Analysis of thin triangular conducting elements printed on planar dielectric slabs

In this study, scattering characteristics of thin triangular conducting elements periodically printed on planar dielectric slabs are investigated theoretically for transverse electric (TE) and transverse magnetic (TM) incident plane waves. Such surfaces are known as frequency selective surfaces (FSS) and they show bandpass or stop band filter characteristics.Since the conducting elements are etched periodically on such a surface, all fields and currents must satisfy Floquet?s condition and should be written as Floquet modes. Using Floquet?s theorem and satisfying the required boundary conditions, an integral equation is obtained for the unknown induced current density on the surface of a triangular conducting element in a unit cell. This current is then expressed as a finite sum of piecewise triangular basis functions having unknown coefficients. The resulting integral equation is then converted to a linear matrix equation by using the Moment Method (MM) and inversion of the matrix equation yields the unknown current coefficients which are used to obtain the reflection and transmission coefficients.Numerical results for the reflection and transmission coefficients are then plotted versus frequency for freestanding and dielectric backed triangular-shaped FSS elements. Furthermore, the variation of reflection characteristics with dielectric constant ( ), slab thickness ( ), length and width of the triangle ( ), incidence angle ( ) and lattice dimensions ( ) are presented in the form of graphs.Key words: Triangular Conducting Elements, Frequency Selective Surfaces, Moment Method