Abstract: A power amplifier negates a memory effect and is applied a linearizer using a digital predistortion system even in an inexpensive device. The power amplifier compares an input signal power against a sampled component of an output power, and provides predistortion to the input signal power so as to minimize a difference as a result of the comparison. The power amplifier comprises a gain lookup table storing a gain coefficient value corresponding to a temperature address determined for an input power; a phase lookup table storing a phase coefficient value corresponding to the temperature address determined for the input power; a transversal filter, which is input with the input power, and which outputs the temperature address; and a coefficient multiplier modulating the input signal using a gain coefficient value and a phase coefficient value, which correspond to the temperature address and which are read out from the gain coefficient lookup table and the phase lookup table.

Abstract: A dipole part of a length shorter than half of an antenna resonance wavelength is placed so as to be rolled and enables a feeding part 11 to feed a chip. An inductance part 12 for adjusting the inductance of the antenna is provided so as to sandwich the feeding part 11. The inductance 12 is provided using an empty space of the inside of the rolled dipole part. By providing the inductance part 12, the inductance of the antenna can be adjusted so as to resonate at a predetermined frequency with the capacitance of the chip connected to the feeding part 11. At this time, although the radiation resistance of the antenna becomes extremely large according to calculations, it is actually almost the same as the resistance of the chip due to loss, and the power received by the antenna can be provided to the chip.

Abstract: A distortion compensating apparatus calculates a distortion compensation coefficient in such a manner that a difference signal between a reference signal, which is a transmit signal, and a feedback signal will be diminished, updates an old distortion compensation coefficient by the calculated distortion compensation coefficient and applies distortion compensation to the transmit signal based upon this distortion compensation coefficient. In this apparatus, a phase correcting interval, which is for correcting the phase difference between the reference signal and the feedback signal, and a distortion compensation coefficient updating interval are generated alternately, a correction is applied so as to null the phase difference in the phase correcting interval, and the distortion compensation coefficient is updated in the distortion compensation coefficient updating interval.

Abstract: A plane antenna comprises a substrate having a first surface and a second surface, a first radiating element, a first power feeding pattern connected to the radiating element, and a first non-power feeding loop type radiating element provided adjacent to the first radiating element, all disposed on the first surface of the substrate, and a second radiating element, a second power feeding pattern connected to the radiating element, and a second non-power feeding loop type radiating element provided adjacent to the second radiating element, all disposed on the second surface of the substrate.

Abstract: An antenna for a radio frequency identification tag, includes a dielectric board; and a pair of conductive plates; wherein the pair of the conductive plates has a point symmetrical configuration with respect to a mounting position of a radio frequency identification tag integrated circuit. The pair of the conductive plates and the mounting position of the radio frequency identification tag integrated circuit may be arranged along a standard line on the surface of the dielectric board.

Abstract: The container for accommodating at least one article bearing a wireless tag that wirelessly communicates with a reader/writer antenna includes a conductor which electromagnetically couples with an antenna of the wireless tag when an interrogation signal is radiated from the reader/writer antenna toward the wireless tag or when a response signal is radiated from the wireless tag toward the reader/writer antenna.

Abstract: A wireless tag adapted for mounting inside a hollow electrically conductive pipe, includes: a contact placed in contact with the electrically conductive pipe so as to be electrically connected to the electrically conductive pipe; a lead wire placed inside the electrically conductive pipe along a longitudinal direction of the electrically conductive pipe and spaced a prescribed distance away from an inside wall of the electrically conductive pipe, thereby forming a coaxial line together with the electrically conductive pipe; and a wireless tag circuit, electrically connected at one end to the contact and at the other end to the lead wire, for generating a response signal in response to an interrogation signal transmitted from a reader/writer.

Abstract: A RFID tag having a loop antenna comprises: a flat plate shaped dielectric member 51; first and second loop antenna patterns 52, 53 that are formed on a first and second surface of the dielectric member 51 so that they are separated from each other by a specified space, and so that each is continuous from the first surface to the second surface of the dielectric member 51; and an IC chip 54 that electrically connects the first and second loop antenna patterns 52, 53 on one of the surfaces.

Abstract: An antenna having a construction enabling simple adjustment of impedance at the antenna connection terminal has a grounded plate; a plate-shape radiating conductor, positioned parallel to the grounded plate; a feed line conductor, one end of which is connected to a feed point of the plate-shape radiating conductor, the other end of which is connected, as an antenna terminal, to an inner conductor of a coaxial cable, and which is perpendicular to the plate-shape radiating conductor; and a conductor disc, electrically connected to the feed line conductor, and positioned parallel to the ground plate, the distance from the conductor disc to the grounded plate being adjustable.

Abstract: To provide a compact and low-cost glass antenna in which an antenna position can be easily recognized by emitting a light near the antenna position, and thus a passerby or the like can easily grasp the position when he or she holds up a tag. The glass antenna has plate-like glasses 11A and 11B, antennas 12A and 12B provided on the plate-like glasses 11A and 11B, and a light emitting unit 16a that is provided so as at least a part thereof to be overlapped with the antennas as seen from the direction that the antennas 12A and 12B are directed, and scatters the light guided by the plate-like glasses 11A and 11B to emit light in the vicinity of the antenna.

Abstract: In a folded dipole antenna, both ends of a first dipole portion with a feeding portion are connected to both ends of a second dipole portion so that a slot portion may be formed, and the first and the second dipole portion have a width for generating a linearly-polarized wave in a slot mode (in a longitudinal direction) when an RFID chip is mounted on the feeding portion. A terminal of a chip is actually connected to an antenna terminal of the feeding portion of the folded dipole antenna to realize a tag.

Abstract: An RFID antenna that can be disposed in a space-saving manner. The RFID antenna comprises an outermost peripheral conductive line that is bent in a manner extending along sides of a generally rectangular shape having a predetermined size, and a power-feeding conductive line that is disposed close to an inner periphery of the outermost peripheral conductive line in a manner extending parallel therewith, and is electrically connected to the outermost peripheral conductive line at ends thereof, the power-feeding conductive line including a portion thereof formed with a feeder part. Therefore, the antenna fits into a rectangle having a predetermined size, such as a card size.

Abstract: A power amplifying apparatus includes a high-speed low pass filter which inputs an envelope signal included in a transmission signal therein, a low-speed low pass filter which inputs the envelope signal therein, a determination unit which inputs the envelope signal therein and determines rising or falling of the envelope signal, a selecting unit which selects one of the high-speed low pass filter and the low-speed low pass filter according to a determined result of the determination unit, and a voltage supply unit which generates a voltage based on a signal input according to a selection by the selecting unit and supplies the voltage to a power amplifier which inputs the transmission signal therein so as to amplify a power of the transmission signal.

Abstract: A distortion compensation apparatus of the present invention is used in a transmitter that produces and outputs a second signal from a first signal. This apparatus comprises a delay unit for delaying a feedback signal obtained from by the second signal; and a delay control unit for determining a delay quantity of said delay means so that a timing difference between a reference signal obtained from the first signal and the feedback signal delayed by the delay unit is made small. The delay control unit limits the delay quantity within a predetermined limit value.

Abstract: An RF tag to accompany a conductive object 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. The antenna has an effective length shorter than half of a wavelength used in communication.

Abstract: The present invention relates to a tag-use antenna allowing a miniaturization while maintaining a constant minimal change of a communication distance. The tag-use antenna has a feed part of a folded dipole antenna of a size of 53 mm long and 7 mm wide being connected to, and equipped with, an LSI chip of Rc=500 ohms and Cc=1.4 pF and is covered with plastic resin 13 of the dielectric constant ?r=3 and thickness of t=0.75 mm on both sides of the antenna. The dipole part of 1 mm wire path width of the tag-use antenna is formed in a rectangular spiral by being bent inward from both ends at bending parts at four places. The entire length of the dipole antenna when extending the four bending parts straight is featured so as to be shorter than one half of a resonance wavelength of the antenna. An inductance part is featured in the intermediate part of the both dipole parts in the neighborhood of the center of the antenna.

Abstract: The present planar antenna include: a linear antenna element to which electric power is to be supplied and a loop-shaped parasitic antenna element placed in the vicinity of said linear antenna element, which are provided on one side of a dielectric substrate. This simple arrangement makes it possible to provide a planar antenna with good circular polarization characteristics.

Abstract: The present invention relates to a tag-use antenna allowing a miniaturization while maintaining a constant minimal change of a communication distance. The tag-use antenna has a feed part of a folded dipole antenna of a size of 53 mm long and 7 mm wide being connected to, and equipped with, an LSI chip of Rc=500 ohms and Cc=1.4 pF and is covered with plastic resin 13 of the dielectric constant ?r=3 and thickness of t=0.75 mm on both sides of the antenna. The dipole part of 1 mm wire path width of the tag-use antenna is formed in a rectangular spiral by being bent inward from both ends at bending parts at four places. The entire length of the dipole antenna when extending the four bending parts straight is featured so as to be shorter than one half of a resonance wavelength of the antenna.

Abstract: With the RFID comprising a transmitting and receiving antenna, a detecting block formed in the circumference of the antenna, and an electronic component connected to the antenna and detecting block to detect breakdown of the detecting block, illegal use can be prevented, matching between the tag antenna and IC chip can also be attained with inclusion of the detecting means, and higher radiation and receiving characteristics of antenna can also be obtained without deterioration of antenna gain. Moreover, the RFID is very effective for keeping security because illegal use of the RFID tag through re-adhesion thereof to an item can be prevented.

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.