Null modification by metal strips on a finite aperture

Electromagnetic wave scattering and transmission by slits on a conducting plate has been studied extensively by using the Fourier transform and mode matching method, finite element method (FEM) and boundary integral equation, and so on. Different approaches have also been proposed to study the scattering properties of periodical or nonperiodical metal strips. The scattered field can be expressed in terms of the induced strip current, or an equivalent multimode network representation. We propose a combined mode matching and moment method to analyse the scattering properties of an incident TE wave by metal strips on an aperture of finite extent. The current densities on the metal strips are approximated by Chebyshev polynomials with appropriate edge conditions. A potential application is to use the strips to redirect the transmitted signal through the aperture (window) so that nulls of the transmitted field pattern can be avoided.