Fujitsu Corporation

Makoto Mukai

Shinichi Ohtsu

Kenji Nagase

Sekiji Nishino

Tomoyuki Nakao

Takeshi Kishimoto

Shinichi Otsu

Yoshirou Tanaka

Shinya Yamaguchi

Takashi Yamagajo

Katsumi Homma

Takamitsu Tsuchimoto

Takao Uehara

Katsuyuki Hamada

Masaki Ogawa

Motozane Hiraki

Hideo Masuzawa

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

When an electric current flowing through an electronic appliance is simulated by solving simultaneous linear equations defined depending on an analytic frequency, the simultaneous linear equations are solved in the direct method using a frequency other than the frequencies on both ends of an analytic frequency area as an analysis target, and the simultaneous linear equations are solved in the iterative method while transforming the simultaneous linear equations using the coefficient matrix analyzed in the direct method on the frequencies other than the above described frequency defined as the analysis target.

Apparatus and method for simulating electric current in electronic appliances

A method for calculating the intensity of an electromagnetic field emitted from a device and a storage medium for storing a program of the method are disclosed. The method uses a moment method in which a mutual impedance between shell elements and a supplied voltage are assumed to be known quantities and the current flowing through the shell element is assumed to be an unknown quantity. The method comprises the steps of obtaining a plurality of shell elements including at least one triangular shell element by virtually dividing the device into a mesh, and setting an unknown quantity of a current directed from each side of the triangular shell element toward its apex only when a conductive wire is connected to the apex, setting an unknown quantity of a current directed from each side of the triangular element toward its apex when the side is common with a side of the other shell element, or setting an unknown quantity of a current parallel to a side of the triangular shell element when there is a shell element adjacent to the triangular shell element.

Electromagnetic field intensity calculating method and a storage medium for storing a program for executing the method

In calculating an electromagnetic field intensity by a moment method, real and imaginary parts of a mutual impedance, mutual admittance, and mutual reaction between elements and of the elements themselves are approximated by a sum of terms each with a frequency raised to a power. The mutual impedances, etc. at a plurality of sample frequencies are calculated using known mathematical equations, and simultaneous equations obtained by substituting the sample frequencies and the mutual impedances at the respective sample frequencies into an approximate equation are solved to calculate approximation coefficients for the approximate equation. Using the thus obtained approximate equations, the mutual impedance, etc. at a designated frequency are calculated, and substituted into simultaneous equations describing a boundary condition for each element; by solving the simultaneous equations, the electric current, equivalent electric current, and equivalent magnetic current of each element are calculated, from which the electromagnetic field intensity is calculated.

Calculation of electromagnetic field intensity by moment method

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 simulation apparatus, using the moment method and at high speed, simulates the intensity of an electromagnetic field, etc. of a time domain. A transforming unit obtains a frequency spectrum by segmenting time series data of a wave source and applying a Fourier transform thereto. A calculating unit calculates the mutual impedance at a sampling frequency, generates an approximate expression of the mutual impedance from the calculated mutual impedance and the sampling frequency and calculates the mutual impedance at respective frequencies obtained by the transforming unit by using the generated approximate expression. A simulating unit finds a current spectrum flowing in each element, according to the moment method, from the mutual impedance calculated by the calculating unit and the frequency spectrum obtained by the transforming unit and finds the spectrum of a voltage, an electric field, and a magnetic field from the found current spectrum. An inverse transforming unit applies an inverse Fourier transform to the spectra found by the simulating unit and outputs the result.

Simulation apparatus and simulation method for electromagnetic field

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

Makoto Mukai