Patents by Inventor Osamu Isaji
Osamu Isaji 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).
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Patent number: 7724802Abstract: A radar apparatus includes a transmission section, a delay device, a reception section, a switch control section, a switching frequency detection section, and a relative distance calculation section. The transmission section transmits a signal wave, which is spectrum spread by using a spread code. The delay device gives delay to the spread code. The reception section receives a wave reflected by an object and spectrum despreads the reflected wave with using the delayed spread code to output a despread signal. The switch control section switches at a switching frequency an operation of at least one of the transmission section, the reception section, and the delay device. The switching frequency detection section detects the switching frequency from the despread signal. The relative distance calculation section calculates a distance to the object based on a detection result provided by the switching frequency detection section and an amount of the delay.Type: GrantFiled: September 23, 2004Date of Patent: May 25, 2010Assignee: Fujitsu Ten LimitedInventors: Kanako Honda, Osamu Isaji
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Publication number: 20100075618Abstract: A signal processing apparatus is to be incorporated in a radar transmitter receiver including a transmission antenna which is configured to transmit a transmission signal, a plurality of reception antennas each of which is configured to receive the transmission signal reflected by a target object, and a generator which is configured to generate a plurality of beat signals for each of the receiving antennas. A synthesizer is configured to synthesize the beat signals to generate a synthesized beat signal. A detector is configured to detect an azimuth angle of the target object based on the synthesized beat signal and one of the beat signals.Type: ApplicationFiled: September 18, 2009Publication date: March 25, 2010Applicant: FUJITSU TEN LIMITEDInventor: Osamu ISAJI
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Patent number: 7605745Abstract: Provide an on-vehicle radar device that performs transmission control of a monitoring signal, following fixed rules, so that interference with other radar devices can be avoided with certainty. An on-vehicle radar device comprises a transceiver which transmits/receives a monitoring signal at a specified frequency band and transmits a priority order signal at a frequency within the above-mentioned frequency band, and a controller which switches the signals transmitted by the transceiver. The transceiver receives a priority order signal of another radar device, and when interference with the signal of the other radar device is detected, the controller, based on the priority order of that other device and on the priority order of the device itself, shifts, by a specified frequency amount, the frequency band of the monitoring signal transmitted by the transceiver.Type: GrantFiled: March 30, 2007Date of Patent: October 20, 2009Assignees: Fujitsu Ten Limited, Fujitsu LimitedInventors: Kanako Honda, Osamu Isaji, Kazuo Shirakawa, Naofumi Ohkubo, Tetsuo Seki
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Patent number: 7504990Abstract: Disclosed is a DBF radar apparatus comprising: an antenna for radiating a transmit signal; a plurality of antennas for receiving the transmit signal reflected from an object; a first selector switch section for sequentially selecting output terminals of the plurality of antennas one at a time for connection to an input terminal by performing switching with a first period; a first downconverting section for downconverting, by using a portion of the transmit signal, a received signal input from each antenna; a low-frequency cut-off filter connected to an output of the first downconverting section; a second selector switch section for connecting an output of the low-frequency cut-off filter to a sequentially selected one of a plurality of A/D converters; and a digital signal processing section for receiving outputs of the plurality of A/D converters, and for applying prescribed processing to the outputs to detect the distance to the object or the relative velocity with respect to the object, wherein, when each aType: GrantFiled: January 14, 2005Date of Patent: March 17, 2009Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Patent number: 7495603Abstract: The invention is directed to reducing the number of high-frequency components in a phase monopulse radar. A received signal selected by alternately selecting two antennas by a first switch is amplified by a receiver amplifier and mixed in a mixer with a portion of a transmitter signal. Each beat signal output from the mixer is distributed via a second switch to a selected one of two processing systems.Type: GrantFiled: September 7, 2005Date of Patent: February 24, 2009Assignee: Fujitsu Ten LimitedInventors: Kanako Honda, Osamu Isaji
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Patent number: 7450056Abstract: The search/detection apparatus modulates a carrier signal by a modulation signal, generates a probe signal for detecting the location of a target, and receives the probe signal reflected by the target as an echo signal. Then, the search/detection apparatus detects the existence of an interference signal other than the echo signal from the received signal and modifies the parameter of the modulation signal and/or carrier signal.Type: GrantFiled: May 31, 2006Date of Patent: November 11, 2008Assignees: Fujitsu Limited, Fujitsu Ten LimitedInventors: Kazuo Shirakawa, Naofumi Ohkubo, Tetsuo Seki, Kanako Honda, Osamu Isaji
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Patent number: 7439905Abstract: In a radar apparatus constructed to perform switching between a plurality of receiving antennas by using a switch, the effect of noise induced by the antenna switching is eliminated. A situation where there is no echo signal from a target is created, for example, by turning off a transmitter amplifier, and the Fourier transformed result obtained at this time is taken as a correction value and stored in a memory. During radar operation, the effect of the noise induced by the antenna switching can be eliminated by subtracting the correction value from the Fourier transformed result.Type: GrantFiled: August 23, 2005Date of Patent: October 21, 2008Assignee: Fujitsu Ten LimitedInventors: Kanako Honda, Osamu Isaji
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Publication number: 20080231501Abstract: Disclosed is a DBF radar apparatus comprising: an antenna for radiating a transmit signal; a plurality of antennas for receiving the transmit signal reflected from an object; a first selector switch section for sequentially selecting output terminals of the plurality of antennas one at a time for connection to an input terminal by performing switching with a first period; a first downconverting section for downconverting, by using a portion of the transmit signal, a received signal input from each antenna; a low-frequency cut-off filter connected to an output of the first downconverting section; a second selector switch section for connecting an output of the low-frequency cut-off filter to a sequentially selected one of a plurality of A/D converters; and a digital signal processing section for receiving outputs of the plurality of A/D converters, and for applying prescribed processing to the outputs to detect the distance to the object or the relative velocity with respect to the object, wherein, when each aType: ApplicationFiled: January 14, 2005Publication date: September 25, 2008Inventor: Osamu Isaji
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Publication number: 20080106458Abstract: Provide an on-vehicle radar device that performs transmission control of a monitoring signal, following fixed rules, so that interference with other radar devices can be avoided with certainty. An on-vehicle radar device comprises a transceiver which transmits/receives a monitoring signal at a specified frequency band and transmits a priority order signal at a frequency within the above-mentioned frequency band, and a controller which switches the signals transmitted by the transceiver. The transceiver receives a priority order signal of another radar device, and when interference with the signal of the other radar device is detected, the controller, based on the priority order of that other device and on the priority order of the device itself, shifts, by a specified frequency amount, the frequency band of the monitoring signal transmitted by the transceiver.Type: ApplicationFiled: March 30, 2007Publication date: May 8, 2008Applicants: FUJITSU TEN LIMITED, FUJITSU LIMITEDInventors: Kanako Honda, Osamu Isaji, Kazuo Shirakawa, Naofumi Ohkubo, Tetsuo Seki
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Publication number: 20070188373Abstract: The search/detection apparatus modulates a carrier signal by a modulation signal, generates a probe signal for detecting the location of a target, and receives the probe signal reflected by the target as an echo signal. Then, the search/detection apparatus detects the existence of an interference signal other than the echo signal from the received signal and modifies the parameter of the modulation signal and/or carrier signal.Type: ApplicationFiled: May 31, 2006Publication date: August 16, 2007Applicants: Fujitsu Limited, Fujitsu Ten LimitedInventors: Kazuo SHIRAKAWA, Naofumi Ohkubo, Tetsuo Seki, Kanako Honda, Osamu Isaji
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Patent number: 7248209Abstract: The present invention relates to a radar apparatus that uses a plurality of transmitting/receiving antennas A1-A4 and receives a reflected wave, of a transmitted wave, reflected from a target. By utilizing the property that the path of the transmitted wave from an antenna A1 and its reflected wave and the path of the transmitted wave from the next selected antenna A2 and its reflected wave share the same spatial system, and therefore that both received signals have the same characteristics in terms of frequency and phase, a judgment is made as to whether there exists any difference between the receiving characteristics of the antennas, and the received signal is corrected in accordance with the result of the judgment. It is also possible to judge the presence or absence of a change in the characteristic of each antenna, and apply a correction accordingly, even during the normal operation of the apparatus.Type: GrantFiled: June 6, 2005Date of Patent: July 24, 2007Assignee: Fujitsu Ten LimitedInventors: Nobukazu Shima, Osamu Isaji
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Patent number: 7221309Abstract: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.Type: GrantFiled: August 22, 2003Date of Patent: May 22, 2007Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Patent number: 7190305Abstract: In a radar apparatus, a receiving antenna includes a plurality of antenna elements, each receiving, as a reception signal, radio waves emitted into space and reflected off a target object. An analog signal is obtained by downconverting and putting a bandwidth constraint on the reception signal, and is then converted to a digital signal. Based on the digital signal, a signal processing unit detects the bearing of the target object. The signal processing unit performs processing based on outputs of two sets of the antenna elements.Type: GrantFiled: March 3, 2005Date of Patent: March 13, 2007Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Patent number: 7183968Abstract: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.Type: GrantFiled: December 1, 2005Date of Patent: February 27, 2007Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Patent number: 7173561Abstract: The present invention relates to a radar device for forming multi-beams in multiple channels from reflected waves of a transmitted wave by using a minimum number of antennas. The device has: antennas used for both transmission and reception A1–A4; transmission/reception switching means 5 of each antenna; a transmitter 2; and a receiver 4 for receiving the reflected waves of the transmitted wave. The ratio of the distance between adjacent antennas A1 and A2 to the distance between adjacent antennas A2 and A3 or A3 and A4 is 1:2. The transmitted signal is transmitted from each of the antennas selected sequentially and the received signal is processed by DBF in a signal processing controller 1, wherein eleven channels can be implemented by using four antennas and a space for six antennas.Type: GrantFiled: February 12, 2004Date of Patent: February 6, 2007Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Publication number: 20060103571Abstract: In an FM-CW radar system, a frequency modulating said modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.Type: ApplicationFiled: December 1, 2005Publication date: May 18, 2006Inventor: Osamu Isaji
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Patent number: 7034745Abstract: Disclosed is a radar apparatus equipped with a function for detecting an FM-AM conversion noise peak. When the direction of radiation is swept, any peak whose level remains substantially unchanged is judged to be a peak due to FM-AM conversion noise. Further, when FM modulation is stopped, any peak appearing in a region not lower than 50 kHz is judged to be a noise peak.Type: GrantFiled: March 3, 2004Date of Patent: April 25, 2006Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji
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Publication number: 20060055589Abstract: The invention is directed to reducing the number of high-frequency components in a phase monopulse radar. A received signal selected by alternately selecting two antennas by a first switch is amplified by a receiver amplifier and mixed in a mixer with a portion of a transmitter signal. Each beat signal output from the mixer is distributed via a second switch to a selected one of two processing systems.Type: ApplicationFiled: September 7, 2005Publication date: March 16, 2006Applicant: FUJITSU TEN LIMITEDInventors: Kanako Honda, Osamu Isaji
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Publication number: 20060055593Abstract: In a radar apparatus constructed to perform switching between a plurality of receiving antennas by using a switch, the effect of noise induced by the antenna switching is eliminated. A situation where there is no echo signal from a target is created, for example, by turning off a transmitter amplifier, and the Fourier transformed result obtained at this time is taken as a correction value and stored in a memory. During radar operation, the effect of the noise induced by the antenna switching can be eliminated by subtracting the correction value from the Fourier transformed result.Type: ApplicationFiled: August 23, 2005Publication date: March 16, 2006Applicant: Fujitsu Ten LimitedInventors: Kanako Honda, Osamu Isaji
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Patent number: 7002512Abstract: In an FM-CW radar system, a frequency modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control, the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON-OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.Type: GrantFiled: September 26, 2001Date of Patent: February 21, 2006Assignee: Fujitsu Ten LimitedInventor: Osamu Isaji