Research Of Electromagnetic Scattering Characteristics From Wire Antenna And Antenna Array

Electromagnetic scattering characteristics have always been one of the important issues by many people. With the development of the stealth and anti-stealth technology, antennas which transmit and receive information, play an important role in the whole system. And the properties of electromagnetic scattering from antennas will certainly affect the overall stealth effect. In this thesis, we started from electromagnetic scattering analysis of wire antenna, and then calculated the surface induced current and radar cross section (RCS) from wire antenna under the 2-D ideal situation and the finite-length case. The RCS results of several different antenna arrays are given. The main contributions of author's work are as follows:The research background and significance of RCS were introduced firstly, and several numerical methods applied in electromagnetic scattering and radiation problems were also illustrated. Then the theory of method of moments was introduced, and the solving process of radar cross section for objects was illuminated.Secondly, the asymptotic waveform evaluation technique combined with MoM, is adopted to analyze electromagnetic scattering of wire antenna and antenna array in the 2-D ideal situation. This method can get fast calculation results of RCS during the given frequency-band, and the computational results are in good agreement with that achieved by MoM. After this, the higher order of rational function based on AWE is used to explore the problem of expanding bandwidth and computational accuracy. Numerical results demonstrate that results of the higher order rational function get wider bandwidth and more accurate than that of low order rational function.Finally, the antenna thin-wire kernel method is adopted to compute electromagnetic scattering characteristics of wire antenna. The accurate integral kernel functions and sinusoidal basis function combined with reaction integral equation are used to solve the discrete matrix equation. The singularity arising in the calculation of impedance matrix elements is approximated by the semi-analytical method. Numerical results validate that the method of eliminating singularity is valid and efficient, and RCS results of different wire antenna arrays are computed at last.