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Abstract-A three-dimensional (3-D) finite-difference timedomain (FDTD) algorithm is developed to study the transformation of an electromagnetic wave by a dynamic (time-varying) inhomogeneous magnetized plasma medium. The current density vector is positioned at the center of the Yee cube to accommodate the anisotropy of the plasma medium due to the presence of a static magnetic field. An appropriate time-stepping algorithm is used to obtain accurate solutions for arbitrary values of the collision frequency and the electron cyclotron frequency. The technique is illustrated by calculating the frequency shifts in a cavity due to a switched magnetoplasma medium with a timevarying and space-varying electron density profile.

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The effect of switching a plasma medium of finite width (slab) on a time-harmonic plane electromagnetic wave propagating in free space is considered. The transient solution is obtained through the use of Laplace transforms. The solution is broken into two components: A component which in steady state has the same frequency as the incident wave frequency (ω0) and a B component which has an upshifted frequency ω1 =√ω20+ω2p. Here ωp is the plasma frequency of the switched plasma slab. Numerical results are presented to show the effect of the slab width on the reflected and transmitted waves. A proper choice of ω0, ωp and the slab width will yield a transmitted electromagnetic pulse of significant strength at the upshifted frequency.

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