Five ADI-FDTD papers

Anyone having these papers? thanks very much.

Modification to convolution CFS-PML for the ADI-FDTD method, Feb 2006, Microwave and Optical Technology Letters

A simple method to determine the time-step size to achieve a desired dispersion accuracy in ADI-FDTD, March 2004, Microwave and Optical Technology Letters


Analysis of planar circuits using an unconditionally stable 3D ADI-FDTD method , July 2005, Microwave and Optical Technology Letters


A hybrid ADI-FDTD subgridding scheme for efficient electromagnetic computation
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields

ZT-ADIPML: Unconditionally stable PML algorithm for FDTD simulations
Microwave and Optical Technology Letters
Volume 48, Issue 2, Date: February 2006, Pages: 393-396

Microwave and Optical Technology Letters
Volume 48, Issue 2 , Pages 261 - 265


Modification to convolution CFS-PML for the ADI-FDTD method

Linnian Wang 1 2, Changhong Liang 1, Long Li 1
1National Laboratory of Antennas and Microwave Technology, Xidian University, Xi'an, Shaanxi 710071, P. R. China
2Department of Physics, Luliang High College, Lishi, Shanxi 033000, P. R. China

Keywords
alternating direction implicit (ADI) . FDTD method . perfectly matched layer (PML) . convolution . complex frequency shifted (CFS)

Abstract
A new implementation of perfectly matched layer (PML) using the recursive-convolution technique is introduced for an alternating-direction implicit (ADI) finite-difference time-domain (FDTD) method. Based on a complex frequency-shifted (CFS) scaling function, this PML boundary condition is highly effective at absorbing low-frequency evanescent waves. The numerical results show that, compared with its previously suggested analogue, the new method improves the reflection error by 30 dB for large time-step sizes

Microwave and Optical Technology Letters
Volume 48, Issue 2 , Pages 393 - 396


ZT-ADIPML: Unconditionally stable PML algorithm for FDTD simulations
Omar Ramadan
Computer Engineering Department, Eastern Mediterranean University, Gazi Magusa, Mersin 10, Turkey

Keywords
perfectly matched layer (PML) . alternating direction implicit (ADI) . finite-difference time-domain (FDTD) . -transform

Abstract
Unconditionally stable formulations of the perfectly matched layer (PML) are presented for truncating linear dispersive finite-difference time-domain (FDTD) grids. In the proposed formulations, the -transform theory is employed in the alternating-direction implicit FDTD (ADI-FDTD) algorithm to obtain update equations for the field components in dispersive media. The validity of the proposed formulations is shown through a numerical example carried out in 1D linear Lorentz dispersive FDTD domain.

Microwave and Optical Technology Letters
Volume 40, Issue 6 , Pages 487 - 490

Published Online: 4 Feb 2004


A simple method to determine the time-step size to achieve a desired dispersion accuracy in ADI-FDTD
Guilin Sun, C. W. Trueman
Department of Electrical Engineering Concordia University Montreal, QC H4B 1R6, Canada

Keywords
FDTD . numerical method . dispersion

Abstract
This paper presents a simple approach to determine the time-step size required in the alternate-direction-implicit finite-difference time-domain (ADI-FDTD) method in order to obtain a desired numerical dispersion accuracy. The Courant number, the desired dispersion accuracy, and the maximum mesh size max = max(x, y, z) are governed by the numerical dispersion relation, which can be solved by a simple root-finding algorithm to evaluate the Courant number and hence the time-step size for a given mesh size and accuracy. The time-step size is independent of the aspect ratio. To determine if ADI-FDTD is more efficient than the Yee's FDTD, this paper provides a simple relation to evaluate the relative Courant-Friedrich-Levy number (CFLN) from the Courant number and the aspect ratio. The ADI-FDTD method is more efficient than Yee's FDTD when the aspect ratio is high or the mesh density is very large.

International Journal of Numerical Modelling: Electronic Networks, Devices and Fields
Volume 17, Issue 3 , Pages 237 - 249

Special Issue: Special Issue on the 5th CEM-TD .


A hybrid ADI-FDTD subgridding scheme for efficient electromagnetic computation
Iftikhar Ahmed, Zhizhang (David) Chen *
Department of Electrical and Computer Engineering, Dalhousie University, Halifax, N.S., Canada
email: Iftikhar Ahmed (iahmed@dal.ca) Zhizhang (David) Chen (z.chen@dal.ca)

*Correspondence to Zhizhang (David) Chen, Department of Electrical and Computer Engineering, Dalhousie University, Halifax, N.S., Canada

Keywords
FDTD . unconditional stability . subgridding . hybrid method . interpolation

Abstract
Subgridding has been a challenge in FDTD modelling. While it can significantly decrease memory requirements by using coarse and dense grids or meshes wherever they are needed, a small time step must normally be applied to the dense or fine mesh due to the Courant-Friedrich-Levy (CFL) stability condition. In this paper, a technique that combines FDTD and ADI-FDTD methods for subgridding is proposed to circumvent the problem. The solution domain is divided into coarse grid regions and fine subgridded regions whenever necessary. The conventional FDTD is then applied to the coarse grid regions, while the ADI-FDTD is used in the finely subgridded regions. In comparison with subgridding schemes using solely the conventional FDTD, the hybrid method allows the use of a much larger time step and therefore reduces the CPU time. In comparison between the subgridding scheme and pure ADI-FDTD schemes, the hybrid method minimizes the use of the memory because the conventional FDTD algorithm is applied to the coarse grid region. Numerical examples are given to validate these advantages.

Microwave and Optical Technology Letters
Volume 46, Issue 2 , Pages 175 - 179



Analysis of planar circuits using an unconditionally stable 3D ADI-FDTD method

https://www.edaboard.com/viewtopic.php?p=548194#548194

thanks a lot