Other

Ntt Docomo, Inc.

Tohoku University

Intelligent Cosmos Research Institute

Kitayoshi, Hitoshi

Kunio Sawaya

Hitoshi Kitayoshi

Tamami Maruyama

Qiang Chen

Qiaowei Yuan

Tatsuo Furuno

Jianfeng Li

Yasuhiro Oda

Shinji Uebayashi

Tomoyuki Ohya

Koji Mizuno

Hiroyasu Sato

Yoshihiko Wagatsuma

Shiwei Qu

Long Li

A disclosed dual antenna system includes a receiving antenna which includes a first surface orthogonal to an incident wave, the first surface being a first antenna aperture, and a transmitting antenna which includes a second surface parallel to a reflection direction which is a transmission direction, the second surface being a second antenna aperture. A portion of a structure of the transmitting antenna is shared by the receiving antenna.

Dual antenna system

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

A reflectarray, including: a substrate; and a plurality of patches formed on each of areas into which a principal surface of the substrate is divided, wherein the plurality of patches are formed by including a gap.

Reflectarray

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 reflect array () according to the present invention includes a plurality of array elements () forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and a ground plane (). The ground plane () has a structure with a frequency selective function.

Reflect array

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.

RF ID tag device

There is provided a method for designing a corrugated Fermi antenna having a broad-band and circular directivity required for receiving an image by using a wave of millimeter order. As a first step, an inflection point of the Fermi-Dirac function as a taper function of the Fermi antenna is changed so as to set the beam width of plane H to a beam width having a target directivity. After the beam width of the plane H is set to the target value, the aperture width of the Fermi antenna is changed so as to set the beam width of the plane E to a beam width having a target directivity. Thus, by adjusting the beam width values of the planes H and E independently from each other and matching them with the target values, it is possible to design a Fermi-antenna having a broad-band and circular directivity in a short time.

Growing community of inventors

Miyagi, Japan

Kunio Sawaya