This letter presents a new hybrid method that efficiently combines two versatile numerical techniques, viz., the finite difference time domain (FDTD) and the method of moments in the time domain (MoMTD). The hybrid method is applicable to complex geometries comprising arbitrary thin-wire and inhomogeneous dielectric structures. It employs the equivalence theorem to separate the original problem...

The correct choice of time-step size is of crucial importance in the case of the (2, 4) finite-difference time-domain (FDTD) method, as it affects the algorithm’s overall accuracy and convergence rate. A description of the inherent discretisation error is introduced, which is exploited for the derivation of a simple, yet reliable, approximation of the optimum temporal sampling density. As the p...

FDTD has become a popular tool in acoustic modelling in recent years. A main attraction of FDTD is that it can be implemented in computer code easily using simple straightforward marching algorithms and finite difference equations. However, this simplicity comes at a price. Dispersion errors, source scattering, and frequency dependent boundary reflections are just a few of the problems that FDT...

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...

An efficient method is presented for rigorous analysis of incident field coupling to high speed interconnects. The method is based on generating time domain equivalent sources from incoming fields through finite difference time domain analysis (FDTD) and incorporating them with a circuit level simulator such as SPICE. With this approach, it is possible to perform a circuit analysis of arbitrari...

This paper describes a new unconditionally stable numerical method for the full-wave physical modeling of semiconductor devices by a combination of the finite-difference Laguerre time-domain (FDLTD) and alternative direction implicit finite-difference time-domain (ADI-FDTD) approaches. The unconditionally stable method by using FDLTD scheme for the electromagnetic model and semi-implicit ADI-FD...

In this letter, finite-difference time-domain (FDTD) computed radiation patterns of mobile telephones are carefully compared with those measured in our laboratory. The question on the capability of the FDTD method to correctly predict the radiated electromagnetic fields of today’s structurally complex mobile telephones is addressed. Two commercially available cellular telephones equipped with t...

A simple alternative way to position dielectric materials in the finite-difference time-domain (FDTD) Yee cell grid is proposed. Plane-wave illuminated spheres are used as examples to study the performance of the alternative method compared to the standard FDTD method. Although the performances are generally equally good, the alternative method may sometimes give significantly improved accuracy...

It is known that the digital waveguide (DW) method for solving the wave equation numerically on a grid can be manipulated into the form of the standard finite-difference time-domain (FDTD) method (also known as the “leapfrog” recursion). This paper derives a simple rule for going in the other direction, that is, converting the state variables of the FDTD recursion to corresponding wave variable...

We present a three-dimensional (3D) analysis of subwavelength diffractive optical elements (DOE's), using the finite-difference time-domain (FDTD) method. To this end we develop and apply efficient 3D FDTD methods that exploit DOE properties, such as symmetry. An axisymmetric method is validated experimentally and is used to validate the more general 3D method. Analyses of subwavelength grating...