Numerical Calculation Method Of Radar Cross Section Of Object With Slots In The Surface

Since the 1980s, with the rapid development of stealth technology and it's application in certain military and defense field, the Radar Cross Section (RCS) of many tapical radar targets such as aircrafts,warships reduced greatly. Thus, the impact of weak scattering centres which originally contribute smaller to the RCS can not be ignored.In this thesis, we mainly study the RCS of electrically large bodies with small slot in the surface and propose Hybrid Method of high-frequency approximation method combined with numerical method, it can make up for their deficiencies in the separate calculation. The main research work and contributions are as follows:1. Put forward a method of picking up the amplitude and phase of the field to steady-state electromagnetic problem. Basing on this method, the technology of near-far-field transformation is optimized. In this way, it not only reduces the amount of codes and improves the speed of computing, but also simplifies the programming process and makes the programmes more readable. At last, the RCS value of conductor objects under beaming of steady-state electromagnetic wave computed by FDTD method are coincided relatively with the data of Method of Moments (MOM). This shows corrective measures are effective and have high calculation accuracy.2. Use the FDTD method to extract the equivalent aperture magnetic currents of a slot and then acquire RCS of the slot.3. Introduce the basic principles of Physical Optics (PO) and Physical Theory of Diffraction (PTD) in high-frequency approximation method. The method which combine PO and PTD to correct the error of not considering the impact of the edge of the conductor by using of PO is proposed, and achieve the anticipated effect.4. Proposed a new hybrid method of FDTD/PO-PTD which combing FDTD method with PO and PTD, analyses the feature of electromagnetic scattering of complicated large target, the hybrid method has many advantages such as saving the number of units of storage in computer, improving the computed speed, compared with other similar methods.