In this paper, we propose two time domain formulations, based upon the
use of Whitney elements, on tetrahedral meshes for solving transient
responses of electromagnetic problems. Among the two formulations, one
is an implicit unconditionally stable scheme, whereas the other is an
explicit scheme which does not involve matrix inversions. Although th
e implicit scheme results in worse computational complexity, it is ext
remely appealing for modeling EM problems with fine features. This is
because the time step used in the algorithm is determined by accuracy
not by stability. Furthermore, we also present in this paper stability
analysis using the Z-transform, computational complexity, and several
numerical results for the implicit algorithm.