Abstract: An amplifier includes an amplifying element that amplifies an input signal; an output terminal that outputs the signal amplified by the amplifying element; a matching circuit disposed in series between the amplifying element and the output terminal, and performing impedance matching; an impedance converter disposed in series between the amplifying element and the matching circuit or between the matching circuit and the output terminal; and a first resonator and a second resonator connected at the ends of the impedance converter.

Abstract: An amplifier includes: an amplifying device configured to amplify an input signal; and a matching circuit coupled to the amplifying device, and including an impedance transformer and a parallel resonance circuit coupled to a wiring which spans from the impedance transformer to the amplifying device, wherein a circuit length of the impedance transformer is longer than one-fourth of wavelength of an electronic wave having a frequency which is substantially equal to a resonance frequency of the parallel resonance circuit.

Abstract: A power amplification device, includes: an amplifier to amplify an input signal; a switched capacitor, provided at an output stage of the amplifier, to change capacitance based on a first control signal; a matching unit, provided at the output stage of the amplifier and including a varactor pair in which two varactor diodes are coupled in series or a varactor pair in which two varactor diodes are coupled in parallel, to change capacitance based on a second control signal; a detection circuit to detect power of the input signal; a quantization circuit to quantize a detected power value, form a quantized bit string having a high-order bit group and a low-order bit group, and output the high-order bit group as the first control signal to the switched capacitor; and a conversion circuit to convert the low-order bit group into an analog value and form the second control signal.

Abstract: A tag patch antenna includes: a slit formed in the vicinity of an edge of an antenna pattern along a part of the edge; and a feeding point to which a tag LSI is connected and which is formed by cutting an intermediate portion of the part of the edge separated by the slit from a body of the antenna pattern by a width of the slit.

Abstract: A metal pipe includes a slot having a predetermined length in a longitudinal direction of the metal pipe and a wireless tag that is placed inside the metal pipe and includes a power feeding unit to feed electric power to the slot and an IC chip connected to the power feeding unit, thereby functioning as an antenna of the wireless tag. The metal pipe is thus managed by the wireless tag.

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: A metal-resistant radio frequency tag that has a broader band pass band (frequency versus communication range) characteristic compared to conventional techniques is achieved. For this purpose, the radio frequency tag according to the present invention includes a first resonator pattern, the first resonator pattern including a chip connecting section to which a chip is to be connected, and an inductance section that is capable of adjusting an impedance matching with the chip; and a second resonator pattern that is fed through electromagnetic induction coupling via the inductance section.

Abstract: A first amplification section and a second amplification section included in an amplification apparatus amplify two constant amplitude signals generated by vector decomposition. An impedance inverting circuit inverts the impedance of the signal amplified by the second amplification section. A combining circuit corrects the phases of the signal amplified by the first amplification section and the signal whose impedance is inverted by the impedance inverting circuit, and combines and outputs these signals. The combining circuit includes a line which is (?/4)+? in length and which is an asymmetrical circuit element and a line which is (?/4)?? in length and which is an asymmetrical circuit element.

Abstract: The wireless tag includes an antenna conductor; a first power-supply conductor which is electromagnetic-inductively coupled with the antenna conductor; and a second power-supply conductor which is loop-shaped and which is electrically coupled with the first power-supply conductor.

Abstract: An RFID tag having a tag antenna and an LSI chip, comprising: a power-supply pattern on which the LSI chip is mounted; a patch antenna that functions as the tag antenna; and a high-frequency connection section that makes a high-frequency connection between the power-supply pattern and the patch antenna. The high-frequency connection section is formed, for example, by forming a slot in the patch antenna, layering one end of a small dipole antenna that functions as the power-supply pattern over the slot so that it crosses over the slot, and supplying power from the small dipole antenna to the patch antenna.

Abstract: An aperture antenna includes an outer conductor with substantially fixed inner diameter; and an inner conductor, an end thereof receding from an aperture of the outer conductor in a direction of electromagnetic radiation.

Abstract: A wireless frequency tag includes a loop-shaped antenna pattern that is electrically connected to a chip connecting section, and a conducting member that electrically couples a part of the antenna pattern.

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: 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.

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: An RFID tag having a tag antenna and an LSI chip, comprising: a power-supply pattern on which the LSI chip is mounted; a patch antenna that functions as the tag antenna; and a high-frequency connection section that makes a high-frequency connection between the power-supply pattern and the patch antenna. The high-frequency connection section is formed, for example, by forming a slot in the patch antenna, layering one end of a small dipole antenna that functions as the power-supply pattern over the slot so that it crosses over the slot, and supplying power from the smalI dipole antenna to the patch antenna.

Abstract: An RFID tag having a tag antenna and an LSI chip, comprising: a power-supply pattern on which the LSI chip is mounted; a patch antenna that functions as the tag antenna; and a high-frequency connection section that makes a high-frequency connection between the power-supply pattern and the patch antenna. The high-frequency connection section is formed, for example, by forming a slot in the patch antenna, layering one end of a small dipole antenna that functions as the power-supply pattern over the slot so that it crosses over the slot, and supplying power from the small dipole antenna to the patch antenna.

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: 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: 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.