An E-plane waveguide circulator for use in a high power microwave circuit is provided. The circulator has three or more waveguide ports intersecting at a junction, wherein the junction has an upper inner surface and a lower inner surface positioned in an opposing relationship to said upper inner surface. The circulator further includes at least one radial composite resonator positioned within the junction, the resonator being comprised of a composite made of a centrally disposed ferrite element and a solid dielectric layer disposed concentrically with and adjacent externally to said centrally disposed ferrite element. In use, a magnetic field source applies an external magnetic field to the radial composite resonator, the external magnetic field having a magnitude above the magnetic resonance associated with the radial composite resonator.