Patents by Inventor Tetsuo Onodera

Tetsuo Onodera has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7088954
    Abstract: A wireless communication apparatus of the present invention has an interference signal cutoff circuit (10) for cutting off electric waves having interference frequencies of ?f=|frx±ftx| interposed between a receiving antenna (1) and a receiver (5). A transmitter (6) is connected to a transmitting antenna (11). In this way, provision of the interference signal cutoff circuit (10) makes it possible to prevent degradation of reception characteristics, the degradation being caused such that the transmission wave radiated from the transmitter (6) and input to the receiver (5), mainly via the receiving antenna 1 is modulated with interference waves by active elements provided in the receiver (5) to generate interference waves having the same frequency as the reception frequency frx.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: August 8, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tai Miyagawa, Kaoru Okabe, Tetsuo Onodera
  • Publication number: 20030143970
    Abstract: A wireless communication apparatus of the present invention has an interference signal cutoff circuit (10) for cutting off electric waves having interference frequencies of &Dgr;f=|frx±ftx| interposed between a receiving antenna (1) and a receiver (5). A transmitter (6) is connected to a transmitting antenna (11).
    Type: Application
    Filed: September 30, 2002
    Publication date: July 31, 2003
    Inventors: Tai Miyagawa, Kaoru Okabe, Tetsuo Onodera
  • Patent number: 6442146
    Abstract: The present invention is directed to a TDMA communication system which is adapted to different communication environments or prepares different communication environments and allows each mobile station to be set for working in any one of the different communication environments. The communication system commonly uses a TDMA format that has a fixed frame-length and a constant number of bits for each of the slots composing the frame. The communication environments have prepared respective sets of communication conditions, each set including a transmission power, a modulating method, the number of multiplexed signals, error-correction, an antenna gain, a frequency hopping value and a diversity value. At each mobile station and each base station, one of plural sets of communication conditions for respective environments is selected to establish communication with each other under the selected environment.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: August 27, 2002
    Assignees: Sharp Kabushiki Kaisha, Hitachi Ltd., Mitsubishi Denki Kabushiki Kaisha, Communication Research Laboratory, Ministry of Posts and Telecommunications, Nippon Telegraph And Telephone Corporation, NTT Mobile Communications Network, Inc., YRP Mobile Telecommunications Key Technology Research Laboratories Co. Ltd.
    Inventors: Tetsuo Onodera, Hiroshi Usami, Akihiro Shibuya, Eimatsu Moriyama, Kiyoshi Hamaguchi, Yoichi Saito, Tadashi Matsumoto, Mitsuhiko Mizuno
  • Patent number: 5832373
    Abstract: An output power control device is provided with an isolator, to which a transmission signal, that has been power amplified by a power amplifier, is input. The transmission signal is input via a transmission line connected to an output side of the power amplifier. The isolator only passes a progressive wave component of the transmission signal. The output power control device also includes a detection circuit for forming an actual output power detection signal by extracting part of an output power from a point of input of the isolator. Further, a reactance adjusting element connected to the point of input of the isolator cancels a parasitic reactance associated with the extracting section of the detection circuit.
    Type: Grant
    Filed: December 3, 1996
    Date of Patent: November 3, 1998
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera
  • Patent number: 5818392
    Abstract: In a mobile radio transceiver, an antenna has a fixed element and a movable element. When the movable element is in an extended state, the movable element functions. On the other hand, when the movable element is in a retracted state, the fixed element functions. An impedance matching circuit preferentially performs impedance matching relative to the fixed element. A reactance element is further provided which is connected to the movable element when the movable element is in the extended state. On the other hand, the reactance element is out of connection to the movable element when the movable element is in the retracted state. With this arrangement, the impedance matching circuit and the reactance element cooperatively achieve impedance matching relative to the movable element when the movable element functions.
    Type: Grant
    Filed: November 14, 1995
    Date of Patent: October 6, 1998
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Shinji Oka, Eiichi Nakanishi, Tetsuo Onodera, Hiroshi Shimizu
  • Patent number: 5771442
    Abstract: In a dual mode transmitter for modulating, in a digital mode, an input digital signal and transmitting a modulated digital signal and modulating, in an analog mode, an input analog signal and transmitting a modulated analog signal, a digital modulating section modulates the input digital signal to thereby generate the modulated digital signal, and outputs the modulated digital signal. An analog modulator/carrier generator modulates the input analog signal to thereby generate the modulated analog signal, and outputs it. Also, the analog modulator/carrier generator generates a carrier signal for up-converting the modulated digital signal. The up-converter up-converts, in the digital mode, the modulated digital signal by using the carrier signal and receives, in the analog mode, the modulated analog signal and passes it therethrough.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: June 23, 1998
    Assignee: OKI Electric Industry Co., Ltd.
    Inventors: Hefeng Wang, Tetsuo Onodera
  • Patent number: 5722062
    Abstract: A linear receiver is disclosed which includes a linear receiver having: a preamplifier for amplifying linearly a modulated carrier signal (RF signal) having a first frequency trapped by an antenna; a mixer for converting the RF signal into an intermediate frequency signal having a second frequency less than the first frequency in accordance with a local oscillation signal; an IF stage for analogue delivering a demodulated output signal by saturatedly amplifying the intermediate frequency signal and for outputting an RSSI signal which indicates a level of the RF signal; an IF stage for digital incorporating therein an AGC input terminal for controlling an amplitude gain thereof for outputting an in-phase (I) signal and a quadrate (Q) signal, respectively, with the intermediate frequency signal by linearly amplifying the intermediate frequency signal; a first feed back loop circuit for providing a first feed back control signal to the AGC input terminal so as to keep demodulation levels of the I signal and the
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: February 24, 1998
    Assignee: Oki Electric Industry Co., Ltd
    Inventors: Eiichi Nakanishi, Tetsuo Onodera
  • Patent number: 5701597
    Abstract: According to a first aspect, a portable electronic device has at least two load circuits which are independently powered by different batteries. According to a second aspect, the load circuits are powered by the same battery, but their power lines are branched from a node located close to the battery, thereby reducing common impedance. According to a third aspect, two power lines are coupled through switches to two independent batteries, and are mutually coupled through a third switch. The switches are controlled according to the discharge states of the batteries. According to a fourth aspect, a battery charger charges two or more batteries by supplying current to them for short intervals in turn, so that all batteries reach full charge at substantially the same time.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: December 23, 1997
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera
  • Patent number: 5606285
    Abstract: A power control circuit having a saturation preventing control loop including a variable gain amplifier, an RF power amplifier, a directional coupler, a detecting circuit, a comparator, a switch, and an adder. When the signal level of an output signal of the comparator is low, the switch is turned on. When the signal level of the output signal of the comparator is high, the switch is turned off. A system power control loop includes a system power control terminal, the adder, and the variable gain amplifier. Since the saturation preventing control loop is provided with the switch, the saturation preventing control loop operates only when the signal level of the amplified signal is larger than a reference value. The system power control loop can properly operate according to a system power control signal supplied from the system power control terminal.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: February 25, 1997
    Assignee: OKI Electric Industry Co., Ltd.
    Inventors: Hefeng Wang, Tetsuo Onodera
  • Patent number: 5247542
    Abstract: A quadrature phase-shift keying modulator produces a QPSK signal which is amplified by a power amplifier. The amplitude gain of the power amplifier is controlled in response to an amplitude difference between the QPSK signal output by the modulator and the amplified QPSK signal output by the power amplifier. A phase detector, connected in series between the modulator and the power amplifier, eliminates amplitude variations from the QPSK signal prior to amplification. A voltage-controlled phase shifter, connected in series between the phase detector and the power amplifier, shifts the QPSK signal in phase by an amount responsive to amplitude information in the QPSK signal.
    Type: Grant
    Filed: April 9, 1991
    Date of Patent: September 21, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Tetsuo Onodera, Eiichi Nakanishi
  • Patent number: 5230095
    Abstract: A radio receiver for data communication of the type handing digital signals has a radio frequency (RF) section for receiving an RF signal having a predetermined frequency band from an electromagnetic wave which comes in through an antenna. A first frequency converting section converts the RF signal received by the RF section to a first intermediate frequency (IF) signal. A first IF filter filters the first IF signal and is implemented by a surface acoustic wave filter. A second frequency converting section converts the output signal of the first IF filter to a second IF signal. A data amplifying section picks up the above-mentioned frequency band from the output of the second frequency converting section and amplifies the resultant, picked-up band. A detector detects the output of the data amplifying section. An equalizer corrects a deviation of group delay time with each of respective frequencies of the output of the detector.
    Type: Grant
    Filed: April 19, 1991
    Date of Patent: July 20, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Tetsuo Onodera, Kazuhide Watanabe
  • Patent number: 5182527
    Abstract: A power amplifying apparatus according to the present invention can provide a stable electric power output with wide range by controlling both of the output amplifier for amplifying the electric power and the pre-amplifier disposed at the front of the output amplifier. Furthermore, in order to avoid the disadvantage that a transmission spectrum is expanded because of no supply of a stable voltage to be supplied to the electric power amplifier, thereby producing a cross-talk, a stabilizing power source circuit is provided to stabilize the voltage between the power amplifier and the power source for supplying the voltage.
    Type: Grant
    Filed: August 13, 1991
    Date of Patent: January 26, 1993
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera
  • Patent number: 5144258
    Abstract: A power amplifier system suitable for a mobile radio receiver/transmitter is described. A wave form signal to be transmitted is made smooth during its rise and fall times, thereby making it possible to prevent a transmission spectrum from expanding and interfering with the adjacent channels. The power amplifier system compares an envelope signal of an inputted RF signal and that of an RF signal to be outputted, whereby the power amplifier system as a whole provides linear amplification.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: September 1, 1992
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera, Haruhiko Akiyama
  • Patent number: 5138274
    Abstract: In a linear amplifier circuit, an amplifier amplifies an input signal to produce an output signal, an input signal envelope detector detects the envelope of the input signal, and an output signal envelope detector detects the envelope of the output signal. The difference between the outputs of the envelope detectors is determined, and the amplifier is controlled in accordance with the difference so that the level of the output signal is linearly related to the input signal. Compensation circuits are provided for temperature compensation of the linearity in the characteristic of the envelope detectors.
    Type: Grant
    Filed: May 30, 1991
    Date of Patent: August 11, 1992
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera
  • Patent number: 5126688
    Abstract: A power amplifying apparatus according to the present invention can provide a stable electric power output with wide range by controlling both of the output amplifier for amplifying the electric power and the pre-amplifier disposed at the front of the output amplifier. Furthermore, in order to avoid the disadvantage that a transmission spectrum is expanded because of no supply of a stable voltage to be supplied to the electric power amplifier, thereby producing a cross-talk, a stabilizing power source circuit is provided to stabilize the voltage between the power amplifier and the power source for supplying the voltage.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: June 30, 1992
    Assignee: Oki Electric Co., Ltd.
    Inventors: Eiichi Nakanishi, Tetsuo Onodera