Research On Reconstruction Method Of Surface Roughness For Electronic Equipment

Electronic equipment has the tendency to high frequency band, high gain, high density and miniaturization with its development, the effects of structural factors on its electrical performance have become more prominent, the surface roughness is concerned due to its properties of universality, random distribution and complexity. This paper takes the surface roughness of the inner surface of cavity structure of electronic equipment as the research object in the support of National Natural Science Foundation, and a further research aiming at the reconstruction of surface roughness. The main content includes three parts: the models of one-dimensional surface roughness are built by application of three typical functions; the onedimensional surface rough is reconstructed based on the theory of electromagnetic scattering; the two-dimensional surface rough is reconstructed.1. Modeling of the surface rough profile Firstly, the model of surface roughness is established, secondly, the scattering data incident on the surface rough generated by electromagnetic wave is calculated; and finally the rough surface is reconstructed by processing the scattering data. According to this idea, the models of period function, random function and fractal function are built. A one-dimensional random roughness profile of Gauss by the Monte Carlo method is built, and the effects of RMS height and the correlation length on the one-dimensional rough model are verified. A model of periodic function is built and the relationship between the parameters and rough shape is discussed. A model of one-dimensional WM fractal function is built, and its properties of self-radioactive and self-similarity are verified, and the influence of the main parameters of fractal function on rough profile is discussed.2. The reconstruction of one-dimensional surface rough The basic idea: The electric field integral equation of one-dimensional rough contour is discredited by the method of moment; the complex integral equation is transformed into simple linear equations so as to obtain the scattering data. The relationship between one dimensional rough outline of the source term and the incident angle and the relationship between the amplitude spectrum and surface height fluctuation are obtained via simulation, and the equivalence relation between the source term and the incident field is verified, and the equivalence relation between the spectral amplitude and scattering field is verified. Three kinds of small scale and one-dimensional rough profile including period function, random function and fractal function are reconstructed by using the hybrid algorithm of perturbation method and the method of moment. Because the fractal function has the property of continuous everywhere but nowhere differentiable, so the scattering data can’t be calculated by the existing theory accurately, and the process of reconstruction can’t be carried out. This paper introduces the theory of fractional calculus of fractal geometry into this problem, solves the nondifferentiable problem of fractal function of integer order and realizes the accurate reconstruction of onedimensional fractal rough profile.3. The reconstruction of two-dimensional surface rough A two-dimensional random rough surface is established by using the Monte Carlo method for the two-dimensional random rough surface and the analysis and discussion of the effect of the RMS height and correlation length on the rough surface is carried out. The two-dimensional random rough surface is approximately converted into a large number of discrete strip models of one-dimensional rough outline by the thoughts of Gauss, The process of electromagnetic scattering of the two-dimensional Gauss random rough surface is simplified into many processes of surface electromagnetic scattering of one-dimensional Gauss random rough, and the accurate reconstruction of twodimensional Gauss random rough profile is thus realized finally.