DESC:TECHNICAL FIELD
This invention relates to Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) and more particularly to a system and method for ensuring EMC within a system which is comprised of one or more sub-systems.
BACKGROUND OF INVENTION
Technological advancements in electronic devices and systems have transformed every aspect of human life including work, transport, communication and entertainment in the digital era. An electronic device or a system may have different components or sub-systems, which need to be integrated in a proper manner to achieve the desired outcomes. The integration of the various components or sub-systems need to be accomplished in such a manner as to minimize Electromagnetic Interference (EMI) from each other. EMI is the interference caused in an electronic path or circuit by an external source or another component in the system. EMI is caused by the spurious and noise components generated in circuits or sub systems during integration into a system. EMI affects the signal propagation thereby affecting proper functioning of the individual components or the system as a whole. EMI in a system can be radiated EMI or conducted EMI. In radiated EMI, the interference is through air medium whereas in conducted EMI, the interference is through a conductor such as copper.
Electromagnetic compatibility (EMC) on the other hand, is the ability of various components or sub-systems within a system to operate in an electromagnetic environment without adversely affecting the functioning of each other. EMC is achieved by limiting inadvertent generation, propagation and reception of electromagnetic energy by the components. EMC is essentially the act of ensuring system integrity despite the prevalence of EMI. EMC standards ensure that the operation of a device does not disturb other devices or systems adjacent to it. EMC standards specify the acceptable limit of EMI in an electrical or electronic system and regulate selling products with EMI higher than the acceptable limit.
The various components or sub-systems may be supplied by multiple vendors to the manufacturers of a full system. In the conventional systems, EMC of the individual sub-systems may be satisfactory. However, during the stage of final integration of the various individual sub-systems into the full system, the EMC of the full system may not be within the acceptable limit. Detection of noncompliance to the EMC standards at the final stage of development may delay the product launch, thereby causing financial loss to the manufacturers of the full system. Additionally, in case any malfunction of one of the sub-systems or the full system is identified at a later stage after launching of the product, the manufacturers will have to undertake retrofit or recall, which in turn lead to higher financial loss.
Therefore, there is a need for a unique solution that addresses the problem of noncompliance of EMC standards at the final integration stage of full systems.
The above-mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and studying the following specification.
OBJECT OF INVENTION
The principal object of the embodiments herein is to provide a system and method for ensuring EMC to be within acceptable limit in the full system during final EMC compliance test.
Another object of the present invention is to provide a system and method for computing Sub-system Black-Box Emission Model (SSBBEM) comprising conducted noise sources and S/Y/Z port parameters and equivalent electric and magnetic currents on the Surrounding Closed Surface (SCS) outside the sub-system.
Yet another object of the present invention is to predict system-level EMC behaviour, wherein the electromagnetic emissions include conducted emission and radiated emission
Yet another object of the present invention is to provide a system and method for ensuring the EMC of sub-systems to be within permissible limit right from the design phase of sub-systems by the full system manufacturers without compromising the data privacy of the sub-system vendors.
SUMMARY
Accordingly, the embodiments herein provide a system and method for ensuring Electromagnetic Compatibility (EMC) of a full system to be within an acceptable limit. The method includes generating a model at a sub-system-level. Further, a system-level EMC simulation is executed using the model.
Additionally, at the full system-level, a plurality of sub-system models may be combined for performing a system-level EMC simulation.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The example embodiments herein will be better understood from the following description with reference to the drawings, in which:
Figure 1 illustrates a system for ensuring the information of the sub-systems be captured in the system-level using models, without compromising data privacy of sub-system vendors, in accordance with an embodiment of the present invention.
Figure 2 illustrates, a Sub-system Black Box Emission Model (SSBBEM), in accordance with a current source-based model.
Figure 3 illustrates, a Sub-system Black Box Emission Model (SSBBEM), in accordance with a voltage source-based model.
Figure 4 illustrates the placement of the sub-system for model generation, in accordance with an embodiment of the present invention.
Figure 5 illustrates the definition of ports, in accordance with an embodiment of the present invention.
Figure 6 illustrates a voltage source-based model, in accordance with an embodiment of the present invention.
Figure 7 illustrates a current source-based model, in accordance with an embodiment of the present invention.
Figure 8 illustrates a mathematical representation of electric and magnetic current densities on the Surrounding Closed Surface (SCS), in accordance with an embodiment of the present invention.
Figure 9 illustrates measurement-based model parameter computation in terms of S/Y/Z port parameters, in accordance with an embodiment of the present invention.
Figure 10 illustrates measurement-based model parameter computation in terms of conducted noise sources, in accordance with an embodiment of the present invention.
Figures 11a and 11b illustrate measurement-based model parameter computation in terms of equivalent electric and magnetic current density on the Surrounding Closed Surface (SCS), in accordance with an embodiment of the present invention.
Figure 12 illustrates simulation-based model parameter computation in terms of S/Y/Z port parameters, in accordance with an embodiment of the present invention.
Figures 13a and 13b illustrate model usage in system-level simulation, in accordance with an embodiment of the present invention.
Figure 14 illustrates a flow chart showing the generation of SSBBEM through measurement-based and simulation-based approaches, in accordance with an embodiment of the present invention.
Figure 15 illustrates a flow chart showing system-level simulation using SSBBEM, in accordance with an embodiment of the present invention.
Figures 16a, 16b, 16c and 16d illustrate results of circuit-based validation, in accordance with an embodiment of the present invention.
Figures 17a, 17b, 17c, 17d and 17e illustrate an exemplary embodiment of two sub-systems and correlation with measured performance, in accordance with an embodiment of the present invention.
Figures 18a, 18b, 18c, 18d and 18e illustrate an exemplary embodiment of a Device Under Test (DUT) process to correlate the system-level results of a black-box emission model with a white-box model for various sub-system vendor components, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words “retaining”, “connecting”, “charging”, “latching”, “transmitting”, "enabling”, "establishing", “attaching” and other forms thereof, are intended to be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. The terms “comprises,” “comprising,” “has,” “having,” “includes” and/or “including” as used herein, specify the presence of stated features, elements, and/or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The term “an embodiment” is to be read as “at least one embodiment.” The term “another embodiment” is to be read as “at least one other embodiment.” Although any system and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary system and methods are now described.
The disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments described but is to be accorded the widest scope consistent with the principles and features described herein.
There is a need for a unique solution that addresses the problem of noncompliance of EMC standards at the final integration stage of full systems.
The term “model-based full system-level EMI/EMC compliance testing system” refers to “model generator” and can be used interchangeably. Further, the term “model” refers to “data model’’ and can be used interchangeably. Additionally, the term “data privacy’’ can include but not limited to technical design information.
It may be noted that the terms such as terminals, pins, connectors, and receptacles may be referred to as synonyms to each other and are represented as well understood concepts or the conventional terminologies used in the present art of the invention. It may further be noted that the interchangeable use of the terms does not limit the scope of the present invention in any way. In one embodiment, the term “terminals” refers to pins that are used to establish a plurality of connections.
Figure 1 illustrates a system 200 for ensuring the information of the sub-systems be captured in the system-level using models, without compromising data privacy of the sub-system vendors, in accordance with an embodiment of the present invention. The sub-system 1 vendor 202 uses the EMI/EMC compliance testing system 102 to generate model 1 204. The model 1 204 can provide enough information to the full system manufacturer for system-level EMC simulation 206 but cannot be used to regenerate the sub-system 1 design. Similarly, the sub-system 2 vendor 208 uses the EMI/EMC compliance testing system 102 to generate model 2 210. The model 2 210 can provide enough information to the full system manufacturer for system-level EMC simulation 206 but cannot be used to regenerate the sub-system 2 design. The full system as described in the present invention may include but not limited to automotive systems.
Figures 2 and 3 illustrates, a Sub-system Black-Box Emission Model (SSBBEM) 300, in accordance with an embodiment of the present invention. The SSBBEM 300 comprises of a combination of one or more of the following; conducted noise sources 302 and S/Y/Z port parameters 304 and equivalent electric and magnetic currents on the Surrounding Closed Surface (SCS) 306 outside the sub-system.
Figure 4 illustrates placement of the sub-system 402 for model generation in an automotive application 400, in accordance with an embodiment of the present invention. The sub-system 402 is placed on top of a metal plate 404, representing the automotive body. The sub-system 402 is separated from the metal plate 404 by a separator 406 made of an insulating material such as styrofoam as used in an automotive. The distance “d”, which is the distance of the embedded sub-system 402 from the automotive body, may be specified by the full system manufacturer.
Figure 5 illustrates the definition of ports 500 in accordance with an embodiment of the present invention. An electrical port, referred to here as a “port” 502 is a pair of terminals connecting an electrical network or circuit as a point of entry or exit for electrical energy. In the present invention, a port 502 may be defined between each terminal and its corresponding projection on the metal plate 404.
Figure 6 illustrates a voltage source-based model 600 in accordance with an embodiment of the present invention. A mathematical representation of conducted noise sources and impedance is provided as a voltage source-based model with respect to four ports 502. The mathematical description of the system is given by:
[¦(¦(V_1@V_2@V_3 )@V_4 )]=[¦(Z_11&Z_12&Z_13&Z_14@Z_21&Z_22&Z_23&Z_24@Z_31&Z_32&Z_33&Z_34@Z_41&Z_42&Z_43&Z_44 )][¦(¦(I_1@I_2@I_3 )@I_4 )]+[¦(¦(V_1^src@V_2^src@V_3^src )@V_4^src )]
Figure 7 illustrates a current source-based model 700 in accordance with an embodiment of the present invention. A mathematical representation of conducted noise sources and impedance is provided as a current source-based model with respect to four ports 502. The mathematical description of the system is given by:
[¦(¦(I_1@I_2@I_3 )@I_4 )]=[¦(Y_11&Y_12&Y_13&Y_14@Y_21&Y_22&Y_23&Y_24@Y_31&Y_32&Y_33&Y_34@Y_41&Y_42&Y_43&Y_44 )][¦(¦(V_1@V_2@V_3 )@V_4 )]+[¦(¦(I_1^src@I_2^src@I_3^src )@I_4^src )]
Figure 8 illustrates a mathematical representation 800 of electric and magnetic current densities on the Surrounding Closed Surface (SCS) 306 in accordance with an embodiment of the present invention. The electric and magnetic current densities on the SCS 306 may accurately represent the electric or magnetic field radiation emanating from the sub-system 402 inside the SCS using the surface equivalence principle. The SCS may be discretized into several small surface elements characterized by a particular electric and magnetic current density value.
Figure 9 illustrates measurement-based sub-system level model 900 parameter computation in terms of S/Y/Z port parameters, in accordance with an embodiment of the present invention. Multiple conditions need to ensured in the measurement-based model parameter computation. The conditions include the sub-system to be powered OFF and the Vector Network Analyzer (VNA) measurements need to be made with respect to the metal plate 404. The conditions further include L-clamp to be de-embedded for obtaining model S-parameters. The S-parameters can be extracted using VNA measurements, which may be converted to equivalent Y/Z parameters.
Figure 10 illustrates measurement-based sub-system level model 900 parameter computation in terms of conducted noise (voltage or current) sources, in accordance with an embodiment of the present invention. In this embodiment i.e. measurement-based model parameter computation in terms of conducted noise (voltage or current) sources, multiple conditions need to be ensured. The conditions include sub-system 402 to be powered ON and the other cables are kept open except from the cable/port/terminal that is being measured. The conditions further include a Cathode Ray Oscilloscope (CRO) or spectrum analyzer to be used for the measurements with respect to the metal plate 404. The conditions further include L-clamp to be de-embedded for obtaining conducted voltage sources. The conducted voltage sources may be converted to equivalent conducted current sources with the help of the measured S/Y/Z parameters.
Figures 11a and 11b illustrate measurement-based sub-system level model 900 parameter computation in terms of equivalent electric and magnetic current density on the Surrounding Closed Surface (SCS) 306, in accordance with an embodiment of the present invention. The equivalent electric and magnetic currents on the gridded SCS can be obtained through measured near electric and magnetic fields on the grid points, using surface equivalence principle. The said principle yields an equivalent problem for a radiation problem by introducing an imaginary closed surface and fictitious surface current densities. The said principle describes each point on a wavefront as a spherical wave source. The equivalence of the imaginary surface currents may be enforced by the uniqueness theorem in electromagnetism, which states that a unique solution can be determined by fixing a boundary condition on a system. With the appropriate choice of the imaginary current densities, the fields inside the surface or outside the surface may be deduced from the imaginary currents. In a radiation problem with given current density sources, electric current density J and magnetic current density M, the tangential field boundary conditions necessitate that where J and M correspond to the imaginary current sources that are impressed on the closed surface. E and H represent the electric and magnetic fields inside the surface. Both the original and imaginary currents may produce the same external field distributions.
J=n ^×H
M=-n ^×E
In the present embodiment multiple conditions need to be ensured. The conditions include sub-system 402 may be powered ON and the cables may be terminated as per conditions at the system-level. The conditions further include the surface may be in the form on cuboid (as illustrated in fig. 11a and 11b) or in other shapes like a sphere and the discretization of the surface may be in the form of rectangles (as illustrated in fig. 11a and 11b) or in other shapes like a triangle.
In the present embodiment, the electric and magnetic field may be computed at the center of each discretized cell of the SCS. Additionally, the equivalent electric and magnetic current densities on each discretized cell of the SCS may be computed from the measured electric and magnetic fields.
In the present embodiment, generating a measurement-based sub-system level model of EMC 900 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on a Surrounding Closed Surface (SCS) 306, for ensuring EMC is within a predefined limit at the sub-system 402 level, wherein the measurement-based conducted noise sources are at least one of a voltage source-based model and a current source-based model.
Figure 12 illustrates simulation-based sub-system level model 1200 parameter computation in terms of S/Y/Z port parameters, in accordance with an embodiment of the present invention. In this embodiment, multiple conditions need to be ensured. The conditions include sub-system 402 to be powered OFF and the port definition for each cable terminal may be made with respect to the metal plate 404. The conditions further include de-embedding of the delta-gap port for obtaining the model S-parameters, which may be converted to equivalent Y/Z parameters.
In the present embodiment, generating a simulation-based sub-system level model of EMC 1200 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on the SCS 306, for ensuring EMC is within the predefined limit at the sub-system 402 level, wherein the simulation-based conducted noise sources are at least one of a voltage source-based model and a current source-based model.
In another embodiment, the conducted noise sources may be obtained with a similar arrangement as depicted above with the delta-gap connections to the table. In this embodiment multiple conditions need to ensured. The conditions include the sub-system to is simulated with internal IC-noise waveform sources representing a power-ON situation. The conditions further include, when computing the equivalent voltage source-based approach, it may be preferred to keep all the cable terminals open so as to ensure .
[¦(¦(V_1@V_2@V_3 )@V_4 )]=[¦(Z_11&Z_12&Z_13&Z_14@Z_21&Z_22&Z_23&Z_24@Z_31&Z_32&Z_33&Z_34@Z_41&Z_42&Z_43&Z_44 )][¦(¦(I_1@I_2@I_3 )@I_4 )]+[¦(¦(V_1^src@V_2^src@V_3^src )@V_4^src )]
Additionally, the conditions further include when computing the equivalent current source-based approach, it is preferable to keep all the cable terminals connected to metal plate using delta-gaps i.e. . Further, the equivalent conducted current source method may be obtained from the equivalent voltage source-based method and vice-versa.
In yet another embodiment, similar to the measurement-based method, the electric and magnetic field can be simulated at the center of each discretized cell of the SCS 306. A 3D full-wave electromagnetic solver or similar may be employed for this purpose. The rest of the process may be similar to the measurement-based method. In this embodiment, multiple conditions need to be ensured. The conditions include sub-system 402 to be simulated with internal IC-noise waveform sources representing a power-ON situation. The conditions further include the cables to be terminated as per conditions at the system-level using delta-gap connections to the table and the SCS 306 may be in the form on cuboid (as illustrated in figures 11a and 11b) or in other shapes like a sphere. Additionally, the conditions include the discretization of the SCS 306 may be in the form of rectangles (as illustrated in figures 11a and 11b) or in other shapes like a triangle. The obtained model can be parameterized with respect to plurality of parameters such as the spacing between the sub-system and the metallic table.
Figures 13a and 13b illustrate model usage in system-level simulation 1300, in accordance with an embodiment of the present invention. As illustrated in figure 13a, at the system-level, the sub-systems 402 may be embedded together connected by wiring harness and surrounded by the full system geometry. The sub-systems 402 whose internal details are available are kept in their original geometry form. The sub-systems whose internal details are not available may be replaced by their equivalent SSBBEM model 300. As illustrated in figure 13b sub-systems SS1, SS3 and SS4 are replaced by their equivalent SSBBEM while the harness, car-body and the sub-systems with internal layout data available may be retained as intact.
Additionally, when connecting the sub-systems to the system-level environment, the ground node of the S/Y/Z parameters is shorted to the nearest chassis location. The system-level simulation 1300 may be performed in a 3D electromagnetic solver environment.
In the present embodiment, combining at least one of the measurement-based sub-system level models and the simulation-based sub-system level models at the system-level to create a combined system-level representation.
In another embodiment, performing a system-level EMC analysis 1300 using the combined system-level model of EMC for ensuring the EMC to be within a predefined limit at the system level while ensuring data privacy of sub-system vendors 202, 208.
In yet another embodiment, the sub-systems 402 whose internal details are available are kept in their original geometry form.
In yet another embodiment, the sub-systems 402 whose internal details are not available may be replaced by their equivalent sub-system black-box emission model (SSBBEM) 300.
In yet another embodiment, the combined system-level model EMC analysis 1300 is performed in a 3D electromagnetic solver environment.
In yet another embodiment, simulating electromagnetic emissions and interactions among sub-systems using the combined system level model to predict system-level EMC behaviour, wherein the electromagnetic emissions include conducted emission and radiated emission.
In yet another embodiment, ensuring EMC compliance by comparing the simulated system-level results against the predefined EMC limits.
Figure 14 illustrates a flowchart 1400 showing the generation of SSBBEM 300 through measurement-based and simulation-based approaches, in accordance with an embodiment of the present invention. The generation of SSBBEM 300 can be performed by either the sub-system vendor or the full system manufacturer. The sub-system vendor may generate the model and transfer it to the full system manufacturer in order to maintain data privacy and to address intellectual property concerns of the sub-system vendor.
In the simulation-based approach 1400a, step 1402 depicts the import of Printed Circuit Board (PCB) layout and components – Electronic Computer Aided Design (ECAD). In step 1404, the 3D mechanical geometry is imported – Mechanical Computer Aided Design (MCAD). In step 1406, ECAD and MCAD data from steps 1402 and 1404 may be assembled to represent the sub-system. Step 1408 depicts the running of the simulation resulting in the generation of the SSBBEM in step 1410.
In the present embodiment, the entire simulation-based approach 1400a is performed in an electromagnetic simulation environment.
In another embodiment, by executing a simulation 1408 to generate the simulation-based sub-system level model of EMC 1200 comprising conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on the SCS 306.
In the measurement-based approach 1400b, step 1412 depicts the setting up of the physical sub-system. At step 1414, the measurements are performed. Step 1416 depicts performing of necessary mathematical post-processing resulting in the generation of the SSBBEM in step 1410.
In the present embodiment, the mathematical post-processing 1416 to compute the conducted noise sources 302, and equivalent electric and magnetic currents on an SCS 306 includes: powering on the sub-system 402; performing oscilloscope or spectrum analyzer measurements with respect to a metal plate 404 to obtain the conducted noise sources; performing electric and magnetic near-field probing measurements to compute the electric and magnetic fields on an SCS; using surface equivalence principle the equivalent electric and magnetic currents on an SCS 306 are obtained.
In another embodiment, the mathematical post-processing 1416 to compute port parameters 304, includes: powering off the sub-system 402; performing Vector Network Analyzer (VNA) measurements with respect to the metal plate 404; de-embedding of an L-clamp for obtaining model S-parameters; extracting the model S-parameters using the VNA measurements; and converting the model S-parameters to equivalent Y/Z parameters.
In yet another embodiment, the port for measuring of the port parameters 304 is made between any cable coming out of the sub-system with respect to the metal plate 404.
Figure 15 illustrates a flowchart 1500 showing System-level simulation using SSBBEM, in accordance with an embodiment of the present invention. In step 1502, harness, automotive body, cable, geometrical or electrical model may be imported. Checking for inclusion of all sub-systems may be done at step 1504. At step 1506 the availability of internal data for all sub-systems may be checked. This is followed by either import of ECAD or MCAD in the system-level setup at step 1508 or the import of SSBBEM in system-level setup at step 1510. In case all the sub-systems are not included at step 1512, the method proceeds to step 1504 via “No”. Additionally, when all the sub-systems are included at step 1512, the method proceeds to step 1514 via “Yes” and running of system-level analysis may be executed.
Figures 16a, 16b, 16c and 16d illustrate the results of circuit-based validation, in accordance with an embodiment of the present invention. The validation was done with the network as illustrated in figure 16a. PCB 1 and 2 represents the 2 sub-systems under investigation. PCB1 and PCB2 are interconnected by cable-interfaces which are represented as resistors for simplicity. PCB1 may be connected to the Line Impedance Stabilization Network (LISN) with a long cable and may be represented by its inductance and resistance for simplicity.
The SSBBEMs for the 2 PCBs are extracted as illustrated in Figure 16b. The PCB-1 may be represented by the 4 port [Y] parameter to capture the noise transfer from PCB-2 to LISN. I1, I2, I3 and I4 are the extracted noises. PCB2 may be represented by a 2 port Y parameter with associated current sources I5, and I6.
Figures 16c and 16d illustrate current and voltage comparison between full network model and SSBBEM model respectively. The current and voltage comparison at LISN between the full network model and the equivalent model shows a very good match.
Figures 17a and 17b illustrate an exemplary embodiment of two sub-systems - DC-charging controller and DC-DC converter - for correlating measured data with the simulated data, in accordance with an embodiment of the present invention. The DC-charging controller sub-system and the DC converter sub-system in the implementation are illustrated in figures 17c and 17d respectively. An SSBBEM model may be generated for both the sub-systems. The system-level cables may be assembled with the two SSBBEM models for system-level simulation. The correlation between the measured and the model-based predicted results are illustrated in figure 17e.
Figures 18a, 18b, 18c, 18d and 18e illustrate an exemplary embodiment of a Device Under Test (DUT) process to correlate the system-level results of a black-box model with a white-box model for various sub-system vendor components, in accordance with an embodiment of the present invention.
In Figure 18a, a reference board of a DC-DC Buck converter from Texas Instruments (TI) serves as the DUT. In Step 1, a white-box system-level simulation is performed, capturing all internal details and harness connections. In Step 2(a), a black-box model is generated for the DUT by focusing on the input-output behavior of the sub-system. In Step 2(b), the black-box model is embedded into the system-level simulation along with the harness. In Step 3, the simulation results of the black-box model (voltage levels at the LISN) are compared with the original white-box outputs. The close match in the graphical representation confirms the accuracy of the black-box model.
In Figure 18b, a reference board of a PMIC from Infineon (IFX) is used as the DUT. Step 1 involves performing a white-box system-level simulation, capturing all details, including harness connections. Step 2(a) focuses on generating a black-box model based on the PMIC’s external behavior. In Step 2(b), the black-box model is embedded into the system-level simulation along with the harness. Step 3 compares the voltage levels at the LISN from the black-box simulation results with those from the white-box simulation. A close match between the two confirms the accuracy of the black-box model.
In Figure 18c, a reference board of a Boost Converter from Analog Devices (ADI) is the DUT. In Step 1, a white-box system-level simulation is performed, utilizing details of all internal elements and parameters, including inductance, capacitance, and resistance. In Step 2(a), a black-box model is generated for the DUT, focusing on the input-output behavior of the Boost Converter. In Step 2(b), the black-box model is embedded into the system-level simulation along with the harness. In Step 3, the simulation results of the black-box model (voltage levels at the LISN) are compared with the outputs from the original white-box model. The close agreement in results confirms that the black-box model is an accurate representation of the DUT and indicates that detailed internal element information is not required for further simulations.
In Figure 18d, a reference board of an Isolated Boost Converter from Texas Instruments (TI) is the DUT. Step 1 involves performing a white-box system-level simulation, capturing all internal details, including its isolated nature and complex structure, along with the harness and interconnections. In Step 2(a), a black-box model is generated based on the input-output characteristics, such as voltage and current behavior at different terminals. In Step 2(b), the black-box model is embedded into the system-level simulation along with the harness. Step 3 compares the output from the black-box simulation with the white-box simulation results, focusing on parameters like voltage levels at the LISN. This comparison confirms the accuracy of the black-box model through a strong correlation between the results, indicating that it can be effectively used in complex system simulations without requiring internal details.
In Figure 18e, a reference board of a DC-DC Buck Converter from Texas Instruments (TI) is used as DUT-1, and a Boost Converter from Analog Devices (ADI) is used as DUT-2. In Step 1, a white-box system-level simulation is performed, including the harness for both DUT-1 and DUT-2. In Step 2(a), a black-box model is generated for DUT-1, and in Step 2(b), a black-box model is generated for DUT-2. In Step 2(c), the black-box models of DUT-1 and DUT-2 are embedded into the system-level simulation along with the harness. Step 3 compares the output from the black-box simulation with the results from the white-box simulation, focusing on parameters like voltage levels at the LISN. The strong agreement between the results demonstrates that the black-box models can accurately replicate the behavior of the combined system, making them suitable for large-scale simulations without compromising data privacy of sub-system vendors.
An embodiment of the invention may be an article of manufacture in which a machine-readable medium (such as microelectronic memory) has stored thereon instructions which program one or more data processing components (generically referred to here as a “processor”) to perform the operations described above. In other embodiments, some of these operations might be performed by specific hardware components that contain hardwired logic (e.g., dedicated digital filter blocks and state machines). Those operations might alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.
The main advantage of the present invention is that EMC may be ensured to be within acceptable limit in the full system during final EMC compliance test.
Another advantage of the present invention is that EMC of the sub-systems may be ensured to be within permissible limit right from the design phase of sub-systems by the full system manufacturers without compromising the data privacy of the sub-system vendors.
A processor may include one or more general purpose processors (e.g., INTEL® or Advanced Micro Devices® (AMD) microprocessors) and/or one or more special purpose processors (e.g., graphics processing unit (GPU) or digital signal processors or Xilinx® System On Chip (SOC) Field Programmable Gate Array (FPGA) processor), MIPS/ARM class processor, a microprocessor, a digital signal processor, an application specific integrated circuit, a microcontroller, a state machine, or any type of programmable logic array.
A memory may include but is not limited to, non-transitory machine-readable storage devices such as hard drives, magnetic tape, floppy diskettes, optical disks, Compact Disc Read-Only Memories (CD-ROMs), and magnetooptical disks, semiconductor memories, such as ROMs, Random Access Memories (RAMs), Programmable Read-Only Memories (PROMs), Erasable PROMs (EPROMs), Electrically Erasable PROMs (EEPROMs), flash memory, magnetic or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions.
Any combination of the above features and functionalities may be used in accordance with one or more embodiments. In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the scope of the invention, and what is intended by the applicants to be the scope of the invention, is the literal and equivalent scope of the set as claimed in claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction.
In the above description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present systems and methods. It will be apparent the systems and methods may be practiced without these specific details. Reference in the specification to “an example” or similar language means that a particular feature, structure, or characteristic described in connection with that example is included as described but may not be included in other examples.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily configure and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. ,CLAIMS:I/ WE CLAIM:
1. A method for ensuring Electromagnetic Compatibility (EMC) of a system 100, comprising:
generating a measurement-based sub-system level model of EMC 900 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on a Surrounding Closed Surface (SCS) 306, for ensuring EMC is within a predefined limit at the sub-system 402 level, wherein the measurement-based conducted noise sources are at least one of a voltage source-based model and a current source-based model;
generating a simulation-based sub-system level model of EMC 1200 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on the SCS 306, for ensuring EMC is within the predefined limit at the sub-system 402 level, wherein the simulation-based conducted noise sources are at least one of a voltage source-based model and a current source-based model;
combining at least one of the measurement-based sub-system level models and the simulation-based sub-system level models at the system-level to create a combined system-level representation; and
performing a system-level EMC analysis 1300 using the combined system-level model of EMC for ensuring the EMC to be within a predefined limit at the system level while ensuring data privacy of sub-system vendors 202, 208;
wherein the sub-systems 402 whose internal details are available are kept in their original geometry form;
wherein the sub-systems 402 whose internal details are not available may be replaced by their equivalent sub-system black-box emission model (SSBBEM) 300;
wherein the combined system-level model EMC analysis 1300 is performed in a 3D electromagnetic solver environment.
2. The method as claimed in claim 1, further comprising the generation of the measurement-based sub-system level model of EMC 900, comprises:
setting up a physical sub-system 1412;
performing measurements on the sub-system 1414 followed by mathematical post-processing 1416 to compute the conducted noise sources 302, and equivalent electric and magnetic currents on an SCS 306, includes:
powering on the sub-system 402;
performing oscilloscope or spectrum analyzer measurements with respect to a metal plate 404 to obtain the conducted noise sources;
performing electric and magnetic near-field probing measurements to compute the electric and magnetic fields on an SCS;
using surface equivalence principle the equivalent electric and magnetic currents on an SCS 306 are obtained;
performing measurements on the sub-system 1414 followed by mathematical post-processing 1416 to compute port parameters 304, includes:
powering off the sub-system 402;
performing Vector Network Analyzer (VNA) measurements with respect to the metal plate 404;
de-embedding of an L-clamp for obtaining model S-parameters;
extracting the model S-parameters using the VNA measurements; and
converting the model S-parameters to equivalent Y/Z parameters.
3. The method as claimed in claim 1, wherein a port 502 for measuring of the port parameters 304 is made between any cable coming out of the sub-system with respect to the metal plate 404.
4. The method as claimed in claim 1, for generating the simulation-based sub-system level data model of EMC 1200, comprising:
importing an Electronic Computer Aided Design (ECAD) of a PCB layout and components 1402 into an electromagnetic simulation environment;
importing a Mechanical Computer Aided Design (MCAD) of 3D mechanical geometry of the sub-system 1404 into an electromagnetic simulation environment;
assembling the ECAD and MCAD data to represent the sub-system 1406;
executing a simulation 1408 to generate the simulation-based sub-system level model of EMC 1200 comprising conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on the SCS 306.
5. The method as claimed in claim 1, for performing system-level EMC analysis 1300 in the 3D electromagnetic solver environment comprises:
simulating electromagnetic emissions and interactions among sub-systems using the combined system level model to predict system-level EMC behaviour, wherein the electromagnetic emissions include conducted emission and radiated emission;
ensuring EMC compliance by comparing the simulated system-level results against the predefined EMC limits.
6. A system for ensuring Electromagnetic Compatibility (EMC) 100, comprising:
one or more processors; and
one or more memories coupled with the one or more processors, the one or more memories storing programmed instructions that, when executed by the one or more processors, cause the system to:
generate a measurement-based sub-system level model of EMC 900 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on a Surrounding Closed Surface (SCS) 306, for ensuring EMC is within a predefined limit at the sub-system 402 level, wherein the measurement-based conducted noise sources are at least one of a voltage source-based model and a current source-based model;
generate a simulation-based sub-system level model of EMC 1200 including conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on the SCS 306, for ensuring EMC is within the predefined limit at the sub-system 402 level, wherein the simulation-based conducted noise sources are at least one of a voltage source-based model and a current source-based model;
combine at least one of the measurement-based sub-system level models and the simulation-based sub-system level models at the system-level to create a combined system-level representation; and
perform a system-level EMC analysis 1300 using the combined system-level model of EMC for ensuring the EMC to be within a predefined limit at the system level while ensuring data privacy of sub-system vendors 202, 208, wherein the combined system-level model EMC analysis 1300 is performed in a 3D electromagnetic solver environment.
7. The system 100 as claimed in claim 6, wherein the generation of the measurement-based sub-system level model of EMC 900, comprising:
a physical sub-system setup;
one or more instruments to perform measurements on the sub-system to compute the conducted noise sources 302, port parameters 304 including S/Y/Z parameters and equivalent electric and magnetic currents on the SCS 306 for capturing electromagnetic emissions;
a processing unit to perform mathematical post-processing to compute conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on an SCS 306.
8. The system 100 as claimed in claim 6, wherein a port 502 for measuring of the port parameters is made between any cable coming out of the sub-system with respect to the metal plate 404.
9. The system 100 as claimed in claim 6, wherein the generation of the simulation-based sub-system level data model of EMC 1200, comprising:
a processor;
a memory storing program instructions which, when executed by the processor, causes the processor to:
import an Electronic Computer Aided Design (ECAD) of a PCB layout and components into an electromagnetic simulation environment;
import a Mechanical Computer Aided Design (MCAD) of 3D mechanical geometry of the sub-system into an electromagnetic simulation environment;
assemble the ECAD and MCAD data to represent the sub-system 402;
execute a simulation to generate the simulation-based sub-system level model of EMC 1200 comprising conducted noise sources 302, port parameters 304, and equivalent electric and magnetic currents on an SCS 306.
10. The system 100 as claimed in claim 6, for performing system-level EMC analysis 1300 in the 3D electromagnetic solver environment comprises:
a processor;
a memory storing program instructions which, when executed by the processor, causes the processor to:
simulate electromagnetic emissions and interactions among sub-systems using the combined system level model to predict system-level EMC behaviour, wherein the electromagnetic emissions include conducted emission and radiated emission;
ensure EMC compliance by comparing the simulated system-level results against the predefined EMC limits.