Browsing by Author "Hwang, Jiunn-Nan"

Now showing 1 - 9 of 9

A modified PML conductivity profile for the ADI-FDTD method with split-field PML
(2007)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
Analysis of stability and numerical dispersion relation of Mur's absorbing boundary condition in the ADI-FDTD method
(2007)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, the stability analysis of the Mur's first order absorbing boundary condition (ABC) in the alternating direction implicit finite-difference time-domain (ADI-FDTD) method is presented. To analysis the stability of this scheme, the amplification matrix is derived. The effect of wave propagation direction on the stability of this scheme is investigated. The numerical dispersion relation of this scheme is also derived analytically from the amplification matrix. From the theoretical stability analysis and numerical simulation, it is found that the Mur's first order ABC in the ADI-FDTD method will be unstable.
Analysis of stability and numerical dispersion relation of Mur's absorbing boundary condition in the ADI-FDTD method
(2007)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, the stability analysis of the Mur's first order absorbing boundary condition (ABC) in the alternating direction implicit finite-difference time-domain (ADI-FDTD) method is presented. To analysis the stability of this scheme, the amplification matrix is derived. The effect of wave propagation direction on the stability of this scheme is investigated. The numerical dispersion relation of this scheme is also derived analytically from the amplification matrix. From the theoretical stability analysis and numerical simulation, it is found that the Mur's first order ABC in the ADI-FDTD method will be unstable.
Analysis of stability and numerical dispersion relation of Mur's absorbing boundary condition in the ADI-FDTD method
(2007-01-01)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, the stability analysis of the Mur's first order absorbing boundary condition (ABC) in the alternating direction implicit finite-difference time-domain (ADI-FDTD) method is presented. To analysis the stability of this scheme, the amplification matrix is derived. The effect of wave propagation direction on the stability of this scheme is investigated. The numerical dispersion relation of this scheme is also derived analytically from the amplification matrix. From the theoretical stability analysis and numerical simulation, it is found that the Mur's first order ABC in the ADI-FDTD method will be unstable.
ELECTROMAGNETIC SIMULATION OF VLSI CIRCUITS BY THE MODIFIED ADI-FDTD METHOD
(2014-11-01)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
交大名義發表
;
電機工程學系
;
National Chiao Tung University
The alternating direction implicit (ADI) finite-difference time-domain (FDTD) method can be used to simulate very large scale integration (VLSI) circuits efficiently as the time step is not restricted by the Courant-Friedrich-Levy stability condition. When the Berenger\'s split-field perfectly matched layer (PML) absorbing boundary condition is used for the ADI-FDTD method for open region simulation, the PML implementation will make this scheme unstable. In this article, the modified PML conductivity profiles are proposed to improve the stability of this scheme. Numerical simulations of the VLSI interconnect and RF inductor in time domain and frequency domain will be demonstrated to show the efficiency and accuracy of this method. (C) 2014 Wiley Periodicals, Inc.
Isolation Enhancement Between Two Packed Antennas With Coupling Element
(2011)
Hwang, Jiunn-Nan
;
Chung, Shyh-Jong
;
電信工程研究所
;
Institute of Communications Engineering
This letter introduces a coupling element to enhance the isolation between two closely packed antennas for 2.4-GHz wireless local area network (WLAN) application. The proposed structure occupies two antenna elements and a coupling element in between. By putting a coupling element that artificially creates an additional coupling path between the antenna elements, the antenna isolation can be enhanced. The advantage of this design is that no extra space is needed for antenna elements. With the proposed design, more than 15 dB isolation can be achieved for two parallel individual inverted-F antennas (IFAs) with 5-mm spacing. Parametric studies for the design are also included to show how to increase isolation bandwidth and control the isolation frequency.
Reduction of the peak SAR in the human head with metamaterials
(2006-12-01)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
The electromagnetic interaction between the antenna and the human head is reduced with metamaterials. Preliminary study of SAR reduction with metamaterials is performed by the finite-difference time-domain method with lossy Drude model. It is found that the specific absorption rate (SAR) in the head can be reduced by placing the metamaterials between the antenna and the head. The antenna performances and radiation pattern with metamaterials are analyzed. A comparative study with other SAR reduction techniques is also provided. The metamaterials can be obtained by arranging split ring resonators (SRRs) periodically. In this research, we design the SRRs operated at 900 and 1800 MHz bands. The design procedure will be described. Numerical results of the SAR values in a muscle cube with the presence of SRRs are shown to validate the effect of SAR reduction. These results can provide helpful information in designing the mobile communication equipments for safety compliance.
Simulation of RF inductor by the modified ADI-FDTD method
(2007)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
電信工程研究所
;
Institute of Communications Engineering
STABILITY ANALYSIS OF THE PML SCHEME FOR CN-FDTD AND ADI-FDTD
(2014-11-01)
Hwang, Jiunn-Nan
;
Chen, Fu-Chiarng
;
交大名義發表
;
電機工程學系
;
National Chiao Tung University
The alternating direction implicit-finite-difference time-domain (ADI-FDTD) method can be seen as a second-order perturbation of the Crank-Nicolson FDTD (CN-FDTD) scheme. When the PML is introduced for the ADI-FDTD method, the perturbation term will affect the stability of the ADI-FDTD method. In this work, the stability analysis of the PML schemes for the ADI-FDTD and CN-FDTD are demonstrated. It is found that the PML equations for ADI-FDTD method will be unstable due to the perturbation term. (C) 2014 Wiley Periodicals, Inc.