Abstract: An antenna device includes: a substrate; first and a second antenna units which are wound coaxially on a surface of the substrate, and include a plurality of antenna elements; and a feeder which feeds power only to the first antenna unit. A separation distance between the antenna elements in each of the first and second antenna units is substantially the same.

Abstract: The object of the invention is to provide a noncontact IC card reader/writer integrated with an antenna that does not require the limitation of an installation location and the adjustment of a resonance frequency of the antenna, is convenient in installation, is provided with a stable characteristic, is small-sized and low-priced. To achieve the object, the invention is provided with a loop antenna that supplies electric power and send data to a noncontact IC card by electromagnetic induction and acquires receive data from the noncontact IC card by load fluctuation, a magnetic body arranged closely at the back of the loop antenna, a first metallic plate arranged on the back side of the magnetic body and a second metallic plate arranged on the back side of the first metallic plate and larger than the first metallic plate in size.

Abstract: It is an object of the present invention to provide a radio communication medium processor having a stable performance that does not receive a limitation for an installed place, especially, the influence of a metallic structure, does not need to adjust the resonance frequency of an antenna or an impedance, is excellent in its convenience and extensibility upon installation and strong for unnecessary noise from a periphery. In electric current fed loop antenna units, non-electric current fed loop antenna are arranged in doughnut shapes outside the substantially same planes of electric current fed loop antennas so as to surround the electric current fed loop antennas. Thus, when non-electric current fed loop antenna units are installed linearly, in radial directions and in arrays adjacently to electric current fed loop antenna units, the influence of the non-electric current fed loop antenna units to the antenna characteristics of the electric current fed loop antenna units can be suppressed.

Abstract: It is an object of the invention to provide an electromagnetic wave shield for attenuating a electric far field while suppressing the attenuation of the vicinal magnetic flux of an electromagnetic wave discharged from a high frequency electromagnetic wave generator. An electromagnetic wave shield according to the invention comprises a plurality of electric conductors, a ground contact for carrying out a connection to a ground, and a lead wire for connecting the electric conductors to the ground contact, the electric conductors being electrically connected to the ground contact through the lead wire, wherein the electric conductors are provided in such a manner that a path reaching the ground contact through the lead wire from an optional point of each of the electric conductors is uniquely determined.

Abstract: An antenna device is provided for which the thickness can be reduced, warping can be prevented, and manufacturing can be easily performed. According to the present invention, the antenna device includes: a support member, formed like a long hollow plate by extruding a resin; and an antenna unit, wherein a plurality of antenna elements, which are thin metal plates formed substantially in a U shape and which include a first coupling portion extended from one end in one direction and a second coupling portion extended from the other end in the opposite direction, grip the external sides of the support member in the longitudinal direction. The first coupling portion of a specific antenna element is connected to the second coupling portion of the adjacent antenna element, and the second coupling portion of the specific antenna element is connected to the first coupling portion of the adjacent antenna element. Since the antenna elements are connected in this manner, the antenna unit is formed like a coil.

Abstract: It is an object of the invention to provide a reader of an RFID tag which can well carry out a communication with a plurality of RFID tags disposed to overlap each other. The reader according to the invention includes an antenna device for supplying a power and transmit data through an electromagnetic induction to a plurality of tags having an IC chip for storing predetermined information and a loop antenna and acquiring the information from the tags depending on a fluctuation in a load, wherein the antenna device has a conductor board, an antenna body provided spirally in a longitudinal direction of the conductor board over an outer peripheral surface of the conductor board, a power feeding portion coupled to the antenna body and serving to feed a power, and a ground connecting portion coupled to the antenna body and connected to a ground.

Abstract: It is an object of the present invention to provide a radio communication medium processor having a stable performance that does not receive a limitation for an installed place, especially, the influence of a metallic structure, does not need to adjust the resonance frequency of an antenna or an impedance, is excellent in its convenience and extensibility upon installation and strong for unnecessary noise from a periphery. In electric current fed loop antenna units, non-electric current fed loop antenna are arranged in doughnut shapes outside the substantially same planes of electric current fed loop antennas so as to surround the electric current fed loop antennas. Thus, when non-electric current fed loop antenna units are installed linearly, in radial directions and in arrays adjacently to electric current fed loop antenna units, the influence of the non-electric current fed loop antenna units to the antenna characteristics of the electric current fed loop antenna units can be suppressed.

Abstract: A gate antenna device has a plurality of loop antennas which supplies power and transmission data to an IC-integrated medium through electromagnetic induction and acquires reception data in the form of a fluctuation of a load from the IC-integrated medium. The plurality of loop antennas include a power-fed loop antenna to which a signal current is supplied and a non-power-fed loop antenna to which no signal current is supplied. The gate antenna device expands the distance and range of communication with an IC-integrated medium and improves the accuracy of communication while suppressing power consumption and leakage electric fields.

Abstract: The object of the invention is to provide a small-sized noncontact IC card reader/writer that can enhance the efficiency of an amplifier at a low cost.

Abstract: A non-contact IC card reading/writing apparatus having a superior reception characteristic includes a loop antenna, a resonant circuit unit, a wireless transmitting unit, and a wireless receiving unit. The resonant circuit unit, the wireless transmitting unit, and the wireless receiving unit are coupled to each other via any one of a directional coupler, a circulator, and an isolator.

Abstract: This invention is a wireless communication medium processing apparatus which carries out communication with a wireless communication medium, to carry out at least one of reading and writing as to information which was stored in the wireless communication medium, and has a plurality of antenna, a transmission divider which was connected to the plurality of antennas, and a reception compositor which was connected to the plurality of antennas, and is characterized in that the transmission divider divides an inputted signal to output the plurality of antennas, and the reception compositor combines signals from the plurality of antennas and outputs it.

Abstract: To provide a loop antenna capable of attenuating the distant electric field with the attenuation of the magnetic flux in the vicinity of an electromagnetic wave restrained, and a contactless IC card read/write apparatus. A loop antenna 10 has an electromagnetic wave shield 1 over at least one side of the loop antenna, the electromagnetic wave shield 1 comprising a plurality of electric conductors 2, a ground contact 3 for grounding the plurality of electric conductors and a lead wire 4 for connecting the plurality of electric conductors 2 to the ground contact 3. The plurality of electric conductors 2 are electrically connected via the lead wire 4 to the ground contact 3 and the plurality of electric conductors 2 are arranged so that the paths of the respective electric conductors 2 from any of their given points to the ground contact 3 via the lead wire 4 are determined uniformly.

Abstract: A small thin integrated antenna type non-contact IC card reader/writer includes a loop antenna for supplying electric power and sending data to a non-contact IC card by electromagnetic induction and for acquiring receiving data from the non-contact IC card by a change in the load; a control portion for controlling a resonance matching circuit, wireless sending pjortion and wireless receiving portion; and a control board on which the control portion is mounted. The control board is accommodated in a shielded case, wherein the components are arranged and assembled so that a centr al axis of the loop antenna in the thickness direction and a central axis of the shielded case in the thickness direction can be made to substantially coincide with each other.

Abstract: This invention is a wireless communication medium processing apparatus which carries out communication with a wireless communication medium, to carry out at least one of reading and writing as to information which was stored in the wireless communication medium, and has a plurality of antenna, a transmission divider which was connected to the plurality of antennas, and a reception compositor which was connected to the plurality of antennas, and is characterized in that the transmission divider divides an inputted signal to output the plurality of antennas, and the reception compositor combines signals from the plurality of antennas and outputs it.

Abstract: It is an object of the invention to provide a loop antenna constituted by a single element which can apply a magnetic field to carry out a communication reliably with high precision irrespective of the position and direction of a radio communication medium. The invention provides a loop antenna 1 including a conductor 2, a plurality of bending portions 50 provided on the conductor 2, and a feeding portion for supplying a signal current to the conductor 2, the conductor being turned circumferentially like a loop by setting the feeding portion to be a base point, wherein the conductor 2 forms a three-dimensional space. Consequently, it is possible to generate a magnetic field to all dimensions, thereby carrying out a communication irrespective of the position and direction of a radio communication medium.