Abstract: A tag antenna is composed of a dielectric spacer, and an antenna pattern which is formed on one of surfaces of the spacer and has a size smaller than one half of a wavelength at an operating frequency, and in which a slit pattern suitable for the resistance and the capacitive components of a chip to be mounted is formed.

Abstract: Disclosed is an adaptive control apparatus having an error calculation unit for calculating the difference between a reference signal and a feedback signal, and an adaptive controller for applying adaptive control so as to diminish the difference and causing the result of adaptive control to be reflected in the reference signal. The adaptive control apparatus has a delay unit for delaying at least one of the reference signal and feedback signal by a set delay time in such a manner that the reference signal and feedback signal will be input simultaneously to the arithmetic unit; a frequency-component detecting unit for detecting a frequency component of the reference signal; a delay-time acquisition unit for acquiring delay time conforming to the frequency component; and a delay-time setting unit for setting the acquired delay time in the delay unit.

Abstract: A radio frequency identification tag includes an antenna including a conductor pattern in a form of dipole, and connected to an integrated circuit chip of the radio frequency identification tag; an adjusting portion including at least one adjusting pattern connected to the conductor pattern to make the antenna compatible with an environment in which the antenna is used; and a marking portion at which directions for an adjusting operation using the adjusting portion is indicated.

Abstract: A crossed dual tag includes two tags each of which comprises, on one plane, a dipole antenna formed with conductors, a feeding part to which an IC chip is connected at the center of the dipole antenna, and a loop-shaped inductance part that is formed between the dipoles of the dipole antenna and connected to the dipoles of the dipole antenna in parallel with respect to the feeding part. The two tags are crossed at right angles, and stacked to contact as closely as possible so that the loops of the inductance parts overlap as wide as possible. A reader/writer of an RFID system sequentially switches the surface of a circular polarized wave of a wireless signal between forward and backward directions, and reads information written to a user memory area from the tag that responds more strongly.

Abstract: A compact antenna structure having substantially no directivity independent of a tag direction in an RFID tag is proposed. The antenna structure includes a pair of dipole antennas is provided in a cross dipole antenna to be applied to an RFID system for communicating information between a reader/writer and the tag using a high-frequency radio signal. The above pair of dipole antennas further includes lines extending from a feed point and mutually intersecting crosswise, and also triangularly expanded lines from the bent ends of the above lines. Each total length of the above pair of dipole antennas is longer than 2/? of a use frequency ?.

Abstract: An RFID tag is constructed by pasting a first component and second component together. The first component includes a tabular first base made of dielectric and a metal layer covering one of the front and back of the first base. The second component includes a sheet-like second base, a metal pattern provided on the second base and electrically connected to the metal layer of the first component to constitute a communication antenna, a circuit chip connected to the metal pattern which carries out a radio communication through the communication antenna, and an adhesive material layer which bonds the second base to the other of the front and back of the first base. The metal layer of the first component and the metal pattern of the second component are electrically connected by the conductive component.

Abstract: An antenna device is disclosed. An antenna such as a dipole antenna and a parallel feeder each formed of a conductor pattern are disposed on a dielectric plate. The connector is connected to the antenna through the parallel feeder. The parallel feeder has a length of an integral multiple of a half wavelength and has an even number of bending points between the connecter and the antenna.

Abstract: An RFID tag that has a tag antenna and a tag LSI comprising: a power-supply element in which the tag LSI is mounted on a power-supply section; a plurality of patch antennas that function as tag antennas and sizes differs; and a high-frequency coupling section that couples the power-supply element with each of the patch antennas by high-frequency coupling.

Abstract: The planer antenna includes: a linear radiating antenna element to which electric power is to be supplied; and multiple linear parasitic antenna elements to which electric power is not to be supplied. The parasitic antenna elements are disposed at a position at which the radiating antenna element and the parasitic antenna elements cross each other without contact. The parasitic antenna elements lying in a direction in which the radiating antenna element and the parasitic antenna elements cross each other, and each of the crossing portions of said plural parasitic antenna elements, which portions cross said radiating antenna element, are bent in such a manner that the crossing portions of the parasitic antenna elements are in parallel with the radiating antenna element. Thus, it is possible to provide a planer antenna which can obtain a good circularly polarized wave with a simple construction. In addition, the planar antenna can be downsized.

Abstract: An RF tag includes a first transmission line which is connected to a grounding conductor and forms an electric closed loop to constitute a dipole antenna. A power supply circuit is connected between a branch point on the first transmission line and the grounding conductor. A second transmission line is connected to the branch point and arranged in parallel with the power supply circuit to constitute an inductor.

Abstract: The purpose of the present invention is to compensate the distortion of an amplifier by a predistorter which compensates the distortion of a power amplifier even when a frequency amplitude deviation exists. The predistorter comprises a distortion compensation coefficient storage unit for storing a distortion compensation coefficient corresponding to the reference value using the characteristic quantity of the envelope of a transmission signal before being inputted to the power amplifier as a reference value; and a reference value conversion unit for converting the characteristic quantity into a predetermined value according to the size of the characteristic quantity, and when the characteristic quantity is, for example, the amplitude value of an envelope and the amplitude value is small, that value is rounded up, for example, to an upper-limit value within a linear range of the amplifier.

Abstract: A DC/DC converter capable of controlling an output signal using a broadband signal input is provided. By employing the above DC/DC converter as a power supply, a highly efficient power amplifier can be configured. The above DC/DC converter includes two class-C amplifiers, a rectifier circuit connected between each output of the two class-C amplifiers, and an oscillator of a predetermined frequency signal. The predetermined frequency signal output from the oscillator is input to each of the two class-C amplifiers, and by controlling the phase difference of the predetermined frequency signal input to the two class-C amplifiers, the magnitude of a direct current voltage output from the rectifier circuit is made variable.

Abstract: The electronic tag authentication device of the present invention authenticates the contents of an electronic tag attached to goods. The electronic tag authentication device comprises an antenna directivity change unit for changing the directivity of an antenna for transmitting/receiving electrical waves in order to authenticate the contents of the electronic tag.

Abstract: A reader/writer apparatus includes a tag search instruction receiving unit that receives a tag search instruction from a host apparatus. The tag search instruction includes a data read instruction and/or a data write instruction on the RFID tag. The reader/writer apparatus also includes a tag identification information requesting unit that transmits to the RFID tag a request for transmission of tag identification information uniquely identifying the RFID tag when the tag search instruction receiving unit receives the tag search instruction; and a data processing requesting unit that transmits a data read request and/or a data write request to the RFID tag identified by the tag identification information based on the read instruction and/or the write instruction when receiving the tag identification information transmitted from the RFID tag in response to the request for transmission transmitted from the tag identification information requesting unit.

Abstract: A first pattern is constituted by a pair of conductors each of which comprises only one turn of bent part. An edge part of one side of each of the pair of conductors is configured as a power feeding point. AC coupling section is formed between the power feeding points. And a second pattern is placed opposite to the first element by sandwiching a dielectric body.

Abstract: An RFID tag includes a dielectric member, an antenna pattern formed on and around a surface of the dielectric member, and an IC chip that is electrically connected to the antenna pattern by means of two chip pads.

Abstract: A radio frequency identification tag that is thin and flexible, and is capable of performing communication when attached to metal, and also can be manufactured at a lower cost. An inverted-F antenna has a radiating element, a short pin, a power supply portion, and a ground bottom board, and is flatly formed on the front surface of a film. The film is an insulting film such as polyethylene terephthalate, and is attached to the metal housing of an electronic device such that the radiating element, the short pin, and the power supply portion of the inverted-F antenna formed on the front surface are projected from the metal housing.

Abstract: In an RFID tag, a ground portion attached to a magnetic recording medium so as to be electromagnetically coupled to a metal surface inside the magnetic recording medium in a high-frequency band, a monopole portion provided on a same plane as the ground portion and inside the ground portion, and a feeding portion connected to one end of the monopole portion and mounting thereon an LSI chip are provided. The ground portion has a ring shape, the monopole portion bent along the ring shape has a length for impedance matching with the feeding portion, and this length can be adjusted by providing a folded portion or a meander portion. Alternatively, the monopole portion may be decentered from the ground portion so as to locate a vicinity of the feeding portion away from the ground portion and to bring a vicinity of the tip portion near to the ground portion, in which case an adjusting portion can be provided at the tip portion of the monopole portion.

Abstract: A disk tag reading device is a device for reading contents of an electronic tag attached to a disk. A holder which is inserted into a central hole of the disk configures an antenna for communicating with the electronic tag attached to the disk.

Abstract: An RF tag is disclosed that includes an antenna and an integrated circuit connected to the antenna. The antenna includes a first radiating element, a second radiating element, a feeding part connected in series between the first and second radiating elements, and an impedance control part connected parallel to the feeding part. An auxiliary radiating element connected to one or both of the first and second radiating elements is used for radio communication with the integrated circuit before completion of the RF tag, and is not used for radio communication after the completion of the RF tag.