JP2019200676A - Radiated electromagnetic wave estimation device, radiated electromagnetic wave estimation method, and radiated electromagnetic wave estimation program - Google Patents

Abstract

To provide a radiated electromagnetic wave estimation device that can be applied even to a printed circuit board with a complicated circuit structure, and can estimate an unnecessary electromagnetic wave in the entire printed circuit board with high accuracy in a short time.SOLUTION: A radiated electromagnetic wave estimation device 1 comprises: a design information acquisition unit 2 that acquires design information on a printed circuit board; a transmission line extraction unit 4 that extracts transmission lines from the design information; a magnetic current distribution calculation unit 5 that calculates a current distribution and a magnetic current distribution for each of the transmission lines by using a spectral range method and a multiwire transmission line method; a surface electric field calculation unit 6 that calculates an electric field distribution in a spectral range on a surface of the printed circuit board on the basis of the current distribution and the magnetic current distribution; and a radiated electric field intensity calculation unit 7 that calculates the electric field intensity of an electromagnetic wave radiated from the printed circuit board on the basis of the electric field distribution.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiated electromagnetic wave estimation device that estimates an electromagnetic wave radiated into a space from a printed circuit board or the like disposed inside an electronic device.

  In the design and development of electronic equipment, the EMC (Electro-Magnetic Compatibility) / EMI (Electro Magnetic Interference) problem is a major issue. In particular, unnecessary electromagnetic waves radiated from electronic equipment may cause problems such as causing malfunction of the equipment by interfering with other equipment. When electronic systems such as medical care and transportation infrastructure malfunction, it becomes a social problem. Therefore, the size of unnecessary electromagnetic waves radiated from electronic devices is regulated by legal or voluntary standards. Therefore, when designing the circuit of an electronic device, it is important to accurately estimate the magnitude of unnecessary electromagnetic waves radiated from the electronic device.

  The latest electronic information systems require real-time transmission and processing of large-scale data, and high signal transmission frequencies such as gigabit and terabit are used. As the performance of the system increases and the power saving and weight reduction progress, it is expected that the wiring density of the circuit used will be increased and the number of layers will be increased. When circuit wiring becomes dense and complicated, unwanted electromagnetic waves are likely to be generated due to defects in the ground structure of an ideal circuit that can suppress the generation of jamming waves, and it is not necessary in conjunction with higher signal frequencies. Electromagnetic waves are expected to increase.

  As a source of unnecessary electromagnetic waves from electronic devices, a printed circuit board placed inside and various cables connected to the board are considered. In order to calculate unwanted electromagnetic waves from a printed circuit board with such a planar structure, at present, simple methods and numerical methods using current distribution on the circuit and mirror image current with respect to the circuit ground are mainly used. Yes. In an ideal case where the ground of the circuit is sufficiently large, unnecessary electromagnetic waves can be calculated at high speed and with high accuracy by using a mirror image current. However, when the ground structure of the circuit is complicated or when there is a defect in the ground, the calculation is performed using a numerical calculation method. The numerical calculation method can calculate unnecessary electromagnetic waves for various circuit structures having a complicated structure, but requires a large storage capacity in the calculation, and the calculation time becomes very long. Therefore, the numerical calculation method cannot efficiently design a circuit and is difficult to use at the design stage. Therefore, a method for accurately estimating unnecessary electromagnetic waves from a circuit having such a structure in a short time is desired, and it is necessary to develop a method for calculating unnecessary electromagnetic waves at high speed.

  For example, Patent Document 1 discloses a technique for estimating the amount of electromagnetic waves radiated due to voltage fluctuations generated between a power plane and a ground plane.

Japanese Patent No. 4760622

T. Itoh, et al., Numerical techniques for microwave and millimeter-wave passive structures, chap. 5, John Wiley & Sons, New York, 1989. C.R.Paul, Analysis of multiconductor transmission lines, chap. 3, John Wiley & Sons, New York, 2008. Teruo Tobana, Takayuki Sasamori, Yoji Kajita, “Analysis of Electromagnetic Coupling between Microstrip Lines via Ground Slots in a Three-Layer Substrate”, IEICE Transactions 2017/3 Vol. J100-B No.3, 2017.

  However, it can be applied to a printed circuit board having a complicated circuit structure, and a technique for estimating unnecessary electromagnetic waves of the entire printed circuit board in a short time with high accuracy has not been proposed.

  The present invention has been made in view of the above-described problems, and its object is to apply to a printed circuit board having a complicated circuit structure, and to prevent unnecessary electromagnetic waves of the entire printed circuit board with high accuracy. It is another object of the present invention to provide a radiated electromagnetic wave estimation device that can be estimated in a short time.

  A first invention for achieving the above-described object is a radiation electromagnetic wave estimation device for estimating an electromagnetic wave radiated from a printed circuit board to space, a design information acquisition unit for acquiring design information of the printed circuit board; A transmission line extraction unit that extracts a transmission line from the design information, and a current and magnetic current distribution calculation that calculates a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method A surface electric field calculation unit for calculating an electric field distribution in a spectral region on the surface of the printed circuit board based on the current distribution and the magnetic current distribution; and a radiation from the printed circuit board based on the electric field distribution. A radiation electric field intensity calculation unit for calculating the electric field intensity of the electromagnetic wave. The radiated electromagnetic wave estimation apparatus according to the first aspect of the invention can be applied to a printed circuit board having a complicated circuit structure, and can estimate unnecessary electromagnetic waves of the entire printed circuit board with high accuracy and in a short time.

  The surface electric field calculation unit in the first invention may calculate the electric field distribution in which the propagation direction of a signal propagating through the transmission line is an electric field direction using a two-dimensional spectral domain method. As a result, the calculation can be performed faster than the numerical calculation method of the three-dimensional structure.

  A second invention is a radiated electromagnetic wave estimation method in which a computer estimates an electromagnetic wave radiated from a printed circuit board to a space, wherein the computer acquires design information of the printed circuit board; and the design information A step of extracting a transmission line from the step, a step of calculating a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method, and a method based on the current distribution and the magnetic current distribution Performing a step of calculating an electric field distribution in a spectral region on the surface of the printed circuit board, and a step of calculating an electric field strength of an electromagnetic wave radiated from the printed circuit board based on the electric field distribution. This is a characteristic method for estimating radiated electromagnetic waves. The radiated electromagnetic wave estimation method according to the second invention can be applied to a printed circuit board having a complicated circuit structure, and can estimate unnecessary electromagnetic waves of the entire printed circuit board with high accuracy and in a short time.

  A third invention is a radiated electromagnetic wave estimation program for a computer to estimate an electromagnetic wave radiated from a printed circuit board to the space, wherein the computer acquires design information of the printed circuit board; Extracting a transmission line from design information; calculating a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method; and the current distribution and the magnetic current distribution. A step of calculating an electric field distribution of a spectral region on the surface of the printed circuit board based on the step of calculating an electric field strength of an electromagnetic wave radiated from the printed circuit board based on the electric field distribution. Is a radiated electromagnetic wave estimation program. By installing the radiated electromagnetic wave estimation program of the third invention in a general-purpose computer, the radiated electromagnetic wave estimation device of the first invention can be obtained and the radiated electromagnetic wave estimation method of the second invention can be executed. .

  According to the present invention, it is possible to provide a radiated electromagnetic wave estimation device and the like that can be applied to a printed circuit board having a complicated circuit structure and can estimate unnecessary electromagnetic waves of the entire printed circuit board with high accuracy and in a short time. it can.

Block diagram showing the configuration of the radiated electromagnetic wave estimation device The figure explaining a transmission line extraction part The figure explaining a surface electric field distribution calculation part and a radiation electric field strength calculation part Flow chart showing process flow of radiated electromagnetic wave estimation device The figure which shows the structure of the printed circuit board in an Example The figure which shows the estimation result in an Example

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the radiated electromagnetic wave estimation apparatus. The radiated electromagnetic wave estimation device 1 is a device that estimates an electromagnetic wave radiated from the printed circuit board to the space. The radiated electromagnetic wave estimation apparatus 1 includes a CPU (abbreviation of “Central Processing Unit”) as a control unit, a memory as a main storage unit, an HDD (abbreviation of “Hard Disk Drive”) or flash memory as an auxiliary storage unit, and a display unit. As a liquid crystal display, a keyboard or mouse as an input unit, a touch panel display, a LAN (Local Area Network) as a wired communication unit, or a wireless module as a wireless communication unit. The auxiliary storage unit stores an OS (abbreviation of “Operating System”), a radiated electromagnetic wave estimation program as an application program for executing processing to be described later, data necessary for processing, and the like. The control unit reads the OS and the radiated electromagnetic wave estimation program from the auxiliary storage unit, stores them in the main storage unit, controls other devices while accessing the main storage unit, and executes processing to be described later.

  The radiated electromagnetic wave estimation apparatus 1 is, for example, a computer such as a desktop PC, a notebook PC, a tablet terminal, or a smartphone. The radiated electromagnetic wave estimation apparatus 1 may be a server, may receive a request from an external computer via a network such as the Internet, execute processing described later, and transmit an estimation result to the external computer.

  As shown in FIG. 1, the radiated electromagnetic wave estimation device 1 extracts a transmission line from design information acquisition unit 2 that inputs design information of a printed circuit board, an estimation condition setting unit 3 that sets an estimation condition, and the design information. A transmission line extraction unit 4, a current and magnetic current distribution calculation unit 5 that calculates a current distribution and a magnetic current distribution in a spectral region for each transmission line, and a spectrum on the surface of the printed circuit board based on the current distribution and the magnetic current distribution. A surface electric field distribution calculating unit 6 for calculating the electric field distribution of the region, and a radiation electric field intensity calculating unit 7 for calculating the intensity of the electric field radiated from the printed circuit board based on the electric field distribution of the spectral region on the surface of the printed circuit board An estimation result output unit 8 for outputting an estimation result.

  The design information acquisition unit 2 includes the shape and layer configuration of the printed circuit board, the structure of the transmission line, semiconductor devices such as LSI and IC, mounted components such as passive elements such as resistors and capacitors, and the length and connection position of the cable to be connected. The design information of the printed circuit board such as is acquired. The design information acquisition unit 2 may read data stored in the auxiliary storage unit as design information, or may acquire data input by the user via the input unit.

  The estimation condition setting unit 3 sets estimation conditions such as the frequency of the signal propagating through the transmission line included in the printed circuit board, information on the signal source, and other physical constants. The estimation condition setting unit 3 may read data stored in the auxiliary storage unit as the estimation condition, or may set data input by the user via the input unit.

  The transmission line extraction unit 4 extracts a transmission line included in the printed circuit board, and acquires a cross-sectional shape and a line length of the transmission line. One or a plurality of transmission lines are extracted. When the circuit structure is complicated, the transmission line extraction unit 4 divides the transmission line at the change point of the transmission line and extracts the transmission line by dividing it into a plurality of transmission lines. The changing points of the transmission line are, for example, a point where the transmission line branches, a point where the transmission line is bent, a point where the transmission line is connected, and the like.

  FIG. 2 is a diagram illustrating the transmission line extraction unit. In the example shown in FIG. 2, the change point 1 is one end point of the parallel two lines, and the change point 2 is a point where the line is bent. The transmission line extraction unit 4 divides the transmission line at the change point 1 and the change point 2, and extracts the transmission line into three transmission lines Line1, Line2, and Line3. The radiated electromagnetic wave estimation device 1 separately calculates the surface electric field and the radiated electric field generated by each transmission line in the calculation process described later, and finally adds the values by considering the difference in phase depending on the position of the transmission line. Estimate the radiated electromagnetic wave of the entire circuit board.

  The current and magnetic current distribution calculation unit 5 calculates a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method. The spectral domain approach (SDA) is a known technique, and is disclosed in Non-Patent Document 1, for example. Also, a multi-conductor transmission line method (MTLM) is a known technique, and is disclosed in Non-Patent Document 2, for example. Furthermore, the present inventors have devised a method of calculating the electromagnetic field distribution in the spectral region in the transmission line using the spectral region method and the multi-wire transmission line method, and is disclosed in Non-Patent Document 3.

  The surface electric field distribution calculation unit 6 calculates the electric field distribution in the spectral region on the surface of the printed circuit board using a two-dimensional spectral region method. Although the two-dimensional spectral domain method is a numerical calculation method, it can be calculated faster than the three-dimensional structure numerical calculation method.

  FIG. 3 is a diagram for explaining a radiation electric field intensity calculation unit. As shown in FIG. 3, in the printed circuit board 11 according to the embodiment of the present invention, the transmission line 12 and mounted components are arranged on the front surface 11a, and the ground 13 is arranged on the back surface 11b. The radiated electric field intensity calculation unit 7 sets the observation point 14 as the far field, and calculates the intensity of the radiated electric field in the far field from the distribution of the electric field (= surface electric field 15) on the surface 11a of the printed circuit board 11. Here, the surface 11a of the printed circuit board 11 is a flat surface, and the transmission line 12 is disposed on the surface 11a. The electric field direction of the surface electric field 15 calculated by the surface electric field distribution calculating unit 6 is determined for each transmission line 12, and is parallel to or perpendicular to the propagation direction D of the signal flowing through the transmission line 12 (= direction from the back of the page to the front). It is.

  The estimation result output unit 8 displays the intensity of the radiated electric field calculated by the radiated electric field intensity calculation unit 7 on the display unit as the estimation result.

  With the above configuration, the radiated electromagnetic wave estimation apparatus 1 can estimate unnecessary electromagnetic waves of the entire printed circuit board in a design stage with high accuracy and in a short time.

  FIG. 4 is a flowchart showing a processing flow of the radiated electromagnetic wave estimation apparatus. As shown in FIG. 4, the design information acquisition unit 2 of the radiated electromagnetic wave estimation apparatus 1 acquires design information of the printed circuit board (step S1).

  Next, the estimation condition setting unit 3 sets estimation conditions such as the frequency of the signal propagating through the transmission line included in the printed circuit board, the generation source of electromagnetic waves, and other physical constants (step S2).

  Next, the transmission line extraction part 4 extracts a transmission line from the design information of the printed circuit board input in step S1 (step S3). When the circuit structure is complicated, the transmission line extraction unit 4 divides the transmission line at the change point of the transmission line and extracts the transmission line by dividing it into a plurality of transmission lines.

  Next, the transmission line extraction part 4 extracts the cross-sectional shape and line length of each transmission line extracted in step S3 from the design information of the printed circuit board input in step S1 (step S4).

  Next, the current and magnetic current distribution calculation unit 5 calculates the self-parameters of each transmission line extracted in step S3 using the spectral domain method (step S5). The calculated self-parameters are a self-capacitance per unit length of the transmission line, a self-inductance per unit length of the transmission line, a phase constant of the transmission line, a characteristic impedance of the transmission line, and the like.

  Next, the current and magnetic current distribution calculation unit 5 calculates the mutual parameters between the transmission lines extracted in step S3 using the spectral domain method (step S6). The calculated mutual parameters are a mutual capacitance per unit length between transmission lines, a mutual inductance per unit length between transmission lines, and the like.

  Next, the current and magnetic current distribution calculation unit 5 uses the multi-wire transmission line method based on the self-parameter calculated in step S5 and the mutual parameter calculated in step S6, for each transmission circuit. And magnetic current distribution is calculated (step S7). The calculation of the current distribution and the magnetic current distribution is disclosed in Non-Patent Document 3, for example.

  Next, the surface electric field distribution calculation unit 6 calculates the electric field distribution in the spectral region on the surface of the printed circuit board using the spectral region method based on the current distribution and the magnetic current distribution calculated in Step S7 (Step S7). S8).

Here, the details of the calculation process in step 8 will be described. Assuming that the surface of the printed circuit board is a plane and the transmission line is a straight line, the direction in which the transmission line extends, that is, the propagation direction of the signal flowing through the transmission line is the x-axis direction, and the direction orthogonal to the surface of the printed circuit board is the z-axis direction. The direction orthogonal to the x-axis and z-axis is taken as the y-axis direction. The radiated electric field vector E (x, y, z) in the far field can be expressed as a superposition of plane waves, and using the electric field vector f (k _x , k _y ) in the spectral region in the z = 0 plane, It can be calculated as:

Here, k _x , k _y and k _z are the wave numbers corresponding to the x-axis direction, the y-axis direction and the z-axis direction, respectively, and f (k _x , k _y ) is an electric field vector in the spectral region in the plane where z = 0. Yes, and is given by

In order to calculate Equation (2), it is necessary to calculate the electric field vector f (k _x , k _y ) in the spectral region. This can be calculated by Fourier transforming the result of a general numerical calculation method, but in the embodiment of the present invention, a spectral domain method capable of directly calculating the electromagnetic field distribution in the spectral domain is used. As a result, the calculation can be performed faster than other methods.

Furthermore, when the signal is propagating on the transmission line in the x-axis direction with a phase constant β, the electromagnetic field distribution along the propagation direction changes only in the phase β, so that the electric field vector f (k _x , k in the spectral region. _y ) can be considered as:

  Here, f ′ is a one-dimensional electric field distribution generated by an electric current, g ′ is a one-dimensional electric field distribution generated by a magnetic current, and the electric field directions are each in the x-axis direction. Using the one-dimensional electric field distributions f ′ and g ′, the radiated electric field vector E (x, y, z) in the far field is expressed by the following equation.

  Here, l (English letter L) is the line length of the transmission line. The one-dimensional electric field distribution f ′ and the phase constant β used in this equation can be calculated by a two-dimensional spectral domain method. The electric field distribution g ′ can be calculated as it is from the magnetic current distribution. Therefore, it is necessary to calculate the second order integral, but the radiated electric field can be calculated faster than the far radiated electric field is calculated using the numerical calculation of the three-dimensional structure. When the circuit structure is complicated, the transmission line extraction unit 4 extracts the transmission line by dividing it into a plurality of transmission lines, and the current and magnetic current distribution calculation unit 5 calculates the current distribution and the phase constant β for each transmission line. Then, the surface electric field distribution calculating unit 6 calculates a one-dimensional electric field distribution f ′ for each transmission line from the current distribution by using the spectral domain method, and substitutes all the results by substituting into the equation (4). The final electric field distribution can be calculated.

  Returning to the description of FIG. Next, the radiated electric field intensity calculation unit 7 sets the observation point as the far field, and calculates the intensity of the radiated electric field in the far field from the electric field distribution in the spectral region on the surface of the printed circuit board calculated in step S8 (step S9). ). The intensity of the radiated electric field is normalized by a maximum value, for example.

  Next, the estimation result output unit 8 outputs the intensity of the radiated electric field in the far field calculated in step 9 as an estimation result (step S10).

  The radiated electromagnetic wave estimation apparatus 1 according to the embodiment of the present invention can be applied to a printed circuit board having a complicated circuit structure, and can estimate unnecessary electromagnetic waves of the entire printed circuit board with high accuracy and in a short time. It becomes.

  Conventionally, in order to estimate the unnecessary electromagnetic wave of the entire printed circuit board, a circuit having a ground with an infinitely large defect and a circuit current distribution and a mirror image current with respect to the ground (= mirror image method) is used. It was. For a printed circuit board having a complicated structure, a method of calculating an electromagnetic field distribution in a closed region surrounding a circuit by a numerical calculation method of a three-dimensional structure that requires a lot of calculation time has been mainly used. According to the radiated electromagnetic wave estimation apparatus 1 in the embodiment of the present invention, it can be applied to a circuit on the ground having a complicated structure having a defect that cannot be calculated by a conventional mirror image method, and the application range of calculation can be expanded. In addition, the calculation can be performed at a higher speed than the numerical calculation method of the three-dimensional structure.

  In this example, the radiated electromagnetic wave estimation apparatus 1 in the embodiment of the present invention was applied to a printed circuit board having a microstrip line as a transmission line, and electromagnetic waves radiated from the printed circuit board to the space were estimated.

  FIG. 5 is a diagram illustrating the structure of the printed circuit board in the embodiment. The printed circuit board 21 shown in FIG. 5 has a 0.8 mm-thick FR4 (= Flame Retardant Type 4) board as a ground plane, a transmission line 22 having a width wg = 1.2 mm and a length l = 100 mm. A strip line was constructed on the surface. The characteristic impedance of the transmission line 22 is approximately 50Ω. One end of the transmission line 22 is the origin, and a power source 23 is arranged at the origin to supply power. In order to obtain a non-reflective termination, the other end of the transmission line 22 was terminated with a resistor 24 of 50Ω. The direction in which the straight transmission line 22 extends, that is, the signal propagation direction is the x-axis direction, the direction perpendicular to the surface of the printed circuit board 21 is the z-axis direction, and the direction perpendicular to the x-axis direction and the z-axis direction is the y-axis. The direction. The length W in the y-axis direction and the length L in the x-axis direction of the printed circuit board 21 were estimated as infinite sizes.

The frequency of the signal propagating through the transmission line 22 was two patterns of 1 GHz and 2 GHz. The radiated electromagnetic wave estimation apparatus 1 scans the θ direction (−90 degrees ≦ θ ≦ 90 degrees, z-axis direction when θ = 0 degrees) on the XZ plane as a far field observation point, and estimates the intensity of the far field electric field. did. Electric field direction is parallel from the origin on the XZ plane the circumference of the fixed distance, i.e. the E _theta direction. The strength of the far-field electric field, which is an estimated value, was normalized with the maximum value.

  FIG. 6 is a diagram illustrating an estimation result in the example. As a comparative example, for the same model except that the substrate size is finite, analysis is performed using the FDTD method (Finite-Difference Time-Domain method), which is one of the numerical calculation methods. went. In FIG. 6, the calculation result (= Proposed) by the radiated electromagnetic wave estimation apparatus 1 is indicated by a solid line, and the comparative example (= Numeral) is indicated by a broken line. It can be seen that when the frequency is 1 GHz, the two results almost coincide. It can also be seen that the position where the dip occurs is slightly different when the frequency is 2 GHz. This is considered because the phase constant β obtained by the radiated electromagnetic wave estimation apparatus 1 by the spectral domain method is different from the result by the FDTD method. However, it can be seen that the two results almost coincide with each other even when the frequency is 2 GHz. Therefore, it can be seen that the calculation result by the radiated electromagnetic wave estimation apparatus 1 has the same accuracy as the calculation result by the numerical calculation method which requires a great amount of calculation time.

  The preferred embodiments of the radiated electromagnetic wave estimation apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

DESCRIPTION OF SYMBOLS 1 ......... Radiation electromagnetic wave estimation apparatus 2 ......... Design information acquisition part 3 ......... Estimation condition setting part 4 ......... Transmission line extraction part 5 ......... Current and magnetic current distribution calculation part 6 ......... Surface electric field distribution Calculation unit 7 .... Radiated electric field intensity calculation unit 8 ... ... Estimation result output unit

Claims (4)

A radiated electromagnetic wave estimation device for estimating an electromagnetic wave radiated from a printed circuit board to space,
A design information acquisition unit for acquiring design information of the printed circuit board;
A transmission line extraction unit for extracting a transmission line from the design information;
Using a spectral domain method and a multi-wire transmission line method, a current and magnetic current distribution calculation unit for calculating a current distribution and a magnetic current distribution for each transmission line;
Based on the current distribution and the magnetic current distribution, a surface electric field calculation unit that calculates an electric field distribution in a spectral region on the surface of the printed circuit board;
Based on the electric field distribution, a radiated electric field strength calculating unit that calculates the electric field strength of the electromagnetic wave radiated from the printed circuit board,
A radiated electromagnetic wave estimation apparatus comprising: 2. The radiation according to claim 1, wherein the surface electric field calculation unit calculates the electric field distribution with a propagation direction of a signal propagating through the transmission line as an electric field direction by using a two-dimensional spectral domain method. Electromagnetic wave estimation device. A computer radiated electromagnetic wave estimation method for estimating an electromagnetic wave radiated into a space from a printed circuit board,
The computer is
Obtaining design information of the printed circuit board;
Extracting a transmission line from the design information;
Calculating a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method;
Calculating an electric field distribution in a spectral region on the surface of the printed circuit board based on the current distribution and the magnetic current distribution;
Calculating the electric field strength of electromagnetic waves radiated from the printed circuit board based on the electric field distribution;
The radiation electromagnetic wave estimation method characterized by performing. A computer radiated electromagnetic wave estimation program for estimating electromagnetic waves radiated from a printed circuit board to space,
The computer is
Obtaining design information of the printed circuit board;
Extracting a transmission line from the design information;
Calculating a current distribution and a magnetic current distribution for each transmission line using a spectral domain method and a multi-wire transmission line method;
Calculating an electric field distribution in a spectral region on the surface of the printed circuit board based on the current distribution and the magnetic current distribution;
Calculating the electric field strength of electromagnetic waves radiated from the printed circuit board based on the electric field distribution;
Radiated electromagnetic wave estimation program for running.

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