Full-wave analysis of microstrip structures by time-domain finite difference(TDFD) method

Abstract

Two approaches have been taken with respect to full-wave electromagnetic field analysis. One is a time-domain analysis approach which solves the initial boundary value problem of the wave or Maxwell``s equations, the other is a frequency-domain analysis approach which solves the eigenvalue problem of the vector Helmholtz equation. Mostly it is common to obtain the design data in frequency domain one frequency at a time by the frequency-domain approach. But the time-domain approach is economical rather than the frequency-domain approach when the broad-band results are required. This is because they are calculated at a time through the Fourier transform of time response of a sharp pulse. Also because algorithm implementation is very simple and the crosstalk of interconnections in semiconductor integrated circuit is graphically illustrated. In this thesis, numerical analysis package using time-domain finite difference (TDFD) method is developed to solve the initial value problem of Maxwell``s equation and applied to several microstrip structures. TDFD allows us to show graphically the evolution of the wide band electromagnetic wave propagation along the microstrip line and the crosstalk between microstrip lines. Moreover, we can obtain transmission line parameters and scattering parameters through Fourier transform of TDFD results in easy and efficient ways. TDFD is successfully applied to : i) wide band electromagnetic wave propagation along the single strip line, ii) crosstalk analysis between two microstrip lines, and iii) three metal lines side-coupled filter. Our results show much better agreement with other theoretical or experimental results reported in the literature.