Efficient modeling of discontinuities and dispersive media in printed transmission lines

Abstract

The finite-difference time-domain method is applied\ud to the analysis of transmission lines on printed circuit boards. The\ud lossy, dispersive behavior of the dielectric substrate is accurately\ud accounted for by means of several algorithms whose accuracy is\ud discussed and compared. Numerical results are validated by comparisons\ud with measurements and an equivalent circuit of slot in the\ud ground plane is proposed

Compact Electromagnetic Absorbers for Frequencies Below 1 GHZ

“…8. The equivalent shunt impedance L has been computed using the extraction technique described in [39][40][41][42] passing through the Zparameters of the structure, easily obtained from the S-parameters. …”

Actual challenges in electromagnetic shielding

“…Although the EM field distribution may vary considerably in presence of an even small body, the cumulative distribution of the shielding performance is not strongly affected by a (moderate) content variation, as shown by 6 obtained considering a rod antenna and a typical content represented by a perfectly conducting box in the lower rear region (e.g., a power supply unit) and by a thin dielectric body (e.g., a PC mother board [15]). …”

Analysis of PCB Discontinuities Using FD-TD and Wavelets

“…§ Wavelet Expansion of the time domain input signal; § solution of the system; § inverse Wavelet transform to determine the time domain outputs. The 3D FDTD method described in [8] is here employed in order to isolate only the effect of the discontinuity, minimizing meanwhile the physical and numerical reflections due to either absorbing boundary conditions or mismatch of the impedances. Its meaningful characteristics can be summarized as follows:…”