteristic of increasing the magnetic flux radiated from the antenna (magnetic flux φ = inductance L × current i) is used.
However, the communication distance between the small RFID antenna and the non-contact IC card is assumed to be several tens of millimeters from the contact state. Particularly in communication applications of 30 mm or more, the small antenna element 100 alone is still practically a magnetic flux. The communication distance was insufficient. One reason for the short communication distance is the antenna size.

  Communicates between a reader / writer (R / W) that uses an antenna element for a small RFID and a non-contact IC card (ID-1 type defined in JIS X 6301) that is generally used for credit cards. In this case, since the antenna sizes are different from each other, the magnetic field coupling (mutual inductance) is small, and the communication distance is short compared to the R / W using a large antenna (for example, a size close to the ID-1 type size). Therefore, there is a demand for a method of increasing the magnetic flux and increasing the magnetic flux in order to further improve the communication characteristics (communication distance and compatible non-contact IC card) while maintaining the characteristics of the small antenna element.

Although the magnetic flux φ is proportional to the magnetic flux density B (magnetic flux φ = magnetic flux density B × area S), it is possible to increase the magnetic flux density B by increasing the number of turns of the coil. This is particularly effective when the area of the antenna is limited. However, since the antenna element for small RFID is spirally wound, if the number of turns increases from the antenna element 100 shown in FIG. 11A to the antenna element 100A shown in FIG. Even if the magnetic flux density B can be increased, the magnetic flux φ cannot be increased as a result, and there is a trade-off relationship between the number of turns and the area.
As a method of increasing the number of turns in a layered manner, there is a technique described in Patent Document 3, but there is another problem that the capacity between layers cannot be ignored, the capacity increases, and the resonance frequency decreases. In any case, there is a limit to the use of a small antenna element alone.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an antenna device capable of increasing the magnetic flux generation area and increasing the magnetic flux to improve the communication characteristics.

  The present invention employs the following configuration in order to solve the above problems. That is, an antenna device according to a first aspect of the present invention includes a circuit board on which a feed line is formed, and an antenna unit that is connected to the feed line and is provided on the circuit board to receive data. A plurality of coiled conductors connected to the feeder line, and at least one of the plurality of coiled conductors is built in a multilayer chip antenna mounted on the circuit board; Is formed in a chip shape, and is provided on a pair of end surfaces facing each other, a plurality of laminated ceramic material layers, a chip-side conductor pattern serving as the coiled conductor provided between adjacent ceramic material layers. A pair of end electrodes connected to the ends of the chip-side conductor pattern and connected to the feeder line, and the plurality of coiled conductors are arranged on the circuit board. Together are characterized in that the current flows in the same direction with respect to the central axis and wound in the same direction.

  In this antenna device, a plurality of coiled conductors are arranged side by side on the circuit board, and are wound in the same direction so that current flows in the same direction with respect to the central axis. Magnetic fluxes generated by the conductors form an open loop, and a large amount of magnetic flux is generated over a wide area. Therefore, the area where the magnetic flux is generated and the generated magnetic flux are increased by the plurality of coiled conductors arranged in the same winding direction, so that the communication distance can be improved. In addition, at least one of the plurality of coiled conductors is incorporated in a small multilayer chip antenna, and compared to a case where a plurality of coiled conductors are configured only by a plurality of substrate-side conductor patterns formed on a circuit board. Thus, it is possible to increase the magnetic flux with a small size as a whole.

The antenna device according to a second invention is characterized in that, in the first invention, one of the plurality of coiled conductors is a board-side conductor pattern formed in a pattern on the circuit board.
That is, in this antenna device, since one of the plurality of coiled conductors is a board-side conductor pattern formed on the circuit board, the board-side conductor pattern can be formed as an extension of the feeder line on the circuit board. The magnetic flux can be increased without increasing the number of members. Further, by employing a small multilayer chip antenna, it is possible to arrange the substrate-side conductor pattern by utilizing the excess surrounding space, and it is possible to generate a magnetic field efficiently.

An antenna device according to a third invention is characterized in that, in the first or second invention, a plurality of the laminated chip antennas are mounted side by side on the circuit board.
That is, in this antenna device, since a plurality of laminated chip antennas are mounted side by side on the circuit board, a plurality of regions having a large magnetic flux can be provided within a relatively small range by mounting a small number of laminated chip antennas side by side. They can be arranged, and the area for generating magnetic flux more efficiently can be increased.

An antenna device according to a fourth invention is the antenna device according to any one of the first to third inventions, wherein the ceramic material layer is formed of a mixed material in which a dielectric material and a magnetic material are added and laminated. A magnetic layer made of a metal oxide magnetic material or a material obtained by mixing the magnetic material and a sintering aid glass material, which is a material layer and is laminated on the lowermost ceramic material layer. It is characterized by being.
That is, in this antenna apparatus, the ceramic material layer is formed of a metal oxide magnetic material layer or a material obtained by mixing the magnetic material and a sintering aid glass material, which is laminated on the lowermost ceramic material layer. Since the magnetic layer is provided, the magnetic flux concentrates on the magnetic layer with a high real part of the magnetic permeability and a low imaginary part, and the magnetic flux flows in the magnetic layer without loss, and the inductance does not change. Communication is obtained. In addition, since a plurality of ceramic material layers and magnetic layers laminated via the chip-side conductor pattern are integrally formed into a chip and end electrodes are formed on a pair of end surfaces, characteristic variation In addition, it can be further miniaturized and can be surface-mounted by a reflow process.

An antenna device according to a fifth invention is the RFID reader device according to any one of the first to fourth inventions, wherein the antenna device reads at least data from the RFID tag by electromagnetic induction or electromagnetic coupling.
That is, since this antenna device is an RFID reader device, it can read data satisfactorily without contact and can be miniaturized.

The present invention has the following effects.
That is, according to the antenna device of the present invention, a plurality of coiled conductors are arranged side by side on the circuit board, and are wound in the same direction so that current flows in the same direction with respect to the central axis. The area where magnetic flux is generated and the generated magnetic flux are increased, and the communication distance can be improved.
Therefore, the present invention is suitable for an RFID reader device and the like because an antenna device with good communication characteristics can be obtained.

It is the top view which shows 1st Embodiment of the antenna device which concerns on this invention, and explanatory drawing which shows the state of magnetic flux. In 1st Embodiment, it is simple sectional drawing which shows a laminated chip antenna. In 1st Embodiment, it is a disassembled perspective view except the edge part electrode of the multilayer chip antenna. It is explanatory drawing which shows the plan view and the state of a magnetic flux which show the antenna apparatus with which the mutual winding direction of a chip | tip side conductor pattern and a board | substrate side conductor pattern is reverse. It is a top view which shows 2nd Embodiment of the antenna device which concerns on this invention. It is a top view which shows 3rd Embodiment (a) of the antenna apparatus which concerns on this invention, and the antenna apparatus (b) from which the mutual winding direction of two chip | tip side conductor patterns is reverse. It is a top view which shows 4th Embodiment of the antenna device which concerns on this invention. In the Example of the antenna device which concerns on this invention, it is explanatory drawing which shows the magnetic field strength measurement method. FIG. 2 is a plan view showing a configuration of an RFID reader / writer device in a conventional example of an antenna device according to the present invention. It is a top view which shows the RFID reader / writer apparatus using an antenna element. It is explanatory drawing for showing the state of the magnetic flux when changing the number of turns of the chip side conductor pattern (a) (b).

  Hereinafter, a first embodiment of an antenna apparatus according to the present invention will be described with reference to FIGS. 1 to 4. In each drawing used for the following description, the scale is appropriately changed in order to make each member recognizable or easily recognizable.

  The antenna device 1 according to the first embodiment is an RFID reader device that reads at least data from an RFID tag by, for example, electromagnetic induction or electromagnetic coupling, and includes a circuit in which a feed line FP is formed as shown in FIG. A board 2 and an antenna unit 3 connected to the feeder line FP and provided on the circuit board 2 for receiving data are provided. The feeder line FP is a metal wiring pattern formed on the circuit board 2.

The circuit board 2 can be a printed board, a rigid board, or a flexible board.
The antenna unit 3 has a plurality of coiled conductors connected to the feeder line FP, and at least one of the plurality of coiled conductors is built in the multilayer chip antenna 4 mounted on the circuit board 2. .

  2 and 3, the laminated chip antenna 4 is formed in a chip shape as a whole, and is provided between the laminated ceramic material layers 12A to 12D and the adjacent ceramic material layers 12A and 12B. A chip-side conductor pattern 13 serving as a coiled conductor, and a pair of end electrodes 14 provided on a pair of opposing end surfaces and connected to the ends of the chip-side conductor pattern 13 and connected to the feeder line FP. ing.

  One of the plurality of coiled conductors is a board-side conductor pattern 5 that is patterned on the circuit board 2. The substrate-side conductor pattern 5 is spirally provided next to the laminated chip antenna 4 in which the chip-side conductor pattern 13 is built, and a part thereof is formed on the back surface side through the through hole H1. That is, the substrate-side conductor pattern 5 and the chip-side conductor pattern 13 are formed in the same winding direction with respect to their own central axes. For example, Cu, Ag, Au, Sn, or an alloy material thereof can be used as the material of the substrate-side conductor pattern 5, but other materials may be used as long as they are conductors.

  In addition, as shown in FIG. 1, the antenna device 1 includes a circuit unit 6 that feeds power to the antenna unit 3 through a feed line FP. The circuit unit 6 is connected to an oscillator (not shown) and connected to the reader / writer IC unit 7 mounted on the circuit board 2, and the IC unit 7 and wiring on the circuit board 2. And a matching circuit unit 8 that is a matching circuit connected to the feeder line FP.

  The plurality of coiled conductors, that is, the chip-side conductor pattern 13 and the board-side conductor pattern 5 are arranged side by side on the circuit board 2 and are wound in the same direction and in the same direction with respect to the central axis. The current is set to flow. In the present embodiment, the chip-side conductor pattern 13 and the substrate-side conductor pattern 5 are electrically connected in series, but may be connected in parallel. Note that the matching circuit constant can be made smaller in the series, and more current flows through the antenna unit and the magnetic flux is larger than in the parallel case. In each figure, the direction of current flow at a certain point is indicated by an arrow.

The ceramic material layers 12 </ b> A to 12 </ b> D are a plurality of ceramic material layers formed and laminated with a mixed material in which a dielectric material and a magnetic material are added.
The laminated chip antenna 4 is a magnetic body formed of a metal oxide magnetic material layer or a material obtained by mixing the magnetic material and a sintering aid glass material, which is laminated on the lowermost ceramic material layer 12D. Layer 15 is provided.

  The chip-side conductor pattern 13 is a conductor wiring formed of a single noble metal such as gold, silver, platinum, palladium, or an alloy thereof. The chip-side conductor pattern 13 is formed in a spiral pattern on the outer periphery of the upper surface of the rectangular flat ceramic material layer 12B. The inner end of the chip-side conductor pattern 13 passes through the through hole H2. It is connected to a connecting conductor pattern 13a formed on the lower ceramic material layer 12C. The connection conductor pattern 13 a is connected to the end electrode 14. Thus, the chip side conductor pattern 13 is connected to the end electrodes 14 at both ends to constitute a chip antenna.

The multilayer chip antenna 4 of this embodiment has a flat chip size of, for example, 10 mm × 15 mm × 1 mm, and the chip-side conductor pattern 13 is wound with 5.5 turns (in FIG. Omitted). The chip-side conductor pattern 13 may be wound as long as one turn or more.
The chip-side conductor pattern 13 is formed on the ceramic composite material green sheet by printing or photolithography.

Each ceramic material layer 12A-12D is formed by laminating ceramic composite material green sheets made of the above-mentioned mixed material formed by a sheet casting method, a printing method, or an extrusion molding method.
Various known materials can be used as the dielectric material of the ceramic material layers 12A to 12D, but PbO / La ₂ O ₃ / BaTiO ₃ / Ag ₂ O / ZrO ₂ / TiO ₂ / WO ₃ relaxor system A material is preferred. As the magnetic material of the ceramic material layers 12A to 12D, various known materials can be used, but an Fe ₂ O ₃ / Ni ₂ O / CuO / ZnO based ferrite material is preferable.

The magnetic layer 15 is made of a magnetic material green made of a metal oxide magnetic material formed by a sheet casting method, a printing method, or an extrusion method, or a material obtained by mixing the magnetic material and a glass material of a sintering aid. It is formed by using a sheet.
As the magnetic material of the magnetic layer 15, various known materials can be adopted, but an Fe ₂ O ₃ / Ni ₂ O / CuO / ZnO-based ferrite material is preferable.

For example, as the PbO / La ₂ O ₃ / BaTiO ₃ / Ag ₂ O / ZrO ₂ / TiO ₂ / WO ₃ relaxor material of the dielectric material, PbO: 45-60 wt%, La ₂ O ₃ : 3 _{10wt%, BaTiO 3: 5~10wt%} , Ag 2 O: 0.1~1.0wt%, ZrO 2: 15~30wt%, TiO 2: 3~10wt%, WO 3: contained 3～10Wt% What has a component composition is employ | adopted.
Further, as the Fe ₂ O ₃ / Ni ₂ O / CuO / ZnO ferrite material of the magnetic material, Fe ₂ O: 55 to 70 wt%, ZnO: 10 to 20 wt%, NiO: 5 to 15 wt%, CuO: What has the component composition containing 5-10 wt% is employ | adopted.

  In order to manufacture the multilayer chip antenna 4, first, a ceramic composite material green sheet on which the chip-side conductor pattern 13 is not formed, a ceramic composite material green sheet on which the chip-side conductor pattern 13 is formed, a magnetic green sheet, A predetermined number of sheets are prepared. Next, these green sheets are laminated in a predetermined order, and through holes H2 are formed to connect the chip-side conductor patterns 13 to form a sheet laminate.

Furthermore, after cutting this sheet | seat laminated body into a chip shape, it bakes and it is set as a chip-shaped sintered compact. In addition, after baking a sheet | seat laminated body, it is good also as a chip-shaped sintered compact by cut | disconnecting in a chip shape. Next, the pair of end electrodes 14 are formed on the pair of side surfaces of the chip-shaped sintered body by a technique such as printing or roll coating, and the laminated chip antenna 4 is manufactured.
The pair of end electrodes 14 serves as a power receiving / power feeding terminal and a mounting terminal. In addition, a mounting pad portion (not shown) that is bonded to the end electrode 14 with a solder material or the like is disposed at the end of the power supply line FP that is disposed immediately below the end electrode 14 and extends from the substrate-side conductor pattern 5. Is formed.

  As described above, in the antenna device 1 of the present embodiment, the plurality of coiled conductors are arranged side by side on the circuit board 2 and are wound in the same direction so that current flows in the same direction with respect to the central axis. Therefore, as shown in FIG. 1B, magnetic fluxes generated by a plurality of coiled conductors (chip-side conductor pattern 13 and substrate-side conductor pattern 5) arranged side by side form an open loop and have a large area in a large area. Magnetic flux is generated. As shown in FIG. 4A, when the winding directions of the chip-side conductor pattern 13 and the substrate-side conductor pattern 5 are opposite to each other, as shown in FIG. The magnetic flux is reduced because the magnetic flux is in reverse phase and a closed loop is formed.

  Therefore, by adopting a plurality of coiled conductors arranged in the same winding direction as in the present embodiment, the area where the magnetic flux is generated and the generated magnetic flux are increased, and the communication distance can be improved. When at least one of the plurality of coil-shaped conductors is built in the small multilayer chip antenna 4 and the plurality of coil-shaped conductors are configured only by the plurality of substrate-side conductor patterns formed on the circuit board 2. Compared to the above, it is possible to increase the magnetic flux with a small size as a whole.

  In addition, since one of the plurality of coiled conductors is the board-side conductor pattern 5 patterned on the circuit board 2, the board-side conductor pattern 5 is formed on the circuit board 2 as an extension of the feeder line FP. The magnetic flux can be increased without increasing the number of members. In addition, since the small multilayer chip antenna 4 is employed, the board-side conductor pattern 5 can be arranged by utilizing the excess surrounding space, and a magnetic field can be generated efficiently.

  In addition, since the magnetic layer 15 is formed of a metal oxide magnetic material or a material obtained by mixing the magnetic material and a sintering aid glass material, which is laminated on the lowermost ceramic material layer, Magnetic flux concentrates on the magnetic layer 15 having a high real part and a low imaginary part, and the magnetic flux flows in the magnetic layer 15 without loss, and good communication is obtained without any change in inductance. A plurality of ceramic material layers 12A to 12D and a magnetic layer 15 laminated via the chip-side conductor pattern 13 are integrally formed into a chip, and end electrodes 14 are formed on a pair of end surfaces. Therefore, there is little variation in characteristics, and further miniaturization is possible, and surface mounting by a reflow process or the like is possible.

The dielectric material of the ceramic material layers 12A to 12D is a PbO / La ₂ O ₃ / BaTiO ₃ / Ag ₂ O / ZrO ₂ / TiO ₂ / WO ₃ relaxor material, and the magnetic material is Fe _2. Since it is an O ₃ / Ni ₂ O / CuO / ZnO ferrite material, the lead composite perovskite crystal structure of the dielectric material and the spinel crystal structure of the magnetic material are not changed by sintering and are maintained. Accordingly, the ceramic material layer has a capacitance obtained by the dielectric material characteristics of the relaxor material having stable DC bias characteristics, and the magnetic material of the ferrite material having high reliability even when mixed and fired to the relaxor material. It is possible to combine both the characteristics obtained by the material characteristics and the inductance.

  Next, second to fourth embodiments of the antenna device according to the present invention will be described below with reference to FIGS. In the following description of each embodiment, the same constituent elements described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, a plurality of coiled conductors are formed on the circuit board 2 and the chip side conductor pattern 13 built in the multilayer chip antenna 4. Whereas the conductor pattern 5 is employed, in the antenna device 21 of the second embodiment, the laminated chip antenna 4 incorporating the chip-side conductor pattern 13 is formed on the surface of the circuit board 2 as shown in FIG. It is a point that two are mounted side by side.

That is, in the second embodiment, two laminated chip antennas 4 are mounted on the circuit board 2 with the end electrodes 14 facing each other, and the internal chip-side conductor pattern 13 is set in the same winding direction. ing. Note that the two laminated chip antennas 4 are connected in series with the end electrodes 14 facing each other connected by a feeder line FP.
As described above, in the antenna device 21 according to the second embodiment, since a plurality of the laminated chip antennas 4 are mounted side by side on the circuit board 2, it is relatively small because the small laminated chip antennas 4 are mounted side by side. A plurality of regions having a large magnetic flux can be arranged in the range, and the area for generating the magnetic flux more efficiently can be increased.

Next, the difference between the third embodiment and the second embodiment is that, in the second embodiment, the two laminated chip antennas 4 are mounted with the end electrodes 14 facing each other. In the antenna device 31 of the third embodiment, as shown in FIG. 6A, two laminated chip antennas 4 are mounted with a pair of end electrodes 14 arranged in a direction orthogonal to the opposing direction. Is a point.
As described above, in the third embodiment, similarly to the second embodiment, a plurality of regions having a large magnetic flux can be arranged within a relatively small range by mounting the small laminated chip antennas 4 side by side.

  As shown in FIG. 6B, if two laminated chip antennas 4 are mounted with the winding directions of the chip-side conductor patterns 13 reversed, as in the case of FIG. Since the closed magnetic flux is formed in a reverse phase, it is necessary to prevent the wrong orientation when mounting the laminated chip antenna 4.

  Further, the difference between the fourth embodiment and the second embodiment is that in the second embodiment, two laminated chip antennas 4 are mounted side by side, whereas in the antenna device 41 of the fourth embodiment, As shown in FIG. 7, the four laminated chip antennas 4 are mounted side by side. That is, in the fourth embodiment, four laminated chip antennas 4 are arranged in two vertical rows and two horizontal rows, and two laminated chip antennas 4 connected in parallel are connected in series by a feeder line FP. ing.

  Therefore, in the antenna device 41 of the fourth embodiment, the four laminated chip antennas 4 arranged can generate a magnetic flux in a wider area than when the two laminated chip antennas 4 are arranged.

  Comparative Example 1 of an antenna device in which only one multilayer chip antenna 4 is mounted without the substrate-side conductor pattern 5 and Example 1 which is an antenna device of the second embodiment in which two multilayer chip antennas 4 are arranged are read. -Using as a writer, a communication distance test was performed on a non-contact IC card of FeliCa standard and a non-contact IC card of Type A standard. Table 1 shows the maximum communication distance at that time. Moreover, in Example 1, it measured by changing the space | interval of the two laminated chip antennas 4 to 0-50 mm. In Table 1, Comparative Example 1 is described as “when only one stacked small chip RFID antenna is used”, and Example 1 is expressed as “when two stacked small chip RFID antennas are connected in series to change the gap from 0 mm to 50 mm”. doing.

  As a result of these tests, in Comparative Example 1, the communication distance with the non-contact IC card of the FeliCa standard was 26 mm, whereas in Example 1, the communication distance was further improved by 4 mm or more, and the interval was increased to 30 mm. It was improved by up to 9 mm in the state where it was done. In Comparative Example 1, the communication distance with the Type A non-contact IC card was 17 mm, whereas in Example 1, the communication distance was further improved by 10 mm or more, and the distance was increased to 30 mm. Improved by up to 15 mm.

  The technical scope of the present invention is not limited to the above embodiments and examples, and various modifications can be made without departing from the spirit of the present invention.

For example, in each of the above embodiments, the coiled conductor is wound in a rectangular spiral shape, but may be wound in a circular or elliptical spiral shape. In addition to a single-layer chip-side conductor pattern, a multilayer structure connected through through holes may be used, or a three-dimensional coil shape or a spiral shape may be used.
In each of the above embodiments, the magnetic layer is simultaneously fired together with the ceramic material layer, but may be separately fired and bonded together with an adhesive such as a glass material to be integrated.

  DESCRIPTION OF SYMBOLS 1, 21, 31, 41 ... Antenna device, 2 ... Circuit board, 3 ... Antenna part, 4 ... Laminated chip antenna, 5 ... Board side conductor pattern, 12A-12D ... Ceramic material layer, 13 ... Chip side conductor pattern, 14 ... End electrode, 15 ... Magnetic layer, FP ... Feed line

Claims (5)

A circuit board on which a feed line is formed;
An antenna unit connected to the feeder line and provided on the circuit board for receiving data;
The antenna unit has a plurality of coiled conductors connected to the feeder line,
At least one of the plurality of coiled conductors is built in a multilayer chip antenna mounted on the circuit board,
The multilayer chip antenna is entirely formed in a chip shape, and a plurality of laminated ceramic material layers, and a chip side conductor pattern serving as the coiled conductor provided between the adjacent ceramic material layers, face each other. A pair of end electrodes provided on a pair of end surfaces and connected to an end of the chip-side conductor pattern and connected to the feeder line,
The antenna device, wherein the plurality of coiled conductors are arranged side by side on the circuit board and are wound in the same direction so that current flows in the same direction with respect to the central axis. The antenna device according to claim 1,
One of the plurality of coiled conductors is a board-side conductor pattern in which a pattern is formed on the circuit board. In the antenna device according to claim 1 or 2,
A plurality of the laminated chip antennas are mounted side by side on the circuit board. In the antenna device according to any one of claims 1 to 3,
The ceramic material layers are a plurality of ceramic material layers formed and laminated of a mixed material obtained by adding a dielectric material and a magnetic material,
Characterized in that it is provided with a magnetic layer formed of a metal oxide magnetic material or a material obtained by mixing the magnetic material and a sintering aid glass material, which is laminated on the lowermost ceramic material layer. Antenna device to do. In the antenna device according to any one of claims 1 to 4,
An antenna device, wherein the antenna device is an RFID reader device that reads at least data from an RFID tag by electromagnetic induction or electromagnetic coupling.

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