Abstract: An amplifier includes a first amplification element configured to amplify a first signal in one of first and second operation classes, a second amplification element configured to amplify a second signal in one of first and second operation classes, a first transmission line through which the amplified first signal is transferred, and a coupler configured to couple the transferred first signal and the amplified second signal, wherein the first amplification element amplifies the first signal in the first operation class and the second amplification element amplifies the second signal in the second operation class, when the first signal and the second signal have a first frequency band, and wherein the first amplification element amplifies the first signal in the second operation class and the second amplification element amplifies the second signal in the first operation class, when the first signal and the second signal have a second frequency band.

Abstract: An amplifying apparatus includes a first amplifier that amplifies a first signal of a constant amplitude; a second amplifier that amplifies a second signal identical in amplitude and differing in phase with respect to the first signal; a first transmission line of which, a first end is connected to an output terminal of the first amplifier; a second transmission line differing in length with respect to the first transmission line and of which, a first end is connected to an output terminal of the second amplifier and a second end is connected to a second end of the first transmission line; and an amplitude balance adjusting element connected to the first or the second transmission line. The amplifying apparatus outputs from a connection node of the first and the second transmission lines, a signal that is a combination of output signals of the first amplifier and of the second amplifier.

Abstract: A signal amplification device includes: a signal generator which divides an input signal so as to generate a plurality of division signals having a specified amplitude and different phases; a plurality of amplifiers which amplify the plurality of division signals by using a field effect transistor, respectively; transmission lines through which the division signals pass, the division signals being amplified with individual amplifiers of the plurality of amplifiers, the transmission lines have different lengths and no isolation is provided between ends of the transmission lines; and a detector which performs a comparison between gate currents input to the individual amplifiers to detect whether an input of the division signal to any of the plurality of the amplifiers exceeds a saturation level.

Abstract: A radio-frequency identification (RFID) tag includes a battery that stores therein electricity and supplies the electricity to the RFID tag, an antenna that receives radio waves transmitted from a reader/writer, an electricity generating unit that generates electricity based on the radio waves received by the antenna, and supplies the electricity to the RFID tag, an electricity storage determining unit that determines whether electricity is stored in the battery, an electricity supply switching control unit that, when the electricity storage determining unit determines that electricity is stored, selects a connection of a circuit to operate the RFID tag with the electricity supplied from the battery, and an electricity generating unit switching control unit that, when the electricity storage determining unit determines that electricity is stored, selects a connection of a circuit not to input the radio waves received by the antenna to the electricity generating unit.

Abstract: A signal amplification device includes: a signal generator which divides an input signal so as to generate a plurality of division signals having a specified amplitude and different phases; a plurality of amplifiers which amplify the plurality of division signals by using a field effect transistor, respectively; transmission lines through which the division signals pass, the division signals being amplified with individual amplifiers of the plurality of amplifiers, the transmission lines have different lengths and no isolation is provided between ends of the transmission lines; and a detector which performs a comparison between gate currents input to the individual amplifiers to detect whether an input of the division signal to any of the plurality of the amplifiers exceeds a saturation level.

Abstract: A radio-frequency identification (RFID) tag includes a battery that stores therein electricity and supplies the electricity to the RFID tag, an antenna that receives radio waves transmitted from a reader/writer, an electricity generating unit that generates electricity based on the radio waves received by the antenna, and supplies the electricity to the RFID tag, an electricity storage determining unit that determines whether electricity is stored in the battery, an electricity supply switching control unit that, when the electricity storage determining unit determines that electricity is stored, selects a connection of a circuit to operate the RFID tag with the electricity supplied from the battery, and an electricity generating unit switching control unit that, when the electricity storage determining unit determines that electricity is stored, selects a connection of a circuit not to input the radio waves received by the antenna to the electricity generating unit.

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 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: A disclosed RF tag reader receives, from an RF tag, data including at least identification information; replaces part of the identification information with predetermined information; determines whether an error can be detected in the data including the partially-replaced identification information; and transmits a request to the RF tag to resend the data in the event that an error is detected in the data including the partially-replaced identification information.

Abstract: Either one or both of the antenna pattern and a ground pattern, which reflects a radiated radio wave radiated from the antenna pattern, are buried inside the glass substrate. As a result, it is possible to provide high-gain, low-loss glass antennas in which glass is used as their substrates.

Abstract: Antenna switching equipment switches antennas for a reader/writer. A power generation unit generates electric power from an RF signal outputted from the reader/writer. A switching signal generation unit, operating on electric power generated by the power generation unit, generates a switching signal for specifying an antenna port to be used from among a plurality of antenna ports. A high frequency switch unit, operating on electric power generated by the power generation unit, switches a connection between the reader/writer and one of a plurality of antenna ports based on a switching signal generated by the switching signal generation unit.

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 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 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 connector and the antenna.

Abstract: A reader/writer 25 transmits an instruction for changing over between antennas 31 and 32, carried on a high frequency wave in the same format as a common command. A part of the antenna is equipped with a command interpretation circuit 30 which demodulates a high frequency wave received from the reader/writer body 25 and obtains a command content. If this command is an antenna changeover instruction of the reader/writer itself, the command interpretation circuit 30 instructs a changeover signal generation unit 28 for generating a changeover signal and changes over antennas by controlling a high frequency wave switch unit 29.

Abstract: An antenna having directivity receives a harmonic signal generated from a radio tag, and position information corresponding to a direction and reception information indicating whether or not a harmonic signal was received from the direction are output, regarding each of the directions to which the antenna is directed.

Abstract: Either one or both of the antenna pattern and a ground pattern, which reflects a radiated radio wave radiated from the antenna pattern, are buried inside the glass substrate. As a result, it is possible to provide high-gain, low-loss glass antennas in which glass is used as their substrates.

Abstract: Antenna switching equipment switches antennas for a reader/writer. A power generation unit generates electric power from an RF signal outputted from the reader/writer. A switching signal generation unit, operating on electric power generated by the power generation unit, generates a switching signal for specifying an antenna port to be used from among a plurality of antenna ports. A high frequency switch unit, operating on electric power generated by the power generation unit, switches a connection between the reader/writer and one of a plurality of antenna ports based on a switching signal generated by the switching signal generation unit.

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: A process for the production of an integral composite molded item including(i) a surface portion having a synthetic resin phase containing a fibrous reinforcing material,(ii) a core portion having the synthetic resin phase containing bubble-containing particles, and(iii) a separation layer positioned between the surface portion and the core portion, the process including the steps of:providing in a substantially sealed mold (1) a separation layer which does not substantially pass therethrough bubble-containing particles but which is capable of passing a synthetic resin or its precursor that is liquidized at the time of molding; (2) a synthetic resin or its precursor on either or both sides of the separation layer; (3) a fibrous reinforcing material between the separation layer and the mold, and (4) an aggregate of bubble-containing particles on the side of the separation layer opposite to the mold;causing volume expansion of the aggregate;causing the resin to flow through the separation layer to thoroughly di