Integral Equation Analysis of Scattering From Multilayered Periodic Array Using Equivalence Principle and Connection Scheme

An integral equation approach is presented to analyze the two-dimensional (2-D) scattering from multilayered periodic array. The proposed approach is capable of handling scattering from the array filled with different media in different layers. Combining the equivalence principle algorithm (EPA) and connection scheme (EPACS), it can be avoided to find and evaluate the multilayered periodic Green´s functions. For 2^N identical layers, the elimination of the unknowns between top and bottom surfaces can be accelerated using the logarithm algorithm. More importantly, based on EPACS, an approach is proposed to effectively handle the semi-infinitely layered case in which a unit consisting of several layers is repeated infinitely in one direction.