Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Kyowa Electronic Instruments Co., Ltd

Keio University

School Judicial Person Ikutokugakuen

Kiyoshi Egawa

Yoshio Koyanagi

Yutaka Saito

Tomoaki Nishikido

Hideo Ito

Hiroshi Haruki

Jin Mitsugi

Haruhisa Ichikawa

Yuusuke Kawakita

Hidehiro Yanagibashi

Yukari Yamazaki

Masazumi Yamazaki

Yuki Igarashi

Hideo Itoh

A radio communication apparatus is described that includes a reception antenna, a converter, a calculator, and a separator. The reception antenna receives a mixed signal including two or more backscatter signals respectively transmitted from two or more tag devices and the converter converts the mixed signal into complex data on a complex plane. The calculator calculates phase angles of carrier waves of the two or more backscatter signals to approximate the phase angles into a complex data sequence of a predetermined length, and generates a projector matrix formed of a combination of the phase angles of carrier waves of the two or more backscatter signals. The separator separates the two or more backscatter signals from the mixed signal based on an inverse matrix of the projector matrix and the complex data sequence.

Radio communication apparatus, radio communication system and radio communication method

Provided is a wireless communication system which enables wireless communication in which crosstalk due to multiple access is canceled while using a large number of inexpensive wireless terminals. In order to generate an interference component, an analysis data sequence is generated by applying a Hilbert transform, by a Hilbert transform, to a subcarrier data sequence obtained by extracting a target subcarrier wave component from a finite length data sequence, while a carrier phase difference &#x3a8; is estimated by using the regression analysis by a carrier wave phase estimation unit. After rotation calculation configured to return the analysis data sequence by the carrier phase difference &#x3a8; is performed, conversion into an angle is performed. Further, a multiplication by a desired odd number of multiplication is performed, and then an inverse Hilbert transform is applied.

Wireless communication system

A multi-band antenna can be realized by using a common antenna element with a simple configuration. A radio antenna unit includes a ground conductor plateprovided to a casing of a radio device and having a ground potential, a first radio circuithandling a system in a first frequency band and a second radio circuithandling a system in a second frequency band lower than the first frequency band, which are provided in the ground conductor plate, a first feeding lineconnected to the first radio circuitand being a coaxial transmission line having an outer conductorthat is arranged along the ground conductor plate, an antenna elementconnected to the first feeding lineand the outer conductorrespectively, and arranged along the ground conductor plate, and a second feeding linefor connecting the second radio circuitand the outer conductor, wherein the first feeding linefeeds a high frequency power input from the first radio circuitand the second feeding linefeeds a high frequency power input from the second radio circuit

Radio antenna unit and mobile radio device equipped with the same

There is provided a mobile telephone assuring a high reception sensitivity over a wide band without deteriorating the design of the mobile telephone. In the mobile telephone, a helical antenna () operating as an antenna for television reception is formed by winding a conductive element along the external surface of the case several times at the upper end of the upper case (). The helical antenna () is impedance-matched by a matching circuit () in a range of the order from 470 MHz to 700 MHz which is the television broadcast frequency. The matching circuit () is connected to a broadcast reception circuit (). The broadcast reception circuit () operates as a reception circuit for receiving the television broadcast wave.

Mobile telephone with broadcast receiving element

A portable wireless device realizing high-speed transmission in downlink communication in a used state that a foldable portable wireless device is held in a hand of the user and ensuring a high antenna radiation efficiency. In the portable wireless device, platy conductors () are arranged in the longitudinal direction on the back of a display section () of an upper case (). The signal of a transmission circuit () is distributed by a power distributor (). One signal is fed to a platy conductor () through a phase shifter () and the other is fed to the platy conductor () or the platy conductor () from a high-frequency switch () through a transmission/reception duplexer () or a transmission/reception duplexer (). The high-frequency switch () selectively feeds power to either the platy conductor () or the platy conductor () according to the signal from a gravity sensor (). The received signal is extracted by the transmission/reception duplexers (), amplified by a receiving circuit () and a receiving circuit (), and multiplied by a predetermined weight coefficient by a demodulating section () and combined.

Portable wireless device

A mobile radio apparatus that achieves high radiation efficiency in various usage states of a foldable mobile radio apparatus without causing negative impact on communication, and that can realize a thin model. In this mobile radio apparatus that is foldable and that has a mechanism joining a first case and second case at a hinge part and allowing the mobile radio apparatus to open and close, flat conductor (), flat conductor () and flat conductor () that are placed distant from flat conductor () are placed in the first case, gravity sensor () detects an inclination angle of the mobile radio apparatus to judge the usage state of the mobile radio apparatus, and control section () controls high frequency switch () according to the inclination angle and supplies power selectively to flat conductor () and flat conductor (). Furthermore, power is constantly supplied to flat conductor () during communication at a different phase from the phase power is supplied to flat conductor () or flat conductor ().

Mobile radio apparatus

Feed point () performs unbalanced feeding to an antenna element (). A parasitic element () is provided near the antenna element () and a ground plane (), approximately parallel to the width direction of the ground plane (). Moreover, the parasitic element () is configured in a length to operate as a director when provided on the side of the body with respect to the ground plane () during talk time and in a length to operate as a reflector when provided on the opposite side from the body with respect to the ground plane (). By this means, it is possible to improve gain and reduce the specific absorption rate (SAR) during talk time.

Antenna device for radio apparatus

A high gain built-in antenna for a radio communication terminal with less influence from the human body. This built-in antenna for a radio communication terminal includes bar-shaped second passive elementfacing antenna elements making up dipole antenna. The distance between this second passive elementand the antenna elements making up dipole antennais appropriately set in such a way as to widen the band of the input impedance characteristic by changing mutual impedance between second passive elementand the antenna elements making up dipole antenna

Built-in antenna for radio communication terminal

The unbalanced feeding antenna elementis fed power from one end and placed on the upper surface of the circuit substrate. The passive elementhas open both ends, is set to a length corresponding to a predetermined frequency, placed in substantially parallel to the unbalanced feeding elementplaced on the circuit substrateat a distance of approximately 1/10 or less of a wavelength at a frequency used for transmission/reception. This suppresses the antenna current flowing into the circuit substrateto a minimum level and makes radiation from the passive elementdominant compared to radiation from the circuit substrate. This makes it possible to suppress a reduction in the antenna gain caused by the human body when the user uses the communication terminal apparatus.

Antenna for communication terminal apparatus

The built-in antenna for radio communication terminals of the present invention includes a loop antenna with a circumference of approximately one wavelength or less placed at an extremely short distance compared with the wavelength from the plane of the terminal board so that its loop plane may be perpendicular to the plane of said terminal bottom board which is opposite to the human body during communication, and a balanced/unbalanced conversion circuit with an impedance conversion function that supplies power to this loop antenna.

Built-in antenna for radio communication terminals

In a state that a whip antenna is contained in a housing of a cellular phone, a minute space is formed between a feeding spring and an attaching member conductive to a helical antenna base portion, so as to generate electrostatic capacitance, which is equivalent to the impedance characteristic of a mono-pole antenna. Then, electrostatic capacitance and a coil portion of a helical antenna constitute an LC series resonance circuit so as to improve the wide band of the helical antenna.

Growing community of inventors

Tokyo, Japan

Kiyoshi Egawa