Other

Tohoku University

Intelligent Cosmos Research Institute

Kitayoshi, Hitoshi

Hitoshi Kitayoshi

Kunio Sawaya

Hiroki Kuwano

A rotary system mounted piezoelectric generator has a folded beam structure in which the whole or part of a spring is formed with a piezoelectric generation element, in which one end is provided in a drive rotation system and in which a weight is attached to the other end, the degree of freedom of motion of the weight is two or more-dimensional and thus it is possible to easily change the locus thereof. The beam has a spiral structure such that when the drive rotation system is rotated, a centrifugal force applied to the weight is efficiently modulated by a second force other than the centrifugal force. A self-powered wireless communication terminal is operated with an extremely small amount of power consumption by use of a wireless connection control means and a modulation scattering response antenna which perform multilevel phase-shift keying (MPSK).

Rotary system mounted piezoelectric generator, self-powered wireless communication terminal and wireless communication system

An RF tag system is provided, in which in addition to a method of easily sending back MPSK modulated sub-carrier signals on the RF tag side, communication protocols and circuit systems for accurately demodulating modulated waves on the RF tag reader side can be implemented, data transmission from an RF tag to an RF tag reader can be realized over a long operating distance at high speed, and an RF tag can be operated for a long lifetime.

RF tag system which allows a scheduled start RF tag and a remote start RF tag to share the same frequency band

In order to implement novel utilization methods, implementation of a low power consumption and high sensitivity RF receiving system is desired. A microwave frequency band stub resonance booster circuit characterized by boosting the amplitude of an RF signal in a passive operation by resonating in series a 0.2 pF to 0.01 pF micro-capacitor element with a &#x3bb;g/2 open stub element to perform impedance conversion of the input RF signal is used. In addition, since a capacitor which has been conventionally inserted in order to repeat charging and discharging of the RF signal by using two diodes becomes useless by putting a DC resonant component of resonant-boosted output into an open state when voltage-doubling and rectifying the resonant-boosted RF signal, rectified output can be obtained and high-sensitivity reception and detection of the RF signal becomes possible without being affected by the capacitor which imparts comparatively large insertion loss.

Microwave band booster rectifier circuit, and wireless tag device and wireless tag system employing same

RF tag, RF tag reader, and pulse code key detecting circuit, and RF tag system using them

There is provided a sensor tag device capable of detecting event data by a sensor tag all the time even when no radio wave is received, saving power supply for a microprocessor, and enlarging the radio communication distance. The sensor tag device includes generation meansandusing one or more environmental changes, power supply voltage rise control means, and power supply synthesis means, and power is supplied to a microprocessorand event data is stored in the microprocessorwhen an event, i.e., an environmental change has occurred. A power receiving circuit having a transmission/reception antenna, a built-in power receiving circuit, and the microprocessor and capable of bi-directional communication by radio waves is combined with a stab resonance RF boost circuit and a ladder boost rectification circuit.

Sensor tag, sensor tag device, power receiving circuit, and sensor tag device power supply method

A highly efficient thin slot antenna having a cavity and an RFID tag device are provided, in which such flexible properties can be provided to the antenna that the antenna can be worn on the curved surface of a human body, an object, or the like as well as the antenna can be relatively freely deformed, and changes in the characteristics caused by deformation and changes in the characteristics caused by a product to mount the antenna thereon. are extremely small. Conductive foil such as aluminum or foil vapor deposited with conductive metal such as aluminum is used to form a bag shape for configuring a bag-shaped product having a cavity (). A relatively soft dielectric sheet () is provided inside the cavity (), and a slot () is provided lengthwise on one side of the bag-shaped product at the center position in the width direction.

Thin slot antenna having cavity, antenna power feeding method, and RFID tag device using the antenna and the method

The present invention aims to overcome the drawback with conventional RFID tag devices having a short communication range, and expand the communication range to several times or more that in the conventional scheme. The conventional scheme is based on equilibrium feeding/equilibrium modulation (a two-terminal circuit for antenna operation), whereas the present invention is based on disequilibrium feeding/equilibrium modulation (a three-terminal circuit for antenna operation). The conventional scheme is based on simple rectification of received RF signals, whereas the present invention employs a circuit based on a combination of a stub resonance-based, impedance transformation boosting scheme and a ladder boosting scheme. The conventional scheme is based on ASK or BPSK modulation, whereas the present invention is based on passive modulation, but can employ a QPSK modulation circuit.

Growing community of inventors

Miyagi, Japan

Hitoshi Kitayoshi