Abstract: An antenna apparatus used in a wireless communication medium or a wireless communication medium processing apparatus constructed by a constitution of including a magnetic member in which a magnetic ceramic powder is used as a major component thereof and which is provided with flexibility; an antenna formed at a surface or inside of the magnetic member, and a matching circuit of the antenna formed at the surface or the inside of the magnetic member.

Abstract: A method to produce a rod tag and tag produced according to the method, wherein the method comprises at least the steps of: providing a magnetic core having a cylindrical shape and two end, winding a wire around said core to form an antenna, positioning in longitudinal extension a chip at one of the ends of said rod where the wound wire ends terminates, bonding said wire ends to contacts of said chip, displacing said bonded chip at least partially on said end of said rod, introducing said core with said wire and said chip in an encapsulating means containing a stabilizing material, whereby the chip is further positioned on said end by the friction between said chip and said material during introduction.

Abstract: An antenna device that includes coil antennas each having a coil conductor wound around a winding axis and a planar conductor including a surface and an edge end portion, the surface extending along the winding axis of the coil conductor, the edge end portion being adjacent to a coil opening of the coil conductor. A current flowing through the coil conductor induces a current in the planar conductor, this current produces a magnetic flux in a direction normal to the planar conductor, and thus the planar conductor acts as a booster antenna. The antenna device has directivity in the direction normal to the planar conductor because the magnetic flux produced by the coil antennas and that produced by the planar conductor are combined. This enables the antenna device to occupy a small area while achieving a predetermined communication distance.

Abstract: This disclosure provides systems, methods and apparatus for wireless power transfer using resonant ferrite antennas to transmit and receive power. Ferrite structures concentrate magnetic flux lines into the structure, thereby creating a magnetic path and field with less interference and eddy current losses than in device electronics, thereby improving the efficiency of magnetic power distribution. The disclosure describes tuning the resonance frequency by mechanically adjusting the position of the coil on the rod. The ferrite rod antennas described herein may be used to transfer power to handheld communication devices.

Abstract: A composite magnetic antenna for information communication utilizes a magnetic field component as well as a composite RF tag using the composite magnetic antenna, which can be embedded in metals while maintaining a sufficient communication sensitivity unlike conventional RF tags which are unusable in the metal embedding applications. The composite RF tag for transmitting and receiving information using an electromagnetic induction method includes a magnetic antenna on which an IC is mounted, and an insulating material and a metal material or a conductive material which are formed around the magnetic antenna. The magnetic antenna includes a central core formed of a magnetic material, and an electrode material formed into a coil around the central core. The insulating material is formed around the magnetic antenna except for one longitudinal end of the coil of the magnetic antenna. The metal material or the conductive material is formed on an outside of the insulating material.

Abstract: An antenna device or a communication terminal device including the antenna device includes ground conductor, which serves as a plate-shaped conductor and is provided in an inner layer of a circuit board. An antenna coil is mounted so that a first main surface of a magnetic core faces the circuit board. The antenna coil is arranged so that a first conductor portion of a coil conductor is at a position that is closer to the ground conductor than a second conductor portion. The antenna coil is arranged so that the first conductor portion of the coil conductor is positioned in the vicinity of a longitudinal direction end portion of a casing, and the first conductor portion of the coil conductor is bent in a direction toward the ground conductor.

Abstract: A directional resistivity tool includes a pair of transmitters deployed between at least one pair of receivers. Each of the transmitters and receivers preferably includes collocated z-mode and x-mode antennae. Exemplary embodiments may further include additional receivers, for example, additional pairs of receivers deployed axially about the transmitters or one or more deep reading receivers deployed on one axial end of the transmitters. Tools in accordance with the invention enable directional resistivity measurements to be acquired at multiple depths of investigation using fewer transmitter firings than conventional tools.

Abstract: A communication device includes a conductor plane, a first loop antenna disposed on one surface of the conductor plane via a first magnetic sheet, a second loop antenna being in a loop direction opposite to a loop direction of the first loop antenna and having an opening structure approximately identical in shape to the first loop antenna, the second loop antenna being disposed on another surface of the conductor plane via a second magnetic sheet so as to be roughly superposed on the first loop antenna, and a communication circuit processing a communication signal transmitted and received by the first and second loop antennas.

Abstract: An antenna device includes an antenna coil including a first conductive pattern disposed on a first major surface of a magnetic sheet, a second conductive pattern disposed on a first major surface of a non-magnetic sheet, and an interlayer conductor connecting the first conductive pattern and second conductive pattern. The antenna coil including the first conductive pattern and second conductive pattern defines a spiral or substantially spiral pattern. The antenna device is a resin multilayer structure in which its base body is a laminate of the magnetic layer and non-magnetic layer and the predetermined patterns are disposed inside and outside the laminate.

Abstract: A radio-wave receiver is provided with a hollow-cylindrical case, a plate-like module member accommodated within the cylindrical case, a transparent member closing one opening end of the cylindrical case, a cover closing the other opening end of the cylindrical case, and an antenna structure disposed on the side position of the plate-like module member. The antenna structure is provided with a core including a plurality of plate-like magnetic members layered on each other in a direction perpendicular to the thickness direction of the plate-like module member, a coil wound around a central straight part of the core, and bent end portions extending from both ends of the core and bent to conform to the inner periphery of the cylindrical case.

Abstract: The claimed invention discloses an antenna including: a magnetic core (11); a coil winding section (14a, 14b) in which a conductive wiring line is wound around the magnetic core; and an adjustment section (13) connected to one end of the coil winding section. The adjustment section (13) is disposed at an end part of the magnetic core (11) and includes a plurality of adjustable conductive wiring lines (13b-13d) formed by dividing a conductive wiring line connected to one end of the coil winding section (14a, 14b) into multiple conductive wiring lines in a direction intersecting with a winding axis direction of the coil winding section (14a, 14b).

Abstract: The present invention provides an antenna coil which can be made smaller and intends to improve a receiving sensitivity in consideration of all directions. According to one embodiment of the present invention, an antenna coil including: a first coil 4 having an X-axis coil wound on an X axis of a first core and a Z-axis coil wound on a Z axis of the first core, the thickness direction of the first core being determined to be the Z-axis, an axis orthogonal to the Z axis being determined to be the X axis; a second coil 5 having a Y-axis coil wound around a second core, the second core having flanges at both ends; four external terminals 3 each connected to a corresponding end of the X-axis coil or the Z-axis coil and additionally provided on the first core; and two external terminals 3 each connected to a corresponding end of the Y-axis coil and additionally provided on the second core.

Abstract: An antenna includes an elongated magnetic core, a secondary magnetic path member, a spacer and a coil. The secondary magnetic path member is disposed near the core, and forms a secondary magnetic path. The spacer is disposed between the core and the secondary magnetic path member so as to prevent the core and the secondary magnetic path member from being magnetically coupled. The coil is formed by winding a wire around the core in such a way as to bundle the core and the secondary magnetic path member together.

Abstract: In antenna device, a coil conductor of an antenna coil module and a conductor layer at least partially overlap. A current flows in the conductor layer to block a magnetic field generated by a current flowing in the coil conductor. A current flows along the periphery of a slit and around the periphery of the conductor layer due to a cut-edge effect. Since magnetic flux does not pass through the conductor layer, magnetic flux attempts to bypass the conductor layer along a path in which the conductor opening of the conductor layer is on the inside and the outer edge of the conductor layer is on the outside. As a result, the magnetic flux generates large loops that link the inside and the outside of a coil conductor of an antenna on a reader/writer side to couple an antenna device and the antenna on the reader/writer side.

Abstract: An inexpensive planar antenna fabricated as a plurality of parallel layers of multi turn spiral loops co-located with conductive material at the center of the loops, there being an exclusion zone free of conductive material between the innermost loop and the conductive material at the center. The conductive material may comprise circuit elements, for example batteries, amplifiers, antenna drivers or other functional elements as well as passive elements. In one embodiment, the loop traces may be staggered. In another embodiment, the loop traces are varied in width as a function of position within the loop cross section. In further embodiments, the planar form is integrated with additional orthogonal planar antennas substantially coplanar with the first planar antenna and having axes orthogonal to the first planar antenna and to one another. In further embodiments the exclusion zone is extended by design rules and confining routes in a circuit section.

Abstract: A resin member fitting structure including a first resin member, which is a rectangular hollow tube, has at least one inner wall surface. A second resin member, which is a hollow or solid rectangular tube, has at least one outer wall surface fitted to the at least one inner wall surface of the first resin member. The inner wall surface of the first resin member and the outer wall surface of the second resin member come into contact with each other and define at least one set of fitting surfaces. The second resin member has a hygroscopic expansion coefficient that is smaller than that of the first resin member. The at least one fitting surface includes a plurality of recess-projection engagement structures spaced apart from each other in a circumferential direction that intersects a longitudinal direction of the first and second resin members.

Abstract: An antenna coil includes a magnetic layer such as a flat magnetic sheet, a transmission coil portion defined by a coiled conductor, a reception coil portion defined by a coiled conductor, a transmission coil connection defined by the conductor and defining a portion of the transmission coil portion, and a reception coil connection defined by the conductor and defining a portion of the reception coil portion. The transmission coil portion and the reception coil portion are at least partly formed side by side on the magnetic layer and are arranged to be connected to a wiring pattern on an external circuit.

Abstract: The antenna device includes an electrical conductor extending on a substrate and having at least one gap therein, and with an outer ring portion to define a radiating antenna element, and at least one inner ring portion to define a feed coupler and connected in series with the outer ring portion and extending within the outer ring portion. A coupling feed element is adjacent the at least one inner ring portion, and a feed structure is connected to the coupling feed element to feed the outer ring portion.

Abstract: An electronic entity (2) includes an electronic circuit (4) having connected thereto an antenna. The antenna includes a loop (6) electrically connected to the electronic circuit (4) and a resonator (8) coupled with the loop (6). The resonator (8) can be capacitively coupled to the loop. The resonator can be formed from a turn facing the loop (6) over at least a portion of its perimeter.

Abstract: An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance.

Abstract: An antenna coil may include a first coil portion wound with coil wire; a second coil portion wound with coil wire and intersecting with the first coil portion; and a case having a coil receiving portion receiving the first coil portion and the second coil portion, in which the first coil portion and the second coil portion are disposed so that extending directions of the respective coil portions are directed in diagonals direction of the coil receiving portion.

Abstract: An antenna system for use with very low frequency or low frequency RF tags include a plurality of ferrite core coils disposed at an angle with respect to each other. The antenna system further includes a secondary coil disposed around at least one of the primary coils. The antenna system can provide a multi-axis antenna including two, three, or more than three antenna elements. The antenna system can be disposed in a gang box for a less aesthetically intrusive installation.

Abstract: A core assembly comprising first and second core members each having a rectangular body around which an X-axis coil and a Y-axis coil are wound, and flanges integrally and diagonally extending from the body; and a bobbin having an annular portion and projections diagonally extending therefrom; the projections of the bobbin being provided with terminal members connected to coil ends of the X-axis coil, the Y-axis coil and the Z-axis; the annular portion of the bobbin acting as a space for disposing the first core member from one side, and providing a space receiving at least partially the body of the second core member from the other side, such that the body of the first core member is at least partially adjacent to the body of the second core member; and a space for winding the Z-axis coil being provided between the projections of the bobbin and the flanges of the second core member.

Abstract: An antenna comprising a first current probe having an aperture; a first transceiver operatively coupled to the current probe; a signal enhancer disposed approximately inside the aperture, wherein the signal enhancer comprises an inlet, a first outlet, and a housing having an internal volume, and wherein the outer dimensions of the housing are nearly equivalent to the dimensions of the aperture; a pump configured to pump electrolytic fluid through the internal volume via the inlet and the first outlet; and a first nozzle hydraulically coupled to the first outlet so that when electrolytic fluid is pumped through the internal volume the electrolytic fluid exits the first nozzle in a stream.

Abstract: The present invention relates to an RF tag comprising a magnetic antenna for transmitting and receiving information using an electromagnetic induction method, and an IC mounted to the magnetic antenna, wherein the magnetic antenna comprises a magnetic core and a plurality of coils formed on the magnetic core; the coils each have an inductance L1 satisfying the specific relational formula, and are connected in parallel to each other in an electric circuit and disposed in series on the magnetic core; and a combined inductance L0 of the magnetic antenna satisfies the specific relational formula. The RF tag of the present invention is used as a magnetic antenna for information communication using a magnetic field component which is capable of satisfying both reduction in size and improvement in communication sensitivity.

Abstract: There is disclosed an antenna arrangement having a parasitic conductive loop (1) and at least one active radiating element (9). The conductive loop (1) comprises first and second electrically conductive passive radiating elements (2, 3) each with first and second ends. The first ends of the passive radiating elements are each connected to ground, and the second ends of the radiating elements are each connected respectively to mutually discrete metalized surface regions (8) of a dielectric block (7). The at least one active radiating element (9) is not conductively connected to the passive radiating elements (2, 3). The passive radiating elements (2, 3) are configured to be fed parasitically by the at least one active radiating element (9). The antenna arrangement has excellent resistance to detuning and can be located in different regions of a PCB substrate without significantly affecting performance. Further, the antenna is small in size and may be arranged for dual band operation.

Abstract: An antenna coil includes a wound body including a magnetic core, a bobbin surrounding the magnetic core, and a coil wound around the bobbin, a case in which the wound body is placed, and a foam disposed in a gap between the wound body and the case. The foam is compressed at a rate of about 45% to about 65% on the basis of a thickness of the foam in a non-load state. The antenna coil prevents breakage of the magnetic core and is suitable for use in a short-distance communication system in an LF-band.

Abstract: An antenna device having a magnetic core to be surface-mounted on a circuit substrate includes a pair of coil portions spaced apart from each other at a predetermined interval. The coil portions are connected by a connecting conductor. An end of the magnetic core includes a curved or bent portion curved toward the circuit substrate. This structure defines an RFID antenna device having an improved receiving sensitivity that can be surface-mounted without increasing the thickness of a casing of a mobile electronic device.

Abstract: Stable receiving action is achieved with a receiver of simpler configuration. When a human hand is held over the panel unit 201, the electric field in the vicinity of the human body is coupled to the sensor electrode 2122 of the coil sensor 212 from the receiving electrode 211 of the panel unit 201, and alternate current is generated at the sensor electrode 2122. This alternate current then induces a magnetic flux inside the central opening of the coil 2121 in proportion to the strength of the electric field in the vicinity of the human body. Depending on the changes in this magnetic flux, electric current passes through the coil 2121. The electric current passing through the coil 2121 is converted by the electric current detecting circuit 2124 of the coil sensor 212 to voltage signals and transmitted as received signals to the demodulator 22.

Abstract: According to one embodiment, an antenna device includes a feeding portion, first and second wire-like metal portions, third and fourth plate-like metal portions and a fifth metal portion. One ends of the first and second wire-like metal portions are connected to the feeding portion. The third and fourth plate-like metal portions are respectively connected to the other ends of the first and second metal portions and disposed separately from each other with a predetermined distance therebetween. The fifth metal portion is configured to connect the third metal portion to the fourth metal portion. A total electrical length of the first to fifth metal portions is 3/2 wavelength at operating frequency band.

Abstract: A device includes a first substrate that has a first antenna having a first loop and second loop that form loop shapes viewed in a planar projection; and a second substrate that has a second antenna having a third loop and fourth loop that form loop shapes viewed in the planar projection. The first substrate and the second substrate are disposed so that the first antenna and the second antenna face each other. At least when the first substrate and the second substrate operate, the first antenna and the second antenna are in a state that the first antenna and the second antenna are capable of being magnetically coupled.

Abstract: The present invention relates to an antenna device (10) for executing several functions, particularly a transmitting function, a receiving function, and an energy transmitting function, comprising a rod core (20) made from a material that can be magnetized, extending along a rod core axis (22) and at least one rod core winding (24) about the rod core axis (22), a charged core (30) from a material that can be magnetized, extending along a charged core axis (32), and at least one charged core winding (34) about the charged core axis (32), with the charged core axis (32) and the rod core axis (22) being arranged angular in reference to each other.

Abstract: An antenna apparatus includes a power supply coil, a booster electrode sheet, a magnetic sheet, and a ground substrate arranged in this order from the top. The power supply coil includes a spiral coil conductor located on a flexible substrate. The booster electrode sheet includes a booster electrode located on an insulating substrate. The booster electrode includes a conductor region covering the coil conductor, a conductor aperture covering a coil window, and a slit portion connecting the outer edge of the conductor region and the conductor aperture in plan view. The magnetic sheet covers the booster electrode sheet so that the magnetic sheet covers a region slightly larger than a region including the conductor aperture and the slit portion of the booster electrode.

Abstract: Antenna structures made of bulk-solidifying amorphous alloys and methods of making antenna structures from such bulk-solidifying amorphous alloys are described. The bulk-solidifying amorphous alloys providing form and shape durability, excellent resistance to chemical and environmental effects, and low-cost net-shape fabrication for the highly intricate antenna shapes.

Abstract: A portable electronic device includes a circuit board and an antenna coil installed on the circuit board. The antenna coil includes a magnetic core and a coil wound at either side of an unwound portion. The winding direction of the coil is changed at either side of the unwound portion. When the length of the magnetic core is defined as X and the distance between two intersecting points at which a virtual line formed by projecting the central line of the magnetic core onto the circuit board intersects the outer periphery of the circuit board is defined as Y, the antenna coil satisfies Y?X?0.8Y.

Abstract: A highly sensitive magnetic antenna and an antenna device achieve strong coupling with magnetic flux substantially perpendicular to main surfaces of a magnetic core, an enlarged antenna opening, and increased efficiency of magnetic flux radiation. The magnetic antenna includes a flexible substrate and a magnetic core preferably having a substantially rectangular plate shape. The flexible substrate has a spiral coil conductor located thereon, and the coil conductor has a conductor opening located at the center of the winding center thereof. The flexible substrate is bent in the vicinity of the two sides of the coil conductor spaced apart from the center of the conductor opening and along the two sides of the magnetic core, so as to wrap around the upper surface, left and right surfaces, and portions of the lower surface of the magnetic core.

Abstract: This disclosure provides an antenna device and a mobile terminal equipped with the antenna device. The antenna device includes a coil conductor spirally wound to have a conductor opening portion at the center of winding and is formed on a flexible substrate. A magnetic sheet is disposed near, or proximal to the flexible substrate and between the coil conductor and a flat conductor of a circuit board. A side of the antenna coil that is near an edge of the flat conductor is bent toward the circuit board.

Abstract: In antenna device, a coil conductor of an antenna coil module and a conductor layer at least partially overlap. A current flows in the conductor layer and blocks a magnetic field generated by a current flowing in the coil conductor. A current, which flows around the periphery of an opening of the conductor layer, flows along the periphery of a slit and around the periphery of the conductor layer due to a cut-edge effect. Since magnetic flux does not pass through the conductor layer, magnetic flux attempts to bypass the conductor layer along a path in which the conductor opening of the conductor layer is on the inside and the outer edge of the conductor layer is on the outside. Accordingly, the magnetic flux generates relatively large loops linking the inside and the outside of a coil conductor of an antenna on a reader/writer side.

Abstract: A vehicle antenna assembly includes an element coil, a holder, and a retainer. The element coil can have a polygonal configuration in a cross-section taken normal to a coil access. The holder can include rails. The retainer can engage the rails and apply a compressive load on the element coil to fix the element coil with respect to the holder. A method for holding an antenna element is also disclosed.

Abstract: An antenna coil is obtained by winding a flexible substrate around a magnetic core. Conductors are provided on the flexible substrate, whereby a first coil portion and a second coil portion are provided on either side of the magnetic core except for in a middle portion. A non-winding portion including no conductors is provided between the first coil portion and the second coil portion on a main surface of the magnetic core.

Abstract: A radio wave receiver comprising an antenna structure placed within a case. The antenna structure has a rod-like core around which a coil is wound. A pair of opposite external magnetic members are each provided in a respective one of a pair of cavities provided so as to extend along the inner periphery of the case from adjacent the respective ends of the rod-like core toward the end points of an inner diameter of the case parallel to the axis of the rod-like core. The pair of external magnetic members is substantially the same permeability as the core. Thus, the antenna core is magnetically coupled to the pair of external magnetic members.

Abstract: The present invention provides an antenna apparatus (60) for use in a non-contact type IC card into and from which data can be written and read by an electronic apparatus having a communication function, by virtue of inductive coupling. The antenna apparatus includes a loop coil (61) and a magnetic member (62). The loop coil (61) is produced by winding a conductive wire in a plane and configured to perform the inductive coupling with the electronic apparatus. The magnetic member (62) covers one region (61a) of the loop coil, provided at one side, from one surface of the loop coil, passes through the loop coil, and covers the other region (61b) of the loop coil, provided at the other side, from the other surface of the loop coil.

Abstract: An antenna coil includes a magnetic layer such as a flat magnetic sheet, a transmission coil portion defined by a coiled conductor, a reception coil portion defined by a coiled conductor, a transmission coil connection defined by the conductor and defining a portion of the transmission coil portion, and a reception coil connection defined by the conductor and defining a portion of the reception coil portion. The transmission coil portion and the reception coil portion are at least partly formed side by side on the magnetic layer and are arranged to be connected to a wiring pattern on an external circuit.

Abstract: This disclosure provides an antenna device including an antenna coil having a plate-shaped magnetic core with first and second main surfaces and a coil conductor wound around the magnetic core, and a flat conductor adjacent to the antenna coil. For instance, the flat conductor can be a ground electrode formed on or within a circuit substrate. The coil conductor includes a first conductor portion adjacent to the first main surface of the magnetic core and a second conductor portion adjacent to a second main surface thereof. The first conductor portion of the antenna coil is closer to an end portion of the flat conductor than the second conductor portion, with the second main surface of the magnetic core facing the flat conductor.

Abstract: A battery pack having a main surface and a side surface, and the external appearance thereof is an approximately rectangular parallelepiped shape. An antenna coil is provided on the main surface. The antenna coil is obtained by forming a coil conductor pattern on a flexible substrate. A substantially slit-shaped aperture is formed on the flexible substrate, and a magnetic material core is inserted into the aperture. In the antenna coil, the center of the coil aperture portion is offset from the center of the main surface of the battery pack in the outside edge portion direction of the main surface. A first end in the magnetic path direction of the magnetic material core is stretched along the side surface of the battery pack, and the second end of the magnetic material core is opened toward the center of the main surface of the battery pack.

Abstract: There is provided a magnetic antenna and an antenna device that increase the packaging density of a portion where the magnetic antenna is mounted in an electronic apparatus, and suppresses degradation of antenna performance. A flexible substrate has first and second substantially spiral-shaped coil conductors formed thereon. Conductor-opening-side through holes are formed in the respective conductor openings of the coil conductors, and non-coil-conductor-forming-area through holes are formed in areas in which the coil conductors are not formed. First and second magnetic cores are arranged so as to extend through the respective conductor-opening-side through holes from a first main surface of the flexible substrate and to extend through the respective non-coil-conductor-forming-area through holes in a direction from a second main surface side to the first main surface of the flexible substrate.

Abstract: An antenna unit includes an antenna formed on a magnetic sheet. A transmission circuit includes an inductor, a matching capacitor, and the antenna connected in series, and a reception circuit includes the antenna, the matching capacitor, a resistor, and a capacitor connected in series. The antenna is formed as one turn, and the size of the antenna and the resistor involves a predetermined relationship.

Abstract: An antenna for receiving and/or transmitting radio frequency signals in a predetermined frequency band, the antenna comprising: a first antenna portion comprising at least one conducting loop about a first material having an initial permeability of at least 4; and a second antenna portion embedded within a second material having a dielectric constant of at least 4; wherein the first and second antenna portions are electrically coupled together so as to form a compound antenna having a size such that the diameter of the smallest sphere which encloses all of the first and second antenna portions of the compound antenna is less than 1/30 of the wavelength of the radio frequency signals at the centre of the predetermined frequency band.

Abstract: Provided are a transmission/reception antenna and a transmission/reception device using the same wherein the transmission/reception antenna comprises an excitation loop antenna (12) having a loop of a single turn and a transmission/reception loop antenna (14) having a pair of loops (14a, 14b) of a plurality of turns which are closely wound around a magnetic member (11). The two loops of the transmission/reception loop antenna are located on either side of the excitation loop. A resonance capacitor (15) is connected across one ends of the two loops of the transmission/reception loop antenna, and a connecting portion (14c) is connected between the ends of the two loops opposite to those connected to the resonance capacitor. The frequency property is expanded without increasing the power consumption.

Abstract: An antenna device is constructed such that an antenna coil including a magnetic core and a flexible substrate is mounted to a circuit board. A first coil portion having a coil axis parallel or substantially parallel with a main surface of the magnetic core includes a first coil and a third coil. A second coil portion includes a second coil and a fourth coil. A conductor-free portion is located between the first and second coil portions. The flexible substrate includes a projection, and first to fourth coil connections are drawn out at the projection. The antenna device is constructed such that each of the coils is connected on the circuit board by connecting to a conductor pattern on the circuit board at the projection of the flexible substrate.