Abstract: A flexible wristband includes conductive silicone rubber loops and an insulating rubber portion. The conductive silicone rubber loops are formed parallel to one another, and substantially define a circumference of the wristband. The conductive silicone loops are connected through a radio frequency identification (RFID) integrated circuit package to form a loop antenna. The insulating silicone rubber portion is formed parallel to the conductive silicone rubber loops, separating the conductive silicone rubber loops and providing an insulating break in the conductive loops. The RFID integrated circuit package includes multiple terminals respectively connected to the conductive silicone rubber loops to create a loop antenna, enabling the RFID integrated circuit package to transmit data through the loop antenna.

Abstract: A multi-band antenna apparatus is provided. The multi-band antenna apparatus comprises a circuit board, a planar printed antenna with a feed-in point and a telescopic antenna. The planar printed antenna is printed on the circuit board. The telescopic antenna is coupled to the circuit board through the feed-in point. The planar printed antenna receives a first radio frequency signal, and then transmits the first radio frequency signal to the circuit board through the feed-in point. The telescopic antenna receives a second radio frequency signal and then transmits the second radio frequency to the circuit board.

Abstract: The present invention provides a magnetic sheet with improved resistance to folding while maintaining good magnetic characteristics and reliability; a method for producing the magnetic sheet; an antenna; and a portable communication device. A magnetic sheet of the present invention includes a flat magnetic powder, and a resin binder capable of dissolving in a solvent, wherein the magnetic sheet has a gradient of the content ratio of the magnetic powder to the resin binder in a thickness direction thereof, wherein, in use, the magnetic sheet is folded so that, of the front and back surfaces thereof, one surface whose magnetic powder content is lower than that of the other is folded inward, and wherein the difference in glossiness measured at a light-incident angle of 60° between the front and back surfaces is 9.4 or more.

Abstract: Aspects of a method and system for identifying a radio frequency identification (RFID) tag location using a switchable coil are presented. Aspects of the systems may include one or more processors that enable selection of an inductor coil from a plurality of inductor coils. The selection of the inductor coil may be based on a change in an electromagnetic field, with respect to an initial electromagnetic field, as detected by the selected inductor coil. The processors may enable transmission of a signal, having a transmitter frequency in the UHF frequency band, via the selected inductor coil.

Abstract: A mobile communication device includes an antenna structure which includes a grounding element and an antenna element. There is a notch at an edge of the grounding element. The antenna element is disposed in the notch and includes a metal loop portion and a monopole antenna. The metal loop portion is electrically connected to the grounding element with at least one shorting point, such that a short-circuited closed metal loop is formed. The monopole antenna has a first end and a second end, wherein the first end of the monopole antenna is a feeding point connected to a signal source, and the second end of the monopole antenna is an open end surrounded by the closed metal loop.

Abstract: A dual band antenna device and method of formation is provided. In one embodiment, the method comprises providing a planar conductive sheet; forming a slot antenna in the conductive sheet; the slot antenna configured to communicate at a first frequency; forming a multi-turn antenna in the conductive sheet; the multi-turn antenna configured to communicate in a second frequency that is different from the first frequency; and connecting at least one integrated circuit to said first antenna and said second antenna; enclosing said first antenna, said second antenna, and said at least one integrated circuit in a wearable enclosure.

Abstract: A combination EAS/RFID antenna for use in an EAS/RFID surveillance system. The antenna includes an EAS antenna element and an RFID antenna element. The EAS antenna element includes an EAS loop antenna defining an interior area. The RFID antenna element is positioned within the interior area defined by the EAS loop antenna and includes a ground plane and RFID patch antenna. The ground plane and/or the RFID patch antenna have a segmented conductor pattern etched thereon. The segmented conductor pattern minimizes eddy currents in the ground plane produced by current flow through EAS loop antenna. The RFID antenna element is situated proximate the EAS loop antenna in such a fashion that the overall size of the antenna is reduced.

Abstract: A multi-band antenna includes a loop conductor, a first conductor arm, and a second conductor arm. The loop conductor is configured to resonate in a first frequency band and includes a feed-in end for feeding of signals and a main body that extends from the feed-in end, and that has a grounding point disposed adjacent to the feed-in end. The first conductor arm is configured to resonate in a second frequency band and extends from the feed-in end. The second conductor arm is configured to resonate in a third frequency band and extends from the feed-in end. At least one of the loop conductor, the first conductor arm, and the second conductor arm is bent so as to be disposed in different planes.

Abstract: An antenna element is disclosed. A substrate is made of dielectric material and has a first face. A first antenna element is made of conductive material and is provided on the first face. A first power feeding portion is made of conductive material and is disposed on the first antenna element. A second antenna element is made of conductive material, is provided on the first face, and forms a loop surrounding the first antenna element with a gap. A second power feeding portion is made of conductive material. The second power feeding portion is extended from the second antenna element toward the first antenna element and is arranged to form an electromagnetic coupling with the first antenna element. A perturbation element is made of conductive material and is extended from the second antenna element. A length of loop is twice a circumferential length of the first antenna element.

Abstract: Dual-band antenna including a shorted loop slot antenna and a spiral antenna.

Abstract: The present invention relates to a self-contained counterpoise compound field antenna. Improvements relate particularly, but not exclusively, to compound loop antennas having coplanar electric field radiators and magnetic loops with electric fields orthogonal to magnetic fields that achieve performance benefits in higher bandwidth (lower Q), greater radiation intensity/power/gain, and greater efficiency. Embodiments of the self-contained antenna include a transition formed on the magnetic loop and having a transition width greater than the width of the magnetic loop. The transition substantially isolates a counterpoise formed on the magnetic loop opposite or adjacent the electric field radiator.

Abstract: Aspects of a method and system for identifying a radio frequency identification (RFID) tag location using a switchable coil are presented. Aspects of the systems may include one or more processors that enable selection of an inductor coil from a plurality of inductor coils. The selection of the inductor coil may be based on a change in an electromagnetic field, with respect to an initial electromagnetic field, as detected by the selected inductor coil. The processors may enable transmission of a signal, having a transmitter frequency in the UHF frequency band, via the selected inductor coil.

Abstract: A helical element, which is operated in the frequency band of FM broadcast, is wound around the outer periphery of a rod-shaped support member 10. A line-shaped element 12, which is operated in the frequency band of terrestrial digital television broadcast, is disposed in a first groove 10a of a predetermined length formed on the outer periphery of the support member 10 from the lower end thereof. With this arrangement, a multi-frequency antenna 1, which is operated in the frequency band of FM broadcast and the frequency band of terrestrial digital television broadcast, can be arranged, and the entire length L of the helical element can be reduced and it can be operated in a plurality of frequency bands with the effect of the line-shaped element 12.

Abstract: A combination EAS/RFID antenna for use in an EAS/RFID surveillance system. The antenna includes an EAS antenna element and an RFID antenna element. The EAS antenna element includes an EAS loop antenna defining an interior portion. The RFID antenna element includes an RFID patch antenna having a hatched conductor pattern. The RFID antenna element is situated proximate the EAS loop antenna in such a fashion that the overall size of the antenna is reduced.

Abstract: A long term evolution antenna includes a dielectric substrate, a primary antenna structure disposed on a surface of the dielectric substrate, and a metal plate disposed on the dielectric substrate and connected to the primary antenna structure. The primary antenna structure includes a trunk section, and a first conductor arm, a second conductor arm and a loop conductor which all extend from the trunk section. The metal plate is connected to the first conductor arm and the second conductor arm so as to form a first radiator section for resonation in a first frequency band with the first conductor arm and a second radiator section for resonation in a second frequency band with the second conductor arm. The loop conductor extends from the trunk section to form a loop for resonation in a third frequency band.

Abstract: According to one embodiment, an electronic apparatus includes a housing, a first board contained in the housing, a second board contained in the housing on the inner side of the first board, a first antenna part, and a second antenna part. The first antenna part includes a loop antenna provided on the first board, and configured to communicate with a communication module opposed to the loop antenna. The second antenna part includes an element part provided in an area surrounded by the loop antenna, and positioned in the same plane as the loop antenna, and a ground part provided on the second board, and configured to communicate with a communication module opposed to the element part.

Abstract: A sonde array that is useful in locating buried utilities includes at least three substantially mutually orthogonal antennas. Each antenna includes a substantially cylindrical ferromagnetic core, an insulating layer surrounding the core, and a length of a conductor wrapped around the insulating layer to form a coil. The coils of the antennas are substantially identical.

Abstract: The hybrid multiple-input multiple-output antenna module includes a grounding unit, a plurality of radiating units, loop units and filter units. The radiating units and the loop units are arranged around a geometric center of the grounding unit and are alternately and symmetrically arranged on the grounding unit. The loop units are arranged along the outer peripheral side of the grounding unit. The filter units are respectively electrically connected to the loop units. The present invention not only has some advantages such as small size, low profile, good isolation, high antenna gain and good radiation properties, but also can replace the external dual-band access-point antenna of the prior art for 2.4/5 GHz operation with no need of an extra diplexer. In addition, the hybrid multiple-input multiple-output antenna module can be hidden in the wireless communication device in order to enhance the appearance of the product.

Abstract: An antenna configuration is described for high frequency (HF) or very high frequency (VHF) radars contained in a single vertical post. The radar may include a vertical dipole or monopole transmitting antenna collocated with a three-element receive antenna. The three antennas including two crossed loops and a vertical element are used in a direction-finding (DF) mode. Isolation between the three antennas produces high quality patterns useful for determining target bearings in DF mode. The single vertical post is sufficiently rigid mechanically that it may be installed along a coast without guy wires.

Abstract: An improved RFID antenna system using a first RFID antenna device (in the form of a magnetic antenna (15)) and using a second RFID antenna device (21, 21?) using a flat antenna is distinguished by the following features: the second RFID antenna device comprises one flat antenna (21, 21?) or a group antenna with at least two flat antennas (21, 21?), and the metal plane of the flat antenna (21, 21?) and/or the earth or reflector plane (31; 31.1; 31.2) is divided into metal, earth or reflector plane sections (31.1; 31.2) by slots, interruptions and or recesses (133), wherein the metal, earth or reflector sections (31.1; 31.2) are electrically conductively separated from one another or are electrically conductively connected to one another.

Abstract: Wireless repeaters comprising antennae having high electrical isolation are presented. Multi-band antennae are placed on opposing sides of a conductive ground plane to achieve high electrical isolation, preferably higher than 30 dB. The antennae are preferably placed at a distanced from the ground plane that is less than 0.5 wavelengths of a frequency associated with frequency bands to which the antennae are responsive. The presented antennae system reduces the minimum amount of isolation required for stable operation.

Abstract: The invention relates to an antenna that produces a radiation pattern that is axisymmetric about a geometrical axis (X) and exhibits a radiation maximum in a plane perpendicular to the direction of said X axis that includes a feed wire extending along said axis (X) from a first end situated level with a conducting surface forming an earth plane of the antenna to a second end that feeds a set of N radiating strands, N being an integer, characterized in that it also includes at least one earth return rod for the strands, said rod linking one of the radiating strands of the set to the earth plane.

Abstract: The present invention provides a high/low frequency dual wireless location detection and information transmission system which is high in reliability and maintainability, and can be easily installed. A leakage coaxial inner conductor and a conductor line provided in parallel are short-circuited at an end, a single leakage coaxial operation and a loop operation of the inner conductor and the conductor line are performed at the same time, the ID of a tag is communicated using magnetic fields which locally exist near the conductor line by the loop, and wireless position detection and information communications which are less affected by the influence of ambient environments due to electromagnetic waves in a closed area are realized by open-type lines.

Abstract: To provide an antenna device capable of diminishing gain changes caused by a human body. An antenna device has a magnetic current antenna 401 that takes a magnetic current as a source of emission; an electric current antenna 402 that takes an electric current as a source of emission; and an electric current/magnetic current distribution control circuit 403 that feeds signals to the magnetic current antenna 401 and the electric current antenna 402, wherein the magnetic current antenna 401 and the electric current antenna 402 are arranged in such a way that a polarized wave emitted from the magnetic current antenna 401 and a polarized wave emitted from the electric current antenna 402 cross each other at right angles. The electric current/magnetic current distribution control circuit 403 controls distribution of a radio wave emitted from the magnetic current antenna 401 and a radio wave emitted from the electric current antenna 402.

Abstract: To provide a dual polarized antenna capable of reducing correlation between antenna elements. A dual polarized antenna is constituted by a vertically polarized antenna and a horizontally polarized antenna formed on a printed circuit board and radiates two kinds of polarized waves.

Abstract: There is disclosed an antenna for reception of circularly polarized satellite radio signals. The antenna comprises at least one two-dimensional or three-dimensional antenna conductor structure connected with an antenna output connector. The multi-dimensional antenna conductor structure is configured so that it comprises a plurality of antenna conductor sections, which, with reference to a spatial reference point (z) common to the antenna conductor sections, are disposed in pairs, symmetrically and extending in the same direction.

Abstract: A radio communication device is obtained which is provided with an RFID tag function which can ensure the mounting area of each antenna as large as possible, and which is sharable with an LF band RFID system or an HF band RFID system and a UHF band RFID system, while having a communication range equivalent to the communication range of each of an LF band an HF band and a UHF band. The device is provided with an integrated circuit (4) having a communication function in a first frequency band, a conductive object (3) connected to one of input and output terminals of the integrated circuit (4), an integrated circuit (5) having a communication function in a second frequency band, and a second conductive object connected between input and output terminals of the integrated circuit (5). The second conductive object is composed of a spiral conductive object (2). The other of the input output terminals of the integrated circuit (4) is connected to a part of the spirally wound conductive object (2).

Abstract: A multi-band antenna apparatus is provided. The multi-band antenna apparatus comprises a circuit board, a planar printed antenna with a feed-in point and a telescopic antenna. The planar printed antenna is printed on the circuit board. The telescopic antenna is coupled to the circuit board through the feed-in point. The planar printed antenna receives a first radio frequency signal, and then transmits the first radio frequency signal to the circuit board through the feed-in point. The telescopic antenna receives a second radio frequency signal and then transmits the second radio frequency to the circuit board.

Abstract: The present invention relates to a wireless communication device, such as a transponder, that has a plurality of antennas for multi-frequency usage. The wireless communication device comprises a control system, communication electronics, memory, and the aforementioned antennas. A wireless communication device having a pole antenna may be used with one or more loop conductor antennas to achieve the desired operating frequencies. A wireless communication device having a dipole antenna may be coupled across a loop conductor antenna to provide different loop conductor configurations depending on the frequency.

Abstract: According to one embodiment, an antenna comprises a plurality of elongated side radiating elements having longitudinal axes oriented at angles of between about 10° and about 80° from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements, and a cavity positioned between the side radiating elements defined by at least one non-radio frequency-transparent sidewall. In another embodiment, a system comprises a plurality of elongated side radiating elements each lying along a unique side plane and having longitudinal axes oriented at angles of between about 10° and about 80° from a line perpendicular to an imaginary base plane extending across ends of the side radiating elements, and a cavity being positioned between the side radiating elements defined by at least one non-radio frequency-transparent sidewall, wherein the at least one sidewall has sides each lying along a plane about parallel to the unique side plane.

Abstract: Described are antenna assemblies and methods for forming antenna assemblies. An antenna assembly includes a dual polarized far-field antenna and a near-field loop antenna. The near-field loop antenna is electromagnetically coupled to the dual polarized far-field antenna. The near-field loop antenna includes two contacts for electrically connecting to a chip.

Abstract: An antenna used in portable electronic devices includes a first antenna unit shaped as a planar inverted-F antenna (PIFA) and a second antenna unit shaped as a loop antenna and connected to the first antenna unit. The first antenna unit receives/sends wireless signals at relatively higher frequencies, the second antenna unit receives/sends wireless signals at relatively lower frequencies, and the first antenna unit is coupled with the second antenna unit to regulate the working frequency band of the antenna.

Abstract: A security tag includes an EAS component having a defined surface area, and an RFID component having a defined surface area. The EAS component surface area is configured to at least partially overlap the RFID component surface area. The RFID component includes an antenna which at least partially overlaps the first surface. A substantially planar spacer having a thickness is at least partially disposed between the defined surface areas of the EAS and RFID components. The RFID element read range is affected and controlled by the spacing between the RFID element and the EAS element. The RFID reader is capable of activating the RFID component when the RFID component is within the read range. The antenna includes a magnetic loop antenna in electrical contact with a spiral antenna to increase near field read response.

Abstract: An antenna apparatus includes: a ground substrate; and a loop antenna having first and second polarized wave surfaces, which are perpendicular to the substrate. The substrate provides an antenna, which is excited and vibrated together with the loop antenna. The antenna has a first polarized wave component in parallel to the first polarized wave surface and a second polarized wave component in parallel to the second polarized wave surface. A polarized wave ratio between the first polarized wave component and the second polarized wave component in the substrate is substantially equal to a polarized wave ratio between the first polarized wave surface and the second polarized wave surface in the loop antenna.

Abstract: A security tag includes an EAS component having a defined surface area, and an RFID component having a defined surface area. The EAS component surface area is configured to at least partially overlap the RFID component surface area. The RFID component includes an antenna which at least partially overlaps the first surface. A substantially planar spacer having a thickness is at least partially disposed between the defined surface areas of the EAS and RFID components. The RFID element read range is affected and controlled by the spacing between the RFID element and the EAS element. The RFID reader is capable of activating the RFID component when the RFID component is within the read range. The antenna includes a magnetic loop antenna in electrical contact with a spiral antenna to increase near field read response.

Abstract: To attain sensitivity not deviating in any of XYZ directions. A three-axis antenna with a cross-shaped core 2 having a pair of X-axis arms 22a, 22b projecting in the X-axis direction in an orthogonal coordinate system and a pair of Y-axis arms 23a, 23b projecting in the Y-axis direction orthogonal to aforementioned X-axis direction, and having Z-axis winding wire 26 provided in a substantially rectangular frame shape outside the head sections of aforementioned X-axis arms 22a, 22b and the head sections of aforementioned Y-axis arms 23a, 23b. Aforementioned Z-axis winding wire is housed in a case having a bottom so as to cover the entire head surfaces of X-axis arms 22a, 23b and head surfaces of Y-axis arms 23a, 23b in aforementioned cross-shaped core 2.

Abstract: To provide a cell phone equipped with a broadcast receiver that delivers a high receiving sensitivity and antenna performance in various usage states. A loop element 12 as an antenna for receiving television broadcast is arranged in a range (c) of an upper end portion of an upper housing 1. An end part of an upper circuit board 6 is matched with a portion shown by (a) so that a conductor other than the antenna element does not exist in the range (c). A monopole element 19 for cell phone communication is arranged at a lower end portion of a lower housing 2.

Abstract: The size of an antenna coil is reduced, and it is possible to prevent a lowering of the reception sensitivity due to a difference of the arrangement position of the antenna coil. On a winding frame of a ferrite core, a first coil and a second coil are wound in such a manner that their winding axes orthogonally intersect each other. A third coil is wound around an outer circumference of the first coil and the second coil in such a manner that the third coil's winding axis orthogonally intersects the winding axes of the first coil and the second coil.

Abstract: An antenna module and a portable communication terminal equipped with the antenna module are provided. The antenna module has a space-saving design, and also has both a capability for long communication distance for a tag function and a capability for wide communication range for a reader/writer function. A first antenna coil (11) for communication with a reader/writer and a second antenna coil (12) for communication with an IC tag are disposed on a base substrate (10). The first antenna coil (11) is disposed in an outermost periphery section of the base substrate (10) so that a communication distance is attained. The second antenna coil (12) is disposed within an inner periphery of the first antenna coil (11) so as to achieve overall size reduction of the module.

Abstract: An antenna assembly is disclosed. The antenna assembly includes a dual band vertical loop wire antenna extending from a printed circuit board positioned over a ground plane, wherein the wire antenna includes: at least one coiled section, at least one straight wire section, and at least one feeding post section.

Abstract: Provided is a broadband internal antenna including a ground plate and an antenna unit. The antenna unit can include a feed point; a first radiator, formed with a bar shape having the feed point as one end part and the other end part from which an uncurved ‘C’ shape is extended; a ground point, connected to the ground plate; a second radiator, having one end part on which the ground point is mounted and the other end part that is connected to an area from which the uncurved ‘C’ shape of the first radiator starts to be formed in an open loop form; a first protrusion part, protruded from the uncurved ‘C’ shape of the first radiator to be formed in a closed loop form; and a second protrusion part, formed inside the open loop shape of the first radiator in an inverse L’ form.

Abstract: A fabrication method of a radio frequency identification (RFID) antenna coil is provided. First, a substrate is processed by a surface modified procedure, to form a self-assembly membranes (SAMs) on a surface of the substrate. A catalyst is sprayed on the SAMs of the substrate according to patterning. After that, the first electroless plating procedure is first carried out for the substrate to generate a magnetic metal layer corresponding to the wiring pattern on the catalyst, and the second electroless plating procedure is then carried out for the substrate to generate the metal layer on the magnetic metal layer.

Abstract: A dual-band loop antenna for using in a mobile phone for (890˜960 MHz)/DCS(1710˜1880 MHz) application is disclosed to include a ground plane in a substantially rectangular shape having a grounding point and a shorting point, a radiating metallic loop having a feeding end and a shorting end electrically connected to the shorting point of the ground plane and spaced from the feeding end at a predetermined distance, and a radiating metallic plate surrounded by the radiating metallic loop and having one end electrically connected to a vicinity around the shorting end of the radiating metallic loop and spaced from the shorting end of the radiating metallic loop at a distance less than 10 mm.

Abstract: A device having an electric antenna and a magnetic antenna is described, the antennas being spatially arranged in immediate mutual proximity. The electric antenna has at least one current-carrying electric conductor which acts as a resonator for the electric antenna, while the magnetic antenna has a coil with at least one current-carrying conductor loop which acts as an inductor of the magnetic antenna. Thus the electric antenna and the magnetic antenna are spatially arranged relative to each other such that the direction of the current in the electric conductor of the electric antenna extends substantially at right angles to the direction of the current in the conductor loop of the magnetic antenna.

Abstract: An on-vehicle film antenna is constructed with a loop antenna and a monopole antenna and attached to a vehicle windshield. The loop antenna has a first element set in length to correspond to a first radio wave of a first frequency band. One end of the first element is connected to a power supply near a border section between a vehicle chassis and the vehicle windshield, and the other end of the first element is connected to the vehicle chassis. The monopole antenna has a second element set in length to correspond to a second radio wave of a second frequency band. One end of the second element is connected to the power supply near the border section in common with the one end of the first element, and the other end of the second element is disconnected from the vehicle chassis.

Abstract: An antenna element is disclosed. A substrate is made of dielectric material and has a first face. A first antenna element is made of conductive material and is provided on the first face. A first power feeding portion is made of conductive material and is disposed on the first antenna element. A second antenna element is made of conductive material, is provided on the first face, and forms a loop surrounding the first antenna element with a gap. A second power feeding portion is made of conductive material. The second power feeding portion is extended from the second antenna element toward the first antenna element and is arranged to form an electromagnetic coupling with the first antenna element. A perturbation element is made of conductive material and is extended from the second antenna element. A length of loop is twice a circumferential length of the first antenna element.

Abstract: The present invention relates to a wireless communication device, such as a transponder, that has a plurality of antennas for multi-frequency usage. The wireless communication device comprises a control system, communication electronics, memory, and the aforementioned antennas. A wireless communication device having a pole antenna may be used with one or more loop conductor antennas to achieve the desired operating frequencies. A wireless communication device having a dipole antenna may be coupled across a loop conductor antenna to provide different loop conductor configurations depending on the frequency.

Abstract: In addition to an FM reception antenna element for receiving an FM radio wave and an FM receiver connected to the FM reception antenna element, a mobile object is provided with a first antenna element for receiving a satellite signal, a signal processing unit connected to the first antenna, and a second antenna element connected to the signal processing unit. The signal processing unit processes the satellite signal into an FM signal. The second antenna element emits the FM signal as the FM radio wave that may be received in the FM reception antenna and processed by the FM receiver in the manner known in the art.

Abstract: Provided is a transmitting/receiving isolation antenna that can perform wireless bi-directional communication in the co-channel, co-polarization and co-time by acquiring high isolation from transmitting and receiving antennas having co-time, co-channel and co-polarization and set up adjacently. The isolation antenna includes a first antenna; second and third antennas symmetrically positioned in the same distance from the first antenna; a shielding unit symmetrically positioned between the first and second antennas, and between the first and third antennas; and a signal removing unit for removing a signal transmitted from the first antenna to the second and third antennas.

Abstract: An antenna module including a ground plate, a first radiating body and a second radiating body is provided. The first radiating body is disposed above the ground plate for receiving or transmitting a first signal emitted from at least an artificial satellite. The second radiating body is disposed between the ground plate and the first radiating body for receiving or transmitting a second signal emitted from various directions.