Analysis of strip-grating structure with ASBC

The strip grating on dielectric slab is a common periodic structure used in antenna design and microwave component applications. The asymptotic strip-loaded boundary conditions (ASBC) are applied on classical theory of vector potentials to analyze planar strip grating structure rapidly and easily. Dispersion diagram can be obtained by solving a transcendental characteristic equation, which is derived from matrix of system equations which are composed of vector potentials and ASBC. With the roots of the transcendental characteristic equation, we can sketch both TE and TM modes field distributions with closed form equation at any frequency or wave number point we need.