Reference plane component, simulation component model library and signal integrity simulation method

Abstract

The invention provides a reference plane component, a simulation component model library and a signal integrity simulation method. The reference plane assembly comprises a feed structure, an ideal electric conductor and de-embedding processing, and the feed structure comprises a first metal base, a coaxial probe and a coaxial insulator; the ideal electric conductor comprises a first surface and a second surface which are opposite to each other, and a feed hole corresponding to the position of a first target signal transmission port of the initial signal simulation model; and when the first target signal transmission port is an input end, the de-embedding processing is set based on the upper surface of the coaxial insulator. The method solves the problem that in the field of high-speed design, accurate calculation of port impedance and correct simulation of a signal path are difficult to guarantee due to the fact that signal integrity simulation of a reference backflow plane model is not provided, and the accuracy of signal integrity simulation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of signal simulation, and in particular to a reference surface component, a simulation component model library, and a signal integrity simulation method. Background Art

[0002] Signal integrity simulation is a process of simulating the signal quality in an electronic system through computer engineering software. It focuses on the impact of various interferences on the signal quality during the transmission process, so as to quickly locate problems and optimize solutions to improve research and development efficiency. The simulation process is as follows: model establishment--stackup setting--boundary condition setting--excitation port setting--simulation solution--result analysis--design optimization.

[0003] For the signal to be simulated, when setting the excitation port, it is necessary to find a return plane as the reference plane in the signal transmission process. Usually, the ground plane or power plane that is close to the signal line and relatively complete in the design is used as the reference plane to establish the return path and set the simulation port. However, for some cases that do not have a reference return plane model due to design limits and high-speed connectors, such as in the field of high-speed design, it is usually difficult to ensure the accurate calculation of port impedance and correct simulation of signal paths without a reference plane that meets ideal conditions, which reduces the accuracy of signal integrity simulation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a reference plane component, a simulation component model library, and a signal integrity simulation method, which solves the problem that in the signal integrity simulation in the field of high-speed design, it is difficult to ensure the accurate calculation of port impedance and the correct simulation of signal path, which reduces the accuracy of signal integrity simulation.

[0005] According to an embodiment of the present invention, a first aspect provides a reference surface assembly, comprising: A feeding structure comprises a first metal base, a coaxial probe and a coaxial insulator; the lower surface of the first metal base is electrically connected to a first target signal transmission port of an initial signal simulation model, the coaxial probe passes through the coaxial insulator, the upper surface of the coaxial insulator and the lower surface of the coaxial insulator are flush with the upper surface of the coaxial probe and the lower surface of the coaxial probe respectively, and the lower surface of the coaxial probe and the lower surface of the coaxial insulator are in contact with the upper surface of the first metal base; An ideal electric conductor comprises a first surface and a second surface facing each other, and a feeding hole corresponding to the position of the first target signal transmission port; the coaxial insulator is tightly embedded in the feeding hole, the vertical center axis of the coaxial insulator is parallel to the vertical center axis of the ideal electric conductor, and the upper surface of the coaxial insulator and the lower surface of the coaxial insulator are flush with the first surface of the ideal electric conductor and the second surface of the ideal electric conductor respectively; De-embedding processing, wherein the de-embedding processing is set based on the upper surface of the coaxial insulator when the first target signal transmission port is an input port.

[0006] Optionally, a second metal base is also included; The lower surface of the second metal base is electrically connected to the second target signal transmission port of the initial signal simulation model, and the upper surface of the second metal base is electrically connected to the second surface of the ideal electrical conductor.

[0007] Optionally, the second metal base has the same material properties as the second target signal transmission port, and the vertical central axis of the second metal base coincides with the geometric center point of the second target signal transmission port and is perpendicular to the plane where the second target signal transmission port is located.

[0008] Optionally, the first metal base has the same material properties as the first target signal transmission port, and the vertical central axis of the first metal base coincides with the geometric center point of the first target signal transmission port and is perpendicular to the plane where the first target signal transmission port is located.

[0009] Optionally, the coaxial probe is in the shape of a cylinder, and the coaxial insulator is in the shape of a cylinder; The diameter of the coaxial probe is 1 / 5 of the diameter of the coaxial insulator.

[0010] Optionally, the material properties of the coaxial probe are the same as the material properties of the ideal electrical conductor.

[0011] Optionally, the material properties of the coaxial insulator are set according to the material properties of the ideal electrical conductor and an impedance matching condition.

[0012] Optionally, the de-embedding process is provided on the upper surface of the coaxial insulator, comprising: A de-embedding distance from the upper surface of the coaxial insulator to the first target signal transmission port is defined.

[0013] A second aspect provides a simulation component model library, which stores the above-mentioned reference surface component; and also includes a component data folder and an interactive data structure file corresponding to the reference surface component; The component data folder includes: a model concept document of a simulation component, a model design document of a simulation component, a model description file of a reusable simulation component, and a model executable file of a reusable simulation component, wherein the model executable file includes a model configuration menu for adjusting parameters of the reference surface component; The interaction data structure file is used to store the interaction data structure for calling the reference surface component.

[0014] A third aspect provides a signal integrity simulation method, comprising: When receiving the simulation instruction, obtaining the initial signal simulation model of the device under test and setting the simulation conditions; the simulation conditions at least include the excitation port and the boundary conditions; Before setting the excitation port and boundary conditions, if the excitation port to be set in the simulation condition is a wave port, searching for a return flow plane that meets preset conditions based on the initial signal simulation model; When a return plane that meets the preset conditions is not found, the above-mentioned simulation component model library is called to obtain a reference surface component, and an equivalent signal simulation model is obtained based on the initial signal simulation model and the reference surface component to set the excitation port and boundary conditions according to the equivalent signal simulation model.

[0015] Optionally, obtaining an equivalent signal simulation model based on the initial signal simulation model and the reference plane component includes: Acquire a first target signal transmission port, a second target signal transmission port, and an impedance matching condition in the initial signal simulation model; The number of feeding structures in the reference plane component is set according to the number of the first target signal transmission ports, and the number of second metal bases in the reference plane component is set according to the number of the second target signal ports; Setting the material properties of the feeding structure and the material properties of the second metal base according to the impedance matching condition; An electrical connection is established between the first target signal transmission port and the feeding structure, and an electrical connection is established between the second target signal transmission port and the second metal base to obtain the equivalent signal simulation model.

[0016] Optionally, setting boundary conditions according to the equivalent signal simulation model includes: Create a radiation boundary coincident with the waveport face.

[0017] Optionally, setting an excitation port according to the equivalent signal simulation model includes: If the first target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports, and the feeding structure includes a de-embedding process; If the second target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports.

[0018] The reference plane component provided by the present invention is different from the structure of the initial signal simulation model. It is a newly constructed reference plane that meets ideal conditions. It avoids the situation in the field of high-speed design where the reference plane around the signal cannot be designed due to design limit restrictions, ensures the accurate calculation of port impedance and correct simulation of signal path, and improves the accuracy of signal integrity simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a reference surface assembly according to an embodiment of the present invention; Figure 2 for Figure 1 Structural schematic diagram of the mid-feed structure; Figure 3 for Figure 1 Schematic diagram of the structure of an ideal electrical conductor; Figure 4 A schematic diagram of the combined relationship between an ideal electric conductor and a feeding structure according to an embodiment of the present invention; Figure 5 A schematic diagram of de-embedding processing in an embodiment of the present invention; Figure 6 A schematic diagram of the composition structure of a simulation component model library according to an embodiment of the present invention; Figure 7 for Figure 6 Schematic diagram of component data folders and interactive data structure files; Figure 8 Schematic diagram of the implementation process of the signal integrity simulation method according to an embodiment of the present invention; Fig. 9 It is a front view of a partial signal model of a simulated circuit captured based on an embodiment of the present invention; Fig.10 A side view of a partial signal model of a simulated circuit captured based on a high-speed circuit according to an embodiment of the present invention; Fig.11 It is a structural schematic diagram of an equivalent signal simulation model according to an embodiment of the present invention; Fig.12 It is a side view of an equivalent signal simulation model of an embodiment of the present invention; Fig.13 The simulation result of the differential signal return loss S11 of the embodiment of the present invention; Fig.14 The simulation result of the differential signal insertion loss S21 of the embodiment of the present invention; Fig.15 This is a simulation result of differential signal impedance of an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0021] like Figures 1 to 5 As shown, an embodiment of the present invention proposes a reference plane component for providing a reference plane that meets ideal conditions as a return plane in signal integrity simulation, especially in signal integrity simulation in the field of high-speed design, to ensure accurate calculation of port impedance and correct simulation of signal path, thereby improving the accuracy of signal integrity simulation. Figure 1 In the embodiment, the reference plane component 100 includes: a feed structure 10 and an ideal electric conductor 20. The influence of the reference plane component on the accuracy of the simulation result is eliminated to a certain extent by de-embedding. In a specific application, the number of the feed structures 10 is set according to the structure of the initial signal simulation model; and the de-embedding process is set according to the specific situation when the excitation port is set.

[0022] The embodiment of the present invention is Figures 2 to 5 The detailed structures of the above-mentioned feeding structure 10 and the ideal electric conductor 20 as well as the setting method of the de-embedding process are described.

[0023] like Figure 2 As shown, in the embodiment of the present invention, the feeding structure 10 includes a first metal base 11 , a coaxial probe 12 and a coaxial insulator 13 . Figure 2 The combined state of the above three structures is shown, wherein the lower surface of the first metal base 11 is used to be electrically connected to the first target signal transmission port of the initial signal simulation model, the coaxial probe 12 passes through the coaxial insulator 13, the upper surface of the coaxial insulator 13 and the lower surface of the coaxial insulator 13 are flush with the upper surface of the coaxial probe 12 and the lower surface of the coaxial probe 13 respectively, and the lower surface of the coaxial probe 12 and the lower surface of the coaxial insulator 13 are in contact with the upper surface of the first metal base 11.

[0024] It should be noted that the coaxial probe and the coaxial insulator refer to a probe and an insulator whose vertical center axes coincide with each other, and the upper surface and the lower surface in the embodiment of the present invention refer to two relative surfaces, such as the upper surface of the first metal base and the lower surface of the first metal base, the upper surface of the coaxial probe and the lower surface of the coaxial probe, and the upper surface of the coaxial insulator and the lower surface of the coaxial insulator, which are all two relative surfaces.

[0025] It should be noted that the first target signal transmission port is the port of the signal line to be simulated or the surface of the via pad. Therefore, in the embodiment of the present invention, the feeding structure is electrically connected to the first target signal transmission port to complete the setting of the port excitation in the simulation conditions. Figure 1The reference plane assembly shown is exemplarily applied to an initial signal simulation model using a double-ended transmission line. In this initial signal simulation model, at least two signal lines to be simulated are included. Therefore, the number of the first target signal transmission ports is two. Figure 1 It can be understood that if the initial signal simulation model uses a single-ended transmission line, the number of the first target signal transmission port is one, and then Figure 1 The number of the middle feed structure is also one.

[0026] In addition, the initial signal simulation model also includes a port or via pad surface of a signal line that is not used for simulation, which is a second target signal transmission port in the embodiment of the present invention, and a second metal base is provided to establish a connection between the reference surface component and the initial signal simulation model to ensure the integrity of the simulation signal. Exemplarily, the lower surface of the second metal base is electrically connected to the second target signal transmission port of the initial signal simulation model, and the upper surface of the second metal base is electrically connected to the second surface of the ideal electrical conductor. In addition, in a preferred implementation, the second metal base has the same material properties as the second target signal transmission port, and the vertical center axis of the second metal base coincides with the geometric center point of the second target signal transmission port and is perpendicular to the plane where the second target signal transmission port is located.

[0027] for Figure 2 The feeding structure shown in the figure, in one embodiment, to ensure the consistency and stability of the signal, the coaxial probe is in the shape of a cylinder, and the coaxial insulator is in the shape of a cylinder; the diameter of the coaxial probe is 1 / 5 of the diameter of the coaxial insulator, and the geometric center of the lower surface of the coaxial probe is aligned with the geometric center of the upper surface of the first metal base. In one embodiment, to ensure impedance matching, the material properties of the coaxial probe are the same as the material properties of the ideal conductor. In addition, in order to meet the different impedance requirements for different devices in the system, the material properties of the coaxial insulator are set according to the material properties of the ideal conductor and the impedance matching conditions. In addition, in a better implementation, the material properties of the first metal base are the same as those of the first target signal transmission port, and the vertical center axis of the first metal base coincides with the geometric center point of the first target signal transmission port and is perpendicular to the plane where the first target signal transmission port is located to restore the signal transmission path. Among them, material properties include but are not limited to material, dielectric constant, dielectric loss factor, conductivity, etc.

[0028] like Figure 3 As shown, in the embodiment of the present invention, the ideal electric conductor 20 includes a first surface 21 and a second surface 22 facing each other, and a feeding hole 23 corresponding to the position of the first target signal transmission port of the initial signal simulation model. Figure 4As shown, the relationship between the ideal electric conductor 20 and the feeding structure 10 is: the coaxial insulator 13 is tightly embedded in the feeding hole 23, the vertical center axis of the coaxial insulator 13 is parallel to the vertical center axis of the ideal electric conductor 20, the upper surface of the coaxial insulator 13 and the lower surface of the coaxial insulator 13 are respectively flush with the first surface 21 of the ideal electric conductor 20 and the second surface 22 of the ideal electric conductor, and it can be understood that the coaxial probe 12 passes through the coaxial insulator 13, the upper surface of the coaxial insulator 13 and the lower surface of the coaxial insulator 13 are respectively flush with the upper surface of the coaxial probe 12 and the lower surface of the coaxial probe 12, then the upper surface of the coaxial probe 12 and the lower surface of the coaxial probe 12 are also flush with the first surface 21 and the second surface 22.

[0029] The embodiment of the present invention is applicable to the port excitation of the wave port, therefore, an ideal electric conductor is used as the reference boundary, and its notable feature is that the electric field is vertically distributed on the surface, which can effectively reduce the radiation of the signal to the rear, thereby enhancing its radiation energy. In addition, it should be noted that the reference plane component provided by the embodiment of the present invention is a reference plane that meets ideal conditions and is newly constructed from the original structure of the initial signal simulation model in the signal integrity simulation, and the above-mentioned feeding structure and the second metal base are both constructed based on the above-mentioned ideal electric conductor.

[0030] In the embodiment of the present invention, the de-embedding process is set according to the specific situation when the initial signal simulation model sets the excitation port. Since the setting of the port excitation in the simulation condition is completed by the feeding structure in the embodiment of the present invention, the feeding structure is electrically connected to the first target signal transmission port. Therefore, the above-mentioned specific situation includes that when setting the excitation port, if the first target signal transmission port as the transmission line port is the input port, it is necessary to perform the de-embedding process based on the upper surface of the coaxial insulator; if the first target signal transmission port as the transmission line port is the output port, it is not necessary to perform the de-embedding process based on the upper surface of the coaxial insulator.

[0031] In specific applications, de-embedding can eliminate the influence of the reference plane components on the accuracy of simulation results to a certain extent and maintain the actual path of signal transmission. Figure 5 As shown, the de-embedding process is set on the upper surface of the coaxial insulator 13, including: defining a de-embedding distance from the upper surface of the coaxial insulator 13 to the first target signal transmission port; wherein the upper surface end face of the coaxial insulator 13 is represented by a shadow filled with horizontal lines; the center of the first target signal transmission port is on the central axis of the coaxial probe 12, therefore, it can be understood that, Figure 5The pointing arrow in coincides with the central axis of the coaxial probe 12. It should be noted that, under the same conditions, that is, when the first target signal transmission port is the input port, if the number of the above-mentioned feeding structures is at least two according to the structure of the initial signal simulation model, the above-mentioned de-embedding process will be performed on each coaxial insulator.

[0032] The reference plane assembly provided by the embodiment of the present invention is applied to the field of high-speed design, especially in the signal integrity simulation where the excitation port needs to be a wave port, including but not limited to single-ended transmission lines, differential signal pairs, via pads, etc. The reference plane assembly of the embodiment of the present invention provides a reference plane that meets ideal conditions as a return plane, avoiding the situation where the reference plane around the signal cannot be designed due to design limit restrictions, and on the one hand, ensures accurate calculation of port impedance to ensure that impedance matching conditions are met and correct simulation of signal paths to improve the accuracy of signal integrity simulation; on the other hand, it can also ensure efficient transmission of signals, reduce electromagnetic interference, and meet different impedance matching conditions of various systems at the same time.

[0033] Another embodiment of the present invention further provides a simulation component model library, which stores the above-mentioned reference surface components. Figure 6 As shown, a simulation component model library 60 also includes a component data folder 61 and an interactive data structure file 62 corresponding to the reference surface component. The component data folder 61 includes: a model concept document of the simulation component, a model design document of the simulation component, a model description file of the reusable simulation component, and a model executable file of the reusable simulation component. The model executable file includes a model configuration menu for adjusting the parameters of the reference surface component. The interactive data structure file 62 is used to store the interactive data structure for calling and adjusting the reference surface component. Figure 7 As shown, it is assumed that the model library stores four models A, B, C, and D for signal integrity simulation. For example, model A is a reference plane component, model B is a transmission line model, model C is a digital I / O buffer, and model D is a memory. Therefore, it includes component data folders a, b, c, and d of the four models A, B, C, and D. Each component data folder includes three files, namely, a model concept document of the simulation component, a model design document of the simulation component, and a model description file of the reusable simulation component, as well as a folder for the model executable file of the reusable simulation component.

[0034] For example, if component data folder a is a component data folder of a reference plane component, the model configuration menu in the model executable file is used to adjust the parameters of the reference plane component, including but not limited to: the number of feed structures, the number of second metal bases, the diameter of the coaxial probe, the diameter of the coaxial insulator, the material properties of the coaxial probe, the material properties of the coaxial insulator, the material properties of the first metal base, the material properties of the second metal base, the positional relationship between the first metal base and the coaxial probe and the coaxial insulator, the position of the second metal base, whether to include de-embedding processing, etc. Exemplarily, the model configuration menu shown in the following table shows some parameters, such as the material properties of the first metal base, the coaxial probe, and the coaxial insulator in the feed structure, and the material properties of the second metal base. In addition, the material properties of the PCB board-level model in the initial signal simulation model are also shown.

[0035]

[0036] like Figure 8 As shown, another embodiment of the present invention further provides a signal integrity simulation method, comprising: S801, upon receiving a simulation instruction, obtaining an initial signal simulation model of the device under test and setting simulation conditions; the simulation conditions at least include an excitation port and boundary conditions; S802, before setting the excitation port and boundary conditions, if the excitation port to be set in the simulation condition is a wave port, searching for a reflow plane that meets preset conditions based on the initial signal simulation model; S803. When a return plane that meets the preset conditions is not found, the above-mentioned simulation component model library is called to obtain a reference surface component, and an equivalent signal simulation model is obtained based on the initial signal simulation model and the reference surface component to set an excitation port and boundary conditions according to the equivalent signal simulation model.

[0037] For the above step S801, in a specific application, the simulation conditions include but are not limited to model establishment, stacking setting, radiation boundary setting, excitation port setting, simulation solution, result analysis, and design optimization. Since the embodiment of the present invention improves the signal integrity simulation part, only the setting of the excitation port and the radiation boundary is shown in the above step S801, and other simulation conditions are set according to the simulation requirements of the device under test. It should be noted that in the above step S801, the initial signal simulation model is a signal simulation model pre-established based on the device under test, so the model establishment in the signal simulation condition has been completed.

[0038] For the above step S802, the embodiment of the present invention improves the signal integrity simulation in the field of high-speed design. Based on this usage scenario, the excitation port to be set in the simulation condition is a wave port. Therefore, the above step S802 determines whether to call the simulation component model library to obtain the reference surface component according to the port type of the excitation port to be set in the simulation condition and whether the initial signal simulation model has a return plane that meets the preset conditions, and then obtains the equivalent signal simulation model. Among them, judging whether the initial signal simulation model has a return plane that meets the preset conditions according to the reference surface with ideal conditions, Exemplarily, according to the structure of the initial signal simulation model, the excitation port to be set usually includes a wave port and a lumped port. Exemplarily, the preset condition is a relatively complete ground plane or power plane that is close to the signal line. In a specific application, if there is no return plane that meets the preset conditions, it is usually impossible to design a reference plane around the signal due to design limit restrictions.

[0039] In the above step S803, the equivalent signal simulation model is obtained based on the initial signal simulation model and the reference surface component, which is a structure that uses the reference surface component as a newly constructed structure of the initial signal simulation model. Finally, in the equivalent signal simulation model, the reference surface component is used as a reference surface of the initial signal simulation model. The implementation steps of the above step S803 include: S8031, obtaining a first target signal transmission port, a second target signal transmission port and an impedance matching condition in the initial signal simulation model; S8032. Set the number of feeding structures in the reference plane component according to the number of the first target signal transmission ports, and set the number of second metal bases in the reference plane component according to the number of the second target signal ports; S8033. Set the material properties of the feeding structure and the material properties of the second metal base according to the impedance matching condition; S8034. Establish an electrical connection between the first target signal transmission port and the feeding structure, establish an electrical connection between the second target signal transmission port and the second metal base, and obtain the equivalent signal simulation model.

[0040] For the above step S8031, the initial signal simulation model is a signal simulation model pre-established based on the device under test, based on which, the above step S8031 can directly obtain the first target signal transmission port, the second target signal transmission port and the impedance matching condition, wherein the first target signal transmission port is the port of the signal line to be simulated or the surface of the via pad, and correspondingly, the second target signal transmission port is the port of the signal line to be simulated or the surface of the via pad.

[0041] For the above steps S8032 and S8033, the material properties of the feeding structure include the material properties of the first metal base, the coaxial probe and the coaxial insulator, and according to the above embodiment, the material properties of the coaxial probe are the same as the material properties of the ideal electrical conductor, and the material properties of the coaxial insulator are set according to the material properties of the ideal electrical conductor and the impedance matching conditions.

[0042] For the above step S8034, the embodiment of the present invention also eliminates the influence of the introduction of the reference plane component on the accuracy of the simulation result to a certain extent through the de-embedding process, and maintains the actual path of the signal transmission. It should be noted that since the feeding structure is the setting object of the port excitation in the simulation condition, the de-embedding process is set based on the feeding structure connected to the first target signal transmission port of the equivalent signal simulation model, and is set according to the specific situation when the excitation port is set according to the initial signal simulation model, that is, according to the specific situation of the first target signal transmission port. Then, setting the excitation port according to the equivalent signal simulation model in the above step S803 includes: If the first target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports, and the feeding structure includes a de-embedding process; If the second target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports.

[0043] In the embodiment of the present invention, the excitation port to be set in the simulation condition is a wave port. Therefore, in the above step S803, setting the boundary condition according to the equivalent signal simulation model includes: Create a radiation boundary coincident with the waveport face.

[0044] It should be noted that when the first target signal transmission port and the second target signal transmission port are set as wave ports, the wave port surface is the upper surface of the coaxial insulator in the feeding structure, that is, the surface flush with the first surface of the ideal conductor.

[0045] like Figures 9 to 12 As shown, in another embodiment of the present invention, taking a high-speed circuit using a pair of differential signal lines as an example, the above-mentioned signal integrity simulation method and the reference plane component called by the signal integrity simulation method in the simulation component model library are explained.

[0046] like Figures 9 and 10As shown in FIG. 1 , a partial signal model of a simulated circuit is captured based on a high-speed circuit, and the embodiment of the present invention performs signal integrity simulation based on the simulated signal model. This circuit model is a connector with a slotted design at the signal line, and the maximum operating frequency is 25 GHz. Since the simulated signal line M1 or the via pad also includes pins M2, vias M3, etc., there is no reflow reference plane, which satisfies the condition that the reflow plane that meets the preset conditions is not found as shown in the above steps S801 and S802. Therefore, according to the above step S803, the reference plane component in the above embodiment is used to establish a reference plane based on the original high-speed circuit, and the following is obtained: Fig.11 The equivalent signal simulation model shown is Fig.11 Part of the feeding structure 10 , the ideal electric conductor 20 and part of the second metal base 30 are marked.

[0047] According to steps S8031 to S8034 shown in the above signal integrity simulation method, the specific operation process is as follows: First, call the reference plane component in the simulation component model library, set the appropriate material system and configuration, and set the parameters through the model configuration menu so that the final reference plane component meets the requirement of 100Ω differential signal impedance, the number of feeding structures for double-ended transmission lines, and the number of second metal bases for differential signal pairs.

[0048] Then, when creating a radiation boundary, it is used to simulate the electromagnetic environment outside the simulation model and define the boundary conditions of the simulation to ensure that the simulation results reflect the behavior of the actual model in the external air as much as possible. By creating a radiation boundary, the transmission of the signal can be better simulated, so as to more accurately analyze the signal integrity problem. Fig.12 As shown, since the excitation port used in this example is a wave port, the radiation boundary R1 is set to coincide with the wave port surface, that is, the radiation boundary R1 coincides with the plane where the upper surface of the coaxial insulator 13 is located.

[0049] Secondly, when setting the excitation port: In this simulation model, a pair of differential signal pairs to be simulated is selected, and the signal pairs are output from a certain layer of the board after passing through the transmission path from the board surface. The excitation port of the differential signal pair input end is set as follows, using a wave port, and the port is de-embedded; at the same time, the excitation port of the differential signal pair output end is set as follows, using a wave port; the two signal lines at the input and output ends are set as differential ports respectively.

[0050] In addition, other simulation conditions, such as solver settings, are exemplified as follows: using the default interpolation frequency sweep method in the software, setting the simulation frequency band to 10 MHz to 50 GHz, and setting the simulation step size to 10 MHz.

[0051] Finally, the simulation results obtained by frequency sweep simulation are as follows Figures 13 to 15As shown, Fig.13 is the simulation result of differential signal return loss S11, Fig.13 The horizontal axis is the frequency in GHz, and the vertical axis is the return loss S11 in dB; Fig.14 This is the simulation result of differential signal insertion loss S21. Fig.14 The horizontal axis is the frequency in GHz, and the vertical axis is the return loss S12 in dB; Fig.15 is the differential signal impedance simulation result, Fig.15 The horizontal axis is time, the unit is ps, and the vertical axis is impedance, the unit is Ω. Fig.13 Point m1 in the graph indicates that the return loss S11 is maintained below -16.48 dB within the 25 GHz frequency band; Fig.14 Point m1 indicates that the insertion loss S21 is maintained within 0.66dB within the 25GHz frequency band; Fig.15 , in both transmission directions of the differential signal, the impedance is maintained at 93ohm~101.5ohm, which meets the tolerance range of 100ohm±10%. In summary, the key simulation parameters all meet the requirements. It can be seen that the embodiments of the present invention provide a practical reference plane that meets ideal conditions for the field of high-speed design, especially in the signal integrity simulation where the excitation port needs to be a wave port, and avoids the situation where the reference plane around the signal cannot be designed due to design limit restrictions. From the simulation results, it can be seen that this signal integrity simulation method and reference plane component, on the one hand, ensure the accurate calculation of the port impedance to ensure that the impedance matching conditions are met and ensure the correct simulation of the signal path to improve the accuracy of the signal integrity simulation. On the other hand, it can also ensure the efficient transmission of the signal and reduce electromagnetic interference, while meeting the different impedance requirements of different devices in each system and meeting the impedance matching conditions.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A reference surface assembly, characterized in that: include: A feeding structure comprises a first metal base, a coaxial probe and a coaxial insulator; the lower surface of the first metal base is electrically connected to a first target signal transmission port of an initial signal simulation model, the coaxial probe passes through the coaxial insulator, the upper surface of the coaxial insulator and the lower surface of the coaxial insulator are flush with the upper surface of the coaxial probe and the lower surface of the coaxial probe respectively, and the lower surface of the coaxial probe and the lower surface of the coaxial insulator are in contact with the upper surface of the first metal base; An ideal electric conductor comprises a first surface and a second surface facing each other, and a feeding hole corresponding to the position of the first target signal transmission port; the coaxial insulator is tightly embedded in the feeding hole, the vertical center axis of the coaxial insulator is parallel to the vertical center axis of the ideal electric conductor, and the upper surface of the coaxial insulator and the lower surface of the coaxial insulator are flush with the first surface of the ideal electric conductor and the second surface of the ideal electric conductor respectively; De-embedding processing, wherein the de-embedding processing is set based on the upper surface of the coaxial insulator when the first target signal transmission port is an input port.

2. The reference surface assembly according to claim 1, characterized in that Also included is a second metal base; The lower surface of the second metal base is electrically connected to the second target signal transmission port of the initial signal simulation model, and the upper surface of the second metal base is electrically connected to the second surface of the ideal electrical conductor.

3. The reference surface assembly according to claim 2, characterized in that The second metal base has the same material properties as the second target signal transmission port, and the vertical central axis of the second metal base coincides with the geometric center point of the second target signal transmission port and is perpendicular to the plane where the second target signal transmission port is located.

4. The reference surface assembly according to claim 1, wherein: The first metal base has the same material properties as the first target signal transmission port, and the vertical central axis of the first metal base coincides with the geometric center point of the first target signal transmission port and is perpendicular to the plane where the first target signal transmission port is located.

5. The reference surface assembly of claim 1, wherein: The coaxial probe is in the shape of a cylinder, and the coaxial insulator is in the shape of a cylinder; The diameter of the coaxial probe is 1 / 5 of the diameter of the coaxial insulator.

6. The reference surface assembly of claim 1, wherein: The material properties of the coaxial probe are the same as the material properties of the ideal electrical conductor.

7. The reference surface assembly of claim 1, wherein: The material properties of the coaxial insulator are set according to the material properties of the ideal electrical conductor and impedance matching conditions.

8. The reference surface assembly according to any one of claims 1 to 7, characterized in that The de-embedding process is provided based on the upper surface of the coaxial insulator, comprising: A de-embedding distance from the upper surface of the coaxial insulator to the first target signal transmission port is defined.

9. A simulation component model library, characterized in that: The reference surface component according to any one of claims 1 to 8 is stored; and the component data folder and the interactive data structure file corresponding to the reference surface component are also included; The component data folder includes: a model concept document of a simulation component, a model design document of a simulation component, a model description file of a reusable simulation component, and a model executable file of a reusable simulation component, wherein the model executable file includes a model configuration menu for adjusting parameters of the reference surface component; The interaction data structure file is used to store the interaction data structure for calling the reference surface component.

10. A signal integrity simulation method, characterized in that: include: When receiving the simulation instruction, obtaining the initial signal simulation model of the device under test and setting the simulation conditions; the simulation conditions at least include the excitation port and the boundary conditions; Before setting the excitation port and boundary conditions, if the excitation port to be set in the simulation condition is a wave port, searching for a return flow plane that meets the preset conditions based on the initial signal simulation model; When a return plane that meets the preset conditions is not found, the simulation component model library as described in claim 9 is called to obtain a reference surface component, and an equivalent signal simulation model is obtained based on the initial signal simulation model and the reference surface component to set the excitation port and boundary conditions according to the equivalent signal simulation model.

11. The signal integrity simulation method according to claim 10, characterized in that: Obtaining an equivalent signal simulation model based on the initial signal simulation model and the reference plane component, comprising: Acquire a first target signal transmission port, a second target signal transmission port, and an impedance matching condition in the initial signal simulation model; The number of feeding structures in the reference plane component is set according to the number of the first target signal transmission ports, and the number of second metal bases in the reference plane component is set according to the number of the second target signal ports; Setting the material properties of the feeding structure and the material properties of the second metal base according to the impedance matching condition; An electrical connection is established between the first target signal transmission port and the feeding structure, and an electrical connection is established between the second target signal transmission port and the second metal base to obtain the equivalent signal simulation model.

12. The signal integrity simulation method according to claim 10, characterized in that: Setting boundary conditions according to the equivalent signal simulation model includes: Create a radiation boundary coincident with the waveport face.

13. The signal integrity simulation method according to claim 10, characterized in that: Setting the excitation port according to the equivalent signal simulation model includes: If the first target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports, and the feeding structure includes a de-embedding process; If the second target signal transmission port is an input port, the first target signal transmission port and the second target signal transmission port are set as wave ports.

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