A new approach for efficient analysis of large finite periodic structures

Periodic structures have attracted much attention in the past decades due to numerous applications such as metamaterials, antenna arrays, frequency selective surface (FSS), photonic band gap (PBG) or electromagnetic band gap (EBG) structures, etc. Infinite periodic structures are impossible in a realistic fabrication. When truncating infinite periodic structures, discontinuities occur at the interface and surface waves will be excited according to mode conversion, which leads to the edge effect of finite periodic structures. The prediction of wave natures in the edge cells of finite periodic structures is an indispensable procedure during the design of finite periodic structures. The conventional element-by-element method is rigorous and suitable for small finite arrays. However, it requires heavy computational resources for very large arrays. The well-established infinite periodic approximation approach neglecting the edge effect, although reduces the computational domain to a unit cell, is not sufficiently accurate for engineering applications.