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Time domain finite-difference method implemented by using digital signal processing technique

A technology of finite difference in time domain and digital signal processing, which is applied in the direction of digital differential analyzer, calculation using non-numerical representation, etc., can solve the problem of increasing calculation time and achieve the effect of improving calculation efficiency

Inactive Publication Date: 2016-05-18
TIANJIN UNIV OF TECH & EDUCATION TEACHER DEV CENT OF CHINA VOCATIONAL TRAINING & GUIDANCE
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

For problems with complex structures, it sometimes increases its calculation time

Method used

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  • Time domain finite-difference method implemented by using digital signal processing technique
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  • Time domain finite-difference method implemented by using digital signal processing technique

Examples

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example 1

[0040] example 1. figure 2 The schematic diagram of the low-frequency RLC circuit is given, and its voltage time-domain distribution and corresponding transfer function are calculated respectively by using the method of the present invention and the traditional finite-difference method in time domain.

[0041] In order to realize the frequency domain analysis of the circuit, it is generally realized by using modulated Gaussian pulse and the like as the excitation source. set up L =10nH inductance, C =10pF capacitance series circuit, and add the internal resistance as R =50Ω voltage source excitation, using the method proposed by the present invention to carry out simulation calculations on this circuit, because the size of the circuit is small, no absorption boundary conditions are set on the calculation area, the total calculation area size is 9 × 9 × 9, Yee element cell size Δ x =Δ y =Δ z =1mm, the simulated circuit components (i.e., inductors, capacitors, and resisto...

example 2

[0044] Example 2. Figure 5 A structure diagram of a microwave low-pass filter is given, and its reflection coefficient is calculated by using the method of the present invention and the traditional finite-difference method in time domain S 11 Curves and Transmission Coefficients S 21 curve.

[0045] This low-pass filter structure belongs to microwave circuits. Set the total size of the calculation area to 76×72×30, set the coordinate stretching and perfect matching layer on the truncated boundary, and its boundary fixed parameters are respectively n pml =3; σ factor =1.3; kappa max =7; α max =7; α min =0; after adding the setting of the boundary conditions, the structure of the low-pass filter is placed in the center of the calculation area, and the method proposed by the present invention is used to carry out electromagnetic simulation on this structure to obtain the reflection coefficient of the low-pass filter S 11 Curves and Transmission Coefficients S ...

example 3

[0048] Example 3. Utilize method of the present invention and traditional time domain finite difference method, calculate dipole respectively at observation point as r =10 δ , θ = 90° electric field with time and error conditions.

[0049] Radiation field of dipole in time domain

[0050]

[0051] Since the current density is introduced in the calculation process, the dipole moment p and current density J Relationship

[0052]

[0053] Because the Yee cell is used as the basic unit, it may be assumed that the Yee cell is a cube, and the length of each side is δ , the above formula can be changed to:

[0054]

[0055] Let the dipole edge z axial vibration, and the dipole consists only of the electric field component E z Generated, using Maxwell's curl formula, the discrete scheme of the finite-difference time domain method can be obtained:

[0056]

[0057] Let the dipole radiation source be ,in T =2ns, the observation point can be obtained as r...

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Abstract

The invention proposes a time domain finite-difference method implemented by using a digital signal processing technique, which is used for the field of design and application of electromagnetic field software. A Courant-Friendrich-Levy time stability condition can be broken through by using the time domain finite-difference method with a hidden alternative direction; in order to simplify the whole electromagnetic calculation process, matrixes and vectors in a hidden time domain finite-difference equation are arranged according to the requirement of digital signal processing, and a discrete difference equation is pre-processed; and for a parallel technology, the time domain finite-difference method with the hidden alternative direction is completed by combining the digital signal processing technique according to a time discrete signal flow chart so as to calculate an electromagnetic field numerical value. With the method proposed by the invention, the electromagnetic field calculation efficiency can be improved; compared with a traditional time domain finite-difference method, the method has the advantages that a Courant-Friendrich-Levy (CFL) factor is appropriately selected, and the calculation efficiency can be improved by 3 to 5 times; and moreover, the method proposed by the invention can be effectively combined with a telescopic coordinate completely-matching layer, unbounded transmission of simulated electromagnetic wave can be achieved, and the method can be more widely applied.

Description

technical field [0001] The invention belongs to the technical field of computational electromagnetics software, and relates to a digital signal processing technology for preprocessing an implicit time-domain finite difference method in alternating directions, thereby improving calculation efficiency. Background technique [0002] The finite-difference time-domain method is one of the commonly used calculation methods in computational electromagnetics. In the time and space domains, Maxwell's equations are directly differentially discretized to simulate the propagation process of electromagnetic waves. This method has been applied to the research of microwave circuits, antennas and target electromagnetic scattering. Traditional methods are limited by the Courant-Friedrich-Levy (CFL) time stability condition: , the CFL factor must be required to be less than or equal to 1, that is, the time step Δ t Limited by the size of the smallest grid in space. Therefore, when analyz...

Claims

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Application Information

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IPC IPC(8): G06F7/64
Inventor 郑宏兴张玉贤彭升王辂万小凤邓东民
Owner TIANJIN UNIV OF TECH & EDUCATION TEACHER DEV CENT OF CHINA VOCATIONAL TRAINING & GUIDANCE
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