Yougang Gao

Analysis of electrode speed correlation of discharge parameters applying short-gap electrostatic discharge model

Electrostatic discharge(ESD) current waveforms in experiment measurement are sorted for charge voltage from 100 V - 3000 V, whereas electrode approach speed effects of discharge parameters are illustrated with the short-gap ESD model. Strong correlation exists between discharge parameters of electrostatic discharge and electrode approach speed. Two processes, surface process and gas electronic avalanche, in short-gap ESD model are employed to analyze the possible mechanism caused the strong correlation.

Analysis of Shielding Effectiveness of Rectangular Cavity with Improved Aperture Model

This article first introduces the improved theory of transmission line method (TLM), which is used to analyze shielding effectiveness of rectangular enclosure with improved aperture model. The calculations show that the contours of TML shielding efficiency is in agreement with the that of FDTD calculation. Then we expand the fundamental formulas to deal with the cases of multi-holes, and arbitrary angle of polarization. Simulation results indicate that: when the frequency is under resonant frequency, the closer to the enclosure, the more the coupling energy is; resonance appears between the aperture and the enclosure, which results in low even negative shielding effectiveness in the metal shell; shielding effectiveness increases when polarization angle increases, and shielding of low frequency is better than that of high frequency; for the same areas, shielding effectiveness of a single hole is worse than that of multi-one. Suggestions to the shielding are proposed.

Application of the transmission line method to the shielding effectiveness with incident wave of arbitrary polarization

This work is performed to investigate the effects of normal incident electromagnetic wave with arbitrary polarization angle on the electric shielding effectiveness of a rectangular metallic enclosure with aperture by using an analytical method and numerical simulation A formulation depending on the polarization angle is successfully determined using transmission line method (TLM). A single mode normal incident transverse electric wave with arbitrary polarization is decomposed into two orthogonal components with electric field perpendicular to the long side and the short side of the aperture respectively. Each component is analysed in terms of TE10 mode by using transmission line method and then combined to obtain the shielding effectiveness. The result is validated by using numerical method FEM(Finite Element Method).

Electrode speed effect on discharge properties in short gap electrostatic discharge

Strong effect of moving electrode speed on discharge parameters exists in short-gap electrostatic discharge. Considering Townsend theory and streamer theory of electrostatic discharge, theoretical analysis with principles of fluid mechanics is employed on mechanism of electrode moving speed effect on discharge parameters. An algorithm is proposed and the simulation result gives estimation of theory description proposed.

Shielding analysis of enclosure with aperture irradiated by plane wave with arbitrary incident angle and polarization direction

An analytical formulation has been developed for shielding effectiveness calculation of rectangular enclosure with an off-center aperture. It deals with more general case including arbitrary located aperture and high frequency incident wave by making use of high-order TEmn mode transmission line model. The incident electromagnetic field impinges on the enclosure with arbitrary incident angle and polarization direction. Oblique incident wave is investigated by decomposing it into perpendicular polarization component and parallel polarization component. Relationship between shielding effectiveness and incident angle, polarization direction, aperture size, test point location as well as frequency are investigated.

Classification of antenna by cube receiving array based on directional diagram

This paper analyzes different spatial distribution of the field strength in the far field of different antenna. We will receive the field strength in the same area by receiving array based on directional diagram, and then send the data to BP neural network to simulate the nonlinear features of different antenna modeling so as to achieve the classification of different antenna. At last we will compare the different classification models to analyze their advantages and disadvantages.

Influence on discharge properties of esd subprocess from large speed of moving electrode

Moving electrode speed has strong effect on discharge parameters in short-gap electrostatic discharge. In view point of fluid mechanics, and based on Townsend theory and streamer theory of electrostatic discharge, theoretical analysis is presented to analyze mechanism of electrode speed effect on discharge parameters. An algorithm is proposed and the simulation result gives estimation of theory description proposed. Electrode fast speed weakens action of avalanche process while strengthens surface process in the whole process of electrostatic discharge. The result shows that discharge current raise up sharply with reduction of air pressure.

Design of parallel computing and simulation system for complex electromagnetic environment

This paper constructed a whole frame of parallel computing and simulation system in complex electromagnetic environment based on file division idea to improve the compute speed of electromagnetic simulation in complex electromagnetic environment. The system was divided into four modules, client, sever, compute node and database. Compared with other simulation software, this system not only provided flexible interfaces to construct simulation platform for users, but also improved the compute speed. This paper presented the design of file division algorithm and database in detail.

Research on accelerate method of ray tracing

Based on the analysis of the factors which affect the computing efficiency of the ray tracing method, an accelerate method of ray tracing method which can be used in open geographic environment was proposed. This method divided the whole terrain into small terrains, then chose the suit terrain which the ray emitted into after the analysis of ray features, so the number of intersection calculation between the ray and triangle faces which consist of the terrain is reduced from whole terrain scale to one smaller terrain scale, so the number of intersection calculation is reduced, therefore the speed of simulation and the efficiency of ray tracing is improved. Simulation results verify the correctness and validity of this method.

Analysis of Air Pressure Reduction Caused by Electrode Speed in Short Gap Electrostatic Discharge(ESD)

Electrode approach speed effect on discharge parameters and its cause have become a hot concern in the field of electrostatic discharge research. With principle and law in fluid mechanics an attempt is made to search mechanism of electrode approach speed effect on discharge parameters. Reduction of air pressure in the gap, based on analysis and derivation, is the dominate factor resulted in the significant action on discharge parameters by electrode moving speed.