The Time-domain Bouncing Ray Method For Electromagnetic Scattering Of Electrically Large Targets

In the field of computational electromagnetics,time domain analysis methods have been widely used in target recognition and ultra-wideband communication.With the development of higher frequencies in the working frequency of moderm communication equipment,the precise numerical methods consume high memory and take a long time to calculate.It can no longer meet the needs of the actual project,so it is especially important to study the time domain response and wide-band radar cross section of the large-size target.This paper firstly introduces the basic principle of time-domain bouncing ray method.Compared with the frequency-domain bouncing ray method,it has the advantage of short computation time.It ouly requires one calculation to obtain the radar cross-section in a wide frequency band.Next,the time-domain bouncing ray method for calculating the transient electromagnetic properties of a homogeneous medium is studied.The traditional time-domain bouncing ray method can only be used to analyze the transient electromagnetic scattering problem of an ideal conductor.This paper introduces a surface equivalent reflection coefficient and considers the medium.The contribution of surface magnetic current to the scattering field,the time-domain bounce ray method is used to analyze the transient characteristics of the uniform medium target and uniform coating target.Compared with the frequency-domain bounce ray method,the calculation time is further shortened.Finally,a time-domain bouncing ray method for calculating the transient electromagnetic properties of inhomogeneous media is proposed.It is used to calculate the plasma sheath and inhomogeneous media targets.Compared with the time-domain bouncing ray method of uniform media,the ray is considered inside the media.Propagation,use the tetrahedron to divide the target,and separate the three-dimensional media target into several tetrahedrons with different electromagnetic parameters.The path tracing and field strength tracking are performed on the ray.When the ray passes through the target,the far-field integral formula is used.Calculating its contribution to the scattering field opens up a new path for analyzing the transient electromagnetic scattering characteristics of inhomogeneous medium targets by the time-domain high-frequency method.