Scattering Analysis of Periodic Structures Using Finite-Difference Time-Domain Method

Abstract

Synthesis Lectures on Computational Electromagnetics will publish 50-to 100-page publications on topics that include advanced and state-of-the-art methods for modeling complex and practical electromagnetic boundary value problems. Each lecture develops, in a unified manner, the method based on Maxwell's equations along with the boundary conditions and other auxiliary relations, extends underlying concepts needed for sequential material, and progresses to more advanced techniques and modeling. Computer software, when appropriate and available, is included for computation, visualization and design. The authors selected to write the lectures are leading experts on the subject that have extensive background in the theory, numerical techniques, modeling, computations and software development. The series is designed to:• Develop computational methods to solve complex and practical electromagnetic boundary-value problems of the 21st century.• Meet the demands of a new era in information delivery for engineers, scientists, technologists and engineering managers in the fields of wireless communication, radiation, propagation, communication, navigation, radar, RF systems, remote sensing, and biotechnology who require a better understanding and application of the analytical, numerical and computational methods for electromagnetics. ABSTRACTPeriodic structures are of great importance in electromagnetics due to their wide range of applications such as frequency selective surfaces (FSS), electromagnetic band gap (EBG) structures, periodic absorbers, meta-materials, and many others. The aim of this book is to develop efficient computational algorithms to analyze the scattering properties of various electromagnetic periodic structures using the finite-difference time-domain periodic boundary condition (FDTD/PBC) method. A new FDTD/PBC-based algorithm is introduced to analyze general skewed grid periodic structures while another algorithm is developed to analyze dispersive periodic structures. Moreover, the proposed algorithms are successfully integrated with the generalized scattering matrix (GSM) technique, identified as the hybrid FDTD-GSM algorithm, to efficiently analyze multilayer periodic structures. All the developed algorithms are easy to implement and are efficient in both computational time and memory usage. These algorithms are validated through several numerical test cases. The computational methods presented in this book will help scientists and engineers to investigate and design novel periodic structures and to explore other research frontiers in electromagnetics.

Investigation of Light-Extraction Efficiency of Flip-Chip AlGaN-Based Deep-Ultraviolet Light-Emitting Diodes Adopting AlGaN Metasurface

“…Figure 1(b) and (c) show cross-sectional views of a YZ-plane cutting the middle of the x-axis and an XYplane cutting the middle of the cylinder's height, respectively. The constant horizontal wavenumber approach is utilized to efficiently analyze the constructed unit cell [17]- [19]. The unit cell's each plane at the end of +x, -x, +y, and -y directions adopt periodic boundaries.…”

“…where 0 = ω/c is the wavenumber with angular frequency ω and the speed of light c in the material [17]. Equation ( 1) implies that the identical θ at different frequencies is satisfied at the different k values.…”

Surface-emitting photonic crystal terahertz quantum cascade laser adopting uniform triangular prism photonic crystal with a double-metal waveguide

“…Photonic band structure (PBS) and radiation constants are calculated by combining finite-difference time-domain (FDTD), discrete Fourier transform (DFT), and filter-diagonalization method (FDM) techniques. [17][18][19][20] Candidate G-point modes for efficient surface-normal emission are sorted out through the unit cell analysis as a first step. After unit cell analysis is finished, we analyze the far-field, field-distribution, and light-extraction efficiency (LEE) for frequencies including the candidate modes, where the modes likely exist only nearby G-point and possess enough radiation constant.…”