A Fast and Accurate Analysis of 2-D Periodic Devices Using Complex Images Green´s Functions

In this paper, a new method based on the complex images technique is presented for analysis of 2-D periodic devices such as waveguides, directional couplers, and coupled cavity waveguides (CCW). The main idea of this method lies in representing the infinite summation of the periodic Green´s functions of such kind of structures in terms of finite terms of complex images. The electric field integral equation has been used to formulate the problem and the method of moments has been applied afterward for solving the equation. The method has been used successfully in the analysis of different waveguides, directional couplers, and CCWs in both rectangular and triangular lattices. Fast convergence, simple formulations, and flexibility of the method in analyzing different structures are the main advantages of the proposed method.