Patents by Inventor Shinichi Ohtsu
Shinichi Ohtsu 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: 7027941Abstract: In order to improve the speed of an electro-magnetic field intensity calculation process in a device capable of performing the cooperation process of a circuit analysis and an electro-magnetic wave analysis, the present invention comprises a determination unit 2 for determining whether a component constituting an electric circuit contained in an analysis target, an analysis processing unit 3 for analyzing an electro-magnetic wave emitted from the analysis target, using an analysis target model containing a linear component if all components are linear, and a cooperation process unit 4 for dividing the analysis target into a circuit analysis model to which a circuit analysis method should be applied, an electro-magnetic wave analysis model to which an electro-magnetic wave analysis should be applied and one or more ports for combining the two models and analyzing an electro-magnetic wave emitted from the analysis target, if one or more components are non-linear.Type: GrantFiled: June 7, 2005Date of Patent: April 11, 2006Assignee: Fujitsu LimitedInventors: Kenji Nagase, Takashi Yamagajo, Shinichi Ohtsu
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Publication number: 20050228601Abstract: In order to improve the speed of an electro-magnetic field intensity calculation process in a device capable of performing the cooperation process of a circuit analysis and an electro-magnetic wave analysis, the present invention comprises a determination unit 2 for determining whether a component constituting an electric circuit contained in an analysis target, an analysis processing unit 3 for analyzing an electro-magnetic wave emitted from the analysis target, using an analysis target model containing a linear component if all components are linear, and a cooperation process unit 4 for dividing the analysis target into a circuit analysis model to which a circuit analysis method should be applied, an electro-magnetic wave analysis model to which an electro-magnetic wave analysis should be applied and one or more ports for combining the two models and analyzing an electro-magnetic wave emitted from the analysis target, if one or more components are non-linear.Type: ApplicationFiled: June 7, 2005Publication date: October 13, 2005Applicant: FUJITSU LIMITEDInventors: Kenji Nagase, Takashi Yamagajo, Shinichi Ohtsu
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Patent number: 6879942Abstract: An apparatus for calculating immunity from a radiated electromagnetic field which makes possible high-speed simulation of the electric current flowing through an electronic apparatus due to a radio wave radiated from an antenna, and a method and a storage medium storing programs used for the same which divides a radio wave radiated from an antenna into a carrier wave, upper sideband wave, and lower sideband wave, and uses the moment method to simulate the effect of the radio wave on an electronic apparatus by calculating the mutual impedance for one frequency component out of the above three frequency components and using that mutual impedance to solve the simultaneous equations under the moment method so as to calculate the electric current flowing through the electronic apparatus.Type: GrantFiled: March 31, 1999Date of Patent: April 12, 2005Assignee: Fujitsu LimitedInventors: Kenji Nagase, Shinichi Ohtsu, Makoto Mukai, Takeshi Kishimoto, Sekiji Nishino
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Patent number: 6845351Abstract: A simulation device and method to simulate the electric current flowing in electronic devices using the moment method, and to execute accurate simulation processing when the electronic device has an amplifier. An allocating device allocates defining dipoles to the input terminal and output terminal of an amplifier of an electronic device for the purpose of deriving the electric current flowing in the element. A creating device creates a simultaneous equation of the moment method having a form such that the amplifier input impedance is inserted into the input terminal dipole allocated by the allocating device, and the amplifier output impedance, or its inverse, and a dependent energy source responding to the amplification characteristics of the amplifier are inserted into the output terminal dipole allocated by the allocating device. A solving device solves the simultaneous equation of the moment method created by creating device.Type: GrantFiled: January 27, 2000Date of Patent: January 18, 2005Assignee: Fujitsu LimitedInventors: Takeshi Kishimoto, Shinichi Ohtsu
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Patent number: 6711511Abstract: An apparatus analyzing electromagnetic waves radiated from an appliance using a net pattern of the appliance and having a coordinates data extracting unit extracting, from net pattern information, coordinates data defining the coordinates of each of terminal points of a plurality of segments constituting the net pattern; and a smoothing unit for dividing the net pattern, based on the extracted coordinates data, into plural object sections, each of a length not greater than a predetermined maximum length, and smoothing the net pattern for each object section, by replacing plural segments in each object section with a single, or a plurality of, straight lines smaller in number than the number of the segments. The electromagnetic field intensity of the electromagnetic waves is calculated on the basis of coordinates data for which smoothing is completed.Type: GrantFiled: March 20, 2001Date of Patent: March 23, 2004Assignee: Fujitsu LimitedInventors: Kenji Nagase, Shinichi Ohtsu
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Publication number: 20030139914Abstract: An independent current source and a voltage-dependent source are arranged at each of ports, and a voltage at each of the ports is calculated with a circuit analysis. A voltage source is arranged at each of the ports by using the calculated voltage value, and a current flowing in an analysis target is calculated with an electromagnetic wave analysis. An analysis time is incremented stepwise, and the calculation of the voltage at each of the ports and the calculation of the current flowing in the analysis target are repeated. As a result, an electromagnetic field intensity calculation can be made with high accuracy even for an analysis target where a plurality of ports exists between a circuit analysis model and an electromagnetic wave analysis model.Type: ApplicationFiled: May 21, 2002Publication date: July 24, 2003Applicant: FUJITSU LIMITEDInventors: Takashi Yamagajo, Kenji Nagase, Shinichi Ohtsu
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Patent number: 6555998Abstract: An apparatus provided with a setting unit for selecting a frequency spectrum to be processed from among a plurality of frequency spectrums contained in an angle-modulated wave source and setting one or a plurality of sample frequencies from among the spectrums, a calculating unit for calculating an intensity of an electromagnetic field radiated from an electronic apparatus by analysis in the frequency domain under the moment method or the like using the sample frequency set by the setting unit as the analyzing frequency, and a computing unit for calculating a physical amount to be calculated other than the physical amount calculated by the calculation unit in the frequency domain of the frequency spectrum to be processed, by using a proportional operation, from the physical amount calculated by the calculating unit and the wave source value of the frequency spectrum to be processed.Type: GrantFiled: November 23, 1999Date of Patent: April 29, 2003Assignee: Fujitsu LimitedInventors: Takeshi Kishimoto, Shinichi Ohtsu
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Patent number: 6499004Abstract: Solving simultaneous equations of the moment method defining relationships between a mutual impedence between elements of an electronic apparatus, a wave source, and an electric current flowing in each element so as to simulate an electric current, provided with a unit for calculating the mutual impedance at a sampling frequency and calculating approximation coefficients, when expressing the mutual impedance by approximation expressions in terms of exponents and exponent powers, from the calculated values and sampling frequency; a unit for forming the simultaneous differential equations by setting the approximation coefficients and initial value with respect to the simultaneous differential equations derived by performing a Fourier transform on the simultaneous equations of the moment method in which the approximation expressions are substituted; and a unit for calculating the electric current in the time domain flowing through the specified element by solving the simultaneous differential equations formed.Type: GrantFiled: December 21, 1998Date of Patent: December 24, 2002Assignee: Fujitsu LimitedInventors: Shinichi Ohtsu, Makoto Mukai
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Patent number: 6456949Abstract: A mesh processor divides a target device into a plurality of patches. A mutual impedance calculator computes a mutual impedance between the patches based on previously computed analytic solutions of a quadruple integration under the condition that the patches are rectangular in shape and are parallel or perpendicular to each other. Finally, an electromagnetic field intensity calculator calculates electromagnetic field intensity based on the computed mutual impedance.Type: GrantFiled: July 11, 2000Date of Patent: September 24, 2002Assignee: Fujitsu LimitedInventors: Takashi Yamagajo, Kenji Nagase, Shinichi Ohtsu, Makoto Mukai
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Publication number: 20020082812Abstract: In Moment method, by regarding the current values of a wave source to be constants, the simultaneous equations of the wave source and the simultaneous equations of a receiving object can be separated and the current values of the wave source and the current values of the object can be separately calculated. Even if the positional relationship between the wave source and object changes, the mutual impedance between the elements of the object does not change. Therefore, there is no need to calculate the coefficient matrix of the simultaneous equations of the object again.Type: ApplicationFiled: May 29, 2001Publication date: June 27, 2002Applicant: FUJITSU LIMITEDInventors: Shinya Yamaguchi, Kenji Nagase, Shinichi Ohtsu, Makoto Mukai
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Publication number: 20020019713Abstract: An electromagnetic wave analyzing apparatus, which analyzes electromagnetic waves radiated from an appliance on the basis of a net pattern taken from the appliance under analysis, comprises a coordinates data extracting unit for extracting, from net pattern information, coordinates data defining the coordinates of each of terminal points of a plurality of segments constituting the net pattern; and a net pattern smoothing unit for dividing the net pattern, based on the extracted coordinates data, into a plurality of object sections so that the length of each of the object sections is not greater than a predetermined maximum length, and for carrying out smoothing of the net pattern for each object section, by replacing a plurality of segments contained in each object section with a single straight line or a plurality of straight lines smaller in number than the number of the segments.Type: ApplicationFiled: March 20, 2001Publication date: February 14, 2002Inventors: Kenji Nagase, Shinichi Ohtsu
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Publication number: 20020007251Abstract: An analytic frequency determination unit determines the range of an analytic frequency used in a moment method as a range nearest to the lowest value of the analytic frequency in the frequencies whose real parts of frequency responses are 0. A transient analysis unit obtains an impulse response as a transient analysis corresponding an analytic frequency in the determined range.Type: ApplicationFiled: March 14, 2001Publication date: January 17, 2002Inventors: Yoshiro Tanaka, Katsumi Homma, Takeshi Kishimoto, Mokoto Mukai, Shinichi Ohtsu
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Patent number: 6285957Abstract: An apparatus and method are provided to calculate the strength of an electromagnetic field radiated from an electric device according to a moment method, wherein the moment method is based on integral equations derived from electromagnetic equations. The apparatus and method include a setting unit to interactively set a name of a two-wire cable arranged in the electric device and coordinates of the two-wire cable at a cable inlet, a cable outlet, and way points in the electric device, the way points being prepared as and when required to bend the two-wire cable between the cable inlet and the cable outlet. Further, the apparatus and method include library unit corresponding to cable names, respectively, and storing attributes of a corresponding cable comprising of the name, type, characteristic impedance, and structural data of the two-wire cable.Type: GrantFiled: March 20, 1998Date of Patent: September 4, 2001Assignee: Fujitsu LimitedInventors: Yoshirou Tanaka, Shinichi Ohtsu, Makoto Mukai
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Patent number: 6185517Abstract: An electromagnetic field intensity computing apparatus for computing electromagnetic field intensity of an electric circuit device in a moment method obtains according to the electric current distribution an electric current of a ground layer and models a transmission line, ground layer, dielectric portion, etc. to be analyzed. When a plate to be analyzed is divided into a plurality of patches, the regularity in given structure data is automatically extracted to compute the mutual impedance among a portion of patches and apply the computation result to other portions. When elements to be analyzed meet the conditions that the electric length of the elements is short and the elements are distant from each other, the mutual impedance can be computed in an approximation obtained under various conditions. Furthermore, approximating a portion near a pigtail portion of a coaxial cable using a polygon allows a vertical electric current to be properly connected to each unit.Type: GrantFiled: February 3, 1998Date of Patent: February 6, 2001Assignee: Fujitsu LimitedInventors: Shinichi Ohtsu, Makoto Mukai
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Patent number: 6182023Abstract: An electromagnetic field intensity computing apparatus for computing electromagnetic field intensity of an electric circuit device in a moment method obtains according to the electric current distribution an electric current of a ground layer and models a transmission line, ground layer, dielectric portion, etc. to be analyzed. When a plate to be analyzed is divided into a plurality of patches, the regularity in given structure data is automatically extracted to compute the mutual impedance among a portion of patches and apply the computation result to other portions. When elements to be analyzed meet the conditions that the electric length of the elements is short and the elements are distant from each other, the mutual impedance can be computed in an approximation obtained under various conditions. Furthermore, approximating a portion near a pigtail portion of a coaxial cable using a polygon allows a vertical electric current to be properly connected to each unit.Type: GrantFiled: February 3, 1998Date of Patent: January 30, 2001Assignee: Fujitsu LimitedInventors: Shinichi Ohtsu, Makoto Mukai
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Patent number: 6129459Abstract: The electromagnetic field intensity of an electromagnetic wave radiating from a multilayer substrate is correctly computed.Type: GrantFiled: March 23, 1998Date of Patent: October 10, 2000Assignee: Fujitsu LimitedInventors: Takeshi Kishimoto, Shinichi Ohtsu, Makoto Mukai
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Patent number: 6083266Abstract: A simulation apparatus for simulating the current flowing through elements of an electronic apparatus using the moment method based on reaction matching and able to achieve high speed simulation processing, comprising a segmenting means for segmenting the electronic apparatus to be analyzed into elements, a calculating means for calculating a mutual impedance between segmented elements of the electronic apparatus, assuming that a triangle function current flows through the monopoles, by using an approximation equation of the mutual impedance between monopoles, expressed by a polynomial of the power of k, derived by exp(-jkr) which is approximated by multiplication of exp(-jkr.sub.0) and a Taylor expansion of exp[-jk(r-r.sub.0)] (where j is an imaginary number, k is a wave number, r is the distance between monopoles, and r.sub.Type: GrantFiled: January 26, 1998Date of Patent: July 4, 2000Assignee: Fujitsu LimitedInventors: Shinichi Ohtsu, Makoto Mukai
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Patent number: 5940310Abstract: A device accurately calculates the strength of an electromagnetic field radiated from an electric circuit apparatus having a data receiving unit, and extractor, a model generator, and a calculator. The data receiving unit receives structural data related to the electric circuit apparatus. The extractor exacts, from the received data, structural data related to a dielectric between a power source layer and a ground layer of a multilayer printed board.Type: GrantFiled: November 13, 1997Date of Patent: August 17, 1999Assignee: Fujitsu LimitedInventors: Shinya Yamaguchi, Tomoyuki Nakao, Shinichi Ohtsu, Makoto Mukai
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Patent number: 5926377Abstract: A multilayer printed board has at least a signal layer, a power source layer, and a ground layer that are formed one upon another with insulation material being interposed among the layers. The board is capable of reducing radio waves to be emitted from the board.The board is provided with capacitors that are continuously or discretely formed at the edges of an overlapping pattern of the power source layer and ground layer, to pass a high-frequency current from the power source layer to the ground layer, thereby reducing the emission of radio waves.Type: GrantFiled: November 17, 1997Date of Patent: July 20, 1999Assignee: Fujitsu LimitedInventors: Tomoyuki Nakao, Shinya Yamaguchi, Makoto Mukai, Shinichi Ohtsu
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Patent number: 5835979Abstract: A wiring pattern includes first halves, each of which is a first half of a corresponding one of one or more intervals into which the wiring pattern is divided, and second halves, each of which is a second half of a corresponding one of the one or more intervals, wherein an electromagnetic field generated by the first half is canceled by an electromagnetic field generated by the second half.Type: GrantFiled: May 28, 1997Date of Patent: November 10, 1998Assignee: Fujitsu LimitedInventors: Motozane Hiraki, Makoto Mukai, Shinichi Ohtsu, Masaki Ogawa