Finite-difference time-domain (FDTD) grids are often described as being divergence-free in a source-free region of space. However, in the presence of a source, the continuity equation states that charges may be deposited in the grid, while Gauss’s law dictates that the fields must diverge from any deposited charge. The FDTD method will accurately predict the (diverging) fields associated with c...

In this paper, an unconditionally stable three-dimensional (3-D) finite-difference time-method (FDTD) is presented where the time step used is no longer restricted by stability but by accuracy. The principle of the alternating direction implicit (ADI) technique that has been used in formulating an unconditionally stable two-dimensional FDTD is applied. Unlike the conventional ADI algorithms, ho...

Acceleration of FDTD (finite-difference time-domain) is very important for the fields such as computational electromagnetic simulation. We consider the FDTD simulation model of cylindrical resonator design that requires double precision floating-point and cannot be done using single precision. Conventional FDTD acceleration methods have a common problem of memorybandwidth limitation due to the ...

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. Th...

Perfectly Matched Layer (PML) is modeled by Split-Field FDTD (SF-FDTD) in order to simulate Radar Cross Section (RCS) of a plasma slab. PML is used as an absorbing boundary, and discrete plane wave (DPW) is employed to generate plane wave. DPW method has a power isolation of −300 dB between scattered-field and total-field regions. The dispersive media is modelled by shiftoperator FDTD. In this ...

Finite-Difference Time-Domain (FDTD) has been proved to be a very useful computational electromagnetic algorithm. However, the scheme based on traditional general purpose processors can be computationally prohibitive and require thousands of CPU hours, which hinders the large-scale application of FDTD. With rapid progress on GPU hardware capability and its programmability, we propose in this pa...

This paper presents the modeling of hemoglobin at optical frequency (250 nm - 1000 nm) using the unconditionally stable fundamental alternating-direction-implicit finite-difference time-domain (FADI-FDTD) method. An accurate model based on complex conjugate pole-residue pairs is proposed to model the complex permittivity of hemoglobin at optical frequency. Two hemoglobin concentrations at 15 g/...

We have developed a systematic design process for recently proposed slanted grating couplers (SGCs) that operates in the strong coupling regime. Based on rigorous analysis of SGC properties, this design process utilizes the k-vector diagram and a rigorous grating leaky-mode solver to intentionally enforce the phase-match and Bragg conditions. We demonstrate that the resultant SGC designs have p...

To model periodic structures with oblique incident waves/scan angles in FDTD, the field transformation method is successfully used to analyze their characteristics. In the field transformation method, Maxwell’s equations are Floquet-transformed so that only a single period of infinite periodic structure can be modeled in FDTD by using periodic boundary conditions (PBCs). A new discretization me...

In the present work we propose a strategy for developing reusable multi-model simulation library for solving Finite-Difference Time-Domain (FDTD) problem for Maxwell’s equations. The described EMTL (Electromagnetic Template Library) architecture is based on the selection of a small number of primitive low-level physical and numerical concepts which are used as parameters and building blocks for...