Efficient analysis of resonant cavities by finite element method in the time domain

A numerical method is presented, based on finite elements in the time domai n associated with spectral analysis techniques for resonant cavity analysis . The method uses edge elements on tetrahedra for the electric field interp olation. Time derivatives are discretised by the Newmark method, which allo ws an unconditionally stable scheme with second-order accuracy to be obtain ed. Standard discrete signal-processing techniques are used to improve the results and reduce the memory requirement. An extensive set of numerical re sults is included.