Qunsheng Cao

Design and analysis of planar printed microwave and PBG filters using an FDTD method

In this paper, various planar printed microwave and photonic band-gap (PBG) filters have been designed and analyzed by applying the finite difference time domain method, together with an unsplit-anisotropic perfectly matched layer technique as treatments of boundary conditions. The implemented solver was first validated by comparing the computed data with those published in literature, and a good agreement was observed between the results. Then, based on the specified design criteria, various microwave and PBG filters were designed and analyzed, in which the theoretical predictions matched well with the computed results for the characteristics of the proposed filters.

A hybrid DGTD-TDIE method for solving complex electromagnetic problems

This paper presents a novel hybrid method that effectively combines two capable numerical methods – the discontinuous Galerkin time domain (DGTD) method and the time domain integral equation (TDIE) method. The hybrid DGTD-TDIE method is highly applicable to the interaction problem between arbitrarily shaped thin wires and dielectric structures with complex media compositions. The Huygens equivalence principle is employed to divide the original problem into two subproblems: (1) the region containing the thin wires, which is calculated by using the TDIE method, and (2) the dielectric region modeled by unstructured grids and analyzed by the DGTD method. A time-stepping scheme is used to match the different time steps between the DGTD and TDIE methods. To validate the hybrid method, several numerical results have been presented, which prove it a promising scheme to solve the complex coupling problems.

Corrigendum to: Design and analysis of planar printed microwave and PBG filters using an FDTD method

School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore, Singapore 639798 Department of Electrical Engineering, Swearingen Engineering Center, University of South Carolina, Columbia, SC 29208, USA Anhui Institute of Optics and Fine Mechanics, Hefei, China Department of Applied Physics, Hefei University of Technology, Hefei, China Army High Performing Computing Research Center, Institute of Technology, University of Minnesota, Minneapolis, MN 55415, USA EMI/Orsted, Technical University Denmark, Orstedplads, DK-2800 Kgs. Lyngby, Denmark Institute of Field Theory and High Frequency Engineering, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland

COMPARATIVE TO FDTD, PSTD AND MRTD METHODS IN STUDIES FOR PLANAR STRATIFIED MEDIA

The Finite Difference Time Domain (FDTD) method has been diversely applied in the area of computational electromagnetics due to its robustness, versatility and simplicity for implementation. However, it requires a fine grid set in order to achieve a good accuracy. To improve the computational efficiency, two other techniques, the Pseudo-Spectral Time Domain (PSTD) and the Multiresolution Time Domain (MRTD) methods, have recently been proposed. In this study, the basic ideas and concepts of these time domain methods are introduced and discussed. They are respectively applied for studies of planar stratified media, and the obtained propagation characteristics are compared. In the area of electromagnetics, it has been a challenge to analytically solve the Maxwell’s equations. Thanks to the advances in computer technology, finding a full-wave solution of the Maxwell’s equations becomes achievable using numerical techniques. One of them is the wellknown Finite Difference Time Domain (FDTD) method [1]. It expands the Maxwell’s equations using central finite differences and is widely adopted due to its robustness, versatility and simplicity for implementation. However, to achieve a certain level of accuracy, it is required to adopt a fine set of grids for discretization, which results in a lot of computational space for storage of electromagnetic-field information. To improve the computational efficiency, other techniques have been proposed. One is called the Pseudo-Spectral Time Domain (PSTD) method [2], which applies the properties of the Fourier Transform (FT) to expand spatial derivatives in the Maxwell’s equations. Another is known as the Multiresolution Time Domain (MRTD) method [3]. It utilizes a series of basis functions to expand the fields in the Maxwell’s equations. In this study, the basic ideas and concepts of the above-mentioned time domain techniques are introduced and discussed. They are respectively applied for studies of planar stratified media, and the obtained propagation characteristics are compared.