Compact and High-Efficiency Magnetron With All-Cavity Diffraction Output

A compact and high-efficiency magnetron with diffraction output is proposed. In this diffraction output configuration, all cavities are tapered onto the horn antenna to extract the RF field of the operating pi mode from every resonator cavity and convert it to the TE 01 mode for high output power. To demonstrate the capability, an S -band ten-cavity magnetron with all-cavity diffraction output is designed. Compared to the conventional design, the cutoff radius of the TE 01 mode is smaller than the TE 51 mode in the circular waveguide. Consequently, the diameter of the output waveguide can be reduced significantly. Moreover, the short length of the diffraction output, about 0.63 lambda ( lambda is the operation wavelength), is designed to further reduce the volume of the proposed magnetron. Simulation results show that the proposed magnetron generates 3.64 MW output power with a power conversion efficiency of 91% at 2.31 GHz when the applied voltage is 46 kV and the axial magnetic field is 0.2 T.