A hybrid method for analyzing scattering from a large planar slotted waveguide array antenna in a real environment

A hybrid numerical method is presented to analyze scattering from a large planar slotted waveguide array antenna. The total scattering consists of two parts, namely the structural scattering and slot scattering. These two parts are solved independently through the application of the equivalence principle. The former is calculated by a high-frequency method, such as the physical optics (PO) and the shooting and bouncing ray (SBR) method. The latter is solved using the method of moments (MoM). Numerical results are presented to demonstrate the effects of a variety of factors on the RCS of a slot array. Also given are the RCS space distribution and probability curves of slot arrays to illustrate their unique scattering characteristics. The RCS of a complicated real slot array in a real environment is given finally to demonstrate the capability of the numerical method as well as the distinct features of its RCS pattern. The numerical method developed is useful in applications such as target identification, electromagnetic compatibility, EMP penetration, and stealth technology.