GdfidL (Gitter drüber, fertig ist die Laube) is a finite difference code that computes resonant fields in lossfree structures and time dependent fields in lossfree or lossy structures. The resonant solver allows periodic boundary conditions. The time domain solver can be used to compute scattering parameters and wake-potentials. GdfidL's main advantage is that it computes only with grid cells where a nonzero field is possible. Electric conducting regions are excluded from the computational volume. GdfidL is strong in computing hollow waveguide problems. Open problems, eg. antenna analysis is not possible. A simple version of GdfidL which uses a staircase approximation to discretise the material distribution is free. The executables for many UNIX-variants are available.

• Original link (28 Apr 2000, offline).