Electromagnetic field analysis program and electromagnetic field analysis method

Abstract

To provide an electromagnetic field analysis program with which electromagnetic field analysis of a coplanar waveguide can be efficiently performed.SOLUTION: An electromagnetic field analysis program causes a computer to execute: a step of, in a coplanar waveguide comprising a dielectric layer, and a conductor pattern 10 that has a signal line 11 and reference potential patterns 12 sandwiching the signal line and provided separated from the signal line and that is provided on the dielectric layer, generating meshes such that a first mesh 26 is generated within a first area 24 that includes the signal line and a part of the reference potential pattern and has a constant width in a direction orthogonal to a direction in which the signal line extends, and a mesh is not generated or a second mesh having larger dimensions than the first mesh is generated within a second area 25 other than the first area; and performing electromagnetic field analysis of the coplanar waveguide by using the mesh.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an electromagnetic field analysis program and an electromagnetic field analysis method.

Background Art

[0002] A coplanar waveguide is used as a transmission line for high-frequency signals. Electromagnetic field analysis using a computer is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is conceivable to perform electromagnetic field analysis of the high-frequency characteristics of a coplanar waveguide using an electromagnetic field analysis method. At this time, it is required to perform electromagnetic field analysis efficiently.

[0005] The present disclosure aims to efficiently perform electromagnetic field analysis of a coplanar waveguide.

Means for Solving the Problems

[0006] One embodiment of the present disclosure is an electromagnetic field analysis program that causes a computer to perform the following steps in a coplanar waveguide: generating a first mesh in a first region of a certain width in a direction perpendicular to the direction in which the signal line extends, including the signal line and a part of the reference potential pattern, and generating a mesh such that no mesh is generated in a second region other than the first region, or a second mesh with dimensions larger than the first mesh is generated; and performing an electromagnetic field analysis of the coplanar waveguide using the mesh.

[0007] One embodiment of the present disclosure is an electromagnetic field analysis method for a coplanar waveguide comprising a dielectric layer and a conductive pattern provided on the dielectric layer having a signal line and a reference potential pattern provided spaced apart from the signal line, the method comprising the steps of generating a mesh such that a first mesh is generated in a first region of a certain width in a direction perpendicular to the direction in which the signal line extends, including the signal line and a part of the reference potential pattern, and no mesh is generated in a second region other than the first region, or a second mesh with dimensions larger than the first mesh is generated; and performing electromagnetic field analysis of the coplanar waveguide using the mesh.

[0008] This disclosure can be implemented not only as a characteristic electromagnetic field analysis program and electromagnetic field analysis method, but also as an electromagnetic field analysis device that processes such characteristic steps. Furthermore, it can be implemented as a semiconductor integrated circuit that implements part or all of the electromagnetic field analysis device, or as an electromagnetic field analysis system including the electromagnetic field analysis device. [Effects of the Invention]

[0009] According to this disclosure, electromagnetic field analysis of coplanar waveguides can be performed efficiently. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a plan view of a coplanar waveguide. [Figure 2] Figure 2 is a cross-sectional view of AA in Figure 1. [Figure 3] Figure 3 is a block diagram of the computer in Example 1. [Figure 4] Figure 4 is a flowchart showing the electromagnetic field analysis method in Example 1. [Figure 5] Figure 5 is a plan view showing an example of the pattern in Example 1. [Figure 6] Figure 6 is a plan view showing an example of the pattern in Example 1. [Figure 7] Figure 7 is a plan view showing an example of the pattern in Example 1. [Figure 8] Figure 8 is a plan view showing an example of the pattern in Example 1. [Figure 9] Figure 9 shows a plan view and a cross-sectional view of the mesh used in the boundary element method. [Figure 10] Figure 10 shows a plan view and a cross-sectional view of the mesh used in the finite element method. [Figure 11] Figure 11 is a plan view showing the first and second regions in a distributor or combiner. [Figure 12] Figure 12 shows the method for generating the first region in Figure 11. [Figure 13] Figure 13 is a plan view showing the first and second regions in the signal line and stub. [Figure 14] Figure 14 shows the method for generating the first region in Figure 13. [Figure 15] Figure 15 is a plan view showing the mesh in the signal lines and stubs. [Modes for carrying out the invention]

[0011] [Description of Embodiments in this Disclosure] First, the contents of the embodiments of this disclosure will be listed and explained. (1) One embodiment of the present disclosure is a coplanar waveguide including a dielectric layer, a conductor pattern provided on the dielectric layer and having a signal line and a reference potential pattern provided with a gap from the signal line across the signal line, generating a first mesh in a first region having a constant width in a direction orthogonal to the extending direction of the signal line including the signal line and a part of the reference potential pattern, and generating no mesh or generating a second mesh having a larger dimension than the first mesh in a second region other than the first region, and a step of electromagnetic field analysis using the mesh, and causing a computer to execute the electromagnetic field analysis program. Thereby, electromagnetic field analysis can be efficiently performed. (2) In the above (1), the step of generating the mesh includes a step of generating the first mesh on the surface of the conductor pattern in the first region and generating no mesh in the second region, and the step of electromagnetic field analysis is a step of electromagnetic field analysis using the boundary element method. (3) In the above (2), the step of generating the mesh includes a step of generating no mesh in the dielectric layer. (4) In the above (1), the step of generating the mesh includes a step of generating the first mesh on the conductor pattern and the dielectric layer in the first region and generating a second mesh on the conductor pattern and the dielectric layer in the second region, and the step of electromagnetic field analysis is a step of electromagnetic field analysis using the finite element method. (5) In any of the above (1) to (4), the step of generating the mesh includes a step of setting a range within a certain distance in a direction orthogonal to the extending direction of the center line with respect to the center line of the signal line as the first region, and setting a region outside the certain distance in the direction orthogonal to the center line as the second region. (6) In the above (5), when the width of the signal line in the orthogonal direction is W1, the distance between the signal line and the reference potential pattern in the orthogonal direction is W2, A is a constant number, and B is a constant number, the certain distance is A × W_1 + B × W_2. (7) In (6) above, A is a constant number between 0.5 and 2.5, and B is a constant number between 1 and 5. (8) In any of (1) to (4) above, the signal line includes a first signal line, a second signal line and a third signal line connected at one location, and the step of generating the mesh includes setting the first region to an area where the following overlaps: a range of a first distance in a first direction perpendicular to the extension direction of the first center line with respect to the first center line of the first signal line, a range of a second distance in a second direction perpendicular to the extension direction of the second center line with respect to the second center line of the second signal line, and a range of a third distance in a third direction perpendicular to the extension direction of the third center line with respect to the third center line of the third signal line, and the first signal in the first direction Let W1a be the width of the line, W2a be the distance between the first signal line and the reference potential pattern in the first direction, W1b be the width of the second signal line in the second direction, W2b be the distance between the second signal line and the reference potential pattern in the second direction, W1c be the width of the third signal line in the third direction, W2c be the distance between the third signal line and the reference potential pattern in the third direction, and when A and B are constant numbers, the first distance is A × W1a + B × W2a, the second distance is A × W1b + B × W2b, and the third distance is A × W1c + B × W2c. (9) In any one of (1) to (4) above, the signal line includes a first signal line and a second signal line having a first end connected to the first signal line and a second end that is open. The step of generating the mesh includes setting a first region as a region where a range of a first distance in a first direction orthogonal to the extending direction of the first center line of the first signal line within a range of the first distance and a range of a third distance in a second direction orthogonal to the extending direction of a line obtained by extending the second center line of the second signal line from the second end of the second signal line by a second distance overlap. Let the width of the first signal line in the first direction be W1a, the distance between the first signal line and the reference potential pattern in the first direction be W2a, the width of the second signal line in the second direction be W1b, the distance between the second signal line and the reference potential pattern in the second direction be W2b, A be a constant number, and B be a constant number. Then, the first distance is A×W1a + B×W2a, the second distance is A×W1b + B×W2b - W1b / 2, and the third distance is A×W1b + B×W2b. (10) One embodiment of the present disclosure is a coplanar waveguide including a dielectric layer, a conductor pattern provided on the dielectric layer and having a signal line and a reference potential pattern provided so as to sandwich the signal line and be separated from the signal line. In the coplanar waveguide, a first mesh is generated within a first region having a certain width in a direction orthogonal to the extending direction of the signal line, including the signal line and a part of the reference potential pattern, and no mesh is generated in a second region other than the first region or a second mesh having a larger dimension than the first mesh is generated. The method includes generating a mesh and performing electromagnetic field analysis of the coplanar waveguide using the mesh. Thereby, electromagnetic field analysis can be efficiently performed.

[0012] [Details of Embodiments of the Present Disclosure] Specific examples of electromagnetic field analysis programs and electromagnetic field analysis methods according to embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to these examples, and all modifications within the meaning and scope of the claims are intended to be included.

[0013] At least some of the embodiments described below may be combined in any way. The electromagnetic field analysis device is configured to include a computer, and each function of the electromagnetic field analysis calculation device is performed by the computer program stored in the computer's storage device being executed by the computer's CPU (Central Processing Unit). The computer program can be stored on a storage medium such as a CD-ROM (Compact Disc Read Only Memory) or a DVD (Digital Versatile Disc).

[0014] [Example 1] First, let's explain the coplanar waveguide (CPW). Figure 1 is a plan view of the coplanar waveguide. Figure 2 is a cross-sectional view AA of Figure 1. The stacking direction of the dielectric layer 16, the conductive layer 14, and the dielectric layer 18 is the Z direction, the extension direction of the signal line 11 is the Y direction, and the direction that is planar and perpendicular to the Y direction is the X direction.

[0015] As shown in Figures 1 and 2, in a coplanar waveguide, a conductive layer 14 is provided on a dielectric layer 16, and a dielectric layer 18 is provided on the conductive layer 14. Either the dielectric layer 16 or 18 may be air. The conductive layer 14 forms a conductive pattern 10. The conductive pattern 10 has a signal line 11 and a reference potential pattern 12. The signal line 11 is a line through which a high-frequency signal is transmitted. The high-frequency signal is, for example, a microwave or millimeter wave with a frequency of 0.3 GHz or higher. The reference potential pattern 12 is a conductive pattern to which a reference potential such as ground potential is supplied, and is provided spaced apart from the signal line 11 in the X direction, sandwiching the signal line 11. The space between the signal line 11 and the reference potential pattern 12 is a gap region 13 where the conductive layer 14 is not provided. The characteristic impedance of the coplanar waveguide depends mainly on the width W1 of the signal line 11 in the X direction, the width W2 of the gap region 13 in the X direction, and the dielectric constants of the dielectric layers 16 and 18.

[0016] In Figure 2, the arrows 50 pointing from the signal line 11 to the reference potential pattern 12 within the dielectric layers 16 and 18 indicate the electric field between the signal line 11 and the reference potential pattern 12. The dashed line 52 surrounding the signal line 11 indicates the magnetic field. Thicker arrows 50 indicate a larger electric field, indicating a larger electromagnetic field coupling between the signal line 11 and the reference potential pattern 12. The electromagnetic field coupling between the region of the reference potential pattern 12 close to the signal line 11 and the signal line 11 is large, but the electromagnetic field coupling between the region of the reference potential pattern 12 far from the signal line 11 and the signal line 11 is small. Let's call the point 22 a location at a distance L1 from the center line 20 of the signal line 11. The reference potential pattern 12 outside of point 22 is hardly electromagnetically coupled to the signal line 11. Region 24 is the region inside point 22, and region 25 is the region outside point 22. The distance L1 is, for example, A × W1 + B × W2 (where A and B are constant numbers). As an example, by setting the distance L1 to 1.5W1 + 3W2, the electromagnetic field coupling with the signal line 11 in region 25 becomes smaller.

[0017] [Computer block diagram] Figure 3 is a block diagram of the computer in Example 1. Computer 30 functions as an electromagnetic field analysis device that performs electromagnetic field analysis in cooperation with software. Computer 30 executes an electromagnetic field analysis program and an electromagnetic field analysis method.

[0018] The computer 30 comprises a processor 32, memory 34, input / output device 36, and internal bus 38. The processor 32 is, for example, a CPU, and executes an electromagnetic field analysis program and an electromagnetic field analysis method. The memory 34 is, for example, volatile memory or non-volatile memory, and stores data used by the processor 32 when executing the electromagnetic field analysis program and the electromagnetic field analysis method. The memory 34 may also store the electromagnetic field analysis program executed by the processor 32. The input / output device 36 inputs data acquired by the processor 32 from an external device and outputs data output by the processor 32 to an external device. The internal bus 38 connects the processor 32, memory 34, and input / output device 36 and transmits data. The electromagnetic field analysis program is stored in a storage medium 35. The storage medium 35 is, for example, a tangible medium that is not temporary, such as a CD-ROM or DVD.

[0019] [flowchart] Figure 4 is a flowchart of the electromagnetic field analysis method in Example 1. Figures 5 to 8 are plan views showing examples of patterns in Example 1. As shown in Figure 4, the processor 32 acquires pattern data and the like from an external device via the input / output device 36 (step S10). At this time, the processor 32 acquires information on the positions where high-frequency signals are input, information on the positions where high-frequency signals are output, and information on the positions where a reference potential is supplied in the conductive pattern 10. The processor 32 also acquires information such as the dielectric constant and thickness of the dielectric layers 16 and 18.

[0020] As shown in Figure 5, the pattern data is data indicating the region where the conductive pattern 10 is provided, and is represented in the first layer. For example, in the first layer, the numerical value of the coordinate where the conductive pattern 10 is provided is set to 1, and the numerical value of the coordinate where the conductive pattern 10 is not provided is set to 0. Position P1 is the position where the high-frequency signal is input, and position P2 is the position where the high-frequency signal is output. Position P3 is the position where the reference potential is supplied. The conductive pattern 10 has a signal line 11 and a reference potential pattern 12.

[0021] Returning to Figure 4, the processor 32 sets the centerline 20 of the signal line (step S12). As shown in Figure 6, for example, the processor 32 recognizes the pattern in the conductive pattern 10 where positions P1 and P2 exist as the signal line 11, and the pattern where position P3 exists as the reference potential pattern 12. The processor 32 sets the centerline 20 of the signal line 11 as a line connecting the midpoints of the signal line 11 in a direction perpendicular to the extension direction of the signal line 11. An example in which the signal line 11 extends in a straight line is described, but the signal line 11 may also extend in a curved shape. In this case, the centerline 20 will be a curve.

[0022] Returning to Figure 4, the processor 32 sets the first region 24 (step S14). As shown in Figure 7, for example, the processor 32 sets a location 22 at a distance L1 from the center line 20 in the X direction (a direction perpendicular to the extension direction of the signal line 11). The processor 32 sets the area between locations 22 as the first region 24. The first region 24 includes the signal line 11 and the region 15 of the reference potential pattern 12 that is close to the signal line 11. For example, the processor 32 represents the first region 24 in a second layer, and in the second layer, the coordinate values ​​of the first region 24 are set to 1, and the coordinate values ​​of the second region 25 other than the first region 24 are set to 0.

[0023] Returning to Figure 4, the processor 32 generates a mesh for electromagnetic field analysis in the first region 24 (step S16). As shown in Figure 8, for example, the processor 32 generates a mesh 26 in the conductive pattern 10 within the first region 24. The processor 32 can generate a mesh 26 in the signal line 11 and in the region 15 within the first region 24 of the reference potential pattern 12 by generating a mesh 26 in a region where, for example, the first layer is 1 and the second layer is 1. The condition for forming a mesh in region 24 is the first condition.

[0024] Returning to Figure 4, the processor 32 generates a mesh for electromagnetic field analysis in the second region 25 (step S18). In the example in Figure 8, the condition for the processor 32 to generate a mesh in the second region 25 is the condition of not generating a mesh. Therefore, no mesh is formed in the second region 25. Thus, the condition for forming a mesh in the second region 25 is the second condition, which is different from the first condition.

[0025] Returning to Figure 4, the processor 32 performs electromagnetic field analysis (step S20). For example, a discretization analysis method is used for the electromagnetic field analysis. Discretization analysis is a numerical analysis method that deals with small spaces obtained by dividing space. Examples of discretization analysis methods include the finite element method and the boundary element method. In the electromagnetic field analysis, when a high-frequency signal is input from the input port, Maxwell's equations are solved to find the electric and magnetic fields in the mesh over time. This calculates the high-frequency characteristics of the conductive pattern 10 or the characteristics of the pattern. The high-frequency characteristics of the conductive pattern 10 include, for example, the S-parameters or impedance between the input and output ports of the high-frequency signal. The characteristics of the pattern include, for example, the current and / or voltage, and the strength of the electric and / or magnetic fields within the conductive pattern 10.

[0026] The processor 32 outputs the results of the electromagnetic field analysis to an external device via the input / output device 36 (step S22). Then it terminates.

[0027] Coplanar waveguides allow for the formation of transmission lines with a simple structure because they have electromagnetically coupled signal lines 11 and reference potential patterns 12 on the same planar layer. For example, in a microstrip line (MSL), the signal line is provided on the upper surface of the dielectric layer, and the reference potential pattern is provided on the entire lower surface of the dielectric layer. Therefore, in order to connect the electronic components on the upper surface of the dielectric layer to the reference potential pattern, through electrodes that penetrate the dielectric layer must be provided, which complicates the manufacturing process. Furthermore, parasitic inductance of through electrodes becomes a problem with high-frequency signals. For this reason, coplanar waveguides are used in high-frequency devices.

[0028] When performing electromagnetic field analysis on a microstrip line, if we assume that a reference potential pattern is provided across the entire surface, there is no need to generate a mesh on the reference potential pattern. Therefore, the load on electromagnetic field analysis is lighter for microstrip lines. On the other hand, in a coplanar waveguide, the signal line 11 and the reference potential pattern 12 are provided on the same plane. Therefore, a mesh is generated across the entire reference potential pattern 12. As a result, the number of meshes increases in a coplanar waveguide, and the load on electromagnetic field analysis becomes heavier.

[0029] According to Embodiment 1, as shown in step S14 of Figure 4 and in Figure 7, the computer 30 sets a first region 24 of a constant width (2 × L1) in a coplanar waveguide having dielectric layers 16 and 18 and a conductive pattern 10, which includes the signal line 11 and a part of the reference potential pattern 12 (region 15), and sets the area other than the first region 24 as the second region 25. In step S16 of Figure 4, the computer 30 generates a mesh 26 (first mesh) within the first region 24. In step S18, the computer 30 does not generate a mesh 26 within the second region 25. The computer 30 may generate a second mesh within the second region 25 that is larger in size than the mesh 26 in the first region 24.

[0030] Subsequently, as in step S20, the computer 30 uses the mesh 26 to perform electromagnetic field analysis on the coplanar waveguide. As shown in Figure 2, the reference potential pattern 12 in the first region 24 has strong electromagnetic field coupling with the signal line 11, but the reference potential pattern 12 in the second region 25 has weak electromagnetic field coupling with the signal line 11. Therefore, a mesh is not generated in the second region 25, or a mesh with smaller dimensions than that in the first region 24 is generated in the second region 25. This reduces the load on the electromagnetic field analysis in the second region 25, where the electromagnetic field coupling with the signal line 11 is weak. Thus, electromagnetic field analysis can be performed efficiently.

[0031] As shown in Figure 7, the computer 30 sets the area within a certain distance L1 in a direction perpendicular to the extension direction of the center line 20 of the signal line 11 as the first region 24, and the area outside of a certain distance L1 in a direction perpendicular to the center line 20 of the signal line 11 as the second region 25. This makes it possible to set the area where the electromagnetic field coupling between the reference potential pattern 12 and the signal line 11 is weak as the second region 25. Thus, the load on the electromagnetic field analysis can be reduced without reducing the accuracy of the electromagnetic field analysis.

[0032] Let W1 be the width of the signal line 11 in the direction perpendicular to the extension direction of the center line 20, and W2 be the distance between the signal line 11 and the reference potential pattern 12 (width of the gap region 13). Let A and B be a constant number. In this case, the constant distance L1 is A × W1 + B × W2. By setting the distance L1 using the widths W1 and W2 in this way, a second region 25 with weak electromagnetic field coupling between the reference potential pattern 12 and the signal line 11 can be set. In the inventors' experience, A is, for example, 0.5 or more and 2.5 or 1 or more and 2 or less, with 1.5 as an example. B is, for example, 1 or more and 5 or 2 or more and 4 or less, with 3 as an example.

[0033] As shown in Figure 5, the computer 30 sets the conductive pattern 10 as the first layer, and as shown in Figure 7, sets the first region 24 as the second layer. As shown in Figure 8, the computer 30 generates a mesh 26 in the region where the first layer and the second layer overlap. No mesh is generated in the second region 25 other than the first region 24. This allows a mesh to be generated on the conductive pattern 10 within the first region 24.

[0034] [Example of boundary element method] In step S20, the method for generating the mesh in steps S16 and S18 when performing electromagnetic field analysis using the boundary element method will be described. Figure 9 is a plan view and a cross-sectional view showing the mesh used in the boundary element method. The plan view shows the conductive pattern 10 and the dielectric layer 16. As shown in Figure 9, the conductive pattern 10 in the first region 24 is region 15 of the signal line 11 and reference potential pattern 12. As shown in the plan view, a mesh 26 is provided in the signal line 11 and region 15. The points where the lines in the mesh 26 intersect are the grid 27.

[0035] The dimensions of the mesh 26 in the X and Y directions are Mx and My, respectively. The dimensions Mx and My may be the same or different. The dimensions Mx and My may be the same or different for the mesh 26 in the signal line 11 and the mesh 26 in region 15. For example, in regions where the electric field changes significantly, the dimensions Mx and My of the mesh 26 are reduced. When the dimensions Mx and My of the mesh 26 are small, the calculation accuracy improves but the computational load increases. When the dimensions Mx and My of the mesh 26 are large, the computational load decreases but the calculation accuracy decreases. From this perspective, the dimensions Mx and My of the mesh 26 are, for example, 1 / 2 to 1 / 32 times the wavelength of the high-frequency signal, or for example, 1 / 8 to 1 / 16 times. No mesh is generated in the second region 25. In the boundary element method, a mesh is generated at the boundary between the conductor pattern 10 and the dielectric layers 16 and 18, and numerical values ​​such as the electric field on the surface within the mesh 26 are calculated.

[0036] In the boundary element method, a mesh is generated on the surface of the conductive pattern 10. In a microstrip line, since a reference potential pattern is provided across the entire surface, there is no need to generate a mesh on the reference potential pattern; it is sufficient to generate a mesh on the signal line. Therefore, the number of meshes is reduced, and the load on the electromagnetic field analysis is lightened. On the other hand, in a coplanar waveguide, if a mesh is generated across the entire reference potential pattern 12, the number of meshes increases, and the load on the electromagnetic field analysis becomes heavier.

[0037] Therefore, as shown in Figure 9, when performing electromagnetic field analysis using the boundary element method, the computer 30 generates a mesh 26 (first mesh) on the surface of the conductive pattern 10 in the first region 24 in steps S16 and S18, but does not generate a mesh in the second region 25. This reduces the number of meshes generated on the surface of the conductive pattern 10, thereby lightening the load on the electromagnetic field analysis.

[0038] Furthermore, in the boundary element method, the computer 30 does not generate a mesh 26 for dielectric layers 16 and 18 other than the conductive pattern 10, and instead captures information about dielectric layers 16 and 18 as dielectric constant and thickness. This further reduces the load on electromagnetic field analysis.

[0039] [Example of the finite element method] In step S20, the method for generating the mesh in steps S16 and S18 when performing electromagnetic field analysis using the finite element method will be described. Figure 10 is a plan view and a cross-sectional view showing the mesh used in the boundary element method. As shown in Figure 10, the dimensions of the mesh 26a in the X and Y directions in the first region 24 are Mx1 and My1, respectively. The dimensions Mx1 and My1 of the mesh 26a are, for example, 1 / 2 to 1 / 32 times the wavelength of the high-frequency signal, and for example, 1 / 8 to 1 / 16 times. The dimensions of the mesh 26b in the X and Y directions in the second region 25 are Mx2 and My2, respectively. The dimensions Mx2 and My2 are, for example, 2 to 32 times and 8 to 16 times Mx1 and Mx2, respectively.

[0040] The dimension of the mesh 26a in the Z direction of the dielectric layers 16 and 18 in the first region 24 is Mz1, and the dimension of the mesh 26a in the Z direction of the conductive pattern 10 is Mz1a. The dimension of the mesh 26b in the Z direction of the dielectric layers 16 and 18 in the second region 25 is Mz2, and the dimension of the mesh 26b in the Z direction of the conductive pattern 10 is Mz2a. Since no electric field is generated within the conductive layer 14, meshes 26a and 26b are not generated within the conductive layer 14. The dimensions Mz2 and Mz2a are, for example, 2 to 32 times and 8 to 16 times Mz1 and Mz1a, respectively. Meshes 26a and 26b may be triangular. In the finite element method, numerical values ​​such as the electric field in grids 27a and 27b are calculated.

[0041] In the finite element method, meshes are generated not only on the conductive pattern 10 but also on the dielectric layers 16 and 18. This increases the load on the electromagnetic field analysis. Furthermore, the finite element method also forms a mesh 26b in the second region 25, further increasing the load on the electromagnetic field analysis. Therefore, when performing electromagnetic field analysis using the finite element method, in step S16, the computer 30 forms a mesh 26a (first mesh) with dimensions Mx1, My1, Mz1, and Mz1a on the conductive pattern 10 and dielectric layers 16 and 18 within the first region 24. In step S18, the computer 30 generates a mesh 26b (second mesh) with dimensions Mx2, My2, Mz2, and Mz2a on the conductive pattern 10 and dielectric layers 16 and 18 within the first region 24. Dimensions Mx2, My2, Mz2, and Mz2a are larger than dimensions Mx1, My1, Mz1, and Mz1a, respectively. This reduces the number of meshes generated, thereby lightening the load on electromagnetic field analysis. At least one of the dimensions Mx2, My2, Mz2, and Mz2a must be larger than the corresponding dimensions Mx1, My1, Mz1, and Mz1a. There are more meshes in the X and Y directions than in the Z direction. Therefore, by making dimensions Mx2 and My2 larger than dimensions Mx1 and My1, respectively, the number of meshes (26) can be further reduced.

[0042] [Examples of distributors and combiners] The conductive pattern 10 describes a distributor or combiner in which two signal lines are coupled into one signal line. Figure 11 is a plan view showing the first and second regions in the distributor or combiner. The mesh 26 and grid 27 are not shown in Figure 11. As shown in Figure 11, the two signal lines 11b and 11c are coupled to form one signal line 11a. That is, the signal lines 11a, 11b and 11c are connected at one point. The reference potential patterns 12a and 12b sandwich the signal line 11a. Gap regions 13a are provided between the reference potential pattern 12a and the signal line 11a, and between the reference potential pattern 12b and the signal line 11a. The widths of the signal line 11a and the gap region 13a in the direction perpendicular to the extension direction of the signal line 11a are W1a and W2a, respectively. The area within distance L1a from the center line 20a of signal line 11a is region 24a. The reference potential patterns 12a and 12b within region 24a are region 15a. The area outside region 24a is regions 25a and 25b.

[0043] Reference potential patterns 12a and 12c are flanked by the signal line 11b, with gap regions 13b provided between reference potential pattern 12a and signal line 11b, and between reference potential pattern 12c and signal line 11b. The widths of signal line 11b and gap region 13b in the direction perpendicular to the extension direction of signal line 11b are W1b and W2b, respectively. The range from the center line 20b of signal line 11b at a distance L1b is region 24b. Reference potential patterns 12a and 12c within region 24b are region 15b. Outside region 24b are regions 25a and 25c. Reference potential patterns 12b and 12c are flanked by the signal line 11c, with gap regions 13c provided between reference potential pattern 12b and signal line 11c, and between reference potential pattern 12c and signal line 11c. The widths of the signal line 11c and the gap region 13c in the direction perpendicular to the extension direction of the signal line 11c are W1c and W2c, respectively. The range from the center line 20c of the signal line 11c at a distance L1c is region 24c. The reference potential patterns 12b and 12c within region 24c are region 15c. The area outside region 24c is region 25b and 25c.

[0044] The widths W1a, W1b, and W1c may be the same or different from each other. The widths W2a, W2b, and W2c may be the same or different from each other. By making the widths W1a to W1c of signal lines 11a to 11c different, or by making the widths W2a to W2c of gap regions 13a to 13c different, the characteristic impedances of the transmission lines having signal lines 11a to 11c can be made different from each other. The distances L1a to L1c may be the same or different from each other. For example, if L1a = A × W1a + B × W2a, L1b = A × W1b + B × W2b, and L1c = A × W1c + B × W2c, then if the widths W1a to W1c are different from each other, or if the widths W2a to W2c are different from each other, then the distances L1a to L1c are different from each other.

[0045] In step S16 of Figure 4, the processor 32 generates a mesh 26 and a grid 27 in the conductive pattern 10 within regions 24a to 24c. In step S18 of Figure 4, the processor 32 generates a mesh 26 and a grid 27 in the conductive pattern 10 within regions 25a to 25c using different conditions than those in step S16.

[0046] The method by which the processor 32 sets the first region 24 and the second region 25 in step S14 of Figure 4, with respect to the pattern in Figure 11, is described below. Figure 12 shows how the first region 24 is generated in Figure 11. Figure 12 illustrates the signal lines 11a to 11c, the centerlines 20a to 20c, and the regions 24a to 24c. As shown in Figure 12, the computer 30 sets the region 24a at a distance L1a from the centerline 20a in a direction perpendicular to the extension direction of the centerline 20a. Similarly, the computer 30 sets the regions 24b and 24c, respectively, at distances L1b and L1c from the centerlines 20b and 20c in directions perpendicular to the extension directions of the centerlines 20b and 20c. The processor 32 sets the region obtained by combining regions 24a to 24c (i.e., the region obtained by ANDing regions 24a to 24c) as the first region 24. The processor 32 sets all areas except the first area 24 as the second area 25.

[0047] In step S14 of Figure 4, as shown in Figure 12, the computer 30 sets the area within a first distance L1a in a first direction perpendicular to the extension direction of the center line 20a (first center line) of the signal line 11a (first signal line) as area 24a. The computer 30 sets the area within a second distance L1b in a second direction perpendicular to the extension direction of the center line 20b (second center line) of the signal line 11b (second signal line) as area 24b. The computer 30 sets the area within a third distance L1c in a third direction perpendicular to the extension direction of the center line 20c (third center line) of the signal line 11c (third signal line) as area 24c. The computer 30 sets the area where areas 24a, 24b, and 24c overlap as the first area 24. Here, L1a = A × W1a + B × W2a, L1b = A × W1b + B × W2b, and L1c = A × W1c + B × W2c. A is a constant number common to distances L1a, L1b, and L1c, and B is a constant number common to distances L1a, L1b, and L1c. This allows the first region 24 to be set even when widths W1a, W1b, and W1c are different from each other, and widths W2a, W2b, and W2c are different from each other. Although the example given was that there are three signal lines 11a to 11c, there may be two or more signal lines. A is, for example, 0.5 or more and 2.5 or 1 or more and 2 or less, and one example is 1.5. B is, for example, 1 or more and 5 or 2 or more and 4 or less, and one example is 3.

[0048] [Example of a stub 1] The case in which the conductive pattern 10 includes a signal line and a stub will be described. Figure 13 is a plan view showing the first and second regions of the signal line and stub. As shown in Figure 13, signal line 11b is coupled to signal line 11a as an open stub. The first end of signal line 11b is connected to signal line 11a, and the second end of signal line 11b is open. Gap region 13a sandwiches signal line 11a, and gap region 13b sandwiches signal line 11b. A reference potential pattern 12 is provided outside gap regions 13a and 13b.

[0049] The widths of signal line 11a and gap region 13a in the direction perpendicular to the extension direction of signal line 11a are W1a and W2a, respectively. The range from the center line 20a of signal line 11a at a distance L1a is region 24a. The conductive pattern 10 within region 24a is region 15a. The widths of signal line 11b and gap region 13b in the direction perpendicular to the extension direction of signal line 11b are W1b and W2b, respectively. The range from the center line 20b of signal line 11b at a distance L1b is region 24b. The conductive pattern 10 within region 24b is region 15b. At the second end of signal line 11b, the reference point 17 is set at a point W1b / 2 from the second end of signal line 11b, and the area within a distance L1b from the reference point 17 in the extension direction of signal line 11b is region 24b.

[0050] When the characteristic impedance of an open stub having signal line 11b is made different from the characteristic impedance of a transmission line having signal line 11a, the widths W1a and W1b are different, and the widths W2a and W2b are different.

[0051] The method by which the processor 32 sets regions 24 and 25 in step S14 of Figure 4, with respect to the pattern in Figure 13, is described below. Figure 14 is a diagram showing how the first region 24 is generated in Figure 13. Figure 14 illustrates the signal lines 11a and 11b, the centerlines 20a and 20b, and regions 24a and 24b. As shown in Figure 14, the processor 32 sets region 24a at a distance L1a from the centerline 20a in a direction perpendicular to the extension direction of the centerline 20a. The processor 32 uses a point on the centerline 20b inside W1b / 2 from the end 17a of the centerline 20b of the signal line 11b as the reference point 17. The processor 32 extends a line 17c from the end 17a of the centerline 20b in the extension direction of the centerline 20b to point 17b. The distance between the reference point 17 and point 17b is L1b. The processor 32 sets a region at a distance L1b from the center line 20b and line 17c in a direction perpendicular to the extension direction of the center line 20b as region 24b. The processor 32 sets the region obtained by combining regions 24a and 24b (i.e., the region obtained by ANDing regions 24a and 24b) as the first region 24. The processor 32 sets all regions other than the first region 24 as the second region 25.

[0052] [Example of a stub 2] Figure 15 is a plan view showing the first and second regions in the signal line and stub. As shown in Figure 15, the width W1a of the signal line 11a and the width W2a of the gap region 13a are larger than the widths W1a and W2a in Figure 13. The width W1b of the signal line 11b and the width W2b of the gap region 13b are smaller than the widths W1b and W2b in Figure 13. Point 17b, at a distance L1b in the extension direction of the center line 20b from the reference point 17, is located within region 24a. Therefore, region 24b is entirely contained within region 24a, and the first region 24 coincides with region 24a. Thus, when region 24b is completely contained within region 24a, the first region 24 coincides with region 24a.

[0053] In the examples shown in Figures 12 to 15, a signal line 11a (first signal line) and a signal line 11b (second signal line) are provided, with the first end connected to signal line 11a and the second end open. In such cases, in step S14 of Figure 4, as shown in Figure 14, the computer 30 sets the area 24a to be within the range of a first distance L1a in a first direction perpendicular to the extension direction of the center line 20a (first center line) of signal line 11a. The computer 30 sets the area 24b to be within the range of a third distance L1b in a second direction perpendicular to the extension direction of the line (center line 20b + line 17c) obtained by extending the center line 20b (second center line) of signal line 11b by a second distance (L1b - W1b / 2) from the second end 17a of signal line 11b (center line 20b + line 17c). Computer 30 sets the region where regions 24a and 24b overlap as the first region 24. Here, the first distance L1 is A × W1a + B × W2a, the second distance (L1b - W1b / 2) is A × W1b + B × W2b - W1b / 2, and the third distance L1b is A × W1b + B × W2b. This allows the first region 24 to be set even in an open stub. A is, for example, 0.5 or more and 2.5 or 1 or more and 2 or less, and one example is 1.5. B is, for example, 1 or more and 5 or 2 or more and 4 or less, and one example is 3.

[0054] The above-mentioned processor may be any type of processor suitable for computer control, such as a CPU, GPU (Graphics Processing Unit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), or ASIC (Application Specification Integrated Circuit). Furthermore, multiple physically separated processors may cooperate with each other to perform the above-mentioned processes. For example, processors installed in multiple physically separated computers may cooperate with each other via a network such as a LAN (Local Area Network), WAN (Wide Area Network), or the Internet to perform the above-mentioned processes.

[0055] The above program may be installed into the above memory via the above network from an external server device, or it may be distributed on a storage medium such as a CD-ROM, DVD-ROM, or semiconductor memory, and then installed into the above memory from the above storage medium.

[0056] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims, not in the sense described above, and all modifications are intended to be in the sense and scope equivalent to the claims. [Explanation of Symbols]

[0057] 10 Conductive Patterns 11, 11a, 11b, 11c signal line 12, 12a, 12b, 12c Reference potential patterns 13, 13a, 13b, 13c Gap area 14 Conductive layer 15, 15a, 15b, 15c areas 16, 18 Dielectric layer 17 Reference points 17a edge 17b points 17c line 20, 20a, 20b, 20c center line 22 locations 24, 24a, 24b, 24c areas 25, 25a, 25b, 25c area 26 mesh 27, 27a, 27b Grid 30 Computers 32 processors 34 memory 35 Storage medium 36 Input / Output Devices 38 Internal bus

Claims

1. A coplanar waveguide comprising a dielectric layer, a signal line, and a conductor pattern provided on the dielectric layer having a reference potential pattern provided on the dielectric layer with the signal line in between and spaced apart from the signal line, comprising the steps of generating a mesh such that a first mesh is generated in a first region of a certain width in a direction perpendicular to the direction in which the signal line extends, including the signal line and a part of the reference potential pattern, and no mesh is generated in a second region other than the first region, or a second mesh with a larger dimension than the first mesh is generated, The steps include: performing electromagnetic field analysis of the coplanar waveguide using the aforementioned mesh; Have the computer run it, An electromagnetic field analysis program that includes the step of generating the mesh, which includes setting a first region within a certain distance in a direction perpendicular to the extension direction of the center line with respect to the center line, and setting a second region outside the certain distance in the direction perpendicular to the center line.

2. The step of generating the mesh includes generating the first mesh on the surface of the conductive pattern in the first region, and not generating a mesh in the second region. The electromagnetic field analysis program according to claim 1, wherein the step of performing electromagnetic field analysis is a step of performing electromagnetic field analysis using the boundary element method.

3. The electromagnetic field analysis program according to claim 2, wherein the step of generating the mesh includes a step of not generating a mesh in the dielectric layer.

4. The step of generating the mesh includes generating the first mesh in the conductive pattern and dielectric layer within the first region, and generating the second mesh in the conductive pattern and dielectric layer within the second region. The electromagnetic field analysis program according to claim 1, wherein the step of performing electromagnetic field analysis is a step of performing electromagnetic field analysis using the finite element method.

5. The electromagnetic field analysis program according to claim 1, wherein the width of the signal line in the orthogonal direction is W1, the distance between the signal line and the reference potential pattern in the orthogonal direction is W2, A is a constant number, and B is a constant number, and the constant distance is A × W1 + B × W2.

6. The electromagnetic field analysis program according to claim 5, wherein A is a constant number between 0.5 and 2.5, and B is a constant number between 1 and 5.

7. The aforementioned signal line includes a first signal line, a second signal line, and a third signal line connected at one location. The step of generating the mesh includes setting the first region to be a region in which the following overlaps: a region within a first distance range in a first direction perpendicular to the extension direction of the first centerline of the first signal line, a region within a second distance range in a second direction perpendicular to the extension direction of the second centerline of the second signal line, and a region within a third distance range in a third direction perpendicular to the extension direction of the third centerline of the third signal line. When the width of the first signal line in the first direction is W1a, the distance between the first signal line and the reference potential pattern in the first direction is W2a, the width of the second signal line in the second direction is W1b, the distance between the second signal line and the reference potential pattern in the second direction is W2b, the width of the third signal line in the third direction is W1c, the distance between the third signal line and the reference potential pattern in the third direction is W2c, and A is a constant number and B is a constant number, The first distance is A × W1a + B × W2a, The second distance is A × W1b + B × W2b, The electromagnetic field analysis program according to any one of claims 1 to 4, wherein the third distance is A × W1c + B × W2c.

8. The signal line includes a first signal line and a second signal line whose first end is connected to the first signal line and whose second end is open. The step of generating the mesh includes setting the first region to be a region in which a region overlaps with a first distance range in a first direction perpendicular to the extension direction of the first center line of the first signal line and a third distance range in a second direction perpendicular to the extension direction of a line obtained by extending the second center line of the second signal line by a second distance from the second end of the second signal line, When the width of the first signal line in the first direction is W1a, the distance between the first signal line and the reference potential pattern in the first direction is W2a, the width of the second signal line in the second direction is W1b, the distance between the second signal line and the reference potential pattern in the second direction is W2b, and A is a constant number and B is a constant number, The first distance is A × W1a + B × W2a, The second distance is A × W1b + B × W2b - W1b / 2, The electromagnetic field analysis program according to any one of claims 1 to 4, wherein the third distance is A × W1b + B × W2b.

9. A coplanar waveguide comprising a dielectric layer, a signal line, and a conductor pattern provided on the dielectric layer having a reference potential pattern provided on the dielectric layer with the signal line in between and spaced apart from the signal line, comprising the steps of generating a mesh such that a first mesh is generated in a first region of a certain width in a direction perpendicular to the direction in which the signal line extends, including the signal line and a part of the reference potential pattern, and no mesh is generated in a second region other than the first region, or a second mesh with a larger dimension than the first mesh is generated, The steps include: performing electromagnetic field analysis of the coplanar waveguide using the aforementioned mesh; Includes, An electromagnetic field analysis method comprising the step of generating the mesh, which includes setting a first region within a certain distance in a direction perpendicular to the extension direction of the center line with respect to the center line of the signal line, and setting a second region outside the certain distance in a direction perpendicular to the center line.

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