Small dimensional microstrips embedded with ferromagnetic layers:   Numerical simulations and experimental results
  We use a numerical electromagnetic simulation software to investigate a filtering device consisting of a small dimensional microstrips embedded with a thin layer of ferromagnetic material and we compare our results to experimental results. We are able to show good correlation of simulation versus experiment for the magnitude of insertion loss and phase shift. The microstrips considered have dimensions on the order of the skin depth of the conductor and hence the field distribution is not easily calculated by analytic methods. We show that numerical simulation methods provide an accurate means of characterizing these structures. 
Jonah N. Gollub, Bijoy Kuanr, Zibigniew Celinski, Robert Camley, and   David R. Smith