Xia Yingqing

Research on the electromagnetic scattering near the field

We calculate and analyze the scattering near the field from some simple and complex targets using the method of picture elements (PEL), based upon the method of high-frequency approximation. It introduces the critical distance of the near field and the far field which is related with the dimension of the target. The problem of the EMS near field from large size objects can be transformed to the problem of the far field by parting it to many very small size elements. By calculating the EMS near fields of some simple and complex targets based on the SCTE (scattering from complex targets and environments) system, the results show that there are much difference between the near field and the far field. And the characteristics of the near field are more complicated. This work has practical engineering value in the area of the electromagnetic compatibility (EMC), electromagnetic interference (EMI) prediction and electromagnetic scattering (EMS).

Research on the angular glint of targets in the near-zone

This paper presents a method to analyze and calculate the angular glint of targets. By parting the target to very small size cells, using high-frequency approximation, the near-field radar cross section (RCS) is calculated based on the scattering from complex targets and environments (SCTE) system, and the angular glint is calculated by the phase grads. The results show that the angular glint can be calculated exactly in the SCTE system, and this method is correct and efficient. In the near-zone, the far-field theory is not applicable and the angular glint should be calculated by the near-field theory.

The Analysis about Targets Near-field Scattering Characteristics under the Influence of Doppler frequency-shift

Under the influence of Doppler frequency-shift, the theory model about targets near-field bistatic scattering is established with PO method and cell-method depending on SCTE. The formula of bistatic RCS is obtained and it can be degenerated to describe monostatic RCS. Then some curves are presented which are in accordance with the results given by references

Analyzing the Scattering Near-Field from Complex Targets

This paper presents a theory method to calculate and analyze the scattering near field from some simple and complex targets, using high-frequency approximation. By calculating the near-field RCS of some simple and complex targets based on the SCTE (scattering from complex targets and environments) system, the results show that there are much difference between the near field and the far field. And the characteristics of the near field are more complicated. This method has practical engineering value in the area of the electromagnetic interference (EMI) prediction and electromagnetic scattering (EMS) et al

Study on the EM scattering of rivets on the plate

The electromagnetic (EM) scattering by rivets on the conducting plate is studied for the first time by using electric field integral equation (EFIE) in conjunction with the moment method. The surfaces of the rivets and the plate are partitioned into triangular cells, the current distribution on the patches is represented by sub-domain type basis function, the EFIE is translated into matrix equation by the Galerkin method, then the current coefficient is obtained. The results show the properties of radar cross section (RCS) varying with the incident angle when there are rivets on the plate.

Predicting the secondary electromagnetic reflection on the complex targets

This paper presents a quick and effective arithmetic to search geminate cells where secondary scattering exists between them, and establishes a secondary scattering theory model in the near-field. The secondary incidence field on a cell is decided by geometrical optics (GO). And physical optics (PO) decides the secondary scattering field. It can also be applied to far-field and near-field.

The reflection and transmission of electromagnetic wave from small particle-dielectric composites sheet

The electromagnetic properties of composites which are made of small particles imbedded in an insulating matrix have been studied. The electromagnetic fields inside and outside the sphere particles were derived using Mie theory, and the renormalized permittivity and permeability that take into account effect of retardation were introduced. When the skin effect in metal is strong by high frequency electromagnetic field under conditions for the metal-dielectric composites, the developed effective medium theory (DEMT) is more suited than the effective medium theory (EMT) to describe the properties of composites. Numerical results exhibit the characteristics of reflection and transmission of electromagnetic waves at composite sheets.

Analysis of the electromagnetic scattering of rivets on the conducting plate

In this paper, the electric field integral equation (EFIE) in conjunction with the moment method is used to analyze the electromagnetic scattering problem of rivets on the conducting plate. The surfaces of the rivets and the plate are partitioned into triangular cells, the current distribution on the patches is represented by a subdomain-type basis function, the EFIE is translated into a matrix equation by the Galerkin method, then the current coefficient is obtained. Results show the properties of RCS varying with the incident angle when there are rivets on the plate. Furthermore, we can see the effect of rivets on RCS.

EM Scattering from conducting flat plates coated with thin RAM

According to the equivalence principles, high frequency approximation and boundary conditions, a method has been developed to deal with the EM scattering by a rectangular conducting flat plate coated with uniaxial anisotropic radar absorbing material (RAM). The simple and effective method is available to the system of RCS prediction in which the large complex targets modeled by facets and wedges. Numerical results show some properties of EM scattering by conducting plate coated with thin uniaxial anisotropic RAM.

Investigation on the characteristics of the electromagnetic scattering near field from complex targets

Calculation and analysis of the scattering near field from some simple and complex targets using a method of picture elements (PEL) and a computer program are discussed. The analysis is based upon a method of high-frequency approximation. The uniqueness of this method is derived from the simplicity of the theoretical basis such as the physical optics (PO) and the vector potential. The calculated results show that there are large differences between the near field and the far field. The characteristics of the near field are more complex. This work has practical engineering value in the area of the electromagnetic compatibility (EMC), electromagnetic interference (EMI) prediction and electromagnetic scattering.