Asahi Kasei Microdevices Corporation

Ntt Docomo, Inc.

Yuta Takagi

Shoichi Narahashi

Hiroshi Okazaki

Takayuki Furuta

Kunihiro Kawai

Kei Satoh

Edson Gomes Camargo

Toshiaki Fukunaka

Masanori Masuda

Yuji Goda

Sosuke Nishida

Provided are a gas concentration measurement system, gas concentration computation section, and gas concentration measurement method enabling high-accuracy gas concentration measurement. The gas concentration measurement system includes: a gas concentration measurement section () including a light-emitting element () and a first sensor element; a light-emitting element drive section that drives the light-emitting element; a signal acquisition section () that acquires at least an output signal of the first sensor element, a first drive signal that is a first voltage value or first current value of the light-emitting element, and a second drive signal that is a second voltage value or second current value of the light-emitting element; and a computation section () that computes gas concentration based on signals acquired by the signal acquisition section. The computation section, based on the first and second drive signals, corrects the output signal of the first sensor element and computes the gas concentration.

Gas concentration measurement system

A light emitting and receiving apparatus includes a controller and a calculator. The controller acquires a first detection current from a light-receiving element when supplying a first drive current to a light-emitting element and acquires a second detection current from the light-receiving element when supplying a second drive current to the light-emitting element. The calculator generates a signal indicating deterioration of the light-emitting element when a reference value and an aging value satisfy a deterioration judgment condition, the aging value being a ratio between the first detection current and the second detection current. The detection accuracy of the light emitting and receiving apparatus is thereby improved.

Light emitting and receiving apparatus and method of diagnosing deterioration

A light-emitting/receiving device including: a diode-type light-emitting element formed on a semiconductor substrate; a diode-type light-receiving element formed on the semiconductor substrate; a light source driving unit configured to supply a first common voltage to an anode or a cathode of the light-emitting element to drive the light-emitting element; and a light signal processing unit configured to perform current/voltage conversion on an output current outputted from the light-receiving element, by referring to a second common voltage.

Light-emitting/receiving device and light-detecting method

An infrared-sensor filter member includes an optical filter disposed in an opening portion of a second member and a first member. The infrared-sensor filter member includes a recess portion formed from a light-incident surface of the optical filter and the first member. At least a part of a bottom surface of the recess portion is formed by the light-incident surface and side walls of the recess portion, which are formed by the first member.

Infrared-sensor filter member, manufacturing method thereof, infrared sensor, and manufacturing method thereof

A wireless circuit that can be used in a plurality of frequency bands even if its duplexer is formed of current variable frequency filters is provided. The circuit includes a transmission-reception antenna, a variable frequency duplexer, a double-pole six-throw switch, an RFIC, and a controllerwhich executes switching operations in accordance with control signals. The RFICdetermines a pair of frequency bands for transmission and reception signals input to the variable frequency duplexerand generates and sends the control signals to perform switching control operations to connect a transmission port corresponding to the determined transmission frequency band with the transmission terminal of the variable frequency duplexerand to connect a reception port corresponding to the determined reception frequency band with the reception terminal of the variable frequency duplexerand to perform a frequency switching operation of the variable frequency duplexer

Wireless circuit and frequency pair determination method

A front-end circuit includes an RFIC, an antenna, N duplexers, N variable impedance adjustment circuits, a switch for selecting any two of the N variable impedance adjustment circuits, and a control unit which receives a control signal from the RFIC, where 2&#x2266;N. The control unit executes switching operations of the N variable impedance adjustment circuits and the switch in accordance with control information. The control signal indicates to 1) control the switch to select two variable impedance adjustment circuits corresponding to a p-th frequency band and a q-th frequency band respectively, 2) control a variable impedance adjustment circuit corresponding to the p-th frequency band to increase input impedance in the q-th frequency band as viewed from the antenna side and 3) control a variable impedance adjustment circuit corresponding to the q-th frequency band to increase input impedance in the p-th frequency band as viewed from the side.

Front-end circuit and impedance adjustment method

An multiband resonator of the present invention includes a dielectric substrate including three or more dielectric layers, a ground conductor, a main-line conductor, a sub-line conductor, a sub open stub, a main open stub, a short-circuit conductor, a main through conductor, and a sub through conductor. The short-circuit conductor electrically connects one end of the main-line conductor to one end of the sub-line conductor and to the ground conductor. The main through conductor electrically connects the other end of the main-line conductor to one end of the main open stub that is aligned with that other end of the main-line conductor. The sub through conductor electrically connects the other end of the sub-line conductor to one end of the sub open stub that is aligned with that other end of the sub-line conductor.

Growing community of inventors

Tokyo, Japan

Yuta Takagi