Fujitsu Corporation

Shinichi Ohtsu

Makoto Mukai

Kenji Nagase

Takeshi Kishimoto

Sekiji Nishino

Takashi Yamagajo

Tomoyuki Nakao

Shinya Yamaguchi

Hiroshi Shimamori

Yoshirou Tanaka

Ryuichi Yanagisawa

Masaki Ogawa

Motozane Hiraki

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 unitfor determining whether a component constituting an electric circuit contained in an analysis target, an analysis processing unitfor 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 unitfor 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.

Device and method for calculating electro-magnetic field intensity by cooperation of circuit analyses and electro-magnetic wave analyses

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.

Apparatus for calculating immunity from radiated electromagnetic field, method for achieving calculation, and storage medium storing programs therefor

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.

Simulation device and method and program recording medium

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.

Electromagnetic wave analyzing apparatus and computer readable storage medium

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.

Apparatus and method for simulation of electromagnetic field and storage medium storing programs therfor

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.

Simulation method and apparatus using a Fourier transform

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.

Method and apparatus for calculating electromagnetic field intensity, and a computer-readable recording medium

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. A generation unit is provided to generate a moment-method model of the two-wire cable according to the attributes of the two-wire cable read out of the at least one library unit specified by the name of the two-wire cable set by the setting unit and the coordinates of the two-wire cable at the cable inlet, cable outlet, and way points set by the setting unit. A calculation unit calculates the strength of the electromagnetic field radiated from the electric device according to the moment-method model of the two-wire cable and the moment method.

Apparatus and method for calculating the strength of an electromagnetic field radiated from an electric device

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.

Electromagnetic field intensity computing device

The electromagnetic field intensity of an electromagnetic wave radiating from a multilayer substrate is correctly computed. A radiating electromagnetic wave analysis apparatus comprises a signal layer electric current distribution computation unit for obtaining the distribution of an electric current flowing through a signal layer in a distributed constant line approximation method or a transmission line analysis method; a multilayer substrate electric current distribution computation unit for computing the distribution of an electric current of an entire multilayer substrate in a moment method based on the distribution of the electric current obtained by the signal layer electric current distribution computation unit; and an electromagnetic field intensity computation unit for computing the electromagnetic field intensity of an electromagnetic wave radiating from a multilayer substrate based on the distribution of the electric current of the entire multilayer substrate computed by the multilayer substrate electric current distribution computation unit. The radiating electromagnetic wave analysis apparatus establishes a modelling method for quantitatively analyzing the state of the electric current flowing through a wave source and load and then flowing into a power supply layer and a ground layer.

Apparatus for analyzing radiating electromagnetic wave from multilayer

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.0 is a representative distance between monopoles), and a simulating means, by using the calculated mutual impedances between elements, for finding the current flowing through the elements of the electronic apparatus in accordance with the moment method.

Simulation apparatus and simulation method using moment method

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. The generator refers to the structural data on the multilayer printed board, divides the power source layer and the ground layer into corresponding meshes of metal patches, vertically extends first and second conductive patches from the sides of the metal patches so that the conductive patches are not in contact with one another, arranges a capacitor between each pair of the first and second conductive patches, divides selected metal patches of the power source and ground layers to form two triangle patches, and arranges a noise source between the apexes of the triangle patches, thereby producing a model of the multilayer printed board. The calculator calculates the strength of an electromagnetic field radiated from the electric circuit apparatus according to the model of the multilayer printed board.

Device, method and storage medium for calculating electromagnetic field

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.

Multilayer printed board

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.

Growing community of inventors

Kawasaki, Japan

Shinichi Ohtsu