A method and system for extracting s parameters of microwave passive devices

Abstract

This invention discloses a method and system for extracting S-parameters of microwave passive devices, comprising: geometrically modeling the microwave passive device and then meshing it to obtain a processed device model; discretizing the processed device model according to basis functions, and performing mode function expansion on the ports of the processed device model to establish a transfinite element matrix equation; performing partial LU decomposition of the system matrix in the transfinite element matrix equation using the multi-wavefront method to obtain the Schur complement matrix of the system matrix and the decomposed system matrix; obtaining the dense S-parameter matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix; and solving the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device. This invention effectively reduces the memory usage of matrix calculations and reduces computation time.

Description

Technical Field

[0001] This invention belongs to the field of microwave device simulation and numerical calculation optimization, specifically involving a method and system for extracting S-parameters of microwave passive devices. Background Technology

[0002] Calculating S-parameters is a crucial step in the simulation and design of microwave passive devices, and its computational efficiency directly impacts the product development iteration cycle. In computational electromagnetics, for large-scale or complex models, the finite element method generates a large number of mesh nodes and unknowns when discretizing the model, resulting in an extremely large matrix size. To efficiently calculate the S-parameters of devices with limited computational resources, optimizing the solution process is key. Existing electromagnetic superfinite element methods and finite element methods commonly employ a direct solution to the sparse matrix when calculating the S-parameters of microwave passive devices. This involves a complete matrix decomposition, storing all L (lower triangular matrix) and U (upper triangular matrix) decomposition factors during the decomposition process, and then calculating the field distribution of the entire solution domain through forward and backward substitution. This results in the storage of a large number of unnecessary LU decomposition factors during the matrix decomposition process when only the S-parameters need to be solved, significantly increasing memory usage and limiting the scale of problems that can be solved. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a method and system for extracting S-parameters of microwave passive devices.

[0004] The technical problem to be solved by this invention is achieved through the following technical solution: In a first aspect, the present invention provides a method for extracting S-parameters of microwave passive devices, the method comprising: performing geometric modeling of the microwave passive device followed by mesh generation to obtain a processed device model; Discretize the processed device model according to the basis functions, and perform mode function expansion on the ports of the processed device model to establish the superfinite element matrix equation. The system matrix in the superfinite element matrix equation is partially decomposed using the multi-wavefront method to obtain the Schur complement matrix and the decomposed system matrix. The Schur complement matrix is ​​obtained based on the contribution blocks of each node in a pre-constructed elimination tree. Each node in the elimination tree includes a root node, leaf nodes, and intermediate nodes. The root node of the elimination tree represents the set of port degrees of freedom of the microwave passive device, while the leaf nodes and intermediate nodes represent the independent sub-regions divided within the microwave passive device. The contribution blocks within the LU decomposition factors corresponding to each node in the elimination tree are calculated, passed to the dense wavefront matrix of the parent node, and then marked as coverable. Construct an S-parameter dense matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix; Solve the dense matrix equation of the S-parameters to obtain the S-parameters of the microwave passive device.

[0005] Optionally, the transfinite element matrix equation is expressed as follows: ; in, Represents the system matrix, A matrix representing the interactions between internal degrees of freedom. The matrix representing the coupling effect between the internal degrees of freedom and the port degrees of freedom. The matrix representing the coupling effect between the port degrees of freedom and the interior degrees of freedom. The matrix representing the interaction between the port degrees of freedom. Represents the system's degrees of freedom. Indicates internal degrees of freedom. This represents the S-parameters of the microwave passive device. Indicates system incentives, This indicates port excitation.

[0006] Optionally, the step of using the multi-wavefront method to perform partial LU decomposition on the system matrix in the transfinite element matrix equation to obtain the Schur complement matrix of the system matrix and the decomposed system matrix includes: Construct an elimination tree with the ports of the processed device model as the root nodes; Partial LU decomposition is performed on the dense wavefront matrix of each node in the elimination tree to obtain the LU decomposition factor and contribution block of each node. Once the contribution block of a node has been calculated and passed to the dense wavefront matrix of the parent node, the memory occupied by the LU decomposition factor corresponding to the node is marked as overwhelmable. The contribution blocks from each node are passed to the root node, and the Schur complement matrix at the root node is calculated. The decomposed system matrix is ​​obtained from the Schul complement matrix at the root node.

[0007] Optionally, before constructing the S-parameter dense matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix, the method further includes: The updated transfinite element matrix equation is obtained based on the decomposed system matrix; Solve for the parameter values ​​in the updated superfinite element matrix equation.

[0008] Optionally, solving the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device includes: Solve the S-parameter dense matrix equation based on the parameter values ​​in the updated superfinite element matrix equation; The S-parameters of the microwave passive device are obtained.

[0009] Optionally, the decomposed system matrix is ​​represented as follows: ; in, The lower triangular decomposition factor matrix representing the internal degrees of freedom. The coupling matrix represents the influence of internal degrees of freedom on port degrees of freedom. Represents the identity matrix. The upper triangular decomposition factor matrix represents the internal degrees of freedom. The coupling matrix represents the influence of the port degrees of freedom on the interior degrees of freedom. This represents the Schul complement matrix of the system matrix.

[0010] Optionally, the S-parameter dense matrix equation is expressed as follows: ; in, This represents the S-parameters of the microwave passive device. This represents an intermediate variable for the port.

[0011] Secondly, the present invention provides an S-parameter extraction system for microwave passive devices, the system comprising: The device processing module is used to perform mesh generation on the geometric model of microwave passive devices to obtain the processed device model. The equation establishment module is used to discretize the processed device model according to the basis functions and perform mode function expansion on the ports of the processed device model to establish the transfinite element matrix equation. The matrix decomposition module is used to perform partial LU decomposition on the system matrix in the transfinite element matrix equation using the multi-wavefront method, to obtain the Schur complement matrix of the system matrix and the decomposed system matrix. The equation acquisition module is used to construct an S-parameter dense matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix. The parameter solving module is used to solve the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device.

[0012] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: In the above technical solution, the present invention uses the superfind element method to expand the mode function of the port of the microwave passive device. While calculating the port Schur complement matrix, it releases the LU decomposition factor of the node that has been calculated and skips the forward and backward substitution solution process, and directly constructs the dense matrix equation for solution, which effectively reduces the memory occupation of matrix calculation and reduces the calculation time.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0014] Figure 1 This is a flowchart of a method for extracting S-parameters of microwave passive devices provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the process of constructing an elimination tree and releasing the LU decomposition factor using the multi-wavefront method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an S-parameter extraction system for microwave passive devices provided in an embodiment of the present invention. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0016] Figure 1 This is a flowchart of a method for extracting S-parameters of microwave passive devices provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes: S101. After geometric modeling the microwave passive device, mesh generation is performed to obtain the processed device model.

[0017] S102. Discretize the processed device model according to the basis functions, and expand the mode functions on the ports of the processed device model to establish the superfinite element matrix equation.

[0018] Alternatively, the transfinite element matrix equation can be expressed as follows: ; in, Represents the system matrix. A matrix representing the interactions between internal degrees of freedom. The matrix representing the coupling effect between the internal degrees of freedom and the port degrees of freedom. The matrix representing the coupling effect between the port degrees of freedom and the interior degrees of freedom. The matrix representing the interaction between the port degrees of freedom. Represents the system's degrees of freedom. Indicates internal degrees of freedom. The S-parameters of microwave passive devices are represented. Indicates system incentives, This indicates port excitation. During the generation of this system matrix, the global numbers of all port degrees of freedom were separately assigned at the end, thus placing the port degrees of freedom in the lower right corner of the system matrix.

[0019] S103. The system matrix in the finite element matrix equation is partially decomposed using the multi-wavefront method to obtain the Schur complement matrix of the system matrix and the decomposed system matrix. The Schur complement matrix of the system matrix is ​​obtained based on the contribution blocks of each node in the pre-constructed elimination tree. Each node in the elimination tree includes the root node, leaf nodes, and intermediate nodes. The root node in the elimination tree is the set of port degrees of freedom of the microwave passive device, and the leaf nodes and intermediate nodes are the independent sub-regions divided inside the microwave passive device. The contribution blocks occupied by the LU decomposition factors corresponding to each node in the elimination tree are calculated and passed to the dense wavefront matrix of the parent node and then marked as coverable.

[0020] Optionally, S103 may include: Construct an elimination tree with the ports of the processed device model as the root nodes; Partial LU decomposition is performed on the dense wavefront matrix of each node in the elimination tree to obtain the LU decomposition factor and contribution block of each node. Once the node's contribution block has been calculated and passed to the parent node's dense wavefront matrix, the memory occupied by the node's corresponding LU decomposition factor is marked as overwhelmable. The contribution blocks from each node are passed to the root node, and the Schur complement matrix at the root node is calculated. The decomposed system matrix is ​​obtained from the Schul complement matrix at the root node.

[0021] Understandably, the multi-wavefront method is used to perform partial LU decomposition of the system matrix and return the port Schur complement matrix. During the decomposition process, the LU decomposition factors of nodes that have already contributed blocks to their parent nodes and do not need to be saved are released. Figure 2This is a schematic diagram illustrating the process of constructing an elimination tree and releasing the LU decomposition factor using the multi-wavefront method provided in this embodiment of the invention, as shown below. Figure 2 As shown, specifically, the process of releasing the decomposition factors and returning the port Schur complement matrix during the decomposition includes: a. Construct an elimination tree with the ports of the processed device model as root nodes. Based on the sparse structure of the system matrix, a logical elimination tree is constructed using the multi-wavefront method. In this tree structure, the root node represents the set of port degrees of freedom of the microwave device, while the leaf nodes and intermediate nodes correspond to the various independent sub-regions divided within the device. The calculation follows a bottom-up order, first calculating the leaf nodes, then progressively passing the contribution blocks upwards, and finally calculating the root node.

[0022] b. Complete the assembly and partial decomposition of the dense wavefront matrix. For any node in the elimination tree... Assemble its corresponding dense wavefront matrix This matrix contains the characteristics of the current node and the contribution blocks passed down from its child nodes. Subsequently, a partial LU decomposition is performed on this wavefront matrix, decomposing it into LU decomposition factor parts. , , and contribution blocks The decomposed matrix is The LU decomposition factor describes the field distribution characteristics of the eliminated variables within the node. Specifically, Characteristic factors representing the internal field distribution. This represents the transfer factor from the port inwards. The input represents the feedback factor from the internal port; while the contribution block describes the electromagnetic coupling contribution of the node to the parent node.

[0023] For example, the wavefront matrix of any node k Perform partial LU decomposition, after decomposition Calculating the matrix multiplication on the right side yields: , ,Right now: , ,Right now: , ,Right now: .

[0024] c. Immediately discard LU decomposition factors. In traditional direct solution processes, LU decomposition factors are retained for subsequent back-substitution calculations. However, in this invention, once a node... Contribution block The calculated wavefront matrix is ​​then passed to the parent node for accumulation; at this point, the node is determined. The LU decomposition factor is no longer involved in subsequent Schur complement calculations. At this point, immediately change the node... The memory occupied by the LU decomposition factor is marked as overwhelmable, and subsequent calculations can directly overwrite this part of the memory, thus achieving the goal of discarding the LU decomposition factor and reducing memory usage. Through this step, only the wavefront matrix of the current elimination path needs to be stored in memory at any given time, instead of the entire data of the elimination tree.

[0025] d. Return the port's Shure complement matrix As the elimination process proceeds along the elimination tree to the root node, the contributions of all internal nodes have been propagated upwards through contribution blocks. At this point, the wavefront matrix at the root node no longer contains any internal variables that need to be eliminated; this matrix is ​​the final calculated and returned Schur complement matrix. The matrix fully preserves the input / output characteristics between device ports for subsequent S-parameter extraction.

[0026] Optionally, before S104, the method may further include: The updated transfinite element matrix equation is obtained based on the decomposed system matrix; Solve for the parameter values ​​in the updated hyperfinite element matrix equation.

[0027] It is understandable that the decomposed system matrix obtained by system matrix decomposition is represented as follows: ; in, The lower triangular decomposition factor matrix representing the internal degrees of freedom. The coupling matrix represents the influence of internal degrees of freedom on port degrees of freedom. Represents the identity matrix. The upper triangular decomposition factor matrix represents the internal degrees of freedom. The coupling matrix represents the influence of the port degrees of freedom on the interior degrees of freedom. This represents the Schul complement matrix of the system matrix.

[0028] It is worth mentioning that the system matrix After decomposition, only the Schur complement matrix is ​​actually retained. The remaining LU factorization factors are marked as coverable during the calculation to reduce memory usage. They do not exist after the factorization is complete. They are listed here for mathematical derivation. So that it can be solved directly. ,because It is the original equation middle In port excitation, LU decomposition generally requires finding In other words, in general LU decomposition: First find ,beg It is needed at times Then substitute it into the solution. Solve Only then can the solution be found. This patent pertains to microwave passive devices. (Internal motivation) is 0, which can be determined through mathematical derivation. This allows us to skip the above steps and solve directly. Omitting the above steps includes omitting the solution. Therefore, it is not necessary to use Therefore, all internal LU decomposition factors can be discarded during decomposition without the need for back-substitution calculation.

[0029] The updated transfinite element matrix equation can now be expressed as follows: ; make The transfinite element matrix equation becomes Calculate the first row of the matrix equation to obtain ,Right now Calculate the second row of the matrix to obtain ,Will Substitute and get , As an intermediate variable, For internal intermediate variables, This is an intermediate variable for the port.

[0030] S104. Based on the Schul complement matrix of the system matrix and the decomposed system matrix, the S-parameter dense matrix equation for microwave passive devices is obtained.

[0031] Alternatively, the S-parameter dense matrix equation can be expressed as follows: ; in, The S-parameters of microwave passive devices are represented. This represents an intermediate variable for the port.

[0032] S105. Solve the dense matrix equation of the S-parameters to obtain the S-parameters of the microwave passive device.

[0033] Understandably, through layer-by-layer calculations, all internal electromagnetic influences are superimposed onto the device's ports, resulting in the Schur complement matrix. The entire process involves multiple local nodes (leaf nodes) calculating and propagating contribution blocks, ultimately converging to form the Schur complement matrix of the port degrees of freedom, and then solving for the S-parameters.

[0034] Specifically, obtained through S103 By directly substituting the values ​​into the S-parameter dense matrix equation, we obtain... This refers to the device's S-parameters, eliminating the need for backward substitution in the traditional process. This process reduces computation time.

[0035] In the sparse matrix decomposition process, this invention immediately releases the memory of the LU decomposition factor corresponding to an internal node after the contribution block calculation is completed. Compared with existing direct solution methods, this reduces memory usage from a level related to the total number of nodes to a level related only to the maximum wavefront matrix, significantly reducing memory consumption and enabling more tasks to be computed in parallel simultaneously. Furthermore, by utilizing the matrix arrangement characteristics of the transfinite element method, the right-hand side of the backward substitution is directly obtained as equal to the port excitation, completely skipping the necessary forward and backward substitution processes in the traditional solution process. Compared with existing S-parameter calculation methods based on the standard finite element process, this invention eliminates a large number of calculation steps unrelated to S-parameters, significantly reducing solution time and greatly improving the efficiency of S-parameter extraction.

[0036] Figure 3 This is a schematic diagram of the structure of an S-parameter extraction system for microwave passive devices provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the system 300 may include: The device processing module 301 is used to perform geometric modeling and mesh generation on microwave passive devices to obtain the processed device model. The equation establishment module 302 is used to discretize the processed device model according to the basis function and perform mode function expansion on the port of the processed device model to establish the superfind element matrix equation. The matrix decomposition module 303 is used to perform partial LU decomposition on the system matrix in the transfinite element matrix equation using the multi-wavefront method, to obtain the Schur complement matrix of the system matrix and the decomposed system matrix. The equation acquisition module 304 is used to construct S-parameter dense matrix equations for microwave passive devices based on the Schur complement matrix of the system matrix and the decomposed system matrix. The parameter solving module 305 is used to solve the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device.

[0037] It should be noted that the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0039] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings and the disclosure in carrying out the claimed invention. In the description of the invention, the word "comprising" does not exclude other components or steps, "a" or "an" does not exclude a plurality, and "a plurality" means two or more, unless otherwise explicitly specified. Furthermore, while different embodiments may describe certain measures, this does not mean that these measures cannot be combined to produce good results.

[0040] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for extracting S-parameters of microwave passive devices, characterized in that, The method includes: After geometric modeling the microwave passive device, mesh generation is performed to obtain the processed device model. Discretize the processed device model according to the basis functions, and perform mode function expansion on the ports of the processed device model to establish the superfinite element matrix equation. The system matrix in the superfinite element matrix equation is partially decomposed using the multi-wavefront method to obtain the Schur complement matrix and the decomposed system matrix. The Schur complement matrix is ​​obtained based on the contribution blocks of each node in a pre-constructed elimination tree. Each node in the elimination tree includes a root node, leaf nodes, and intermediate nodes. The root node of the elimination tree represents the set of port degrees of freedom of the microwave passive device, while the leaf nodes and intermediate nodes represent the independent sub-regions divided within the microwave passive device. The contribution blocks within the LU decomposition factors corresponding to each node in the elimination tree are calculated, passed to the dense wavefront matrix of the parent node, and then marked as coverable. The S-parameter dense matrix equation for the microwave passive device is obtained based on the Schur complement matrix of the system matrix and the decomposed system matrix. Solve the dense matrix equation of the S-parameters to obtain the S-parameters of the microwave passive device.

2. The method for extracting S-parameters of microwave passive devices according to claim 1, characterized in that, The transfinite element matrix equation is expressed as follows: ； in, Represents the system matrix, A matrix representing the interactions between internal degrees of freedom. The matrix representing the coupling effect between the internal degrees of freedom and the port degrees of freedom. The matrix representing the coupling effect between the port degrees of freedom and the interior degrees of freedom. The matrix representing the interaction between the port degrees of freedom. Represents the system's degrees of freedom. Indicates internal degrees of freedom. This represents the S-parameters of the microwave passive device. Indicates system incentives, This indicates port excitation.

3. The method for extracting S-parameters of microwave passive devices according to claim 1, characterized in that, The method of using multiple wavefronts to perform partial LU decomposition on the system matrix in the transfinite element matrix equation to obtain the Schur complement matrix of the system matrix and the decomposed system matrix includes: Construct an elimination tree with the ports of the processed device model as the root nodes; Partial LU decomposition is performed on the dense wavefront matrix of each node in the elimination tree to obtain the LU decomposition factor and contribution block of each node. Once the contribution block of a node has been calculated and passed to the dense wavefront matrix of the parent node, the memory occupied by the LU decomposition factor corresponding to the node is marked as overwhelmable. The contribution blocks from each node are passed to the root node, and the Schur complement matrix at the root node is calculated. The decomposed system matrix is ​​obtained from the Schul complement matrix at the root node.

4. The method for extracting S-parameters of microwave passive devices according to claim 3, characterized in that, Before constructing the S-parameter dense matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix, the method further includes: The updated transfinite element matrix equation is obtained based on the decomposed system matrix; Solve for the parameter values ​​in the updated superfinite element matrix equation.

5. The method for extracting S-parameters of microwave passive devices according to claim 4, characterized in that, Solving the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device includes: Solve the S-parameter dense matrix equation based on the parameter values ​​in the updated superfinite element matrix equation; The S-parameters of the microwave passive device are obtained.

6. The method for extracting S-parameters of microwave passive devices according to claim 2, characterized in that, The decomposed system matrix is ​​represented as follows: ； in, The lower triangular decomposition factor matrix representing the internal degrees of freedom. The coupling matrix represents the influence of internal degrees of freedom on port degrees of freedom. Represents the identity matrix. The upper triangular decomposition factor matrix represents the internal degrees of freedom. The coupling matrix represents the influence of the port degrees of freedom on the interior degrees of freedom. This represents the Schul complement matrix of the system matrix.

7. The method for extracting S-parameters of microwave passive devices according to claim 6, characterized in that, The S-parameter dense matrix equation is expressed as follows: ； in, This represents the S-parameters of the microwave passive device. This represents an intermediate variable for the port.

8. A system for extracting S-parameters of microwave passive devices, characterized in that, The system includes: The device processing module is used to perform mesh generation on the geometric model of microwave passive devices to obtain the processed device model. The equation establishment module is used to discretize the processed device model according to the basis functions and perform mode function expansion on the ports of the processed device model to establish the transfinite element matrix equation. The matrix decomposition module is used to perform partial LU decomposition on the system matrix in the transfinite element matrix equation using the multi-wavefront method, to obtain the Schur complement matrix of the system matrix and the decomposed system matrix. The equation acquisition module is used to construct an S-parameter dense matrix equation for the microwave passive device based on the Schur complement matrix of the system matrix and the decomposed system matrix. The parameter solving module is used to solve the dense S-parameter matrix equation to obtain the S-parameters of the microwave passive device.

Images