A cylindrical magnetron using field emission cathodes as the electron source is being developed. In this approach, field emitters are used to provide a distributed cathode in place of a traditional thermionic cathode. The emitters are placed below the interaction space in a shielded structure. The cathode is comprised of facet plates with slits to protect the emitters. The electron trajectories of the structure have been modeled and measurements have been made of electrons injected through the slit structures. Modeling using the 3D simulation ICEPIC has also been performed for a faceted magnetron geometry and the results show oscillation occurs. These results will be presented.