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This paper studies the stability and numerical dispersion of an extension of the original finite-difference time-domain (FDTD) method to incorporate magnetized ferrites. This extension is based on discretizing the ferrite equations by means of central differences and averages. Both partially magnetized and saturated ferrites are considered. With the aim of studying the numerical features of the resulting FDTD algorithms, we have considered the propagation of plane-waves along longitudinally magnetized ferrite materials. This is a simple 1D problem that enables the numerical properties of the algorithms to be studied analytically. A von Neumann stability analysis shows that the stability condition of the original FDTD method is preserved and that the algorithms do not exhibit numerical dissipation. The accuracy of the numerical results is not deteriorated with respect to those obtained in the demagnetized case. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This Letter introduces a novel impedance boundary condition (IBC) for the matched termination of waveguide ports in finite-difference–time-domain (FDTD) simulators. It is based on approximating the wave impedance by a rational function over the frequency band of interest. To show the validity of the proposed IBC, the reflection coefficient of a wideband matched 90° H-plane corner in rectangular waveguide is computed. The results obtained, which are less than -45 dB over the whole waveguide band, are in good agreement with those obtained by a commercial finite-element simulator. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 151–155, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10400 [ABSTRACT FROM AUTHOR]